adarwinstudygroup.org
Illustrations

Our list of illustrations is organized sequentially, in the order that each image appears on the Web site. You can access the Web page on adarwinstudgygroup.org where a listed image is displayed, by clicking onto its thumbnail image on the list of illustrations; to return to list of illustrations, click the full version of that image on its respective Web page.
For many of the images in our list of illustrations, we include links to third-party Web sites, where you can learn more about the cited image or related subjects.
COVER PAGE
The plains of the Masai Mara and the western escarpment of the Great Rift Valley of Africa
Greg and Mary Beth Dimijian
Photograph
Masai Mara, Kenya
Streaked with shafts of sunlight towards end of day, the plains of the Masai Mara rise abruptly on the slopes of the western escarpment of the Great Rift Valley of Africa. Balanites trees and grazing wildebeest dot the peaceful landscape.
INTRODUCTION
About the study group
Ngorongoro Crater in Tanzania
Greg and Mary Beth Dimijian
Photograph
Ngorongoro Crater, Tanzania
Morning light filters across a waterfall of mist cascading into the the Ngorongoro Crater in Tanzania.
View of Arenal, a cone-shaped mountain with spectacular symmetry
Greg and Mary Beth Dimijian
Photograph series
Alajuela Province, Costa Rica
An explosive eruption of Arenal Volcano at night
Arenal is a cone-shaped mountain with spectacular symmetry in Alajuela Province, Costa Rica. Its one of the most active volcanoes on earth, erupting several times every day and night. In the second image, a forty-second time exposure captures an explosive eruption of Arenal Volcano at night. The first orange light was visible six seconds before the massive blast reached our ears.
About Dr. Dimijian
Greg Dimijian
Mary Beth Dimijian
Photograph
Italy, 2004
Dr. Greg Dimijian
A family of elephants in the Masai Mara of Kenya
Greg and Mary Beth Dimijian
Photograph
Masai Mara, Kenya
Toddlers greet and older family members caress them gently, as a family reuintes after being separated, in the Masai Mara of Kenya.
A family of elephants in Botswana
Greg and Mary Beth Dimijian
Photograph
Khwai River, Botswana
In Botswana, a family of elephants pause to drink from the Khwai River.
Two elephant bulls in Savuti, northern Botswana
Greg and Mary Beth Dimijian
Photograph
Savuti, Botswana
In Savuti, northern Botswanawo, two elephant bulls leave a dusty water hole at sundown to join their batchelor herd.
About the photography
Mary Beth and Greg Dimijian
Steven Garren
Photograph
2007
Mary Beth and Greg Dimijian in Tierra del Fuego, at the southern tip of South America, after visiting the Emperor Penguin Colony in the Weddell Sea of Antarctica
A procession of King penguins
Greg and Mary Beth Dimijian
Photograph
A procession of King penguins move along the coastline with a sunset as backdrop.
Dr. Dimijian in action photographing an Emperor Penguin
Greg and Mary Beth Dimijian
Photograph
20 October 2007
Snow Hill Island, Antarctica
Dr. Dimijian photographs the wildlife on Snow Hill Island in the Weddell Sea, Antarctica.
About the seminars
View of the night sky from Berenty, Madagascar
Greg and Mary Beth Dimijian
Photograph
9 November 2003
Berenty, Madagascar
This naked-eye view of the night sky above was photographed during the stunning onset of darkness during a lunar eclipse, on November 9, 2003 at 4:15 a.m., when the bright moon was dimmed by the shadow of Earth. The weird endemic plants of Madagascar are silhouetted against this cosmic horizon.
This young orphan is one of the many children at a local orphanage located in the Honduran countryside
SSgt Derrick C. Goode, USAF
Photograph
Honduras
This young orphan is one of the many children at a local orphanage located in the Honduran countryside. Joint Task Force-Bravo servicemembers often spend their off-duty time in Honduras visiting and providing aid to the local populace. On this day the servicemembers served lunch to the orphans and delivered boxes of donated clothes.
HometownLink: Joint Hometown News Service
U.S. Department of Defense
→ See more photography online in HometownLink: Photographs
SEMINAR ONE
Biology, culture and psychology
An Emperor penguin chick begs for food from its father
Greg and Mary Beth Dimijian
Photograph
October 2007
Snow Hill Island, Antarctica
An Emperor penguin chick, about seventy or eighty days old, stands on its own feet for the first time and begs for food from its father. Adult on left may be its mother or a friend of the father, or even an adult which has lost its own chick and is trying to “baby-snatch.”
A panorama of a thriving Emperor Penguin colony
Greg and Mary Beth Dimijian
Photograph
October 2007
Snow Hill Island, Antarctica
In the sub-freezing winds of the Weddell Sea of Antarctica, we were humbly privileged in 2007 to visit this thriving Emperor Penguin colony with some chicks still “on feet,” young enough not to walk about on their own. A panorama of three images stitched together shows the wide expanse of this awesome colony, deep in the coldest sea of the Antarctic continent.
Large breeding colonies of Lesser Flamingoes
Greg and Mary Beth Dimijian
Photograph
August 1988
Lake Natron, Tanzania
Large breeding colonies of Lesser Flamingoes, built atop crust colored reddish by alkali-loving microorganisms, find protection in the extreme heat of Lake Natron in Tanzania.
The scientific method
A Fleishmann's Glass Frog from Costa Rica
Greg and Mary Beth Dimijian
Photograph
A Fleishmann's Glass frog (Hyalinobatrachium fleischmanni) is less than one inch long and found in parts of Mexico, Central America, and northern South America.
A Clearwing butterfly in the Monteverde Cloud Forest Reserve, Costa Rica
Greg and Mary Beth Dimijian
Photograph
Monteverde Cloud Forest Reserve, Costa Rica
A Clearwing butterfly rests on the blossoms of a Senecio flower on the Continental Divide in the Monteverde Cloud Forest Reserve, Costa Rica.
A squirrel monkey from Costa Rica
Greg and Mary Beth Dimijian
Photograph
Monteverde Cloud Forest Reserve, Costa Rica
A squirrel monkey pauses to gaze at us before scurrying across a palm in a lowland rain forest of Costa Rica.
Nature and nurture
A translucent moth caterpillar from Costa Rica
Greg and Mary Beth Dimijian
Photograph
Costa Rica
Our friend Bill Haber, a biologist who lives in Monteverde, Costa Rica found this spectacular translucent moth caterpillar, just under one inch long. We came across this extraordinary sight, never seen before, while hiking with Bill to a remote cloud forest on Costa Rica's Caribbean slope.
Genetic coding
An excerpt from Piano Concerto Number 5 by Beethoven
Illustration
5 May 2006
Principal theme from Beethoven's Piano Concerto No. 5 for violins
Public domain
Monarch butterflies immobilized in the near-freezing air
Greg and Mary Beth Dimijian
Photograph series
Mexico
Monarch butterflies opening their orange-colored wings
Close up of Monarch butterflies
Monarch butterflies in flight
Early one morning in the mountains north of Mexico City, Mary Beth and I arose to see monarch butterflies immobilized on a fir sapling in the near-freezing air. An hour later they had opened their orange wings and were flying away after being warmed by the first rays of the rising sun. The air was filled with monarchs over our heads.
We learned that these amazing insects make a round-trip every year from the northern United States and southern Canada, overwintering in the montane fir forests of central Mexico. For us, the most amazing thing about the migration is the way it is carried out. One generation makes the 3,000-mile journey from Canada to Mexico, but three generations in succession make the return trip, laying eggs on milkweed plants along the way. The eggs hatch into caterpillars which feed on the milkweed plants and metamorphose into butterflies, and continue the journey.
Crypsis
A Common Pauraque on the forest floor of a Costa Rican cloud forest near Arenal Volcano
Greg and Mary Beth Dimijian
Photograph
Costa Rica
A Common Pauraque female on her eggs, hidden on the forest floor of a Costa Rican cloud forest near Arenal Volcano. It is perfectly camouflaged and keeps its eyes closed and remains immobile until we approach too closely.
A katydid on a plant in the Amazon rain forest of Peru
Greg and Mary Beth Dimijian
Photograph
Peru
A Katydid on a plant in the Amazon rain forest of Peru; its wings are mottled like the leaves around it.
A Scops Owl in the Okavango Delta of Botswana, Southern Africa
Greg and Mary Beth Dimijian
Photograph
Okavango Delta, Botswana
A Scops Owl, a tiny owl only eight inches tall, at its “home” on a naked branch. Its breast feathers look like the bark of the tree it lives in, and it keeps its eyes closed until we approach too closely.
Survival of the hidden
A Leaf-Tailed gecko in a forest in Madagascar
Greg and Mary Beth Dimijian
Photograph series
Madagascar
A Leaf-Tailed gecko in a forest in Madagascar
A Leaf-Tailed gecko in a forest in Madagascar
A Leaf-Tailed gecko in a forest is indistinguishable from its habitat, until it lifts its head and becomes visible
Natural selection and crypsis
Scorpionfish on a Philippine coral reef
Greg and Mary Beth Dimijian
Photograph
Philippines
Scorpionfish, lying in wait for a small passing fish which it will suck into its mouth, is hard to distinguish from the colorful reef encrustations all around it, about sixty feet down on a Philippine coral reef. This photo was taken after nightfall, when the camouflage may not be adaptive, as it is during the day.
A Lonomia moth on the forest floor of the Monteverde Cloud Forest Reserve in Costa Rica
Greg and Mary Beth Dimijian
Photograph
Monteverde Cloud Forest Reserve, Costa Rica
A Lonomia moth lies motionless on the forest floor. Its wings, with a rib running down the middle (resembling a leaf midrib), are hard to tell from the dead leaves around it, and its head—almost invisible—is at left.
A leaf-tailed gecko in Madagascar
Greg and Mary Beth Dimijian
Photograph
Madagascar
A leaf-tailed gecko is active at night and scurries about low branches in search of food.
Two captive Twig Mimic snakes in Madagascar
Greg and Mary Beth Dimijian
Photograph
Madagascar
Two captive Twig Mimic snakes, female above and smaller male below. When they are in trees and remain motionless, they resemble dead twigs.
To eat or to be eaten
An adult female cheetah pursuing a Thomsons gazelle in East Africa
Greg and Mary Beth Dimijian
Photograph series
Serengeti Plains, Tanzania
A female cheetah and its prey
In the first image, we see an adult female cheetah chasing a Thomson's gazelle, at the breakneck speed of sxity to seventy miles per hour. She can run at the fastest speed of any land mammal, but only for short distances, before she becomes winded. This photo op was a lucky break for us, because she first ran directly away toward the gazelle, then followed the gazelle when it made a ninety-degree turn and ran perpendicular to the camera.
In the second image, we see the female cheetah cheetah feeding on the Thomson's gazelle that she killed by strangulation. Her offspring watch and learn.
A Namib viper at the Dallas Zoo
Greg and Mary Beth Dimijian
Photograph series
Dallas Zoo
Dallas, Texas
A Namib viper at the Dallas Zoo
A Namib viper sidewinds its way into the sand, until it becomes hidden in the sand. Nothing appears at the surface except for the two eyes of the snake, which watch for the arrival of its next meal.
→ Learn more about the Dallas Zoo
What is evolution?
A Giant Red Hermit Crab at the Texas State Aquarium in Corpus Christi, Texas
Greg and Mary Beth Dimijian
Photograph
Texas State Aquarium
Corpus Christi, Texas
The stalked eyes of a Giant Red Hermit Crab from the Gulf of Mexico
→ Learn more about the Texas State Aquarium
Bryce Canyon National Park in Utah
Greg and Mary Beth Dimijian
Photograph
Bryce Canyon National Park, Utah
The beautiful séracs (jagged spires) of eroded mountains speak to us of the long expanses of geological time which Darwin knew about when he crafted his theory of natural selection. Evolution occurring over millions, even hundreds of millions, of years is called “macroevolution,” in contrast to “microevolution,” which takes place over much shorter time periods—even as short as days or weeks, in the case of the “cloud” of HIV variants developing in a person with AIDS.
→ Learn more about Bryce Canyon National Park
A Polkadot Tree Frog
Greg and Mary Beth Dimijian
Photograph
Polkadot Tree Frogs (Hyla punctata) are found throughout the Amazon Rain Forest of South America.
A Spider monkey from Costa Rica
Greg and Mary Beth Dimijian
Photograph
Costa Rica
The Spider monkey, found in lowland rain forests from Mexico to South America, has a prehensile tail that is muscular and tactile and is used as an extra hand. The tail is sometimes longer than the body. Both the underside and tip of the tail are used for climbing and grasping and so the spider monkey uses it like a fifth hand. When swinging by the tail, the hands are free to gather food.
Mimicry
A Hawkmoth caterpillar in a Costa Rican cloud forest
Greg and Mary Beth Dimijian
Photograph
Costa Rica
A Hawkmoth caterpillar (Xylophanes sp.) displays two deceptive structures: eyespots (the real eyes are tiny specks on the head, not visible in this photo) and a fake stinger (only a soft appendage).
An Io moth in a Costa Rican cloud forest
Greg and Mary Beth Dimijian
Photograph
Costa Rica
When disturbed,an Io moth displays eyespots on its hind wings, which may make predators think something big is looking back at them.
A caterpillar of the Costa Rican Io moth
Greg and Mary Beth Dimijian
Photograph
Costa Rica
A caterpillar of the Costa Rican Io moth above is “honest,” mimicking nothing and advertising its stinging spines by its red color.
A caterpillar in the Peruvian Amazon
Greg and Mary Beth Dimijian
Photograph
Peru
A caterpillar in the Peruvian Amazon resembles a bird dropping, detering visually oriented predators. It is “lying” not by mimicking a dangerous insect but simply by resembling a deposit of dung.
Leaves of Passiflora, a passion flower vine in Costa Rica
Greg and Mary Beth Dimijian
Photograph
Costa Rica
The leaves of Passiflora produce spots which resembles the eggs of Heliconius butterflies. The butterflies are deterred from laying eggs on these leaves, presumably because they think other members of their species have already laid eggs on the leaf. The plant is thus spared consumption by the voracious caterpillars which would hatch from real eggs. The spots arose by random, cumulative mutations which were selected for at steps along the way.
Microbes
The keynote address from a convention of the World Pathogen Association
Thomas Eisner and Paul R. Ehrlich
Editorial with cartoon
29 June 2001
The keynote address from a convention of the World Pathogen Association
© Thomas Eisner and Paul R. Ehrlich
“All in all, my fellow pathogens, Homo is the opportunity that ultimately can benefit us all. Aside from their prevalence in numbers, they show all the weaknesses that maximize our effective potential. Although they themselves deny that there is such a thing as a free lunch, we know better. There is a free lunch, and it is them.“
New World Pathogen Strategy Disclosed
Science, 29 June 2001, Volume 292 (5526), page 2397
→ Read the entire “speech”
Illustration of the progression of antibiotic resistance
Greg Dimijian
Illustration
Progression of an antibiotic resistance
In any population of bacteria or viruses, a small percentage has a gene variant. When we bathe the population in antibiotics we change the selective pressure on those gene variants, so that different ones now have an advantage. The variants conferring antibiotic resistance (which arose through chance mutations) now survive best, and bacteria or viruses with those alleles come to dominate the population. If it involves an infection of our body, we may die because the antibiotics fail to control the infection.
The symbiosis continuum
Illustration of the symbiosis continuum
Greg Dimijian
Illustration
The symbiosis continuum
A dynamic movement of a colonist and its host move along a continuum between antagonism and cooperation. A pathogen may live with us but not cause disease most of the time, like herpes simplex viruses (that cause fever blisters.) The pathogen occasionally causes serious illness. The movement along the continuum is dynamic and changing.
Lichens adorn a branch of a mesquite tree in the coastal plain of Texas
Greg and Mary Beth Dimijian
Photograph
Texas
Foliose (leafy) and fruticose (spore-producing) lichens adorn a branch of a mesquite tree in the coastal plain of Texas. Lichens consist of a fungus and a photosynthetic partner, either an alga or a cyanobacterium, and can live in harsh environments where neither partner could survive or reproduce alone.
Fig wasps
Greg and Mary Beth Dimijian
Photograph
Tiny fig wasps reproduce inside unripe figs and can be seen if the fig is cut open at the right stage. These wasps and fig trees are “obligate mutualists,” meaning that they cannot reproduce without each other. When we eat the mature figs (which are delicious), the wasps are all gone, or were not there in the first place because we planted the new trees ourselves, using shoots or even branches bent over to the ground (this is called ”vegetative reproduction“). In nature, the wasps and fig trees are essential partners in the reproduction of both/
A remarkable three-way mutualism between an ant, a butterfly caterpillar, and an acacia in the American southwest
Greg and Mary Beth Dimijian
Photograph
A remarkable three-way mutualism appears to have evolved between an ant, a butterfly caterpillar, and an acacia in the American southwest. The caterpillars have nectar organs which the ants drink from, and the acacia tolerates the feeding caterpillars. The ants appear to provide some protection for both plant and caterpillar.
Mutualisms
Ants cultivating fungus
Greg and Mary Beth Dimijian
Photograph series
La Selva Biological Station, Costa Rica
A leafcutter ant in the La Selva Biological Station in Costa Rica
A leafcutter ant with a procession of its siblings
In these three images, we are see ants cultivating a fungus for the mutual benefit of both the fungus and the ants. In the first image, we see the ants distributing the leaves throughout the labyrinth of a fungal colony which has evolved to live with the ants. The fungus breaks down the leaves and derives nourishment from them, and the ants are provided with nutrition by the fungus, often in the form of food droplets. The leaves serve only as food for the fungus. In the second and third images, we see a leafcutter ant cuts off a segment of a leaf in the lowland rain forest of the La Selva Biological Station in Costa Rica, which then joins a procession of its siblings, carrying the leaf segment back to its underground nest.
→ Learn more about the La Selva Biological Station
Crustose lichens in the Colorado Rockies
Greg and Mary Beth Dimijian
Photograph
Colorado
Crustose lichens cling to the bare, exposed surface of metamorphic rock in the Colorado Rockies, where only the hardiest pioneer organisms can survive.
Lichens on the island of Tasmania
Greg and Mary Beth Dimijian
Photograph
Tasmania
Radiating tiers of lichens encrust pink granite on the island of Tasmania.
Bacteria
Zebras along the Mara River in Kenya
Greg and Mary Beth Dimijian
Photograph
Mara River, Kenya
Burchell's zebras from different family groups pause to drink from the Mara River in Kenya before daring to race across the river.
Diagrammatic layouts of the gut of a sheep and a zebra
Diagrammatic layouts of the gut of a sheep and a zebra
The small intestine, very long in the sheep, has been drawn as if neatly folded on a table. It is longer than the small intestine of the zebra, because the sheep is a ruminant ,carrying out most of its digestion in the multi-chambered stomach and then passing the food through the elongated small intestine, where most of it is absorbed. Bacteria in the stomach break down the cellulose cell walls of plant food and manufacture vitamins and amino acids, needed by the host. The bacteria in turn get a constant supply of food and comfortable, warm housing.
The zebra is not a ruminant, but, like us, passes its food on to the hindgut (the large intestine). It is there that most of the bacteria are located, and there that the food is digested. Hindgut fermentation is not as efficient a strategy as foregut fermentation (rumination), so the zebra must eat a large amount of grass in order to get enough nourishment, whereas the sheep feeds on a much smaller amount of higher-quality vegetation with more protein, and recycles it again and again in the stomach to extract the most out of it.
Zebras and wildebeest crossing the Mara River in Kenya
Greg and Mary Beth Dimijian
Photograph
Mara River, Kenya
Wary of crocodiles in the shallow water of the Mara River, Burchell's zebra and wildebeest make a hurried crossing.
Hindgut versus foregut fermentation
Zebras on the Serengeti in Tanzania
Greg and Mary Beth Dimijian
Photograph
Central Serengeti, Tanzania
The image above is only one segment of the much larger panoramic image, which shows a spectacular Burchell's zebra herd, as it moves through the central Serengeti in Tanzania.
Zebra foal cavorting
Greg and Mary Beth Dimijian
Photograph
A zebra foal cavorts under the watchful eye of its mother.
A giraffe giving birth
Greg and Mary Beth Dimijian
Photograph
Dallas Zoo
Dallas, Texas
We were fortunate to be able to photograph a giraffe in the Dallas Zoo giving birth. Giraffe gestation takes from twelve to fifteen months. The mother gives birth standing up and the embryonic sack usually bursts when the calf falls to the ground. Newborn calves are about six feet tall and weigh around 130 pounds. Within a few hours of birth, the calf is able to run.
Chloroplasts and mitochondria
Redwood National Park in California
Greg and Mary Beth Dimijian
Photograph
Redwood National Park, California
Using chloroplasts, forests are essential to life on earth, recycling carbon dioxide into oxygen. In Tall Trees Grove of Redwood National Park, California, gargantuan trunks grow within twenty feet of each other, in a forest carpeted with Swordfern. This is alluvial plain habitat, where the river rises periodically and provides water for some of the largest redwoods, in addition to the water the trees intercept from the frequent fogs which envelop them.
→ Learn more about the Redwood National Park
What natural selection is and is not
An Acacia on the Serenget Plains
Greg and Mary Beth Dimijian
Photograph
Serengeti Plains near Ndutu
An Acacia is silhouetted by a typical African sunset.
A Marabou Stork in the Okavango Delta of Botswana
Greg and Mary Beth Dimijian
Photograph
Okavango Delta, Botswana
A Marabou Stork pauses between mouthfuls of carrion.
A vervet in Okavango sounding an alarm call
Greg and Mary Beth Dimijian
Photograph
In Okavango, a Vervet Monkey (Chlorocebus pygerythrus), also called simply a Vervet, gives off an alarm call, warning of an approaching leopard. A Vervet typically lives in “troops” of twenty or more individuals.
The Vervet Monkey has three alarm calls, for leopards, snakes, and eagles. In making an alarm call, a monkey attracts attention to itself, increasing its personal chance of being attacked, an example of altruistic behavior.
Design or natural selection
Detail of the mechanism in a Swiss watch
Greg and Mary Beth Dimijian
Photograph
Detail of the mechanism in a Swiss watch
The eye of a leaf-tailed gecko
Greg and Mary Beth Dimijian
Photograph
Madagascar
The eye of a leaf-tailed gecko (Uroplatus fimbriatus) from Madagascar is covered by a thin transparent membrane, which the gecko will lick with its thick and sticky tongue to keep clean
Computer model simulation of a hypothetical evolution of an eye
Dan E. Nilsson and Susanne Pelger
Illustration
22 April 1994
Adapted from Computer model simulation of a hypothetical evolution of an eye
© Dan E. Nilsson and Susanne Pelger
Theoretical considerations of eye design allow us to find routes along which the optical structures of eyes may have evolved. If selection constantly favours an increase in the amount of detectable spatial information, a light-sensitive patch will gradually turn into a focused lens eye through continuous small improvements of design. An upper limit for the number of generations required for the complete transformation can be calculated with a minimum of assumptions. Even with a consistently pessimistic approach the time required becomes amazingly short: only a few hundred thousand years.
A pessimistic estimate of the time required for an eye to evolve
Proceedings of the Royal Society B 22 April 1994
Volume 256 (1345), pages 53–58
→ Read the full text (Journal subscription required)
A close-up view of the eye of an elephant
Greg and Mary Beth Dimijian
Photograph
Khwai River, Botswana
When an elephant paused while crossing the Khwai River floodplains, we photographed this close-up view of its eye.
What is natural selection?
A chameleon from Madagascar
Greg and Mary Beth Dimijian
Photograph
Madagascar
A strikingly beautiful chameleon, Calumma oshaughnessyi is one of the many endemic chameleons in Madagascar.
A Squirrel monkey in the coastal tropical rain forest of Golfo Dulce, Costa Rica
Greg and Mary Beth Dimijian
Photograph
Golfo Dulce, Costa Rica
A tiny Squirrel monkey, smaller than a house cat, leaps from eighty feet with her baby clinging to her back, to a cluster of vines on a low tree near the ground, in the coastal tropical rain forest of Golfo Dulce, Costa Rica.
An olive ridley turtle
Greg and Mary Beth Dimijian
Photograph
Nancite Beach, Costa Rica
In the early dawn an olive ridley turtle labors out of the surf of the Pacific Ocean to lay her eggs on Nancite Beach, Costa Rica, at the time of the last-quarter moon—an evolutionary strategy providing the highest tides for the hatchlings.
Sampling of leaves from the Smoky Mountain National Park
Greg and Mary Beth Dimijian
Photograph
Smoky Mountain National Park, North Carolina
The variety of leaf shapes found in the Smoky Mountains in Tennessee and North Carolina provide a fascinating array of colors, shapes and sizes.
Chance and accident
An adult female leopard in the Masai Mara of Kenya
Greg and Mary Beth Dimijian
Photograph
Masai Mara, Kenya
With the setting sun in her eyes, an adult female leopard waits at the base of a small tree, while her cubs feed on an impala carcass she carried to a branch overhead.
A male hippo in the Okavango Delta of Botswana
Greg and Mary Beth Dimijian
Photograph series
Okavango Delta, Botswana
A male hippo in the Okavango Delta of Botswana
A male hippo keeps only eyes, ears, and nostrils above water as he guards his stream territory and watches intruders intently. Hippos are perhaps the most dangerous animal to humans in Africa, apart from mosquitoes. They can charge at thirty miles per hour and chop a human in half. With one of the largest gapes of any mammal, a male hippo will defend his territory by advertising his enormous canine and incisor teeth.
A Black rhinoceros and its calf in Ngoro National Park
Greg and Mary Beth Dimijian
Photograph
Ngorongoro National Park, Tanzania
In Tanzania, we see a Black rhinoceros and its calf in Ngorongoro National Park. Black Rhinoceres are know for their “charge-first-and-ask-questions-later” attitude, which some biologists attribute to their poor vision.
Domesticating animals
A Chihuahua walking with a Great Dane more than fifty times its mass
Science
Cover illustration
6 April 2007
A Chihuahua walking with a Great Dane more than 50 times its mass
© Deanne Fitzmaurice
The extreme diversity in body size among purebred dogs is greater than that of any other mammalian species. Researchers have identified a gene that helps explain this size diversity.
A Single IGF1 Allele Is a Major Determinant of Small Size in Dogs
Nathan B. Sutter et al
Science, 6 April 2007, Volume 316 (5821)
→ Read the full article (Journal subscription required)
A hypothetical model of the ancestry of modern dog
Different geographic subspecies of wolves may have given rise to different dog-breed groups. This model shows one interpretation of the ancestry of modern dog breeds.
A comparison of a bulldog head in 1890 and in 1935
This illustration below shows the shocking deformation of the bulldog head between 1890 and 1935. The modern bulldog's shortened face now causes serious medical problems, and results from breeding for fashion.
A wild African cat
Greg and Mary Beth Dimijian
Photograph
A wild African cat stalks for prey at night.
Domesticating plants
View of Machu Picchu in Peru
Greg and Mary Beth Dimijian
Photograph
Machu Picchu, Peru
On the slopes below Machu Picchu in Peru, the Incas may have selectively bred plants which could tolerate the high altitude. In order to do so, they needed only to plant varieties of crops on the terraces and breed successful plants from year to year.
Domesticating ourselves
An open road in the Sonoran Desert
Greg and Mary Beth Dimijian
Photograph
Sonoran Desert, California
A two-lane ribbon of asphalt cuts through Sonoran Desert of California
Clear cutting in the Amazon
Greg and Mary Beth Dimijian
Photograph
Peru
Commercial logging in the Amazon
In 2005, the Carnegie Institution's Department of Global Ecology found that sixteen percent of rain forests, which had been selectively logged, were completely clear-cut within one year and thirty-two percent of logged areas were completely cleared within four years.
Driven by short-term profits, commercial logging, often illegal but ignored by government agencies, is devastating the Peruvian Amazon, both in terms of its impact on the global environment and its local impact on indigenous peoples.
Selective Logging in the Brazilian Amazon
Greg Asner et al
Science, 21 October 2005, Volume 310 (5747), pages 480–482
→ Read the full article (Journal subscription required)
Social systems
Male and female dung beetles in East Africa
Greg and Mary Beth Dimijian
Photograph
Standing on his front legs and rolling a ball of wildebeest dung, a male dung beetle in East Africa courts a female, who rides along on the rolling ball. At one point, when the ground is just right, he starts digging and the whole party slowly sinks underground. At a depth of several feet he stops, and the female deposits one or more eggs in the dung, which will serve as a rich food source. The young will also be safe from predators. Dung beetles are unsung heroes of nutrient recycling and soil turnover in the tropics; we wear colorful ones on our bodies in the form of scarab jewelry.
Naked mole-rats in East Africa
Greg and Mary Beth Dimijian
Photograph
Naked mole-rats live in large underground colonies in East Africa. They are among the most unusual mammals in the world, almost hairless and almost blind, with only one reproductive female in the colony and several reproductive males. The other colony members perform tasks such as digging tunnels; they forgo reproduction. What does this social organization have in common with eusocial insects such as ants, bees, wasps, and termites?
Orange clownfish in an anemone on a coral reef in the Philippines
Greg and Mary Beth Dimijian
Photograph
Philippines
Orange clownfish find protection in an anemone with stinging tentacles on a coral reef in the Philippines; they are not harmed by the tentacles, as some predators would be. The breeding female is largest and the breeding male second largest. If the female dies, the male changes sex and takes her place, and the largest nonbreeder becomes the breeding male. These fish are born with a hermaphroditic potential and express only one of the two gender choices at any one time, depending on social stimuli.
Pantanal caimans in the Brazilian Pantanal
Greg and Mary Beth Dimijian
Photograph
Pantanal, Brazil
An army of hungry mouths awaits any small animal that crosses this flooded area in the Brazilian Pantanal, their eye reflections shining in our strobe light as we look down from a low bridge. These are Pantanal caimans, crocodilians about five or six feet long. As you can see, they congregate in groups to feed on prey at night. The river is spacious, and each caiman could stalk prey away from the others, but they assemble in groups. This is social behavior, and how does it evolve?
Hominin evolution
An Umbrella Thorn Acacia on the Serngeti Plains
Greg and Mary Beth Dimijian
Photograph
Serengeti, near Ndutu, Tanzania
In the the savanna grassland of the Serengeti, near Ndutu, Tanzania, a mature Umbrella Thorn Acacia (Acacia tortilis) serves as an oasis from the searing heat.
SEMINAR TWO
Evolution of sexuality
A male Resplendent Quetzal of Central America
Greg and Mary Beth Dimijian
Photograph series
Monteverde Cloud Forest, Costa Rica
A male Resplendent Quetzal of Central America
A female Resplendent Quetzal of Central America
Have you ever seen the most beautiful bird in the world? Many consider the male Resplendent Quetzal of Central America to deserve the title of most beautiful bird. I took these photographs of the Quetzal in the cloud forest of Costa Rica.
Shown above in the first two images, we see a splendid male Resplendant Quetzal. In the lead image, he looks out of his nest hole, his long tail still pointing in the direction in which he entered the hole.
In the third image, we see a female Resplendent Quetzal. She is not as “resplendent” as the male. Her colors are more subdued and her tail is not long and elegant.
Detail from the front face of a Quetzal
In Guatemala the Resplendant Quetzal is so admired that the male adorns their currency, with his long tail trailing behind in flight.
Sexual dimorphism
A male Variable Sunbird in East Africa
Greg and Mary Beth Dimijian
Photograph series
A female Variable Sunbird in East Africa
In the first image, we see a male Variable Sunbird of East Africa, which has a glossy green head, throat and nape with maroon breast band and a yellowish belly. In the second image, we see a female Variable Sunbird (Cinnyris venustus), which has grey-brown upperparts and yellowish underparts, and an obvious pale supercilium. These birds are small, only ten centimeters long. They have medium-length thin down-curved bills and brush-tipped tubular tongues, both adaptations to their nectar feeding.
A male and female Furcifer willsii in Madasgacar
Greg and Mary Beth Dimijian
Photograph
In Madagascar, a female Furcifer willsii (a chameleon with no common name) chases a male of her species away from her place on a branch. Because of the striking sexual dimorphism, the male and female could easily be mistaken for different species.
A pair of Rhinoceros beetles from Costa Rica
Greg and Mary Beth Dimijian
Photograph
Relax—these rhinoceros beetles from Costa Rica will not bite! Their sharp claws may give pause, however. These beetles are a nice example of sexual dimorphism, the male being larger than the female and sporting a long horn used to move other males out of his way. Weaponry and large size in males are believed to evolve through male-male competition.
Female choice in sexual selection
An Indian Blue Peacock
Greg and Mary Beth Dimijian
Photograph
One of the most ostentatiously adorned creatures on Earth, the Indian Blue Peacock uses its brilliant plumage to entice females.
Intrasexual selection
Two young Masai giraffe bulls necking in the Masai Mara of East Africa
Greg and Mary Beth Dimijian
Photograph
Masai Mara, Kenya
Two young Masai giraffe bulls perform a slow ballet called “necking,” in which both wrap their long necks around each other and sway far to each side.
Young African elephant bulls in the Okavango Delta of Botswana
Greg and Mary Beth Dimijian
Photograph
Okavango Delta, Botswana
Two young African elephant bulls gently spar with other.
Young impala males in the Okavango Delta of Botswana
Greg and Mary Beth Dimijian
Photograph
Okavango Delta, Botswana
Young impala males clash violently.
The Gay Side of Nature, an article from Time Magazine
Time Magazine
Illustrated article
26 April 1999
…Bagemihl's ideas have caused a stir in the higher, human community, especially among scientists who find it simplistic to equate any animal behavior with human behavior. But Bagemihl stands behind the findings, arguing that if homosexuality comes naturally to other creatures, perhaps it's time to quit getting into such a lather over the fact that it comes naturally to humans too. &lquo;Animal sexuality is more complex than we imagined,” says Bagemihl. “That diversity is part of human heritage.”
For a love that long dared not speak its name, animal homosexuality is astonishingly common. Scouring zoological journals and conducting extensive interviews with scientists, Bagemihl found same-sex pairings documented in more than 450 different species. In a world teeming with more than 1 million species, that may not seem like much. Animals, however, can be surprisingly prim about when and under whose prying eye they engage in sexual activity; as few as 2,000 species have thus been observed closely enough to reveal their full range of coupling behavior. Within such a small sampling, 450 represents more than 20%.
The Gay Side of Nature
Jeffrey Kluger, Time Magazine. 26 April 1999
→ Read the full article by Jeffrey Kluger
Male-male competition
A pair of Green Violet-ear hummingbirds
Greg and Mary Beth Dimijian
Photograph
A Green Violet-ear, a medium-sized hummingbird strikingly colored in dark metallic green with blue-violet cheek and breast patches, is dive-bombing its rival in this photograph we shot in the Monteverde Cloud Forest of Costa Rica. These birds are found in mountain forests, forest clearings, and forest edges, and are common from central Mexico southward into northern South America.
A Tungara frog from Panama
Greg and Mary Beth Dimijian
Photograph
A Tungara frog from Panama
The túngara frog in the two photos above is only an inch long, but what a call he makes in the ponds of Panama! In rapid succession he fills his lungs then exhales the air into his buccal pouch, which acts as a sounding board for his loud calls..
When you're photographing this little fellow you have to take multiple shots in succession and hope you get some at the end points of inhalation and pouch inflation! He is calling to attract females, but the call also attracts predators.
If other males are around, he makes a higher-pitched whine call plus a lower-pitched chuck, the latter call being more attractive to females. If males are not around he makes only the whine call, as he perceives no competition and the call is less noticeable to predators
His choice of whine or whine-chuck appears to be an example of the interplay of natural and sexual selection, natural selection intervening to reduce the attraction of predators. Conscious decision-making is not implied here; as with female choice, this is a behavioral trait with no implications of conscious choice
Natural selection versus sexual selection
A marbled tree frog in the Peruvian Amazon
Greg and Mary Beth Dimijian
Photograph series
The underside of a marbled tree frog
Are the two images above of the same frog? Absolutely—it is the same individual, a male marbled tree frog in the Peruvian Amazon. The photo above showing cryptic coloration was taken when the frog rested on the bark of a tree, and the photo showing bright underside colors was taken after he had been captured and placed in a small lucite aquarium, where we photographed him from below.
A Yellowstone Elk with its harem
Greg and Mary Beth Dimijian
Photograph
Yellowstone National Park, Wyoming
An example of male-male competition is the Yellowstone Elk, a harem-forming mammal in the American west.
Limiting resource in sexual selection
A lion in the Okavango Delta of Botswana
Greg and Mary Beth Dimijian
Photograph
Okavango Delta, Botswana
His nose scarred and mane luxuriant, “Chaca” may have been the only male in a lion pride on a small island in the Okavango Delta of Botswana.
A lioness and her cub
Greg and Mary Beth Dimijian
Photograph
A lioness rests with her cub.
Graph of reproductive success from a study of 140 seals
James L. Gould and Carol Grant Gould
Illustration
1989
© 1989 Scientific American Library
Male and female reproductive success follows very different patters in elephant seals. A few males sire nearly all the pups, while more than 90 percent of males are childless. Female success is much more evenly distributed; the most prolific mother achieves only 11 percent of the reproductive output of the top male, and the majority of females wean at least one pup.
Selection Selection
Scientific American Library, 1989, chapter 6, page 146
Based on the data of B. J. LeBoeuf and J. Reiter in T. Clutton-Brock, Ed., Reproductive Success, University of Chicago Press, 1988.
Limiting resource in sexual selection
A cheetah mother with two of her cubs in the Masai Maya of Kenya
Greg and Mary Beth Dimijian
Photograph
Masai Mara, Kenya
A cheetah mother remains alert to danger with two of her cubs in the Masai Mara of Kenya.
A spotted hyena mother and her cub in east Africa
Greg and Mary Beth Dimijian
Photograph
A spotted hyena mother carefully picks up her cub by the nape of its neck.
An illustration of the unique reproductive tract of a spotted hyena
Greg Dimijian
Illustration
In the mid-1980s, Laurence Frank and his colleague Stephen Glickman captured 20 infant spotted hyenas in Kenya and brought them home to the University of California at Berkeley. The two researchers rightly anticipated that studies of captive hyenas would unravel the mysteries of these animals, which have been famous since the time of Aristotle for being hermaphrodites.
The misconception that spotted hyenas are bisexual was perpetuated well into the twentieth century by people from Hemingway, who as a writer of fiction can be excused, to biologists, who should have known better. The truth about spotted hyenas (Crocuta crocuta) is arguably as bizarre as the myth. To the untrained eye, females look and act almost exactly like males. The two sexes' remarkable resemblance goes right down to the nitty-gritty of their genitals, which appear to be identical. Moreover, the females of this species seem to be even more masculine than the males: Females are some 10 percent larger by weight and are so much more aggressive that they dominate males in nearly every social encounter…
Sex and the Spotted Hyena
Robin Meadows, Smithsonian Zooger, May/June 1995
→ Read the full article by Robin Meadows
The flehmen response
A flehmen response in a lion
Greg and Mary Beth Dimijian
Photograph
A young male lion opens his mouth to sample the air with his vomeronasal organ (on the roof of the mouth), in order to detect a sexual pheromone coming from the female on the left. This is called a flehmen response, and it is distinct from olfaction, or smell, although it seems like the same thing to us.
A lion yawning
Greg and Mary Beth Dimijian
Photograph
In this image, we simply see a lion yawning.
A Temple viper in the Dallas Zoo
Greg and Mary Beth Dimijian
Photograph
Dallas Zoo
Dallas, Texas
A Temple viper, captive specimen from Asia, shown to us by our friend David Roberts, biologist and graphic artist at the Dallas Zoo. The snake, lit from a strobe below the camera, is sampling the air with its forked tongue.
Sperm competition
Cover of Nature from November 6, 2003
Nature
Cover
November 2003
When a female is sexually promiscuous, the ejaculates of different males compete for the fertilization of her eggs; the more sperm a male inseminates into a female, the more likely he is to fertilize her eggs. Because sperm production is limited and costly, theory predicts that males will strategically allocate sperm (1) according to female promiscuity (2) saving some for copulations with new females and (3) to females producing more and/or better offspring.
Whether males allocate sperm in all of these ways is not known, particularly in birds where the collection of natural ejaculates only recently became possible. Here we demonstrate male sperm allocation of unprecedented sophistication in the fowl Gallus gallus. Males show status-dependent sperm investment in females according to the level of female promiscuity; they progressively reduce sperm investment in a particular female but, on encountering a new female, instantaneously increase their sperm investment; and they preferentially allocate sperm to females with large sexual ornaments signalling superior maternal investment. Our results indicate that female promiscuity leads to the evolution of sophisticated male sexual behaviour.
Sophisticated sperm allocation in male fowl
Tommaso Pizzari, et al
Science, Volume 426 (6962), pages 70–74.
→ Read the full article (Journal subscription required)
A pregnant seahorse
Greg and Mary Beth Dimijian
Photograph
Seahorses are truly unique, and not just because of their unusual equine shape. Unlike most other fish, they are monogamous and mate for life. Rarer still, they are among the only animal species on Earth in which the male bears the unborn young.
Found in shallow tropical and temperate waters throughout the world, these upright-swimming relatives of the pipefish can range in size from 0.6 inches (1.5 centimeters) to 14 inches (35 centimeters) long.
Male seahorses are equipped with a brood pouch on their ventral, or front-facing, side. When mating, the female deposits her eggs into his pouch, and the male fertilizes them internally. He carries the eggs in his pouch until they hatch, then releases fully formed, miniature seahorses into the water.
Seahorse Profile
National Geographic
→ Learn more from National Geographic about seahorses
Mating and reproductive strategies
Island of South Georgia in the South Atlantic
Greg and Mary Beth Dimijian
Photograph series
South Georgia, South Georgia and the South Sandwich Islands
A Wandering Albatross from South Georgia
The master birder of the oceans, Peter Harrison, once told me that if he had a week to live, he would spend five days on South Georgia and two days getting there. I photographed the nearly fledged Wandering Albatross (shown above) on the island of South Georgia in the South Atlantic, a magical place which you must visit even if it's the last thing you do.
An Emperor Penguin father and his chick
Greg and Mary Beth Dimijian
Photograph
October 2007
Snow Hill Island, Antarctica
Photographed on the ice shelf of Snow Hill Island the Weddell Sea of Antarctica, an Emperor Penguin father carries his chick on his feet until it grows older and can walk on its own.
Habitat and reproductive strategies
Lake Natron in Tanzania
Greg and Mary Beth Dimijian
Photograph series, August 1988
Lake Natron, Tanzania
Flocks of the flamingoes on Lake Natron in Tanzania
Flamingo colonies on Lake Natron in Tanzania
Flamingo colonies on Lake Natron in Tanzania
In August 1988, I asked a light-plane pilot to fly me over Lake Natron in Tanzania with the right door off. He did, even though it was an illegal flight across the Kenya-Tanzania border and over an oven-hot lake where the air temperature would make stalling a serious risk. I was hoping to see breeding colonies of Lesser Flamingoes far out in the lake, miles from shore.
We then caught sight of flocks of the flamingoes near the deserted shore. Several miles from shore we were exhilarated to see the first colonies, with mud nests built up about a foot above the surface of the hot crust. Then came large colonies, built atop crust colored reddish by alkali-loving microorganisms.
If seeing Emperor Penguin chicks on feet was lucky, this opportunity was even more awesome. I had inadvertently picked a time in mid-breeding season to risk a flight over the torrid heat of the lake.
Sex in nature
A pair of stick insects mating
Greg and Mary Beth Dimijian
Photograph
A pair of stick insects mates. As its name suggests, the stick insect resembles the twigs where it typically lives, providing it with a most efficient defensive camouflage against predators.
A swarm of termites mating in Costa Rica
Greg and Mary Beth Dimijian
Photograph
Golfo Dulce, Costa Rica
In the Golfo Dulce of southwestern Costa Rica, a swarm of mating termites overwhelms anything that gets in its path, including photographers
Pupal mating of two Zebra longwing
Greg and Mary Beth Dimijian
Photograph
Two male Zebra Longwing butterflies await the emergence of the female from her pupa, competing for the chance to fertilize her eggs. She hardly gets the chance to spread her wings!
Monogamy in nature
A cheetah mother and son in the Masai Mara National Reserve
Greg and Mary Beth Dimijian
Photograph
Masai Mara, Kenya
A cheetah mother and son rest in the Masai Mara National Reserve. The son is on left, with a full stomach from a recent kill
A mother cheetah with her six young cubs on plains of the Masai Mara of Kenya
Greg and Mary Beth Dimijian
Photograph
Masai Mara, Kenya
A mother cheetah with her six young cubs strolls across the plains of the Masai Mara of Kenya.
A young female leopard in the Serengeti near Ndutu, Tanzania
Greg and Mary Beth Dimijian
Photograph
Serengeti near Ndutu, Tanzania
Only twemty feet above our open vehicle, a young female leopard seems curious but comfortable with our presence, in the open woodlands of the Serengeti near Ndutu, Tanzania. From a short distance away she was almost invisible.
Sexual behavior in nature
A lion and lioness in the Serengeti-Mara
Greg and Mary Beth Dimijian
Photograph
A lion bites playfully at the tail of the lioness he is mating with over a three-day period.
A lion mounting a lioness
Greg and Mary Beth Dimijian
Photograph
Grimacing just as mating is completed, the male hastens to back off as the female raises her head in an open-mouth threat.
A lioness and her cubes in Bostswana
Greg and Mary Beth Dimijian
Photograph
Okavango Delta, Botswana
A lioness grooms her cubs.
Why sex?
Illustration by Sir John Tenniel from The Looking Glass
Sir John Tenniel
Illustration
1872
“Now! Now!” Cried the Queen. “Faster! Faster!”
Sir John Tenniel's Alice in Wonderland
www.johntenniel.com
Sir John Tenniel's illustrations for Alicel's Adventures in Wonderland and Through the Looking-Glass are considered to be his finest and most enduring achievement. They must also rank among the worldl's best-known children's images.
The Dalziel brothers were commissioned to engrave the boxwood blocks on which Tenniel had made his drawings. The engravers advised Lewis Carroll that the engraved blocks should not be used for printing the illustrations in the books but instead they would act as the masters from which electrotype copies would be made. It was from these electrotypes that all the illustrations in the Alice books were printed with a resultant loss of definition.
In 1985 the original wood engraved blocks were discovered in deed boxes belonging to Macmillan, the original publishers. Jonathan Stephenson at the Rocket Press was awarded the prestigious job of printing 250 sets from the blocks (the first time that they had been used) for worldwide distribution. No further sets will be printed.
Mike Goldman
Goldmark Gallery, Uppingham
→ View more illustrations by Sir John Tenniel
Illustration of the loss of genetic diversity in crops1
Greg Dimijian
Illustration
Sexual reproduction, unlike cloning, produces offspring of different genotypes (different constellations of genes). One individual may survive an infectious or parasitic disease, whereas all may succumb if they are identical genotypes. Sameness kills – consider our disastrous loss of genetic diversity in food crops. In the Irish Potato Famine of 1845–6, a potato crop blight triggered a famine in which almost one-eighth of the Irish population died.
Dolphin gulls on the Falkland Islands
Greg and Mary Beth Dimijian
Photograph
Saunders Island, Falkland Islands
A pair of Dolphin Gulls courts on Saunders Island in the Falkland Islands.
Gamete types
Plasmodial slime mold in Costa Rican rain forest
Greg and Mary Beth Dimijian
Photograph series
Monteverde Cloud Forest Reserve, Costa Rica
Plasmodial slime mold forming fruiting bodies called sporangia
A thing of rare beauty, the plasmodial slime mold shown above was photographed in the moist understory of a Costa Rican rain forest. It is like nothing else on earth. An advancing feeding machine as large as a dinner plate, the thick soup of nuclei called a plasmodium moves at a centimeter per hour, devouring small animals and microorganisms in its path. It is for a short time a single organism with thousands of nuclei in an unbroken matrix which branches in a fractal pattern. It can pass unchanged through a sheet of filter paper.
Then, abruptly, it undergoes a change which advances like a slow wave through it. Some of the nuclei form fruiting bodies called sporangia, which become separate individuals. Shown in the image below, these new individuals form an expanding Lilliputian forest on log and leaf surfaces, even while the brightly colored plasmodium is still moving and feeding a few inches away. The slime mold is changing under our eyes from a single individual into a multitude. The concept of individuality becomes ambiguous.
The life cycle of the slime mold is complete when spores (gametes) from these sporangia fall to the ground, divide, fuse to form zygotes, then create a new multinucleate plasmodium. Up to thirteen different gamete types participate in sexual reproduction. Why and how did such gamete variety evolve, and why is it so rare? Some day we will know.
Somatic embryogenesis
a branch of a Yellow Fever tree (Acacia xanthophloea) in bloom
Greg and Mary Beth Dimijian
Photograph series
Seed pods of the Yellow Fever Tree
In the first image, we see a branch of a Yellow Fever tree (Acacia xanthophloea) in bloom. The bright yellow, golden, ball-like flowers are sweetly scented and grow in clusters on shortened side shoots at the nodes and towards the ends of branches.
The common name for this tree, Yellow Fever Tree, came from the mistaken association of the tree with malaria by early colonialists. The trees occur along river banks and in low-lying swampy areas, as do the mosquitoes which are the actual carriers of malaria parasites.
In the second image, we see the flowers of the Yellow Fever Tree have produced long seed pods, which mature from January to April.
Internal versus external fertilization
A pair of glass frogs in amplexus
Greg and Mary Beth Dimijian
Photograph
Fertilized eggs produced by the glass frogs
The pair of tiny glass frogs (so named because their abdominal skin is semi-transparent) is in amplexus, meaning the male rests atop the female, awaiting her release of eggs onto the leaf. He will try to be the first and only male to fertilize her eggs.
A tiny tadpole will develop inside each gelatinous egg, ready to fall off the leaf into the water of a stream below. If a predator such as a snake starts to eat the eggs, the tadpoles will drop off sooner than they would have otherwise, provided that they are close to being ready anyway
This reproductive strategy involves external fertilization, that is, fertilization outside of the female body. Unlike internal fertilization it provides a male with certainty of paternity.
Golden Toads in amplexus
Greg and Mary Beth Dimijian
Photograph
Monteverde Cloud Forest Reserve, Costa Rica
The beautiful Golden Toads in amplexus were known only from a cloud forest in Costa Rica, where we photographed this pair in 1989, the year that they vanished as a species. No one has seen them since.
Asexuality in nature
Sproangia on the back of a fern frond in Costa Rica
Greg and Mary Beth Dimijian
Photograph
Sproangia on the back of a fern frond in Costa Rica
What is behavioral ecology?
King penguins on the island of south Georgia
Greg and Mary Beth Dimijian
Photograph
South Georgia, South Georgia and the South Sandwich Islands
King penguins fill a black beach in south Georgia.
White-faced capuchin monkeys in the tropical cloud forest of Monteverde, Costa Rica
Greg and Mary Beth Dimijian
Photograph
Monteverde Cloud Forest Reserve, Costa Rica
A small family of white-faced capuchin monkeys stops for a curious glance at human intruders in the tropical cloud forest of Monteverde, Costa Rica.
A leaf beetle from Costa Rica
Greg and Mary Beth Dimijian
Photograph
Monteverde Cloud Forest Reserve, Costa Rica
This tiny colorful leaf beetle, less than one-half inch long, lives in the cloud forests of Costa Rica.
Tubeworms attached to a Montastrea coral
Greg and Mary Beth Dimijian
Photograph
Found in the Caribbean, these colorful Tubeworms, worm-like invertebrates, are attached to a Montastrea coral.
Human sexuality in an evolutionary perspective
Cover of a publication of Just So Stories by Rudyard Kipland
Rudyard Kipling told his children gloriously fanciful tales of how things in the world came to be as they are. He wrote them down for publication as the Just So Stories in 1902, just three years after the tragic death of the daughter for whom they had first been invented. During the 20th century, generations of children were tucked into bed with readings of highly imaginative and wildly improbably explanations such as how the elephant got his trunk.
Rudyard Kipling's ‘Just So Stories’
The British Library
→ Read more about Rudyard Kipling's ‘Just So Stories’ online at the British Library
Sexual stereotypes
Alison Carroll
Tomb Raider, Inc.
Photograph
August 2008
Alison Carroll
© Tomb Raider, Inc.
In 2008, Alison Carroll became the model for the popular video game heroine, Lara Croft, with the release of Tomb Raider: Underworld..
→ See more images of Alison Carroll as Lara Croft
Coevolution
A young girl playing happily with sand and shells in the warm coastal waters of the Caribbean
Greg and Mary Beth Dimijian
Photograph
A young girl plays happily with sand and shells in the warm coastal waters of the Caribbean
Menstrual taboos
A dogon menstrual hut in Mopti
Erwin Bolwidt
Photograph
10 October 2005
Kani Bonzon, Mopti
A dogon menstrual hut in Mopti, Mali
© Erwin Bolwidt
→ View more photography from Mali by Erwin Bolwidt
Despotism
Genghis Khan Memorial in Terelj National Park, outside Ulaanbaatar, Mongolia
Michael Foley
Photograph
4 July 2009
Terelj National Park, Mongolia
Genghis Khan Memorial in Terelj National Park, outside Ulaanbaatar, Mongolia
© Michael Foley
A stainless steel monument to Genghis Khan on a horse, forty meters in height, sits atop the Mongolian steppe. Visitors can walk to a deck on the horse's head, where they can view the Grand Khan face to face.
→ See more photography by Michael Foley
Molecules and pair bonding
The Birth of Venus by Sandro Botticelli
Sandro Botticelli
Tempera on canvas
Around 1485–86
The Birth of Venus
© Galleria degli Uffizi, Florence
The elixir of love
Prairie voles
© Yerkes National Primate Research Center
These prairie voles can remain contentedly bonded to each other as long as researchers don't interfere with the brain chemicals that promote attachment.
A Love Vaccine?
John Tierney, New York Times, 12 January 2009.
→ Read the article by John Tierhney
Illustration by Nicolle Rager Fuller/National Science Foundation
Nicolle Rager Fuller
Illustration
5 June 2005
Illustration by Nicolle Rager Fuller/National Science Foundation
© Nicolle Rager Fuller/National Science Foundation
In the first illustration, random changes that alter the length of microsatellite DNA near the gene for the vasopressin receptor affect social behavior in male voles. A longer microsatellite region resulted in more bonding and care giving.
In the second illustration, the length of a microsatellite DNA region near the vasopressin receptor gene was discovered to have an effect on social behavior in voles. Genome data for this same microsatellite reveals strong similarities in DNA sequences between humans and bonobos (known for its strong social bonds), while DNA of the more-agressive chimpanzees differs from both humans and bonobos in this region..
All Images: Press Release 05-096
Variation in Vole Gene is Bellwether for Behavior
National Science Foundation
→ Read the full article online
Subjugation and denigration of women
Esther Satar
Ash Sweeting
Photograph
Deh Magas, Afghanistan
Esther Satar
© Ash Sweeting
Abdul Satar lost his poppy harvest to a hailstorm. His daughter Esther… will be given as a second wife to a 70-year-old drug lord to pay debt accrued at a grocery shop the dealer runs in Deh Magas, in Badakhshan, Afghanistan.
Officially, it's a marriage.
“We don’t have any choice. If the money lender wants our land or daughters, we have to do whatever makes him happy,” the aging farmer says, his eyes welling with tears as his daughter sits next to him in their mud-brick shack.
Esther quietly fingers the black scarf that covers her hair. Asked how she feels about her impending wedding to local drug baron Khan Mohammed, she looks down at her feet.
“I don't want to marry him,” she whispers.
Almost five years after a U.S.-led invasion of Afghanistan led to the overthrow of the Taliban and the establishment of a democratically elected government, Esther's predicament underscores the persistence of a feudal economic system in parts of rural Afghanistan and the continuing low status of women and girls.
In desperate times, daughter is currency
Rachel Morarjee, Dallas Morning News. 30 May 2006.
→ Read the full article by Rachel Morarjee
Sexual violence against women
Assiya Rafiq
Nicholas D. Kristof
Photograph
Meerwala, Pakistan
Assiya Rafiq, right, in front of her mother, Iqbal Mai
© Nicholas D. Kristof/The New York Times
After being kidnapped at the age of 16 by a group of thugs and enduring a year of rapes and beatings, Assiya Rafiq was delivered to the police and thought her problems were over.
Then, she said, four police officers took turns raping her.
The next step for Assiya was obvious: She should commit suicide. That's the customary escape in rural Pakistan for a raped woman, as the only way to cleanse the disgrace to her entire family.
Instead, Assiya summoned the unimaginable courage to go public and fight back. She is seeking to prosecute both her kidnappers and the police, despite threats against her and her younger sisters. This is a kid who left me awed and biting my lip; this isn't a tale of victimization but of valor, empowerment and uncommon heroism.
Not a Victim, but a Hero
New York Times. 25 July 2009.
→ Read the full editorial by Nicholas D. Kristof
The dark side of religion
Faceplate from the Malleus Maleficarum of Heinrich Kramer and James Sprenger
The Malleus Maleficarum of Heinrich Kramer and James Sprenger
Faceplate illustration
1928
Pope Innocentius VIII
© 1971 Dover Publications, Inc.
As the leading handbook for witch-hunters, and the first encyclopedia of witchcraft, the Hammer of Witches maintained a pre-eminent position of authority for nearly 200 years, providing both foundation and inspiration for all later European treatises on witch-theory and persecution.
Examination of a Witch, painting by T. H. Matteshon
T. H. Matteson
Oil on canvas
1853
Examination of a Witch
© Peabody Essex Museum, Salem
Generally supposed to represent an event in the Salem witch trials, an earlier version of this painting was exhibited by the artist in New York in 1848 with a quotation from John Greenleaf Whittier's book Supernaturalism of New England, 1847: “Mary Fisher, a young girl, was seized upon by Deputy Governor Bellingham in the absence of Governor Endicott, and shamefully stripped for the purpose of ascertaining whether she was a witch, with the Devil's mark upon her.”
Various Images of Salem Witch Trials
The Salem Witch Trials Documentary Archive and Transcription Project
The University of Virginia, 2002.
→ Learn more about the Salem Witch Trials
A tragic history
Photograph of two Afghan women in burkas in a marketplace in Mazar-e-Sharif, Afghanistan
Staff Sgt. Ceclio Ricardo, USAF
Photograph
15 December 2001
Photograph of two Afghan women in burkas in a marketplace in Mazar-e-Sharif, Afghanistan
Defense Visual Information Directorate
U.S. Department of Defense
→ Search the online catalog of imagery at www.defenseimagery.mil
SEMINAR THREE
Warfare, genocide and ethnic conflict
Photograph of the aftermath of the Battle of Gettysburg
Timothy O'Sullivan
Albumen silver print from glass negative
1863
Field Where General Reynolds Fell, Battlefield of Gettysburg (2005.100.502.1)
© The Metropolitan Museum of Art, New York
This photograph of the aftermath of the Battle of Gettysburg appears in the two-volume opus Gardner's Photographic Sketch Book of the War (1865–66). Gardner's publication is egalitarian. Offended by Brady's habit of obscuring the names of his field operators behind the deceptive credit ”Brady,” Gardner specifically identified each of the eleven photographers in the publication; forty-four of the one hundred photographs are credited to Timothy O'Sullivan. Gardner titled the plate Field Where General Reynolds Fell, Battlefield of Gettysburg. But the photograph, its commemorative title notwithstanding, relates a far more common story: six Union soldiers lie dead, face up, stomachs bloated, their pockets picked and boots stolen. As Gardner described the previous plate, aptly titled The Harvest of Death, this photograph conveys ”the blank horror and reality of war, in opposition to its pageantry.“.
Heilbrunn Timeline of Art History
The Metropolitan Museum of Art, New York
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Unexploded ordnance near Sheibah Log Base in Iraq
Spc. Kelly Burkhart
Photograph
6 May 2005
An Iraqi Army Explosive Ordnance soldier looks at landmines that were placed on top of unexploded ordnance at the Explosive Ordnance range near Sheibah Log Base, Iraq.
Defend America
U.S. Department of Defense
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We and they
The we-they dichotomy
Greg Dimijian
Illustration
One of the foremost evolutionary biologists of our time, Edward O. Wilson, has argued that a we-they tendency characterizes human nature. In the we-they dichotomy, people are placed inside and outside of an imaginary mental circle.
Photograph of the 1914 Christmas Truce
Photograph
December 1914
Photograph of the 1914 Christmas Truce (NAM 1995-06-89-1-1)
© National Army Museum, Chelsea
During Christmas 1914, along parts of the Western Front unofficial truces between British and German soldiers took place. In the trenches on Christmas morning carols were sung and rations thrown across the opposing lines. It was not long before the more adventurous soldiers started to take matters into their own hands and venture into no-man's-land.
Here they exchanged food, tobacco, cigarettes, drink, badges and buttons. Both sides saw the lull in fighting as a chance to find the bodies of their comrades and give them a decent burial. Although strict orders were issued against fraternization by the High Command, many junior officers tolerated the truce and allowed events to take their own course. They never doubted that eventually the fighting would resume in all its fury. They were proved correct.
For the rest of the First World War (1914–1918) there was to be no major repeat of the 1914 truce. The event acquired semi-mythic status and has since been celebrated as an act of humanity in a brutal conflict.
Galleries & Exhibitions: Changing the World
A friendly chat with the enemy
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Preemptive preservation
A black-figure amphora
Amphora
Greek, Attic
Around 530 BC
Terracotta, attributed to the manner of the Lysippides Painter
© The Metropolitan Museum of Art, New York
This black-figure amphora is attributed to the manner of the Lysippides Painter, a follower of Exekias who specialized in large pots. With only the essential elements, the artist presents us with a scene both elegant and forceful. Two hoplites (foot soldiers), with their spears and shields poised, prepare to do battle. Each is characteristically equipped with a helmet, cuirass (body armor), greaves (shin guards), large shield, and spear. They wear Corinthian helmets, characterized by cutouts for the eyes, a narrow nosepiece, and a small opening for the lips and chin.
Their intricately incised body armor refers to the actual bronze pieces that would have been modeled after the male torso. Likewise, their large, circular shields stand for the original armor that would have been made of wood faced with bronze. A hoplite's shield was the most important part of his panoply. Since such expensive equipment was usually paid for by the hoplite, military service became not only a distinction of citizenship, but also a symbol of wealth and social status.
Elegant battle scenes like this one must have afforded great pleasure to an aristocratic class that placed considerable emphasis on military valor and athletic competition. The hoplite and his armor were a source of pride—a status symbol and the principle medium for serving one's city-state.
Heilbrunn Timeline of Art History
The Metropolitan Museum of Art, New York
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Rising earth greets Apollo VIII astronauts as they come from behind the moon after the lunar orbit insertion burn. Earth is about 5 degrees above the horizon.
William Anders
Photograph
29 December 1968
306-PSD-68-4049c
The Library of Congress
Rising earth greets Apollo VIII astronauts as they come from behind the moon after the lunar orbit insertion burn. Earth is about 5 degrees above the horizon.
Picturing the Century: Century's End
National Archives and Records Administration
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Ingroup and outgroup
Illustration of the evolutionary roots of warfare
Greg Dimijian
Illustration
At the top of the drawing, friendly people coexist across boundaries. At the bottom a war-prone group at the left consists of members who are altruistic toward each other and hostile toward outsiders; the analysis showed that under conditions likely to have prevailed in early humans, groups with genes predisposing to this tendency would confer greater reproductive success on their group.
→ Read the article, “The Coevolution of Parochial Altruism and War.” (Journal subscription required)
Elders of the Wazir tribe in southern Afghanistan
Reza
Photograph
Afghanistan
© Reza
Elders of the Wazir tribe gather in a farmhouse in southern Afghanistan to discuss how to press a grievance with the U.S. military. American troops searching for Osama bin Laden and other al Qaeda fighters had arrested a young Wazir male for allegedly attacking U.S. troops. Since then the elders, who claim the young man is innocent, have heard nothing about the case. As both American and Pakistani troops comb the rugged Afghan-Pakistani border for Islamic militants, the Wazir and other tribes of the famously independent Pashtun peoples in the area can expect no end to conflict. Whose side are they on? The elders must decide as the military continues its manhunt.
On bin Laden's Trail
Tim McKirk, National Geographic Magazine, December 2004
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The elixir of violence
Joseph Goebbels urges Germans to boycott Jewish-owned businesses
Photograph
1 April 1933
Berlin, Germany
In Berlin on April 1, 1933, Joseph Goebbels addresses a crowd in the Berlin Lustgarten, urging Germans to boycott Jewish-owned businesses. He defends the boycott as a legitimate response to the anti-German “atrocity propaganda” being spread abroad by “international Jewry.&rdquo.
Propaganda Artifact Gallery
United States Holocaust Memorial Museum
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Suicide terrorism
USS BUNKER HILL hit by two Kamikazes in 30 seconds on 11 May 1945 off Kyushu. Dead-372. Wounded-264. 80-G-3237.
Photograph
11 May 1945
80-G-3237
Library of Congress
On the morning of May 11, 1945, while supporting the Okinawa invasion, the aircraft carrier Bunker Hill was hit and severely damaged by two kamikazes. The ship suffered the loss of 346 men killed, 43 missing, and 264 wounded. Although badly crippled, Bunker Hill managed to return to Bremerton via Pearl Harbor.
Pictures of World War II
National Archives and Records Administration
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In Sheepshead Bay, on Bedford and Avenue X, a playground handball court memorializes local firefighters and police officers who died on September 11
Sonja Shield
Photograph
16 April 2006
New York, New York
9/11 Memorial, Sheepshead Bay Handball Court
© Sonja Shield
In Sheepshead Bay, on Bedford and Avenue X, a playground handball court memorializes local firefighters and police officers who died on September 11. In the midst of a handball game, this local youth appears to salute the memorial. The names of the cops and firefighters—Italian, Irish, Latino—tell a story of this changing outer Brooklyn neighborhood.
Exhibitions: Click! A Crowd-Curated Exhibition
Brooklyn Museum
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The front page of the Washington Post on September 12, 2001
Kim Taylor
Photograph
12 September 2001
Washington, D. C.
The front page of the Washington Post on September 12, 2001
© Kim Taylor
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Torture
Prisoners in the concentration camp at Sachsenhausen, Germany
Photograph
19 December 1938
Sachsenhausen, Germany
242-HLB-3609-25
Library of Congress
Prisoners in the concentration camp at Sachsenhausen, Germany
Pictures of World War II
National Archives and Records Administration
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Prisoners in a liberated Nazi concentration camp
Photograph
April 1945
AN 72-3220
Library of Congress
Prisoners pose in liberated Nazi concentration camp
The Harry S Truman Library and Museum
National Archives and Records Administration
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Human nature versus individual psychopathology
Teenagers in Los angeles flaunt their gang sign and play with loaded guns
Teenagers in Los angeles flaunt their gang sign and play with loaded guns. Here is a subculture of violence in the toughest neighborhoods, in which gangs are like rival armies. A Jesuit priest in Los Angeles said, “I've buried kids I loved who were killed by kids I love.”
Streets of Death
Bob Herbert, New York Times, 12 June 2003
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Genocide and ethnic conflict
Remains of genocide victims on display at the Murambi memorial site in Rwanda
Dave Simpson
Photograph
18 April 2003
Murambi Genocide Exhibit, Rwanda
© Dave Simpson
Remains of genocide victims from the Rwanda massacres are on display in Murambi Genocide Exhibit, one of six memorial sites in Rwanda. Whitened by a coating of calcium salts, the remains of the 1,800 corpses of the 27,000 victims are placed on display in the old technical school to serve as a testament to the horrors of the genocide.
→ Learn more about the genocide in Rwanda by visiting the Rwandan National Museum online
Bodies of Rwandan refugees wrapped in straw mats and blankets line the roadside
MSGT Rose Reynolds
Photograph
1 October 1994
Rwanda
DF-ST-02-03035
Bodies of Rwandan refugees wrapped in straw mats and blankets line the roadside. In the background, more bodies are off loaded from a truck. Because of the lack of fresh water and food as many as 50,000 people died in crudely established refugee camps, during an outbreak of cholera. From Airman Magazine's December 1994 issue article ‘Will You Please Pray for Us?’ Relief for Rwandan Refugees.
Defense Imagery
U. S. Department of Defense
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A screen capture of the controversial video game, Postal 2
Running with Scissors, Inc.
Screen capture
October 2003
A screen capture of the controversial 2003 video game, Postal 2, provides a brief glimpse into the virtual world of violence many children experience, all in the name of entertainment. Using demeaning stereotypes and explicit violence, the game reinforces the worst aspects of human nature.
Mobs and militias
A postcard of a lynching of three black men
Photograph
15 June 1920
Duluth, Minnesota
Some of the onlookers who posed for the camera after the lynching of three black men in downtown Duluth on June 15, 1920.
Courtesy of the Minnesota Historical Society
Wielding bricks, rails, and heavy timbers, the mob forced its way into the jail, tearing down doors and breaking windows. They pulled all six blacks from their cells. After a hasty mock trial, Clayton, Jackson, and McGhie were declared guilty and taken one block to a light pole on the corner of First Street and Second Avenue East. A few tried to dissuade the mob, but their pleas were in vain. The three men were beaten and then lynched, first Isaac McGhie, then Elmer Jackson, and lastly Elias Clayton.
Duluth Lynchings Online Resource: The Lynchings
Minnesota Historical Society
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Preventing war and genocide
Long Khanh Province, Republic of Vietnam, 1966
Pfc. L. Paul Epley
Photograph
1966
Long Khanh Province, Republic of Vietnam
111-SC-635974
Library of Congress
SP4 R. Richter, 4th Battalion, 503rd Infantry, 173rd Airborne Brigade, lifts his battle weary eyes to the heavens, as if to ask why? Sergeant Daniel E. Spencer stares down at their fallen comrade. The day's battle ended, the silently await the helicopter which will evacuate their comrade from the jungle covered hills. Long Khanh Province, Republic of Vietnam, 1966.
Pictures of World War II
National Archives and Records Administration
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In 1940, children of an eastern suburb of London, who have been made homeless by the random bombs of the Nazi night raiders, wait outside the wreckage of what was their home.
Photograph
September 1940
London, England
306-NT-3163V
Library of Congress
Children of an eastern suburb of London, who have been made homeless by the random bombs of the Nazi night raiders, waiting outside the wreckage of what was their home
Pictures of World War II
National Archives and Records Administration
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Teaching children
The Blackboard, Poland, 1948
David ‘Chim’ Seymour
Photograph
The Blackboard, Poland (59.559.70)
© David “Chim” Seymour/Magnum Photos
One of the founders of Magnum Photos in 1947, Chim first gained recognition for his photographs of the Spanish Civil War and the Popular Front in Paris during World War II. His intuitive ability to identify and record key moments in the experience of events and of his surroundings allowed him to access wordlessly the emotional heart of a subject, a talent that was particularly useful for photographing children. This image is from a UNESCO-commissioned project to document the effects of World War II on Europe's children. It depicts a child who has lost her parents in the war, and the drawing on the blackboard is her rendition of “home”.
Heilbrunn Timeline of Art History
The Metropolitan Museum of Art, New York
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One page from an antisemitic Nazi coloring book
Archival photograph
United States Holocaust Memorial Museum Collection
Courtesy of Salo Kluger
One page of an antisemitic coloring book widely distributed to children with a portrait of a Jew drawn by the German caricaturist known as Fips. In the upper left hand corner is the Der Stürmer logo featuring a Star of David superimposed over a caricature of a Jewish face. The caption under the star reads: “Without a solution to the Jewish question, there will be no salvation for mankind.”
Propaganda Artifact Gallery
United States Holocaust Memorial Museum
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Closing thoughts
A young girl in Pajshir province, Bazarak district of Afghanistan
Capt. Stacie N. Shafran, USAF
Photograph
8 March 2009
Pajshir, Afghanistan
A young girl listens to a speech during the International Women's Day celebration March 8 in Pajshir province's Bazarak district of Afghanistan.
With burkas and families set aside for a few hours, nearly 125 Afghan women and girls relaxed, enjoyed one another's company and shared their culture during an International Women's Day celebration at the Astana Guesthouse in Bazarak District, March 8.
The event, organized by the Panjshir Director of Women's Affairs, featured a series of guest speakers who highlighted economic, political and social challenges as well as accomplishments of the valley's women.
Afghan women celebrate culture at Women's Day event
Capt. Stacie N. Shafran, U.S. Air Forces Central News, 15 March 2009
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