Mais uma estória da carochinha evolucionária: os animais de estimação 'ajudaram' na evolução humana

domingo, setembro 19, 2010

How animals made us human

What explains the ascendance of Homo sapiens? Start by looking at our pets.

By Drake Bennett

Globe Staff / September 12, 2010

Who among us is invulnerable to the puppy in the pet store window? Not everyone is a dog person, of course; some people are cat people or horse people or parakeet people or albino ferret people. But human beings are a distinctly pet-loving bunch. In no other species do adults regularly and knowingly rear the young of other species and support them into old age; in our species it is commonplace. In almost every human culture, people own pets. In the United States, there are more households with pets than with children.

On the face of it, this doesn’t make sense: Pets take up resources that we would otherwise spend on ourselves or our own progeny. Some pets, it’s true, do work for their owners, or are eventually eaten by them, but many simply live with us, eating the food we give them, interrupting our sleep, dictating our schedules, occasionally soiling the carpet, and giving nothing in return but companionship and often desultory affection.

A prehistoric painting of a bull at Lascaux in southwestern France.
Pierre Andrieu/AFP/Getty Images

What explains this yen to have animals in our lives?

An anthropologist named Pat Shipman believes she’s found the answer: Animals make us human. She means this not in a metaphorical way — that animals teach us about loyalty or nurturing or the fragility of life or anything like that — but that the unique ability to observe and control the behavior of other animals is what allowed one particular set of Pleistocene era primates to evolve into modern man. The hunting of animals and the processing of their corpses drove the creation of tools, and the need to record and relate information about animals was so important that it gave rise to the creation of language and art. Our bond with nonhuman animals has shaped us at the level of our genes, giving us the ability to drink milk into adulthood and even, Shipman argues, promoting the set of finely honed relational antennae that allowed us to create the complex societies most of us live in today. Our love of pets is an artifact of that evolutionary interdependence.

“Our connection with animals had a very great deal to do with our development,” Shipman says. “Beginning with the adaptive advantage of focusing on and collecting information about what other animals are doing, from there to developing such a reliance on that kind of information that there became a serious need to document and transmit that information through the medium of language, and through the whole thing the premium on our ability to read the intentions, needs, wants, and concerns of other beings.”

Shipman’s arguments for the importance of “the animal connection,” laid out in an article in the current issue of Current Anthropology and in a book due out next year, draw on evidence from archeological digs and the fossil record, but they are also freely speculative. Some of her colleagues suggest that the story she tells may be just that, a story. Others, however, describe it as a promising new framework for looking at human evolution, one that highlights the extent to which the human story has been a collection of interspecies collaborations — between humans and dogs and horses, goats and cats and cows, and even microbes.

Shipman, a professor of biological anthropology at Pennsylvania State University, draws together the scattered strands of a growing field of research on the long and complex relationship between human and nonhuman animals, a topic that hasn’t traditionally warranted much scholarly discussion but is now enjoying a surge of interest. The field of so-called human-animal studies is broad enough to include doctors researching why visits by dogs seem to make people in hospitals healthier, art historians looking at medieval depictions of wildlife, and anthropologists like Shipman exploring the evolution and variation of animal domestication. What they all share is an interest in understanding why we are so vulnerable to the charms of other animals — and so good at exploiting them for our own gain.

The traits that traditionally have been seen to separate human beings from the rest of the animal kingdom are activities like making tools, or the use of language, or creating art and symbolic rituals. Today, however, there is some debate over how distinctively human these qualities actually are. Chimpanzees, dolphins, and crows create and use tools, and some apes can acquire the language skills of a human toddler.

A few anthropologists are now proposing that we add the human-animal connection to that list of traits. A 2007 collection of essays, “Where the Wild Things Are Now,” looked at how domesticating animals had shaped human beings as much as the domesticated animals themselves. Barbara King, an anthropologist at the College of William & Mary, published a book earlier this year, “Being With Animals,” that explores the many ramifications of our specieswide obsession with animals, from prehistoric cave art to modern children’s books and sports mascots. King’s primary interest is in the many ways in which myths and religious parables and literature rely on animal imagery and center on encounters between humans and animals.

“[W]e think and we feel through being with animals,” King writes.

Shipman’s argument is more specific: She is trying to explain much of the story of human evolution through the animal connection. The story, as she sees it, starts with the human invention of the first chipped stone tools millions of years ago. Shipman, who specializes in studying those tools, argues that they were an advance made for the express purpose of dismembering the animals they had killed. The problem early humans faced was that even once they had become proficient enough hunters to consistently bring down big game, they had the challenge of quickly getting the meat off the corpse. With small teeth and a relatively weak jaw, human beings couldn’t just rip off huge chunks, it took time to tear off what they needed, and it rarely took long for bigger, meaner predators to smell a corpse and chase off the humans who had brought it down.
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Read more here/Leia mais aqui: The Boston Globe

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Current Anthropology, 51:519–538, August 2010
© 2010 by The University of Chicago. All rights reserved.
0011-3204/2010/5104-0004$10.00
DOI: 10.1086/653816

CA FORUM ON THEORY IN ANTHROPOLOGY

The Animal Connection and Human Evolution

Pat Shipman

Pat Shipman is Professor of Biological Anthropology in the Department of Anthropology of Pennsylvania State University (University Park, Pennsylvania 16802, U.S.A. [pls10@psu.edu ]).

A suite of unique physical and behavioral characteristics distinguishes Homo sapiens from other mammals. Three diagnostic human behaviors played key roles in human evolution: tool making, symbolic behavior and language, and the domestication of plants and animals. I focus here on a previously unrecognized fourth behavior, which I call the animal connection, that characterized the human lineage over the past 2.6 million years. I propose that the animal connection is the underlying link among the other key human behaviors and that it substantially influenced the evolution of humans.

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