Does evolution explain human nature?

"Does evolution explain human nature?" This is a typical Templeton Foundation question, in that it is laden with ambiguities. Only when one figures out the meaning of "evolution," "explain," and "human nature" can one really get to work. I suspect that the Templeton questions are drafted vaguely in order to invite a wide range of participants, who must often roll up their sleeves to define the component elements of the question as part of their answer. I don't mean to sound like a pedant here. The reason I am posting on this question is that despite the wobbly question, Templeton has once again done a good job of assembling a wide range of opinion on an important set of issues. You can read the many responses here. My favorites are Frans de Waal,

If we look at our species without letting ourselves be blinded by the technological advances of the last few millennia, we see a creature of flesh and blood with a brain that, albeit three times larger than that of a chimpanzee, does not contain any new parts. Our intellect may be superior, but we have no basic wants or needs that cannot also be observed in our close relatives . . .

Lynn Margulis

[R]eligion serves an obvious evolutionary function: it identifies, unifies, and preserves adherents. Admonitions to desist from the seven deadly sins inhibit behaviors that threaten group solidarity and survival. Greed, for example, privileges the individual in seasons of limited resources. Lust - the biblical coveting of the neighbor’s wife (in its male-centered perspective) - interferes with ideals for the nurture of healthy children and effective warriors. Prohibiting sloth enhances productive work intrinsic to survival and reproduction of the social unit. Anger, perhaps useful in battle, destroys family and other social relationships. Envy and pride promote individual interests above those of the larger social unit. The survival value of prohibiting sin seems obvious . . .

I disagree with neo-Darwinist zoologists who assert that the accumulation of random genetic mutations is the major source of evolutionary novelty. More important is symbiogenesis, the evolution of new species from the coming together of members of different species. Symbiogenesis is the behavioral, physiological, and genetic fusion of different kinds of being; it leads to the evolution of chimeric new ones.

Geoffrey Miller

My own research has been inspired mostly by good-genes sexual selection theory (the idea that animals choose their partners based on cues about genetic quality) and costly-signalling theory (the idea that only animals in good condition can afford seemingly pointless displays like extravagant plumage). These theories have proved enormously useful in understanding a range of human behaviors that have seemed to have no clear survival payoffs, like music, dance, art, humor, verbal creativity, conspicuous consumption, and altruism.

Robert Wright

What Darwinism tells us is how natural selection gave human life its distinctively rich texture of meaning. Darwinism can also give us guidance as we try to better ourselves and make that meaning richer still. What Darwinism does not tell us is why there is meaning at all.

David Sloan Wilson

Genes are only one mechanism of inheritance. Some immunological, psychological, and cultural processes also count as evolutionary. They too rely on the open-ended variation and selective retention of traits, but they are based on non-genetic inheritance mechanisms. People and cultures shaped by these fast-paced evolutionary processes no longer have the same "nature," any more than two bacterial strains that have diverged by genetic evolution. In this fashion, my simple and seemingly boring formula can be understood to say that humanity as a whole does not have a single "nature." Instead, each and every person and culture has its own "nature."

There's lots more to read (by these authors and others) at the above link

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47 million year old primate fossil

Some scientists are touting a 47 million year old primate fossil as potentially being a direct descendant of humans, though they admit that there is a lot more work to do before making that conclusion with certitude. What is not in dispute is that this lemur-like fossil is extremely well preserved.

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Evolutionary explanations: historical trajectory versus convergence

In the April 16, 2009 edition of Nature (available online only to subscribers), Johan J. Bolhuis and Clive L. Wynne asked "Can Evolution Explain How Minds Work? Their answer is that we need to be careful. Traits don't always smoothly work their way up from ancestors to contemporary species. Sometimes, traits appear as a result of "convergence," namely, these traits arise in species that are not closely related because these species were independently subjected to similar selection pressures. A good example of convergence would be the wings of birds and bats, which are not closely related species. Both species, however, were subjected to similar selection pressures, accounting for the existence of their wings. The authors argue that many studies suggesting that humanlike traits existed in lower primates lacked sufficient controls. Maybe those capuchin monkeys were not reacting on the basis of assessing "fairness" when they shared or rejected slices of cucumbers. Maybe they were rejecting an inferior reward simply because better rewards were potentially available. The authors suggest that their reanalysis of these experiments suggests that it is a mistake to assume the continuous development of mind up through the lower primates, culminating in human beings.

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Humans are so well designed!

I saw this snippet on my New Scientist RSS feed. Some researchers, investigating methods to improve IVF success rates, have discovered that contrary to popular belief, chromosomal abnormalities, and hence miscarriages, are not abnormal occurrences, but are in fact the norm.

As women age, their eggs are more likely to have the wrong number of chromosomes, which can lead to miscarriages. But when Joris Vermeersch from the Centre for Human Genetics in Leuven, Belgium, and colleagues examined 23 embryos from nine young, fertile couples who were undergoing IVF for screening purposes, they found that 21 had chromosomal abnormalities, suggesting these are in fact the norm (Nature Medicine, DOI: 10.1038/nm.1924).
I can only presume god was just being mean when he said 'go forth and multiply' - since he must have known that our ability to multiply was broken.

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Bad news for Creationists: archeologists have discovered yet another transitional fossil

Archeologists in Canada have discovered the fossil of a previously unknown species that shows features of both land- and water-dwelling mammals. Though not a direct ancestor of modern seals, the fossil nevertheless gives clues to how today's water-dwelling mammals evolved. One begins to wonder how complete the fossil record needs to be before Creationists admit they've been wrong all along. Something tells me no amount of completeness will ever satisfy them.

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