Scientists are now zeroing in on some of the genes that were crucial to the
rewiring of dog brains. Their results are fascinating, and not only because
they can help us understand how dogs turned into man’s best friend. They may
also teach us something about the evolution of our own brains: Some of the genes
that evolved in dogs are the same ones that evolved in us.
Some of the genes that evolved early in dog evolution are involved in smell or hearing. Others are active in a region called the prefrontal cortex, where mammals make decisions about how to behave. Some genes are involved in growing connections between neurons. One gene, called SLC6A4, transports a neurotransmitter called serotonin into neurons.
In this situation, aggressive wolves would have fared badly, because humans would kill them off. Mellower wolves, by contrast, would thrive. If this notion turns out to be true, it means that we didn’t domesticate wolves — they domesticated themselves. SLC6A4 may have played a crucial part in this change, because serotonin influences aggression.
To test these ideas, Dr. Zhang and his colleagues are gathering DNA from more dogs and wolves. They also hope to collaborate with cognitive scientists to see how variants of genes like SLC6A4 affect the behavior of dogs today. Their results may also help explain human evolution, because Dr. Zhang and his colleagues found that some of the same genes that evolved in dog brains, such as SLC6A4, also experienced natural selection in human brains.
- More Here from Carl Zimmer
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