Birds Survived Meteor Strike 66M Years Ago To Evolve Human Speech

Most of life was wiped out 66 million years ago after a meteor strike and only a few species of birds survived life on Earth.  Researchers led by Dr. Erich Jarvis at Duke University studied the brains of birds species all the way back to that event. This study investigated the brains of many species of animals for gene expression related to language and vocalization in humans, songbirds, parrots, hummingbirds, macaque monkeys, doves, and quail.  A surprising result? Neuroimaging shows there is a molecular similarity between birds and humans in the areas of birdsong and human speech. This is was only demonstrated in vocal-learning birds such as the zebra finch and was not observed in vocal non-learners such as quails and doves. In short: birds and humans use about the same 50 genes to speak and that ability evolved independently in different bird species many times. Another surprising result?  The human motor area LMC was more similar to an important area (RA) in songbirds than to the motor cortex of a macaque monkey. As reported by Seana Coulson of the Kavli Institute for Brain and Mind at UCSD: “In spite of hundreds of millions of years of divergent evolution, birds and humans share similar brain circuits for vocal learning marked by similar expression of about 50 genes. Researchers studying the neurobiology of language have long been held back by the lack of animal models. The Duke research raises the possibility of using songbirds as a molecular model for studying speech production. In this way we may come to understand how the uniquely human trait of language is a new machine made out of old parts.”

Photo: NOVA/PBS

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