FRIDAY, July 30 (HealthDay News) -- Because of the freedom of movement it offered, the neck may have been a major contributor to the evolution of the human brain, according to researchers who compared human and fish genetics.
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Because they are located at about the same location on the body, it had been assumed that the arms and hands (forelimbs) on humans and the pectoral fins on fish receive nerves from the exact same neurons.
But this isn't the case, found the New York University and Cornell University researchers.
As our early ancestors made the transition from fish to land dwellers, the torso moved away from the head, leading to the development of a neck, the scientists explained in a news release from Cornell. In conjunction, the source for the neurons that control the forelimbs moved from the brain to the spinal cord, they noted.
"A neck allowed for improved movement and dexterity in terrestrial and aerial environments. This innovation in biomechanics evolved hand-in-hand with changes in how the nervous system controls our limbs," Andrew Bass, a professor of neurobiology and behavior at Cornell, said in the news release.
The study was published online July 27 in the journal Nature Communications.
-- Robert Preidt
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SOURCE: Cornell University, news release, July 27, 2010