Amazing stuff!
"... Researchers built on past studies documenting the language abilities—and saliva—of 350 elementary school children. They wanted to analyze genetic regulatory sequences called Human Ancestor Quickly Evolved Regions (HAQERs), which influence how genes get expressed. The students’ DNA helped the team confirm HAQERs’ importance in processing and demonstrating language. Then, the researchers looked for the presence of HAQERs in regions of DNA known to have evolved in ancient primates and hominins.
They found that HAQERs evolved after hominins split from chimps but before Homo sapiens diverged from Neanderthals—meaning complex communication likely preceded our own species. This “sliver of the genome has remained relatively constant, even as other aspects have been going up and up and up to make modern humans smarter and smarter ,” author Jacob Michaelson said in a statement. “We can say humans at least had the ‘hardware’ for language earlier than what we previously thought.”
As for why the HAQERs didn’t continue to evolve much after the Neanderthal-human split, the researchers suggest it’s because they promote fetal development—and give babies bigger heads. That tradeoff would have quickly cost the lives of ancient mothers and infants."
From the abstract:
"Language is a defining feature of our species, yet the genomic changes enabling it remain poorly understood. Despite decades of work since FOXP2’s discovery, we still lack a clear picture of which regions shaped language evolution and how variation contributes to present-day phenotypic differences.
Using an evolutionary stratified polygenic score approach, we find that human ancestor quickly evolved regions (HAQERs) are associated with spoken language abilities (discovery N = 350, total replication N > 100,000).
HAQERs evolved before the human-Neanderthal split, giving hominins increased binding of Forkhead and Homeobox transcription factors, and show evidence of balancing selection across the past 20,000 years.
Language-associated variants in HAQERs appear more prevalent in Neanderthals, and HAQER-like sequences show convergent evolution across vocal-learning mammals. Our results reveal how ancient innovations continue shaping human language."
Ancient regulatory evolution shapes individual language abilities in present-day humans (open access)
Fig. 1. Overview of this study and key findings. (ka, thousand years ago; Ma, million years ago.)
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