科学家揭示大脑进化关键线索 五十万年前基因突变重塑人类行为与认知

Core Insights - The research published in the Proceedings of the National Academy of Sciences reveals two significant genetic changes in the human brain that occurred 500,000 years ago, reshaping human behavior and cognitive abilities, which are key to human evolutionary success [1][2] Group 1: Genetic Changes and Their Implications - The study identifies a biochemical transformation linked to the stability and genetic expression of adenosine deaminase (ADSL), with a modern variant differing from Neanderthals and Denisovans by a single amino acid substitution, leading to decreased enzyme stability [1] - Experiments on mouse models indicate that this genetic change results in increased concentrations of purine metabolites in the brain, which are essential components of DNA and RNA [1] - Female mice carrying the mutation demonstrated enhanced competitiveness for scarce resources, suggesting that reduced ADSL activity may have conferred evolutionary advantages to human ancestors in specific survival tasks [1] Group 2: Evolutionary Pressure and Future Research Directions - Further analysis of the non-coding regions of the ADSL gene revealed a set of genetic variations present in 97% of modern humans, which lower ADSL RNA expression and inhibit enzyme activity, indicating ongoing evolutionary pressure prior to humans leaving Africa [2] - The research provides critical insights into human evolution, emphasizing the need for cautious interpretation of findings, as ADSL is one of the few enzymes uniquely affected by evolutionary changes in modern human ancestors [2] - The research team plans to explore the combinatorial effects of these genetic mutations to gain a more comprehensive understanding of how humans evolved into their current form over the past 500,000 years [2]