Turbocharged Human Evolution
13 Dec, 2007 04:25 pm
I?ve heard people say that selection pressure on humans has relaxed?or we have slipped from its grip to some degree?and that as a result human evolution is slowing down or may even have stopped. A recent analysis of human genetic data shows that the opposite is true.
Larger populations support more genetic variety (Darwin noted the importance of herd size in animal breeding), and humans are no different from other animals: As the human population has grown, we’ve become a more genetically varied species. As we adapt to different environments, people on different continents are becoming more genetically distinct. Approximately 7% of human genes show evidence of recent selection, including genes involved in disease resistance (especially important as humans live in larger groups and more crowded conditions) and in dietary change (e.g., the lactase gene, which allows adults in some populations to digest milk).
This Science Daily story has more details. This press release from the University of Utah gives some interesting background on how this kind of genetic analysis is done. It’s a really exciting story, and it makes me see humankind in a subtly different light. Cultural evolution proceeds at such a swift pace compared to biological evolution, and it’s easy to focus on the frustrating and fascinating mismatches that can result as our meat struggles to keep up with all the new things we can think up to try to do and be. There’s something reassuring about seeing that biological evolution, while necessarily slower than cultural evolution, is still proceeding apace. Thanks to Mark for the Science Daily link and the comment “It makes me feel like a neophyte species.” Me too.
Originally published on: The Thinking Meat