Monday, December 6, 2010

Current Human Evolution/Natural Selection

Natural selection is the process by which traits become more or less common in a population due to consistent effects upon the survival or reproduction of their bearers. The traits differ due to where the population is from and what their environment was at the start of their ancestors. An example of this that i read about was Charles Darwin's discovery that happened over 150 years ago. His discovery is responsible for transforming dinosaurs into birds. Darwin's natural selection is the process by which nature rewards those individuals better adapted to their environments with survival and reproductive success. His validity of his natural selection have been attacked recently by a small group who argue that it cannot explain all the complexity seen in nature.
The human brain is said to still be evolving. Several experts criticized the finding of the brain still evolving. They said that it was far from clear that new alleles(genes) conferred any cognitive advantage or had spread. Also different populations have different allele evolutions. You can compare this to malaria defenses. The genetic defenses against malaria differ in Mediterranean and African populations. Another example is when two people did study on Microcephalin haplogroup D and ASPM haplogroup D. They found that with the Microcephalin haplogroup D it is virtually universal in the new world but with ASPM haplogroup D variant is most common in Europe and West Africa and less so in East Asia. I think this is because the human brain and other traits differ due to the location of the people and what their environment, climate, or life is like.












http://whyevolutionistrue.wordpress.com/2009/04/06/recent-selection-in-human-populations/

http://www.livescience.com/health/051102_natural_selection.html

http://www.pbs.org/wgbh/nova/evolution/are-we-still-evolving.html

1. How can you survey the human genome for recent signs of natural selection?

2. What major part of our body is stilll evolving?

3. What did the evolutionary geneticist Bruce Lahn report about the evolving brain?

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