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?
Monday, December 6, 2010
Thursday, December 2, 2010
Disruptive selection explains changes in population genetics where traits extreme values are superior to its intermediate values. In this instance, the variance of the trait increases dividing the population into two groups. Another name for this is diversifying selection. An example I read was made about a population of rabbits. There were rabbits with black fur, white fur, or gray fur. If the rabbit had black fur that meant the genotype was BB. If it had white fur the genotype bb and with gray fur the genotype is Bb. If these rabbits were in an area with very dark colored rocks and very white colored stone then the rabbits with black or white fur would easily be able to hide from predators by the same colored rock as their fur. The rabbits with gray fur would stand out against the black and white rocks and be at a higher risk for predators seeing them. Due to the environment the gray rabbit is living it would be disruptively selected because of its fur color.
Questions:
1. What is another example of this type of natural selection?
2. What is a genotype and what does it have to do with the fur color of the rabbit?
3. How does this type of selection differ from the other types?
Questions:
1. What is another example of this type of natural selection?
2. What is a genotype and what does it have to do with the fur color of the rabbit?
3. How does this type of selection differ from the other types?
origins debate
http://ejournal.belhaven.edu/religion_philosophy/deconstructing_origins_debate.htm
- What did Stephan Gould argue about concerning religion and evolution?
- What is the supposed probability that evolution could occur?(keyword: random shuffling)
- For what reason is it that evolutionists believe that intelligent design should not be considered science?(after into)
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