This preview shows pages 1–3. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: 1 Mechanisms of Evolution: Microevolution Natural selection works on individuals , yet populations evolve Population: same species, same place, same time Species: can breed and produce fertile offspring Microevolution= changes in a populations gene pool from one generation to the next-if NO change occurs in gene frequency= genetic equilibrium Gene pool : all the genes in the entire population Two factors can cause microevolution: I Mutation/ New Genetic Variation II Evolutionary Mechanisms/ Alteration of existing genetic variation I. Mutation: unpredictable change in DNA- sources of NEW genetic variation-only mutations in sex cells are inherited-mutations change gene pool & increase genetic variation that natural selection can act upon-rare, low rate of occurrence, not a major factor in microevolution http://www2.chinadaily.com.cn/english/doc /2004-06/25/content_342496.htm Human brain size: ASPM gene-contains repeats of isoleucine and glutamine, 75 letters long-in human, 74 repeats-in mouse, 61 repeats-in fruit fly, 24 repeats-in nematode, 2 repeats ASPM regulates # times neuronal stem cells divide & # neurons in adult brain 2 Also inherited: methylation tags on DNA...
View Full Document
This note was uploaded on 02/22/2010 for the course BIO 181 taught by Professor Milton during the Fall '08 term at N.C. State.
- Fall '08