CAS BI 107 Lecture 6: Evidence for Macroevolution
Document Summary
Bi107 - lecture 6 - evidence for macroevolution. Can be used to document the course of life through time: the molecular record. Without these errors, there would be no evolution. Example) human chromosome 2 is a combination of two great ape chromosomes -- why humans have 23 chromosomes while other apes have 24. Example) srgap2 gene -- expressed during development of the brain"s neocortex, region involved in cognition. Found as a single copy in genome of most mammals but was duplicated three times during human evolution for four versions a-d. Stimulates maturation of dendritic spines on surfaces of neurons. C. increased number of immature spins in humans. These may have contributed to the evolution of human cognitive abilities. Example) opsins -- in proteins of cone cells, tuned to specific wavelengths of light. All primates share the short wave opsin gene, which is tuned to violet wavelengths. However, new world apes have a second opsin gene on x chromosome.