EAS100 Lecture Notes - Lecture 36: Main Source, Mutation, Bipedalism

• School: University of Alberta
• Department: Earth and Atmospheric Sciences
• Course: EAS100
• Professor: Korhan Ayranci

Document Summary

Sedimentary rocks contain fossils: remains of organisms buried with the sediment. Most fossils preserve the hard parts of organisms. May consist of original material, chemically altered skeletons, casts and moulds, traces. Many fossils are different from species alive at the present day. Family trees" of fossil groups can be established by collecting from different strata. Charles darwin (1809 -1882) and alfred russel wallace (1823 -1913) were first to suggest a plausible mechanism of evolution, termed natural selection. Individuals well-suited to an environment survive and reproduce. Statistically, offspring that survive to reproductive age are those best suited to their environment. The environment selects those variations that give best survival chances. Variations that increase survival or reproductive chances are most likely to be passed on to next generation. Adaptation: process of change in response to environmental pressure. Variation has long been exploited by farmers and breeders.