BIOL 121 Lecture Notes - Lecture 6: Secondary Sex Characteristic, Heliconius Melpomene, Gregor Mendel
Document Summary
Gregor mendel: genetics (inherited traits); first published 1860. Significance of his work did not come to light until about 20 years after darwin"s death (1900s) Phenotypic variation may be environmental or genetic in origin (not all variation is inheritable), but only genetic changes result in evolutionary adaptation. Genetic variation is the raw material of evolution. Must have variation in a population and that variation must be inherited. Mutation: any changed in the nucleotide sequences of dna: can be a change in a single nucleotide (g>t) (ex. A point mutation which causes sickle cell anaemia: a large region on a chromosome may be transposed, a chromosome lost or gained. Most mutations are either: they are random chance events lomoarcpsd i. Not noticed because they do not affect function of the protein redundancy in the genetic code (ex. Gta, gtc, gtg, gtt= the amino acid, valine) Occasionally a favourable mutation arises which increased the probability of survival ii. iii.
