AN101 Lecture Notes - Lecture 15: Microevolution, Macroevolution, Phyletic Gradualism
Document Summary
What are the differences between micro and macro level evolution. Large scale evolution of a group of species. Evolutionary changes occur over a long period of time and so it involves many generations over millions of. Short-term evolution, changes that occur within a seats particular group of species over relatively few generations (changes in phenotypes such as skin colour etc) Involving one ecological item or the pace of time as experienced by organism living in adapting to their ecological settings - adapting a particular biotic environment in a particular time period. Caused by (1) mutation, (2) gene flow (3) gene drift and (4) natural selection. Growth and decay of many different ecological settings are measured in geological time. Phyletic gradualism: change that is steady, and slow, with a new species eventually emerging. Punctuated equilibrium: slow steady change occasionally interrupted by periods of significant change. It may lack transitional forms of fossil records.
