Genes and Population Genetics I
P I1 I2 I3 EP
4 enzymes
Figure 4.1 Plate tectonic processesPlate tectonics: continental drift
5-10 cm/yr
Common ancestorand speciation bydivergence in isolation
Species of large, flightless birds
Early Cretaceousperiod (c. 140 mya)One land mass
Dots = demes
Geographic distribution of a species
1. Macroevolution2. anagenesis andspeciation
MutationsOccur at different levelsPoint mutations
Shift of reading frame
Genetically based phenotypic variation: the material of natural selection
General patterns of natural selection
• Natural selection results in improved fitness; i.e., improved reproductive success.