Genes and Population Genetics I

P  I1  I2  I3  EP 4 enzymes

Figure 4.1 Plate tectonic processes Plate tectonics: continental drift 5-10 cm/yr

Common ancestor and speciation by divergence in isolation Species of large, flightless birds Early Cretaceous period (c. 140 mya) One land mass

Dots = demes Geographic distribution of a species

Microevolution

1. Macroevolution 2. anagenesis and speciation

Mutations Occur at different levels Point 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.