IV. Diversity of Life

A.Micro evolution: 1. evolution on the smallest scale 2. generation to generation change in frequencies of alleles

B.Gene Pool: 1. consists of all the alleles in all individuals that make up a population 2. reservoir where next generation draws it genes from 3. where genetic variation is stored

C. Changes in the Gene Pool: 1. Natural Selection is not random 2. Environment favors genetic combinations & contribute to survival and reproductive success 3. some alleles may become more common 4. changes in frequency of alleles

D.Hardy-Weinberg Equilibrium 1.Population that does not undergo change in gene pool 2.Are not presently evolving 3.Frequency of gene pool is constant 4.Rarely occurs for long period of time in nature 5.Provides no change baseline for comparison

E.Changes to the Gene Pool? 1. Genetic drift: a change in the gene pool of a population due to chance 2. Natural Selection Genetic drift: When the beetles reproduced, just by random luck more brown genes than green genes ended up in the offspring. Natural selection: Beetles with brown genes escaped predation and survived to reproduce more frequently than beetles with green genes, so that more brown genes got into the next generation.

F.Macro Evolution 1.More dramatic biological changes 2.Evidence found in fossil records 3.Includes: a.Origin of different species b.Extinction of species c.Evolution of major new features of living things

4. Speciation: a. The origin of new species b. Biological diversity c. Increase in number of species