Ch 16: Popln Genetics and Speciation 16.1 Genetic Equilibrium - stable Variation of Traits Within a Popln A. popln genetics – study of evoln from genetic point of view

B. microevoln – small scale – genetics of a population

C. Causes of variation 1. mutation 2. recombination 3. random pairing of gametes

II. Gene Pool A. defn – total genetic info of popln B. allele frequency – how often allele (trait) appears in popln

16.2 Disruption of Genetic Equilibrium Mutation Gene Flow A. gene flow – moving genes from one popln to another B. emigration C. immigration III. Natural Selection

Natural selection in action

IV. Genetic Drift – allele frequencies change by chance

V. Nonrandom Mating – mate selection - due to proximity, calling, etc

16. 3 Formation of Species The Concept of Species A. species – similar organisms that can reproduce and have fertile offspring B. speciation – making a new species

Forming of species

II. Isolation and Speciation A. Speciation begins with isolation B II. Isolation and Speciation A. Speciation begins with isolation B. Geographical isolation 1. physical separation 2. canyons, mountain, water, etc

C. Reproduction Isolation 1 C. Reproduction Isolation 1. prezygotic isolation – premating isolation (before) a. mating call not recognized b. mating times (frogs pg 329)

2. postzygotic isolation – postmating a. offspring may die b 2. postzygotic isolation – postmating a. offspring may die b. offspring may not dev completely c. offspring may be infertile

III. Rates of Speciation A. gradualism – slowly B III. Rates of Speciation A. gradualism – slowly B. punctuated equilibrium – rapid change in little periods

Overview of theory of evolution

Tortoise