biology 113

structure that were inherited from common ancestor

stunted wings in ostrich and remnants of pelvis in whale and snakes

the study of the distribution of plants and animals

development of a species

evolutionary history of a species

involves chance decreases genetic diversity in a small population

a large population reduced in size by a disaster, the remaining individuals are unlikely to have the genetic diversity of the original large population

genetic drift in a new isolated colony

flow of genes between populations by migrating individuals

Based on reproductive isolation Populations of a species can interbreed or are interbreeding Members of a species are reproductively isolated from other species This species concept hold up well for animals, not so well for many plants or bacteria

based on anatomical differences between species Similar to phylogenetic species concept Similar to paleontological species concept utilized to identify fossil species

Distinct mating adaptations by species - molecular, form, behavior Example - peacocks tail

Emphasizes factors that maintain the distinct form and behavior of a species. Factors include such things as reproductive barriers

Species are identified by where they live and how they behave, not what they look like.

Emphasizes the evolutionary history of a species and the species' unique role in the environment Similar to the evolutionary lineage concept

the origin of species

involves geographical isolation lakes,ocean, rivers,deserts

genetically divergent

species arranged in a ring around a geographical barrier- allopatric speciation in progress

extra sets of chromosomes

polyploidy in an individual

formation of a polypoid offspring from two different species

Structures that have evolved under one context can later take on other functions Example - stress sensors have evolved into hearing organs in some insects

The environment is different for the isolated populations If an isolated population comes from a peripheral area If the isolated population is small