Theory+of+Evolution+by+Natural+Selection

=__Theory of Evolution by Natural Selection__= //by Niki Linscott//

Vocabulary

 * **Evolution:** All the changes that have transformed life on Earth.
 * **Natural Selecton:** Success in the reproduction of certain phenotypes due to the organism's environment.
 * **Fossils:** Imprints of organisms from the past.
 * **Artificial selection:** The breeding of plants and animals in a domesticated envirnment.
 * **Homology:** Similar characteristics show in organisms from common ancestry.
 * **Vestigial Organs:** parts of an organism that have little to no use.
 * **Allometric growth:** a difference in the rate of growth of different parts of an organism.
 * **Species:** A certain kind of organism. Organisms that share similar charcteristics and can interbreed.
 * **Speciation:** The origin of new species in evolution.
 * **Branching Evolution:** The building of a new species from a parent species that cotinues to exist.
 * **Prezygotic barriers:** Stop mating between species or hinder the fertilization of ora if membrane of different species try to mate.

Important Objectives and Concepts:
__1. Prezygotic and Postzygotic barriers isolate the gene pools of biological species__ Any factor that stops two species from making a fertile hybrid is part of reproductive isolation. Examples of Prezygotic Barriers:


 * Habitat Isolation: Two species that are in different habitats within an area. They encounter each other hardly ever. This makes it less likely they will try to seek each other out.
 * Behavioral Isolation: Signals that attract mates are different in every species, because of this animals of different species don't mate very often. They can't read each others signs.