Week 13 Vocab Definitions

Speciation Occurs when members of similar populations can no longer interbreed Disruptive selection Individuals at the ends of the curve have higher fitness than those in the middle. If the selective pressure is strong enough and lasts long enough, two distinct phenotypes can result. Stabilizing selection When an ind. at the middle of the curve has higher fitness, causing the curve to narrow. Favors the average.

Directional selection When an ind. at one end of the curve has higher fitness than an ind. in the middle or other end of the curve. This causes the entire curve to move towards one extreme. Geographical isolation Occurs whenever a physical barrier divides a population. (can cause speciation) Mimicry An organisms ability to look or act like another organism

Cladogram A tree-like diagram that shows evolutionary relationships Classification Grouping of objects or information based on similarities

Taxonomy The practice and science of classification Binomial Nomenclature The formal system of naming an organism using the genus and species name