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Genetic Variation and Change Cheat Sheet (DRAFT) by [deleted]

Cheat Sheet for Genetic Variation. Made for Lv 2 NCEA Biology

This is a draft cheat sheet. It is a work in progress and is not finished yet.

Natural Selection

Types of Selection Pressures

Natural Disaster
Changes in Behaviour
Sexual Selection
DNA Mutations
Changes in Climate
Change in Habita­t/E­nvi­ronment
Inters­pecific & Intras­pecific Relati­onships
Availa­bility of food, shelter, water, mates

Factors that Affect the Gene pool

Bottleneck Effect
When a disaster strikes, and only a very few indivi­duals in a population are left
Genetic Drift
Changes in the frequency of alleles in a population caused by random events
Indivi­duals leaving the population
Indivi­duals entering the population
Natural Selection
The best adapted indivi­duals can survive a change in the enviro­nment

Factors that Stabilizes a Genepool

Intrap­opu­lation geneflow
Free geneflow within a popula­tion. A lack of geneflow will lead to lack of genetic diversity in terms of individual indivi­duals in a popula­tion, leading to speciation
Lack of interp­opu­lation geneflow
For the gene pool of a population to remain consis­tent, no genes can migrate from or into the population
Large population
Very large population so that if indivi­duals die by genetic drift, it won't affect the gene pool much.