# When is a Population NOT Evolving? AP Biology Fall 2011.

## Presentation on theme: "When is a Population NOT Evolving? AP Biology Fall 2011."— Presentation transcript:

When is a Population NOT Evolving? AP Biology Fall 2011

Applying the rules of probability to sexual reproduction, mathematician Hardy and physician Weinberg independently came up with a baseline for non-evolving populations The 5 conditions

Allele frequencies for any gene in the shared pool will remain stable unless the population is evolving The formula used to track any deviation from the stable state is: p2 + 2 pq + q2 = 1 p + q = 1 p and q are allelic frequencies for A and a Hardy-Weinberg equation

If traits show up in different proportions to the expected frequencies given Hardy-Weinberg assumptions, it indicates that one or more of the 5 assumptions is not being met and some evolutionary force is affecting the population

Researchers use Hardy-Weinberg to estimate the frequency of carriers of alleles that cause genetic disorders and traits Ex. Genetic disorder hemochromatosis, which affects people of Irish Ancestry, causes individuals to absorb too much iron from their food

Similar presentations