Scribe Post for Tuesday, January 31, 2012

Today in Class

-Turned in Lab pages 17E AND 17F

-Took Notes on Hardy Weinberg

-Started to work on UP pages 31-36

Homework

-UP pages 31-36 due tomorrow!

-Begin studying for the upcoming evolution QUIZ!

Notes

-Modern Synthesis- the fusion of genetics with biology

Looks at gene pools (all of the alleles in all the individuals making up a population)

-There is no incomplete dominance in a gene pool!

-FREQUENCY- decimal answer (Ex: 0.8, 0.72, 0.38)

-PERCENTAGE- actual percentage (Ex: 80%, 72%, 38%)

-P is the relative frequency of the dominant allele. (A)

-Q is the frequency of the recessive allele. (a)

P+Q=1

-If you know p, to find q. q=1-p

-If you know q, to find p. p=1-q

-To find the frequency of a certain type of individuals (AA, Aa, aa), you would multiply the two percentages for that genotype.

-For example, in the Punnett square at the right, aa=q² or q*q

Since each q is equal to 0.2, then q²=0.2*0.2 or 0.04

-To find the frequency of pq, you would need to add the two frequencies 0.16 together since pq appears twice in the Punnett Square.

-This is also written as 2pq.

The general formula is p²+2pq+q²=1

-The Hardy Weinberg equilibrium is used to find the different genotypes in the population if the gene pool is completely stable (non-evolving).

-To prove that genetic recombination does not by itself change the overall composition of the gene pool, they examined the behavior of alleles in an idealized population where five conditions hold:

1. No mutations

2.No one individual can move in our out of the population

3. Large enough population

4. Random mating (no selective breeding)

5. Equally viable alleles (no natural selection)

-However, this doesn't usually happen in normal populations

-This is the Hardy-Weinberg equilibrium

G.H. Hardy G. Weinberg

Thanks everyone! Hope this was helpful!

-Sophia

Next Scribe- ***Eleni***