This document discusses key concepts in population genetics, including defining a population as a group of the same species occupying a certain area. It explains that population sampling is used to study a subset of a population. The document defines a gene pool as all the genes in a population sample and discusses how allele frequencies are calculated based on genotypes in the sample. An example is provided to demonstrate calculating allele frequencies for fur color in a population of 100 rabbits. The principles of Hardy-Weinberg equilibrium are introduced, which state that allele frequencies will remain the same over generations if five strict conditions are met, but these conditions are never fully satisfied in real populations.

1. POPULATION
GENETICS

2. Vocab
Population- group of organisms of the
SAME species that occupies certain area
Species- organisms that can INTERBREED
and produce FERTILE offspring
Ex) Sauerman Woods Crown Point
-whitetail rabbits -deer
-sparrows -squirrels

3. Can we capture all the whitetail
rabbits in Sauerman Woods?
Population Sampling- technique uses
part of population to represent whole
population
Capture 100 random rabbits
– These rabbits are a representation of all the
rabbits in the area.
– We can study many things within this group…

4. Genetics of the Population…
Gene Pool- all of the genes of every
individual in population sample
Frequency- how often something occurs
Population genetics involves studying the
frequency with which certain alleles
occur in a population’s gene pool.
Frequencies can be written as:
percentages, fractions, or decimals.

5. Example
Population Problem #1
100 rabbits – “fur color” How many alleles for fur
trait color are in the gene pool?
B- brown fur b- white fur
30 rabbits are 100 rabbits X 2 alleles
homozygous brown (BB) each=
50 rabbits are 200 alleles
heterozygous brown (Bb) How many dominant alleles are
in the gene pool?
20 rabbits are 60+50 = 110 alleles (B)
homozygous white (bb) How many recessive alleles are
in the gene pool?
50+40 = 90 alleles (b)
What is the frequency of the
dominant allele in population?
110/200= .55 or 55%
What is the frequency of the
recessive allele in population?
90/200= .45 or 45%

6. In 50 years, will the allele
frequencies be the same?
Hardy-Weinberg Equilibrium Principle –
“Under certain conditions, the frequencies of the
dominant and recessive alleles will remain the same
generation after generation.”

7. HARDY WEINBERG
5 CONDITIONS
To keep H-W equilibrium there must be:
No mutations
Large population
Population size remains same (no migration)
Random mating
No “survival of fittest”
***These conditions are NEVER all met in the
REAL world, so populations are always
changing and NOT in H-W equilibrium.