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.
