Unformatted text preview: more significant. Loci become monomorphic
(homozygous), signalling a loss of genetic variation
Partitioning genetic diversity
Heterozygosity: within individuals What happens genetically to declining populations ?
• Genetic drift is enhanced Among individuals in a population – Chance changes in gene frequency increase in size
– Loss of genetic variation as alleles fix randomly • Inbreeding becomes more common
– Heterozygosity reduced
– Inbreeding depression from exposure of rare,
– Loss of heterozygote advantage for fitness Among populations 5 6 -Inbreeding Depression: as a result of the small breeding pool, rare
a nd deleterious alleles multiply in frequency
-Net Result: Genotype frequency changes -> exposing 'bad' alleles > 'bad' alleles multiply in frequency 1 13/03/2013 -Allee Effects: Population falls below a certain size, mating decreases
-Colonial breeders: get into a group to breed
-If the population size is low, the group will not exist
-It is the presence of this group that initiates mating behaviour
-No group means no mating Demographic effects of declining populations Which matters m...
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This document was uploaded on 01/27/2014.
- Winter '14
- Annotated Lecture S