Conservation genetics Flashcards
What is necessary for natural selection to take place?
A range of traits
What is standing genetic diversity?
The raw material for adaptation/ natural selection to take place.
How does standing genetic diversity provide a basis for adaptations to environmental change?
Climate change
New predator, competitor or pathogen
New resource/ opportunity
What is the result of fluctuations in allele frequencies due to genetic drift?
This causes an increase or decrease between generations.
What happens to allele frequency populations when populations become smaller?
The allele frequency fluctuations become larger.
How is Observed heterozygosity different from expected heterozygosity?
Individuals are not mating randomly.
What is Allele richness?
The measure of allele diversity compensates for differences in sample size.
What does the Rare faction allow?
The Allelic diversity of difference-sized samples is to be compared.
How do you calculate rarefaction?
calculate the number of alleles expected in sub-samples of size g from each of the samples.
What is an effective population size?
The number of breeding individuals that have an ideal population is enough to match a healthy population.
What is a census population size?
The number of adult individuals in a population.
What is the difference between an effective population compared to a census population?
Effective population size is usually less than the census.
(e.g. 10x less due to unequal sex ratios and reproductive skews).
Some individuals breed more than others, which causes population sizes to fluctuate.
Is a high rate of genetic diversity loss found in expected or census?
Expected. This is due to the small generations.
How does the monitoring of genetic diversity help us?
Shows us which species are at risk which can guide conservation actions and provide evidence for solutions.
If the proportion of a population is 500 individuals how many would you need for a census population?
Multiply by 10 = 5000.
What are the differences between natural selection and genetic drift?
Genetic drift is random and non - adaptive which doesn’t generally increase fitness, therefore there is no conservation value.
Natural selection results in local adaptations that increase fitness and are considered valuable.
What is an ESU?
An evolutionary significant unit.
A population of a group of populations that are genetically and ecologically distinct from one another and deserve separate management.
What are the isolation and adaptation criteria for ESU?
Long-term genetic isolation
Hundreds of generations
A unique product of evolution that is unlikely to re-evolve.
Why are ESU’s important for future adaptation?
They are reservoirs of genetic and phenotypic variation.
How are Brush-tailed Rock wallabies examples of ESU’s?
They are reciprocally monophyletic with high levels of genetic divergence between ESU’s. This provides evidence for long-term isolation that leads to a high probability.
How do Chromosomal rearrangements cause inbreeding depressions?
There is little exchange of alleles.
What can fragmentation cause?
Genetic bottlenecks.
Cause genetic structure in formerly panmitic populations.
What are multilocus methods?
Model-based clustering methods, which use multilocus genetic datasets (e.g. microsatellites, SNPs, etc.)
What is assumed in K populations?
Each is characterised by a set of allele frequencies at each locus
