Evolution And Conservation

Question 0

Mutational meltdown

Answer 0

Genetic drift + inbreeding depression, things get worse for a population, small population has genetic drift increase deleterious alleles which causes inbreeding depression which leads to an even smaller population and so on

Question 1

Local adaptation

Answer 1

An adaptation within a population in a specific area based on the environment at the time that may increase fitness

Question 2

Two processes that have implications for conservation

Answer 2

Genetic drift and inbreeding depression

Question 3

Genetic consequences of genetic drift

Answer 3

(Long term loss of genetic variation)

1. Decreases potential to evolve on response to future environmental changes
2. Susceptibility to disease
   * important in longer time scale

Question 4

Genetic consequences of inbreeding depression

Answer 4

(Short term reduction in fitness causes by)

1. Decreased reproduction
2. Mutation meltdown (combo of inbreeding depression and genetic drift)
   * important on short term scale

Question 5

Factors affecting rare of loss of genetic variation in small populations

Answer 5

The size and length of the bottleneck, the environmental changes and disease

Question 6

Endangered/threatened species and heterozygosity

Answer 6

Not lost a lot of genetic variation yet based on estimates of size and length of bottlenecks

Question 7

Evidence that reduced heterozygosity can reduce response to environmental change

Answer 7

Yes- drosophila fruit flies, not have same potential to evolve

Question 8

Evidence of reduction in heterozygosity increasing disease susceptibility

Answer 8

Sometimes - European harbor seals have low genetic diversity since phocine distemper virus endemics killed 50-60% and pollution is an issue
Not always - northern elephant seals have low genetic diversity but appear less prone to disease

Question 9

Dealing with and reduced genetic variation and genetic drift in small populations

Answer 9

Strategy 1. Do nothing and let alleles fix (loss of alleles may be ok if different alleles are lost in different populations and genetic variation can be maintained overall and reintroduced later)
Problem: only work if there are multiple populations
Strategy 2. Introduce alleles from another population
Problem: may destroy local adaptation (mix of old and new alleles cause more problems than help)

Question 10

Inbreeding depression common across species?

Answer 10

Yes - African lions, song sparrow, black-footed rock wallaby, etc

Question 11

Stress affect on inbreeding depression

Answer 11

Worse in stressful environments (leads to mutational meltdown and small populations may be at larger risk)

Question 12

Dealing with inbreeding depression in small populations

Answer 12

Strategy 1. Do nothing and let them purge
Problem: may not recover
Strategy 2. Introduce unrelated individuals
Problem: if population already purging, this may add extra deleterious alleles and cause more inbreeding depression

Question 13

Sustainable minimum population sizes to prevent inbreeding depression

Answer 13

50

Question 14

Sustainable minimum population size to maintain genetic variation as drift decreases it

Answer 14

500 with drift alone, 5000 with drift and selection both acting