Kahilainen et al., 2014 - conservation implications of species-genetic diversity correlations

Question 1

Why is intrapopulation genetic diversity important for the long-term persistence of populations?

Answer 1

• genetically determined phenotypic variation equated to a populations adaptive potential
• neutral genetic variation in populations reflect genetic drift & inbreeding which both reduce population viability
• reduced genetic diversity is related to extinction risk
• the ultimate goal of conservation actions is to ensure the long-term persistence of species,
• the conservation of intrapopulation genetic diversity should be of high priority

Question 2

What is SGDC/what are studies on it useful for?

Answer 2

• species-genetic diversity correlations
• info on whether conservation of intrapopulation genetic diversity can conflict w conservation of species diversity / vice versa
• increases in area/connectivity are associated with positive SGDCs and persistence of species diversity

Question 3

What are alpha SGDC (α-SGDC)

Answer 3

• relationship between species diversity in a local community & intrapopulation genetic diversity within the species
• observed both negative and positive in natural systems
• sign of the α-SGDC directly indicates whether there is a conflict between the conservation of the two levels of biodiversity
• postive α- SGDC = actions to conserve species diversity in a community likely to conserve intrapopulation genetic diversity too
• negative α-SGDC = opposite
• driven by stochastic processes, dispersal, and selection
• stronger on islands/island like localities

Question 4

What is beta SGDC (β-SGDC)?

Answer 4

• differentiation between SDGCs at different localities

Question 5

What drives genetic diversity within populations?

Answer 5

• genetic diversity within populations
  (e. g. haplotype diversity, allelic richness, heterozygosity, or quantitative genetic variation)
• influenced by population size, gene flow, and selection
• above can be driven by same environmental characteristics that drive species diversity

Question 6

What is the relationship of SGDCs with area?

Answer 6

• when community size positively correlates with area, area can drive positive α-SGDC
  e. g. via stochastic processes, sampling effect
• # observed species increases with area
• extinction rate declines with area due to reduced demographic stochasticity
• average population size increases with increasing area
• more genetic diversity sampled from the regional gene pool
• reduced
  intensity of genetic drift
• larger populations tend to be more genetically diverse
• expected to drive positive β-SGDCs

Question 7

What is the relationship of SGDCs with connectivity?

Answer 7

• connectivity influences dispersal between localities
• well connected localities more likely to receive immigrants from more species than unconnected ones
• also receive more alleles
• connectivity expected to drive positive α-SGDCs
• connectivity is expected to influence degree of community & genetic differentiation in parallel
• positive β-SGDC

Question 8

What is the relationship of SGDCs with environmental heterogeneity?

Answer 8

• spatial/temporal/spatio-temporal
• increasing environmental heterogeneity = suitable conditions for more species to persist in a locality, less chance of competitive exclusion
• more species in environmentally heterogeneous areas
• can cause disruptive selection
• allow for varying genotypes w/i a population
• BUT can end up selecting for generalists potentially reducing SGDCs (number of species & genetic diversity)
• may also support smaller populations of more species
• increased rare habitats, but smaller habitats
• higher species diversity but lower genetic diversity?