W12L1 ecological genetic

Question 1

What is ecological genetic

Answer 1

• Study of evolutionary forces in an ecological context
• Explores how genetic variation and evolutionary processes interact with ecological factors to shape the distribution, abundance, and evolution of species
• Genetics of ecologically important traits (e.g. survival, reproduction)
• Understanding the extent to which species are able to adapt to changing environmental conditions
• information can lead to Better management and conservation of biodiversity

Question 2

Eco evolutionary dynamic

Answer 2

selection pressure cause evolved genetic change
Causing change in the organism that impact on other organism and ecological communities
Which lead to new selection pressure

Question 3

Examples of eco-evolutionary interactions

Answer 3

• Virus evolution impacting human, animal and plant populations
• Evolutionary decreases in prey size affecting their availability for predators
• Genetic diversity in plants impacting diversity in insect herbivore communities

Question 4

What are the traditional traits analyses in ecological genetic

Answer 4

• Focussed on morphological polymorphisms – discrete variation
• Studied these polymorphisms in nature
• Focus on polymorphisms that are genetically based
  -polymorphism Used to generate information on the nature of selection

Question 5

New traits analysis molecular polymorphism

Answer 5

• Historically focussed on genetically determined enzyme polymorphisms to show these were under selection
• These days appreciate that one polymorphism may only have a small effect, so instead focus on multiple SNP polymorphisms
• SNP polymorphism scans typically carried out across environmental gradients (or time)
• Latitude, elevation, coastal-inland as examples of gradient
• Use Fst analyses to identify outliers, look for loci with very large Fsts (among hundreds or thousands that are scored)
• Ideally gradients are replicated (“replaying the tape”)

Question 6

What is quantitative genetic

Answer 6

• Focuses on phenotypes with continuously distributed variation (versus discrete)
• Quantitative traits important ecologically because:
• Most of the key characteristics linked to fitness of organisms are quantitative traits
• Many of the traits that allow a species to adapt to its environment are quantitative traits
• Trait heritability, h2, the extent to which traits under selection are genetically determined and variable (h2 = VA/VP : additive genetic variation divided by phenotypic variation)

Question 7

Heritability (evolvability) differences between quantitative traits

Answer 7

• Traits differ in heritability
• Heritability differences depend on VE (environmental variance) as well as VA (i.e. VP = VA + VE)
• Selection can decrease heritability
• fitness traits relevant to ecology often have a low heritability

Question 8

Ecological quantitative genetic and pleiotropy

Answer 8

• Pleiotropy: when a single gene influences multiple phenotypic traits
• Evolution on one trait can influence evolution on other traits
• Important for understanding and predicting selection responses
• Positive genetic correlations: enhance adaptation, indirect selection responses
• Negative genetic correlations (antagonistic pleiotropy) can impede evolutionary responses

Question 9

Common garden and reciprocal transplant experiment

Answer 9

• Can be used to determine whether trait differentiation is due to genetic differences and/or local adaptation
• Common garden experiments involve measuring traits across different populations under the same environment (shows phenotypic differences across populations have a genetic basis)
• Reciprocal transplant experiments involve swapping individuals or populations between different environments to assess the effects of local adaptation and environmental factors on their performance or fitness (shows local adaptation)