Week 6 Flashcards
How is inbreeding a violation of HW assumptions?
Exposure of deleterious (harmful) recessive alleles and loss of the heterozygote advantage
Define fitness and describe its components
Fitness is the success of an entity in producing representatives in subsequent generations (a combination of survival and reproductive success)
Components:
(1) Probability of survival to reproductive age (and across multiple reproductive periods)
(2) Average number of offspring produced via female function
(3) Average number of offspring produced via male function
Fertilization success, zygote viability, mating success for both sexes, fucundity
Differentiate between ‘selection for’ and ‘selection of’
Selection of the individuals
Ex) selection of stages with large antlers
Selection for the trait
Ex) selection for antler size
You don’t say selected for more evolution. This is the result not the trait
Identify the different levels of selection and how selection acts on them
4
Individual selection– non-random differences among different phenotypes (or genotypes) within a population in their contribution to subsequent generations
Genic selection– single gene is the unit of selection, such that outcome is determined by fitness values assigned to different alleles (for example cancer cells)
Group selection– differential rate of origination or extinction of whole populations (or species in species selection) on the basis of differences among them in one or more characteristics
Species selection– species with different characteristics increase (by speciation) or decrease (by extinction) in number at different rates
Describe how natural selection differs from genetic drift
Difference in fitness is not just due to chance.
Natural selection has the potential to alter proportions of entities in the population. These differences may or may not be heritable.
Therefore, natural selection contributes a deterministic difference in the contribution of different classes of entities to subsequent generations.
Explain why individual level selection is likely to be more impactful than group level selection
Group selection operates only under specific conditions.
Ultimately, if a single “selflish” individual is introduced to the population, they will outcompete the others and therefore individual selection is often stronger or predominant.
