Modern Synthesis Flashcards
What does the Jumps/Mutation theory imply?
Discontinuous evolution
Who were the Biometricians?
Supporters of Darwinian evolution
Who were the Mendelians
Opposed to Darwinian evolution
Describe the work of the Biometricians
- analysed natural population data
- observed continuous variation
Describe the work of the Mendelians
- analysed controlled laboratory experiments
- observed discontinuous variation
What did the mendelians argue
That selective value on small variations must be ineffective
Describe the mutation theory
- Hugo de Vries
- 1890s
- introduced ‘mutation’
- argued discontinuous variation
What did William Castle show?
You could select on continuous variation to outside the original range, with the rat ‘good’
Who were the principal originators of population genetics theory ?
- RA Fischer
- JBS Haldane
- Sewell Wright
Genes code for proteins, which
regulate the development of morphology, influence behaviour etc.
“The sole surviving theory is natural selection”
Fischer, 1930
Theory and data showed that competing ideas were
Not really in conflict:
- Mendelian inheritance and produce continuous variation
- natural selection can act via Mendelian genetics
What are the four things that can change gene frequencies?
- Drift
- Migration
- Mutation
- Natural selection
What is natural selection, at the conceptual level?
A hypothesis to explain evolution
What did Fischer do?
Formalise natural selection theory
Gene dynamics
Genes which increase fitnes accumulating in a population
The most powerful way to look at natural selection is to
Examine the ways in which individual organisms are adapted to their environment
Fitness definition
- the ability of an organism to make a genetic contribution across generation
- no. Of surviving offspring / lifetime reproductive success
What does reproductive success account for
- offspring quality
What is the trade off in reproductive success
- number of offspring
- offspring quality
Drift is
Stochastic
