Theories and People Flashcards
Dobzhansky, Theodosius
- Defined evolution as a change in the frequency of an allele within a gene pool
Castle, William
- Suggested continuous variation could have mendelian interpretation
- Looked at inheritance of colour patterns in rats – showed selection could have dramatic effect on Mendelian traits
(contributor to the modern synthesis)
The modern synthesis
Mutation AND natural selection are the basis of evolutionary change, mutation is the raw material for evolution to occur
Edward M East
- Worked on potato crosses
- Selection on continuous differences could significantly modify his stocks of potatoes
Fisher, R
¬¬Key in developing the underlying mathematical theories of population genetics which allowed us to understand inheritance of genes (and their mutations) was compatible with natural selection
Pointed out:
1) Individual mutations have a small chance of survival
2) Mutation rates with a low frequency are higher in larger populations
3) Large populations can store many mutations at equilibrium in recessive form
4) Evolution in gene frequency changes in many alleles of small effect that influence phenotype
5) Large populations can store mutations at equilibrium in recessive form
Haldane, JBS
- Provided the mathematical understanding of how mutation, migration and natural selection interact to change gene frequencies in a population
- Evolution is a change in gene frequencies
Huxley, Julian
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Johansen, W
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Mayr, Ernst
Taxonomist, tropical explorer, ornithologist, historian of science and naturalist.
“Species are groups of actually or potentially interbreeding natural populations which are reproductively isolated from other such groups”
Nilsson-Ehle
- Phenotypic traits which looks continuous and inherited by ‘blending’ could actually be inheritance following Mendelian laws.
- Worked with corn, crossing red and white corn which would produce pink corn
o Could also produce different tones of red by breeding
Ohno, Susumu
Once gene duplication has occurred there are various possible outcomes
- We have a gene which has been duplicated
- New gene may not be subject to selection
- Previously forbidden mutations may be allowed to accumulate
- May end up with loss of function
o Creation of a pseudogene which mirrors a gene but doesn’t do anything
- Individuals with new function may have a selective advantage
o Offspring
o Novel mutation gains a foothold in the population
Saltationist view of evolution
Mutationism- the possibility of large evolutionary jumps, including immediate speciation
Weissman, August
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Wright, Sewall
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Linnaeus, Carolus
- Grouped species according to shared physical characteristics originally.
- three groups: Mineral, Animal and Vegetable
- The father of modern taxonomy
