Notes

Topics: Evolution, Genetics / Pages: 2 (398 words) / Published: Mar 28th, 2014
Evolution - Changing of things over time to benefit the organism in natural selection.

Biological evolution happened at the level population , not the individual organism level.

Lack of need, Climate change, population change
Adaptations is at population level not individual level they are a result of natural selection
Devolvment of diversity
Because a genetics re combinations mutations and othe mechanisms that lead to variation there is what Darwin called descent with modification

Mechanisms:

Natural selection:

Mutations:

Recombination:

Gene flow:

Genetic drift:

Artificial selection:

Non random mating:

Reproductive isolation:
Derectional selection. A single phenotype at one extreme of the phenotype is favoured. The populations trait distributed shifts toward an extreme

Disruptive selection favours induviduals at both extremes of a phenotype range. Can cause such differences among a species that the variation leads to new species

Stabilizing selection Favours genotypic combination that produce intermediate phenotype. Reduces phenotype variation removes more severe phenotype a
B
Genetic drift is the chance change due to a small population size
Bottle neck effect
Populations are reduced to a small size and recover
Unlikely to be represent ice of original population
Allele frequencies change
Founder effect
Like bottleneck but population grows
Results in revolution
Migration of induviduals between populations potentially introduces new alleles in a population or alters existing allele frequencies
Artificial selection
Non random mating
Recombination leads to genetics material being shuffles this along with sexual reproduction
Grouping organisms based on evolutionary history
Cladogram diagram that shows evolutionary relationships
Traces evolution by focusing on derived characteristics that appear in some organisms but not others
Deprived trait appears recently parts of

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