01:119:115 Lecture Notes - Lecture 21: Genetic Drift, Allopatric Speciation, Punctuated Equilibrium

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beigelion270

18 Apr 2016

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Document Summary

Evolutionary theory must explain how populations evolve and how new species originate. Microevolution changes in allele frequency in a population over time. Macroevolution broad patterns of evolutionary change above the species. Speciation = process by which one species splits into 2+ species. Yield tremendous diversity of life (~1. 8m identified) ~10 and 100 m species exist today. New species share many characteristics descend from a common ancestor. The concept of biological species based on reproductive isolation. Group of populations whose members can interbreed in nature and produce viable, fertile offspring. Do not exchange gene with different species reproductively isolated. Mechanisms to prevent two different species from interbreeding and producing viable, fertile offspring. Hybrids = offspring of crosses between species. Prezygotic barriers: occur before zygote formed prevents fertilisation. Two species live in the same geographic area but live and breed in different habitats in that are rarely meet. Breed at different times (time of year, season, or of day)

Related Questions

Random, chance events that change allele frequencies are knownas:

A. Gene flow

B. Genetic drift

C. Natural selection

D. Balancing selection

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Question 21 pts

What type of selection acts to maintain the two extremephenotypic variants in a population?

A. Disruptive selection

B. Directional selection

C. Positive selection

D. Artificial selection

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Question 31 pts

Approximately, how much of our DNA is shared with our closestrelatives, chimpanzees?

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Question 41 pts

The large canines of male baboons are likely the result of________, while the fact that some male baboons are very colorfulis probably the result of _______.

A. Mutation; balancing selection

B. Gene flow; sexual dimorphism

C. Male competition; female choice

D. Mate choice; genetic drift

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Question 51 pts

Negative assortative mating results in an increased frequency ofhomozygous genotypes within a population.

True

False

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Question 61 pts

Genetic evidence suggests that humans and Neandertals neverinterbred.

True

False

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Question 71 pts

The specific variant of the FOXP2 gene associated with languageacquisition in humans is found in both humans and Neandertals.

True

False

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Question 81 pts

Industrial melanism describes the change in moth color from paleto dark after pollution from factories resulted in coating treetrunks with a layer of dark soot. Which statement is trueconcerning industrial melanism?

A. After pollution levels increased, all moths became darkercolored because soot got on their wings

B. The dark moths survived better after pollution levelsincreased because they were not poisoned by the pollutants

C. Individual moths changed their color in response to thepollution

D. Dark moths were present in the population before pollutionlevels increased

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Question 91 pts

Patterns of evolution can be seen above the species level

True

False

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Question 101 pts

Inbreeding is problematic because it increases the probabilitythat offspring inherit two copies of a recessive mutation thatcauses disease.