BISC 100 Lecture Notes - Lecture 9: Allele Frequency, Standard Deviation, Genetic Drift

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ultramarineeagle499

7 Mar 2020

School

Simon Fraser University

Department

Biological Sciences

Course

BISC 100

Professor

Leah Bendell- Young

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Document Summary

Speciation the process by which one species splits into two or more species, is at the focal point of evolutionary theory. Microevolution consists of changes in allele frequency in a population over time. Macroevolution refers to broad patterns of evolutionary change above the species level. Speciation forms a conceptual bridge between microevolution and macroevolution. Natural selection, genetic drift, and gene flow can alter allele frequencies in a population: three major factors alter allele frequencies and bring about most evolutionary change, natural selection, genetic drift, gene flow. Natural selection: selection results in alleles being passed to the next generation in proportions that differ from those in the present generation, for example, an allele that confers resistance to ddt in fruit flies increased in frequency after. Natural selection can cause adaptive evolution , a process in which traits that enhance survival or reproduction increase in frequency over time.

Related Questions

17.

Which of the following is the correct binomial nomenclature for the common house mouse?

Mus musculus

Mus Musculus

mus musculus

Mus Musculus

A small population of 500 turtles on an island suddenly suffers a natural disaster leaving only 20 surviving turtles. Before the disaster, the turtles had shells with very different shell patterns. After the disaster, the shells all look very similar. What mechanism can best explain this reduction genetic variation?

Genetic drift

Adaptive radiation

Gene flow

Sexual selection

19.

_____ is the gradual change of the genetic makeup (allele frequency) of a population over time.

		Spontaneous generation
		Microevolution
		Macroevolution
		Transmutation 20. Protists are prokayotes. True False

Which of the following statements is true about the theory of evolution?

The focus of the theory of evolution is to explain the origins of life.

According to the theory of evolution, life evolved entirely randomly.

The focus of the theory of evolution is to explain how life diversified from the first living cells.

According the theory of evolution, only the strongest and toughest can survive.

Which of the following best explains our current understanding of microevolution?

Neither microevolution nor macroevolution can be observed within a human lifespan?

Microevolution is the gradual change of the genetic makeup (allele frequency) of a population over time.

Microevolution and macroevolution occur by very different mechanisms

Microevolution is the evolution of small organisms; macroevolution is the evolution of large organisms.

The Irish elk is a giant species of deer that went extinct about 5,000 B.C. They are well-known for their extremely large antlers (12 feet wide) in males. The antlers likely played some role in protection against predators, but another possible cause for their large size could be

blending genetics

sexual selection

spontaneous generation

inheritance of acquired characteristics

Cross River gorilla is listed as critically endangered species. With only 35 of these gorillas in the world, they are at risk of extinction largely due to poaching and loss to diseases such as Ebola. Genetic studies of the remaining gorillas show very little variability, because several alleles were likely lost due to ______.

		genetic drift
		gene flow
		increased rate of spontaneous mutations
		adaptive radiation

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.