BIO-1802 Chapter Notes - Chapter 24: Secondary Sex Characteristic, Population Genetics, Genetic Drift

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byzantiumbadger603

16 Aug 2016

School

App State

Department

Biology

Course

BIO-1802

Professor

Stephanie Mc Cleneghan

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Document Summary

Natural selection- the process in which beneficial traits that are heritable become more common in successive generations. Detrimental traits that are heritable become less common. Natural selection occurs because some individuals become less common. Natural selection occurs because some individuals possess more favorable phenotypes compared to others. The phenotypes are controlled by the individuals" genotypes. Natural selection is a key mechanism that causes evolution to happen. Over time, natural selection leads to adaptations- changes in populations of living organisms that promote their survival and reproduction in a particular environment. Under new environmental conditions, the relative fitness values may change to favor one genotype, and this will promote the elimination of other genotypes. Stabilizing selection: favors the survival of individuals with intermediate phenotypes and selects against those with extreme phenotypes, tends to decrease genetic diversity. Likely to occur in populations that occupy heterogeneous environments, so some.

Related Questions

Which statement about evolution by natural selection isfalse?

Natural selection allows organisms with higher fitness toreproduce more successfully.

Natural selection favors those traits that confer higherfitness in the environment.

Natural selection is a random change in characteristics of apopulation over generations.

Evolution by natural selection affects populations oforganisms, not individual organisms.

An organism's fitness depends on its _____.

ability to survive and reproduce

ability to swap genetic material with other organisms

physical size

ability to mutate

population

Consider the heavily armored stickleback fish population thatcolonized the lake. If all the individuals in that population weregenetically identical, what do you predict would happen when theycolonized the freshwater lake?

The population would increase, as it has increased foodresources.

The population would evolve through natural selection to bebetter adapted to its environment.

The population would decrease due to more juvenile fish beingeaten.

No answer text provided.

Which of the following are adaptations?

Thicker beaks on finches that allows them to eat large seeds,when large seeds are the most abundant.

Less armor on stickleback fish in freshwater that allows themto grow faster to avoid predation.

More armor on stickleback fish in the ocean that prevents themfrom being eaten by larger predators.

None of the above.

All of the above.

olivemink746

Describe the theory of natural selection Which of thefollowing BEST describes the theory of natural selection? CHOOSEONE

	1 The genetic make-up of apopulation gradually changes from one generation to the next.
	2 Living organisms change overtime.
	3 Each species produces many moreoffspring than can survive long enough to reproduce. The offspringthat do survive contain genes that are inherited from theparents.
	4 There is variation among themembers of a species. Some of this variation is geneticallydetermined and so can be passed on to future generations.
	5 Some individuals have genes thatincrease their chances for survival and reproduction. Theseindividuals are more likely to reproduce and pass on their genes,causing their genes to become more common in the nextgeneration.
	6 There is a struggle for existenceamong the members of a population.

amberleopard326

Community Ecology

6. Competition between species is called ____________ competition. A. interspecific
B. exploitative
C. interference

D. fundamental E. intraspecific

7. A species that plays a critical role in maintaining the structure of an ecological community and helps to determine the types and numbers of various other species in the community is known as
A. a predator.

B. a keystone species. C. the primary species. D. the dominant species. E. the alpha species.

Evolution

1. We build trees because:
A. Organisms are related like members of a family are related.
B. Each lineage has a common ancestor that gave rise to that lineage. C. Characteristics are passed on from parents to offspring.
D. all of the above

2. Evolution basically denotes change in populations to: A. Improve reproductive success.
B. Remove defective individuals.
C. Increase the survival of the most fit individuals.

D. Discover better genes.

3. We can put species into groups based on shared: A. genes.
B. characteristics.
C. ecology.

D. environment.

4. Bats and birds share a common characteristic like having four limbs- homologies- with: A. Amphibians
B. Rodents.
C. Reptiles.

D. all of the above.

5. Which of these are mechanisms of evolution? A. Mutation
B. Migration
C. Gene flow

D. all of the above

6. Natural selection involves the following: A. Variation in traits
B. Differential reproduction
C. Hereditary

D. all of the above

BIO-1802 Chapter Notes - Chapter 24: Secondary Sex Characteristic, Population Genetics, Genetic Drift

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