BIO 201 Lecture 7: Phylogenetics

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fuchsiadeer426

7 Aug 2018

School

Stony Brook University

Department

Biology

Course

BIO 201

Professor

genasbeglia

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Document Summary

Phylogeny - visual representation of the genealogical relationships of life, like a family tree . Conceptual model - integrates observations and inferences in order to help simplify and understand a complex system. Pattern of relationships: represents what (but does not directly tell us why), how are they related. Evolution of new traits (or loss of traits) in a lineage. Speciation is the process or mechanism that causes lineage splitting. The processes that contribute to the origination and continuation of new traits on a phylogeny are natural selection, sexual selection, heredity, and mutation. Mutation is the origin of all genetic variation that can become fixed - two eyes in a population. In order for fixation - mutation has to be heritable, or sexual, natural, or genetic drift has to happen. Traits that are followable in a phylogeny has to be fixed. Eye color would not useful to find out if humans are related to other.

Related Questions

Question 5

Which of the following is FALSE:

Natural selection has foresight, and can mold organisms in accordance with environments in the far future. This is why organisms have a good "fit" to their environments long after they have arisen through speciation.

Selection is an undirected process that can only ever work with the materials at hand.

Human beings have foresight because they possess brains that can think about possible outcomes and the consequences of actions. This is different to a process like natural selection.

The fact that natural selection has no foresight does not mean that it is incapable of producing beings that have foresight.

Question 6

The wings of bats, birds and flying insects are examples of:

Convergently evolved traits (at least in terms of their basic functionality).

Homologous traits.

Plesiomorphies.

None of the above.

Question 7

The effect of a trait depends on the environment because:

Organisms decide to change their behavior every so often to evade predators.

It is only ever in the context of an environment that these traits can exist, and whether they assist the organism or inhibit it will depend on the particularities of that environment in which it must interact.

Sexual selection will not tolerate wasteful and extravagant displays.

The environment is changing too fast for the organism to keep up with in terms of its conscious appreciation of it, so it must rely on its traits to do the work.

Question 8

Which of the following is TRUE:

Natural selection is not random; mutation is random; speciation is necessarily driven by natural selection.

Natural selection is not random; mutation is random; speciation is not necessarily driven by natural selection.

Natural selection is random; drift is random; speciation is not necessarily driven by natural selection.

Natural selection is not random; mutation is random; speciation must occur through the evolution of pre-zygotic barriers to mating.

Question 9

Heritability is:

The same as inheritance.

Another way of stating the degree to which a trait is genetic (for example, you could say that the color of your skin is "80 percent genetic and 20 percent environmental")

The proportion of variance of a trait in a population that is attributable to genetic variance in that population.

Present in populations, but not necessary for evolution by natural selection.

jadelocust741

Evolution and Speciation

Define evolution. Why is it inaccurate for creationists to tout evolution as âjust a theoryâ? (Think about what theory actually means in scientific terms vs. the use of the word âtheoryâ in casual conversations).

Explain what the Hardy-Weinberg equilibrium shows and describe the conditions necessary for the equilibrium to be maintained.

Explain what factors cause populations to diverge from the Hardy- Weinberg equilibrium and how each factor causes the change.

Describe how species evolve via natural selection. (Be sure to discuss the key aspects of natural selection: variation, heredity differential survival and reproductive success in your answer).

What does speciation mean and how can it occur?

What does adaptation mean? Why is natural selection the only agent of evolutionary change that leads to adaptation? (Think about how natural selection works).

Is natural selection all powerful? Can it create any variation that you or I could think of? Why or why not?

Differentiate between natural and sexual selection.

What is reproductive isolation?

Describe prezygotic and postzygotic mechanisms of reproductive isolation and explain how they can contribute to speciation.

Distinguish between allopatric and sympatric speciation and explain how each leads to new species.

What is adaptive radiation?

Be able to read and interpret phylogenetic trees: be able to determine which species are most closely related to each other, what nodes represent, where common ancestors would be located, etc.

What are paraphyletic, polyphyletic and monophyletic groups within a phylogeny?

viridianmanatee515

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.