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21 May 2019

1. How are humans able to affect and alter the phenotype of other organisms through artificial selection? What are they doing that causes a shift in the gene frequencies for "desirable" traits?

2. How are complex structures able to be formed from evolution despite the fact that they would not be able to function with any of their parts missing?

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Jarrod RobelLv2

22 May 2019

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Related questions

Question 11

The wings of birds have evolved to facilitate powered flight, but they are also:

Derived from structures that had other functions, such as thermoregulation and sexual display.

Able to evolve into any other type of structure, given the flexibility of developmental genes.

Unable to revert back to serving other functions (if they ever had them).

Certainly only a transition on the way to something else in the future.

Question 12

Which of the following is TRUE:

For most of life's history, organisms have been multicellular, though hominids only occupy a tiny portion of this history.

For most of life's history, organisms have been a mixture of uni- and multicellular, through hominids have occupied only a fairly small portion of this history.

For most of life's history, organisms have been unicellular, and hominids occupy only a tiny portion of the entire span of time in which life has existed on Earth.

For most of life's history, organisms have reverted back and forth between uni- and multicellular, with a sort of "zig-zag" pattern in which one form of life dominated at any particular time.

Question 13

There are some phenotypic differences among human populations that reflect adaptation to different environments. This indicates that:

Some populations are innately superior to others, because they have what it takes to prevail in those environments.

Selection has been active on these populations.

There are candidates for a program of selective breeding wherein we can pinpoint universally desirable characteristics.

Admixture among human populations is decreasing, and that continued admixture can only mean that humans must stop adapting to their environments. This is neither "good" or "bad", it's simply the way that selection works.

ceruleanwhale664

1/ What is the difference between the different patterns ofselection: directional, stabilizing, anddiversifying?

2/ How do bacteria acquire genetic variation and how does thatdiffer from the mechanism by which humans acquire variation?

3/ What were the key observations made by Darwin to develop thebasic tenants of the theory of evolution? Has thistheory been tested?

4/ What are the most common misconceptionsabout evolution and why are they not valid arguments againstevolution?

5/ The key component of the theory of evolution isnatural selection. Define this process. Why is itcommonly known as âsurvival of the fittestâ? What are examples offactors (selective pressures) that drive evolutionof populations?

6/ What is the indirect evidence of evolution? What arehomologous and analogousstructures? What is convergent evolution?How does similarity of proteins between different species supportthe idea of evolution?

7/ Be able to explain why the following statement is true:Natural Selection works on individuals while evolution works onpopulations over generations. Or to put it another way: Individualsdo not evolve, populations do.

8/ How can evolution explain theformation of complex structures such as the eye or the flagellamotor?

9/ What causes variation in a species? To putthis another way: all humans have the same genes, yet we do notlook alike. What is the reason for the phenotypicdifferences between individuals of the same species? What isgenetic recombination?

10/ What are the dangers of small populations of a species froma genetic and evolutionary standpoint? What is thebottleneck effect?

11. How does speciation occur? What is theimportance of geographic isolation? How is thisillustrated in the Galapagos?

12. What is Darwinian Medicine and how does ithelp us better understand medical conditions?

copperhornet769

Select the statements that correctly represent the theory ofevolution. Select all that apply.

Evolution is partly about inheritance. Evidence of evolution isseen in structures such as wisdom teeth and the tail bone inhumans. These structures are thought to be âleft overâ from ourancestors and no longer appear to have any essential function inmodern humans.

Natural selection means that todayâs organisms are perfectlyadapted after millions of years of fine-tuning. No further changesare necessary because of all the progress that has been made bynatural selection.

We can see evidence of past natural selection in adaptationssuch as the camouflage of moths perched on the bark of their hosttree. We can also see natural selection at work today if we trackhow populations change in rapidly changing environments.

The theory of evolution does not apply to life today. It isstrictly about the history of life: what happened in the past asseen in fossils.

Scientists disagree about the main ideas of evolutionary theorybecause of incomplete or conflicting evidence.

Question 2

Select one answer.

10 points

The ability or tendency of organisms and cells to maintainstable internal conditions is called

metabolism

homeostasis

emergent property

evolution

Question 3

Select one answer.

10 points

Why do organisms maintain fairly steady conditions within theircells and bodies?

They need to keep conditions stable so that they can obtainfood.

Organisms just change along with whatever is happening in theoutside world, which is usually quite steady.

They must maintain stable conditions to keep their enzymesworking and generally to enable the chemical reactions of life.

Unstable conditions will destroy the DNA in cells; this is themost important risk for a cell facing physical or chemicalstress.

Question 4

Select one answer.

10 points

An organism or cell exhibits ____________ when it maintainssteady internal conditions despite changes in the outerenvironment.

homeostasis

evolution

balance

natural selection

Question 5

Select one answer.

10 points

Which type of molecule best illustrates the very strongrelationship between structure and function in biology?

enzymes

oxygen gas

all kinds of organic matter

water

Question 6

Select one answer.

10 points

Which best expresses how nutrients and energy move throughlife?

Nutrients flow from sunlight to organic matter to heat. Energycycles among all life forms.

Nutrients cycle among all life forms. Energy flows from sunlightto chemical energy to heat.

Nutrients and energy both are continually recycled in a greatcircle of life.

Question 7

Select one answer.

10 points

Which of the following is not a recurring theme in biology?

Living organisms maintain homeostasis.

Energy flows through living systems while matter isrecycled.

Evolutionary processes explain both the unity and adaptivediversity of life.

All of these are recurring themes.

Question 8

Select one answer.

10 points

Which statement about evolution is FALSE?

According to evolutionary theory, you are related to abacterium, to a yeast cell, to a snake, and to a whale. In fact,you are related to every species now alive on Earth, and to fossilspecies like dinosaurs as well.

Evolution occurs constantly, without end; there is no endpointin evolution.

Natural selection acts on genetic differences within apopulation to cause evolution. Individuals do not evolve.

Natural selection is about slow but steady progress. Through it,populations constantly get better-adapted. When this process iscompleted for all populations, evolution will come to a stop.

Question 9

Select one answer.

10 points

Imagine you have a peanut butter sandwich in front of you. Thesandwich is an example of _______.

matter

energy

Question 10

Select one answer.

10 points

You provide your gut bacteria with a warm place to live. Theyprovide you with vitamins and other services. This most directlyrepresents an example of...

shared ancestry of all life

natural selection

homeostasis

interdependence of life