PT157.S4.P3.Q19

PrepTest 157 - Section 4 - Passage 3 - Question 19

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P1

Political arguments about biodiversity and the preservation of endangered species generally assume we know what a species is. ███ █████████ ███ ████████ ██ ████ ███████████ █ ██████ ███████ ███ ████ ████ █ █████████ ███ █████████████ █████████ ███

Context · What's a "species"? Arguments about biodiversity assume we know this.
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Debate among ornithologists · Lumpers vs. splitters
Lumpers group separate, but similar bird populations into a single species. Splitters divide those populations into different species.
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Lumpers' perspective · Biological species concept
A species is a group that is reproductively isolated from other groups (not a lot of interbreeding in the wild between the groups).
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Splitters' perspective · Phylogenetic species concept
A species is a population which has a pattern of ancestry and descent. Members of a species have a distinctive, genetically traceable feature.
P2

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Intro to Sibley · Part of splitters. Used DNA-DNA hybridization.
This technique compares DNA to determine relationships between different groups birds.
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Sibley's perspective · Many earlier bird classifications were wrong
Examples: American vultures are more related to storks than European vultures. Loons and grebes aren't closely related.
P3

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One criticism of sibley (not by author) · DNA analysis still requires arbitrary interpretation
DNA shows differences between groups. But there's no clear line when those differences signify different species.
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Sibley's potential response · Acknowledges that "species concept" is slippery
However, for practical reasons, we have to limit the number of species we recognize. (If we said you were a different species from your mom, because you have slightly different DNA, that would lead to billions of different "species" in the world. That's impractical.)
P4

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Implications of debate · How we answer the species question has political and economic consequences
Example: Increasing number of species would likely increase number of endangered species.
Passage Style
Critique or debate
Show answer
19.

If valid, Charles G. Sibley's █████████ ██ █████████ ██ ███ ████ ███ █████████ ██ ███ ██████ ██████████ ████ █████████ █████████ █████ ███ ██ ███ █████████ ███████████

a

A stork population ████ ██████ ██ ██████ ██ ██ ██ ███ ████ ███████ ██ ███ ████ █████ ████████

Sibley’s findings in P2 distinguish between vultures from Europe and vultures from North or South America, not storks from different locations. The passage just talks about storks in general; we don’t know how to classify storks from different locations.

6%
b

A stork population ████ █████ ███████ ██ ██████ ██ ██ ██ █ █████████ ███████ ████ ███ ████ ███████

Sibley’s findings in P2 distinguish between vultures from Europe and vultures from North or South America, not storks from these locations. The passage just talks about storks in general; we don’t know how to classify storks from different locations.

4%
c

A vulture population ████ █████ ███████ ██ ██████ ██ ██ ██ ███ ████ ███████ ██ ███ ████ ███████

Sibley’s findings show that North American vultures are more closely related to storks than to European vultures. If we classify storks and vultures as different species, Sibley probably doesn’t think that vultures from North America are the same species as vultures from Europe, since the North American vultures are more closely related to storks than they are to the European vultures.

61%
d

A vulture population ████ █████ ███████ ██ ██████ ██ ██ ██ █ █████████ ███████ ████ ███ ████ ███████

Sibley’s findings don’t challenge this assertion because Sibley found that South American vultures are less closely related to European vultures. If we say that vultures and storks are different species, then Sibley would agree that vultures from South America are probably a different species from vultures from Europe.

22%
e

A vulture population ████ █████ ███████ ██ ██████ ██ ██ ██ ███ ████ ███████ ██ ███ ████ █████ ████████

The passage doesn’t distinguish North American vultures from South American vultures, so we don’t know whether or not Sibley’s findings challenge this assertion.

7%

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