Self-study
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.
Debate among ornithologists ·
Lumpers vs. splitters
Lumpers group separate, but similar bird populations into a single species. Splitters divide those populations into different species.
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).
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.
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.
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
15.
Which one of the following ████ ██████████ █████████ ███ ████ █████ ██ ███ ████████
a
Classifying biological populations ████ █████████ ███████ ███ ████ █████ ████████ ███ ██████████ ██ █████████████ ███ ████ ██ █████ ████████ ███ ██████ ██ ██████████ ██████ ██ ███ ████ ██ ███████ ██ ██████ ███ ███████
This is descriptively inaccurate. The author
b
Although scientists often ████████ ██ ███ ██████████████ ██ ██████████ ███████████ ████ ████████ ████ █████ ████ ███ ████ ██████████████ ███████ ███████ █████████ █████████
We know that
c
How biological populations ███ ██████████ ████ ███████ ██ █ █████████████ ██████████ █████ ████ █████████ ████████████ ██ ███████ ███████ ████ ███ ████████████ ██ █████████████
This is the main point of the passage. P1-P3 outline the debate between the lumpers and the splitters over the
d
Traditional methods of ███████████ ██████████ ███████████ ████ ███████ ████████ ██ ████ █████ ███████████ ███ █████ ███████ ████ ████ ██████ ████ ████████ ██ ███ ████ ██ ███████ ██ ███████
The main point of this passage is not that Sibley has questioned a traditional view. Instead, the main point is the general debate between the lumpers and the splitters. Sibley’s view serves as an example of the splitter perspective that shows how the different perspectives yield different
e
Charles G. Sibley █████████ █████████████ ███████ ██ ███████████ ██████████ ███████████ ████ ████████ ███ █████ ███████ ████ ███ ████ ██████ █████████
The main point of this passage is not that Sibley’s methods are revolutionary. Instead, the main point is the general debate between the lumpers and the splitters. Sibley’s view is just an example of one of the two general perspectives; his method is not the main point of the passage.