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
22.
Which one of the following, ██ █████ █████ ███████ ███ █████████ ███████ ███ ███ ████████ █████████ ██
a
It is becoming ████████████ █████████ ██ █████ █████████████ ██████████ ██ ███████ ██████████ ████████
(A) is about how international agreements handle things once we know that a species is endangered; the author’s claim in the final sentence is about the number of species that need protection. For the purposes of strengthening the last sentence, we care about classification, not protection. (A) is about a completely different step in the species protection process, so (A) doesn’t support the claim in the last sentence.
b
Increasing the number ██ ███████ ███████ ████████████████ ██ ████ ██████ ██ ██████ ██ ███ █████ ███████ ████ ██ ███ █████████ ████████
This comparison between bird and mammal species is not relevant to the author’s claim in the final sentence of the passage. This doesn’t support the claim that, if we have more species, then more species will need protection.
c
In disputes over ██████████ ██ ██████████ ████████ ████████ ██████████████ █████ ████████ ██████████ █████
This doesn’t tell us why increasing the number of species will probably increase the number of species that need protection. Saying that economic considerations often outweigh scientific considerations doesn’t provide the support that we need.
d
Advances in scientific ██████████ ████ ███████ █████████████ ████ ████████ █████ ███ ███████ ██ ██████████ ██ ███ ████████████ ███████ ████████
(D) says that advances in science will favor the efforts of the splitters, which means that we will probably have more species (because we know that the splitters
e
Proponents of the ████████████ ███████ ███████ ███ ████ ██████ ██ ███████ ██ ███████████ ███████ ██████████████ ██ ████ ██ ███ ██████████ ███████████ ████████ ██ ███████████
The last sentence of the passage claims that, if we increase the number of species, then we are increasing the number of species that need protection. We know that the splitters
(E) supports this assumption. (E) tells us that the splitters are more likely to contest an establish species classification (and split the species) if one of the populations involved is endangered. In other words, the splitters will be disproportionately trying to “split” endangered species, thus increasing the number of endangered species.