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
21.
It can be inferred from ███ ███████ ████ █ █████████ ██ ███ ██████████ ███████ ███████ █████ ██ ████ ██████ ██ ████████ ████ █████ ███ ██ ███ █████████ ███████████
a
There are considerably ████ ████ ███████ ██ ███ █████ █████ ████ ███ █████████ ███████████
We
b
Members of two ████ ███████████ ████ ██████ ████ ████ █████ ██ ███████ ████████ ███████████████ █████ ████████████ ██████ ██ ███ ████ ████████
The lumpers agree with this statement. If there are two populations that have different physical characteristics but are not reproductively isolated (as in, members from these two populations reproduce with each other), then the lumpers would agree that these two populations belong to the same species.
c
Some animal species ████ ███ ██████████ ███████ ██ ████ ████ █████████ ████████
We don’t know what the lumpers would think about this statement. The passage doesn’t mention extinct species (or indicate that lumpers think that extinct species can have surviving members).
d
There is less ████████████ ██ ███ █████ █████ ████ █████ ███ ██ █████ ████
The passage does not indicate that the lumpers think that today’s level of biodiversity is the same as (or higher than) the level of biodiversity 50 years ago, so we can’t say that the lumpers would disagree with this statement.
e
Current debates over ████ ███████████ █ ███████ ███ █████████ █████████ ██ █████████ ██████ ████ ██ ██████████ █████████
We don’t know what the lumpers specifically think about this statement. The passage doesn’t indicate what the lumpers think about political motivations for classifying species.