Reading Comprehension

PT157 · S4 · P3 · Q16 Definition of Species

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

Topic

The challenge and controversy of defining what counts as a "species," especially in ornithology, and the implications of different definitions.

Framework

Present Debate

Main Point

There is an ongoing debate among scientists about how to define a species, with significant practical and political consequences, especially for conservation. ( — opening sentences, and the summary of practical stakes at the end.)

P1: Debate Over What Constitutes a Species

This paragraph introduces the ongoing debate about what a "species" actually is, focusing on the classic divide between "lumpers" (who group similar populations) and "splitters" (who separate populations into more species). Lumpers use the biological species concept (reproductive isolation), while splitters prefer the phylogenetic species concept (diagnosable populations with unique, genetically traceable traits).

P2: Example of a "Splitter" – Sibley's Contributions

Here we get an example in ornithology: Charles G. Sibley, a splitter, used DNA technology to challenge conventional classifications of bird species, arguing for unexpected relationships among birds (like American vultures being closer to storks than to other vultures).

P3: Pushback and the Limits of Classification

Sibley's ideas faced significant criticism. A critic argues that interpreting genetic differences is arbitrary, and even Sibley concedes that species definitions are inherently slippery because many populations don’t fit our tidy definitions.

16.

According to the passage, which one of the following is true of the phylogenetic species concept?

It has effectively discredited other
Too Strong
This answer makes it seem like Splitters won the great war of "how do we decide whether something is its own species". But the passage makes it seem like the debate rages on between lumpers and splitters. So this answer sounds way too victorious, as though the world has embraced phylogenetic (i.e. Splitters) as the correct answer and discredited the alternatives.
8% picked this
Its popularity has declined since
Out of Scope
We never hear anything about Sibley dying, nor do we hear about a decline in the popularity of Splitters. The passage makes it seem like the ornithological debate between Lumpers and Splitters is alive and well.
2% picked this
It is more useful in
Unsupported
The author never compares the Splitter method's usefulness in ornithology to its usefulness in other biological sciences.
8% picked this
Correct
It has more proponents now
Why this is right
We can find support for this in the 1st paragraph: Generally, the lumpers employ what is known as the biological species concept, which until recently was the dominant approach to species classification. Later in the 1st, Splitters, on the other hand, tend to use the increasingly popular phylogenetic species concept. If something is increasingly popular, then it has more proponents now than in the past.
Skill tested: Locate Detail · how this choice captures the passage's function is the move to repeat next time.
68% picked this
It was pioneered by Charles
Unsupported
The first sentence of the 2nd paragraph doesn't tell us who invented the Splitter concept. It just says that Sibley "could be called a splitter". He was "one of the fomenters of a controversial revolution in avian taxonomy", but we have no idea if he invented the phylogenetic concept. He used a special process that might have been pioneered by him, but his DNA-DNA hybridization process is not the same thing as "the phylogenetic species concept". He uses that process in conjunction with that concept to make determinations about what should or shouldn't be considered a species, but the passage never says he invented the concept.
14% picked this

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