Self-study
P1
The French biologist Jean-Baptiste de Lamarck (1744–1829) outlined a theory of evolutionary change in 1809, 50 years before Darwin's . ██ ███ ██████ ██ ████████ █████████ █████ ████ ███ ████ █████████ ██████ ██ ████████ ██ █████ ███████████ ███ ████ ████ ██ ██ █████ █████████ ███ ███ ███████████████ ████ ████ █████████ ███
Lamarck's Theory of Evolution ·
Environmental adaptations could be inherited
Critique ·
Consensus view among scientists is that Lamarck is wrong
Steele ·
Claims to have evidence for Lamarckism
Steele claims to have found evidence for Lamarckian hereditary mechanism in the immune system. Not sure what this means but presumably the rest of the passage will flesh this out.
P2
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Phenomenon ·
Complexity of the immune system
How does our immune system work? If knowledge of how to defend against attacks are coded in the genes, how does it defend against a new disease, something it's never encountered before?
Partial Explanation ·
Some immune system cells mutate a lot
The immune system doesn't know. But "typo" mutations (when an error occurs when transcribing DNA into RNA) happen a lot which allows immune system to test different defenses.
P3
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Steele's Hypothesis ·
Supporting Lamarckism
Steele hypothesizes that the "typo" mutations that end up working gets coded back into the immune cell's DNA. Steele further hypothesizes that a virus then carries the altered immune cell DNA into the DNA of the reproductive cells. That's the mechanism by which an environmentally induced adaptation (in the immune cell) gets inherited.
P4
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Evidence ·
for Steele's Hypothesis?
Steele ·
Yes, circumstantial evidence
Steele claims that there's circumstantial evidence. Something about a pattern of mutations. Not sure what this means.
Other Biologists ·
No, there are simpler explanations for the "pattern of mutations"
Passage Style
Critique or debate
Phenomenon-hypothesis (RC)
23.
The passage is primarily concerned ████
a
offering a historical ███████ ██ ███ ███████████ ██ ██ ████████████ ██████
This isn’t the primary purpose of the passage, because Lamarck’s evolutionary theory is brought up only in the first half of P1, and we don’t get information about how the theory was developed.
b
describing the efforts ██ █ ██████ █████████ ██ █████████ █ ████████████████ ████████████ ██████
This best captures the primary purpose. The
c
answering a set ██ █████████ █████ ███ ██████ ██████ ██ █████ ██ ████████████ ██████
This is too narrow. Although the author does discuss the immune system in P2, this discussion is part of the context for understanding Steele’s hypothesis. The overall purpose of the passage isn’t about the immune system.
d
evaluating the overall ██████ ██ ██ ████████████ ██████ ████ ███ ████ ████████ ██ ████ ██████ ██████████
The author doesn’t “evaluate” the “merits” of an evolutionary theory. She doesn’t assess the quality or usefulness of Lamarck’s theory. If you think (D) is referring to Steele’s hypothesis, it’s still wrong, because we don’t know that “most” (over half) biologists have rejected the hypothesis.
e
presenting a discredited ████████████ ██████ ██ █ ████ █████ ██ ███ ██████████ ██ ███████
This doesn’t capture the author’s focus on presenting Steele’s hypothesis. The author does use Lamarck’s theory as a case study. She doesn’t examine Lamarck’s theory for the purpose of drawing lessons from it.