Mechanisms for recognizing kin are found throughout the plant and animal kingdoms, regardless of an organism's social or mental complexity. ββββββββββββ ββ βββ βββββββ βββββββββββββ ββ βββββ ββββββββββ ββββ ββββββ ββββ βββββββββββ βββββββββ ββ βββ ββββββββ ββ βββ βββ βββββββββββ ββββββ ββ ββββ βββ
Phenomenon Β·Many plants and animals can recognize "kin" (relatives)
Inclusive fitness hypothesis Β·Organisms transmit genetic material through relatives (not just offspring)
Contrast inclusive fitness with traditional view of evolution. Under traditional view, natural selection favors those with the most offspring. Inclusive fitness suggests natural selection also favors organisms who help their relatives (because this helps spread the organism's own genes).
Example of theory applied to cannibals Β·Spadefood toad tadpoles
Some tadpoles eat their own species. But they nip at other tadpoles before eating, and end up eating only nonsiblings. Suggests they're trying to avoid eating their kin. But, they're more likely to eat kin when they're very hungry.
Example showing other explanation Β·Tiger salamander larva
Some larva are cannibals. The bacteria are more deadly to close relatives, because the relatives have a similar immune system to the infected larva. So, when tiger salamanders avoid eating their close relatives, it could be because they just don't want to die from the bacteria in their relatives. This is about the organism's individual self-interest, not about trying to increase overall genetic representation.
The mechanism by which the tadpoles recognize their kin is described in the middle of P2: βThe cannibals have a procedure of discrimination whereby they nip at other tadpoles, eating nonsiblings but releasing siblings unharmed.β
a
It is not βββββββββ ββββββ ββ βββ βββ ββ ββββββ βββββ
Supported. The procedure involves nipping (meaning putting part of the other tadpole in oneβs mouth). This is a non-visual way of determining whether another tadpole is oneβs sibling.
53%
b
It is neither ββββββββ βββ βββββββββ ββ βββββ ββββββββ ββββ ββ βββ ββββββ ββββββββββββββ
Not supported, because we donβt know whether non-cannibal tadpoles nip other tadpoles. Itβs possible some non-cannibal tadpoles have the ability to nip other tadpoles and to determine whether they are siblings.
21%
c
It does not ββββββ βββββ β βββββββ ββ βββββββββββ βββ ββββββββ ββββ ββββββββ ββββ βββ βββ βββββββββ
Not supported, because we donβt know that the technique isnβt 100% successful at determining whether the other tadpoles are siblings.
9%
d
It is rendered βββββββββββ ββ βββββββββββββ βββββββ ββββββββββββ βββ βββββββ βββββ ββββ ββββββββββββββ ββ ββββββββββββββββ
Not supported, because weβre told that the cannibals do in fact nip at other tadpoles to determine whether they are siblings. We have no reason to think that the behavior is unnecessary.
8%
e
It could not ββββ βββββββββ ββ β βββββββ ββ βββββ βββ βββββββ βββ βββββββββββ
Not supported, because we have no information about what would cause the nipping behavior not to develop. Maybe in some species that are omnivores, some animals are still cannibals and would nip to determine whether other members of their species are siblings.
9%
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156
Analysis
Implied
Implied
Stems asking us to infer an idea implied by the claims in the passage (as opposed to identifying an idea that appears explicitly). Similar to most strongly supported questions in LR.
Passages that focus on describing or evaluating potential explanations for a given phenomenon. Causal reasoning features prominently in these passages.