MONDAY, SEPTEMBER 13, 1999 Reading Assignment: Why We
Get Sick: The New Science of Darwinian Medicine, pp. 13-25. CHAPTER 2:
EVOLUTION BY NATURAL SELECTION: How do Nesse & Williams explain the
process of natural selection? Does the British moth example illustrate
natural selection? Does Herbert Spencer's catchy phrase "survival of the
fittest" capture the essence of evolution by natural selection? If not,
what misunderstandings does it promote? NATURAL SELECTION BENEFITS GENES,
NOT GROUPS: Is group selection exemplified by lemmings engaging in mass
suicide when food is scarce? Can group selection ever occur? How does Richard
Dawkins's characterization of organisms as vehicles created by genes in
order to replicate themselves fit in with ideas that evolution tends toward
a world of health, harmony, stability, and happiness? How apt is Dawkins's
moniker "selfish genes"? KIN SELECTION: Does reproduction by a carrier
organism enable a gene to get more copies of itself into future generations?
Always? Suppose that the carrier organism performs actions that increase
the reproductive success of its close relatives. Does this circumstance
also enable a gene to get more copies of itself into future generations?
Why is it called "kin selection"? Explain J.B.S. Haldane's quip that he'd
sacrifice his life for two brothers or eight first cousins, but not for
one brother or seven cousins? Is kin selection the only exception to the
"Nice-guys-finish-last" principle (formulated by Leo Durocher, manager
of the old Brooklyn Dodgers)? What is reciprocity? Does reciprocity amount
to mutual backscratching? Explain how reciprocal behavior by the carrier
organism enables a gene to get more copies of itself into future generations.
What bearing do kin selection and reciprocity have on social behavior and
the possibility of altruism? HOW DOES NATURAL SELECTION OPERATE? Does natural
selection proceed according to some overall plan or scheme? In some particular
direction, e.g., toward better or higher beings? Is it predictable? If
not, is the theory of natural selection untestable? In what five ways does
chance influence natural selection? If one rewound and then replayed the
tape of biological history, would one see the same show? Would there be
humans in the replay? Does natural selection always do what is best for
the long-term welfare of a species? Does it create every adaptation that
would be valuable to a species? Explain how natural selection approaches
perfection by optimizing certain quantitative features of organisms? Give
some animal and human examples. What is the point of the yarn about Henry
Ford and the steering column of his Model T's? What's the connection between
costs and benefits? Does natural selection ever compromise, i.e., does
it ever make decisions based on cost-benefit analyses? Give some animal
and human examples. Are some apparent design mistakes really positive benefits
to an organism? Give examples? TESTING EVOLUTIONARY HYPOTHESES: Aristotle,
the father of functional analysis (What is it for?), stated that the body
as a whole has a special purpose or function. What do Nesse & Williams
take that purpose or function to be? What does it mean to say that a biological
trait or behavior is "adaptive"? Give animal and human examples. Can one
test hypotheses about the adaptiveness of traits or behaviors? Mention
some adaptational hypotheses that are superficially attractive but empirically
false. Mention some adaptation hypotheses that are obviously true. Which
adaptational hypotheses do Nesse & Williams view as "interesting"?
THE ADAPTATIONIST PROGRAM: What is the method of inquiry that has been
called "the adaptationist program"? Does it ever lead to novel predictions?
To empirically testable knowledge? Explain the significance of Nesse &
Williams three examples: How beavers decide which trees to fell; How woodland
songbirds decide how many eggs to lay; and How woodland songbirds determine
the male-female ratio of their offspring. How do adaptationists explain
the 50-50 sex ratio of humans and other sexual animals? What does it have
to do with the genetic fact that an individual has an equal chance of getting
an X or a Y chromosome from its father? What bearing do Nesse & Williams
think the adaptationist program has for the investigation of disease, illness,
and physiological disorders? Do they expect it to lead to important medical
discoveries? Can a trait or behavior have more than one function or purpose?
Give animal and human examples. What experimental limitations does the
adaptationist program encounter? If we cannot reconstruct the history of
a trait or behavior, how can we be confident that it was shaped by natural
selection? How many of the evolutionary (adaptationist) hypotheses advanced
in their book do Nesse & Williams consider to be tested and confirmed?
What is their goal or objective?