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Unformatted text preview: arlier than other society. the peak of fertility is in the early 20s. this correspond well with traditional human
lifespan. humans have babies in their 20s, and live long enough, let's say 10 more years, to raise babies to
independence and thereby successfully reproduce
-the point is that most of modern disease that occur later in life will have little effect on evolution fitness, because
humans reproduce and die largely before the disease set in. As we study human body, the body seem to be
perfectly design (our body fit well with the environment), but there are also serious design flaw (congested heart
failure-circulatory system, weakness of heart muscle lead to its failure as a pump and this lead to changes in the
circulatory system that further weaken the heart muscle, this system design to create a downward spiral, once
there's a weakness, it lead to greater weakness, then death ). why haven't evolution eliminate these diseases?
A: the answer is that these diseases occur too late to have effect on ancestor's fitness. remember again,
evolution is not about health and well-being, it's a...
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This document was uploaded on 03/09/2014 for the course EXSC 301 at USC.
- Spring '09