Unformatted text preview: ances (such as antibiotics). but this
200 years is just 1% of the time our species exist.
-life expectancy of our ancestor is the same in pre-revolutionized france at 1800s, about 25-30 years old.
-most of the organelle functions/disease we will discuss occur in middle or advance age.
-most people in the past do not live long enough to run risk of cardiovascular disease
-the traditional life span of human make sense when you look at human fertility: turkey's women bare children
earlier 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 about reproductive fitness. World Population
Dec 31, 2013 10:55 PST
France (speculative) 30
160,000 – 200,000 years Fertility
vs. Age 1725 1800 1900 1990 Modified from Gluckman et al (2009) www.cairn.info/revue-populationenglish-2005-5-page-505.htm (Primates) Humans Are Bipedal and Have Large Brains Gluckman et al (2009), Figs 5.10c, 7.8 • Evolution results in compromises
• (Bipedalism → narrow pelvis) vs. (newborn survival → large head)
• Babies are altricial; they need extended parental care Human Body is Full of “Design” Flaws LIGHT Inside-Out Retina Silverthorn, Ch 10 Crossing of Trachea & Esophagus Nesse & Williams (1994) Can...
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