of Disease and Living Conditions:
for the relationship between evolution and differing rates in pervasive
diseases and adaptation has been pieced together by epidemiologists and
other health scientists based on genetic, linguistic, archeological, and
anthropological evidence. So there is some uncertainty. Now with genetic
tests to discover similarities between apparently diverse populations,
models of disease and health are becoming more robust. Still, differentiating
between the effects of genes and of the environment is difficult. Usually,
it is a combination. The genetic susceptibility may be dormant till an
environmental factor triggers it, resulting in the disease. We discuss
two cases briefly to show the intricacy, and the times involved in the
changing patterns. One reason for doing this is to bring to our attention
how long-term and significant the consequences of low-level but relevant
exposure to environmental agents may be.
is a deadly disease that emerged among humans recently. Track
the origins and the spread of the AIDS virus.