Welcome to my talk on Detecting Natural Selection Using Molecular Data.
Charles Darwin defined natural selection as the preservation of
favorable variations and the rejection of injurious variations.
The beauty of natural selection is in its simplicity and its explanatory power.
And of course, Mr. Darwin understood this as well as anybody.
But look at the second sentence here.
Variations, neither useful nor injurious,
would not be affected by natural selection and will be left a fluctuating element.
It is in this sentence,
as we will see later,
that we have the basis for detecting signatures of natural selection in our genes.
Natural selection is a slow process and we're used to thinking of its consequences,
that is adaptions, as occurring over vast periods of time.
But new techniques for detecting natural selection based upon the analysis of
genetic variation allow us to see if
genes are evolving by natural selection within populations,
estimate when that natural selection started,
see if separate populations are evolving
differently in response to different environments,
and identify which genes have been evolving the most since two species split.
In the context of evolutionary medicine,
these new techniques allow us to examine the evolution of human traits,
to explain the presence of some inherited diseases,
to identify genes of medical importance,
to understand the processes by which pathogens
adapt to medical intervention and immunity,
and ultimately to investigate what makes us human.