My name is Anna Di Rienzo from
the Department of Human Genetics at the University of Chicago.
Today, I will review recent studies about how
human populations adapted to the different environments in which they live.
I will review the models through which these adaptations took place,
some of the methods used to look for signals of
local adaptations and how to interpret their results.
I will describe some of the biological findings obtained in these studies.
Probably, one of the most striking aspects of evolution of
our species is that tremendous diversity of environments,
illustrated here by a map of the ecoregions,
that humans have encountered during their history and have adapted to.
Both genetic data and the fossil record
indicate that modern humans originated somewhere in Sub-Saharan Africa,
and from there they dispersed across the globe to
occupy every corner of the earth landmass.
In so doing, they have encountered a variety of environmental challenges,
including different climates, different levels of UV radiation,
different pathogens and available resources.
In addition, during this history they have introduced
a number of cultural and technological innovations,
which in turn have created new selective pressures.
In response to these environmental challenges,
human populations have evolved a number of cultural, behavioral,
as well as genetic adaptations that lead to that wonderful phenotypic
and cultural diversity that we see today in contemporary populations.