9
Natural Selection, Genetic Variation,
and Human Diversity
Leslie S. Emery and Joshua M. Akey
Abstract
Patterns of human genetic diversity observed in present-day individuals provide
insight into our species evolutionary history and regions of the genome that have
been influenced by natural selection. In this chapter, we discuss methods and
models that have been used to better understand how selection has impacted
human variation and review studies of natural selection in humans and the stories
they reveal about human history.
9.1
Introduction
A comprehensive understanding of how natural selection has shaped extant patterns
of human genomic variation remains an important, yet elusive, goal. Although it is
becoming increasingly clear that a significant proportion of the human genome has
been impacted by selection (Hahn 2008; Akey 2009), many outstanding questions
remain. These questions include identifying the precise causal alleles that have
been targets of selection, the timing, strength, and form of selection exerted on
causal variants, the mechanistic and molecular pathways selection acts upon, and
ultimately what factors led to differences in fitness among alleles at a given locus.
Answering these questions not only provides a window into human history and the
historical forces that have shaped our past but also provides fundamental insights
into hominin evolution, mechanisms of evolutionary change, and the heritable basis
of disease.
L. S. Emery · J. M. Akey ()
Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
e-mail: jakey@princeton.edu
© The Author(s), under exclusive license to Springer Nature Switzerland AG 2021
K. E. Lohmueller, R. Nielsen (eds.), Human Population Genomics,
https://doi.org/10.1007/978-3-030-61646-5_9
205
Natural Selection, Genetic Variation,
and Human Diversity
Leslie S. Emery and Joshua M. Akey
Abstract
Patterns of human genetic diversity observed in present-day individuals provide
insight into our species evolutionary history and regions of the genome that have
been influenced by natural selection. In this chapter, we discuss methods and
models that have been used to better understand how selection has impacted
human variation and review studies of natural selection in humans and the stories
they reveal about human history.
9.1
Introduction
A comprehensive understanding of how natural selection has shaped extant patterns
of human genomic variation remains an important, yet elusive, goal. Although it is
becoming increasingly clear that a significant proportion of the human genome has
been impacted by selection (Hahn 2008; Akey 2009), many outstanding questions
remain. These questions include identifying the precise causal alleles that have
been targets of selection, the timing, strength, and form of selection exerted on
causal variants, the mechanistic and molecular pathways selection acts upon, and
ultimately what factors led to differences in fitness among alleles at a given locus.
Answering these questions not only provides a window into human history and the
historical forces that have shaped our past but also provides fundamental insights
into hominin evolution, mechanisms of evolutionary change, and the heritable basis
of disease.
L. S. Emery · J. M. Akey ()
Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
e-mail: jakey@princeton.edu
© The Author(s), under exclusive license to Springer Nature Switzerland AG 2021
K. E. Lohmueller, R. Nielsen (eds.), Human Population Genomics,
https://doi.org/10.1007/978-3-030-61646-5_9
205