Biology Reference
In-Depth Information
based on bones and teeth as data sources. The chapter wraps up with a vision for future
research directions in the combined field of genetics and skeletal biology.
GENETICS AND GENOMICS
The word
genetics
1
was first coined in 1906 by William Batson, a British biologist, to refer
to the study of heredity and the science of variation; the word comes from a set of related
Greek words referring to “birth” or “origin.” Following this original sense, “genetics” is
currently used, first and foremost, as an overarching term for the study of biological inheri-
tance, which can cover the pattern, structure, function, and behavior of genes within an
organism's
genome
(the entirety of an organism's hereditary information) and their transfer
to new generations of organisms. Numerous definitions of “gene” exist, but George C.
Wil-
liams' (1996)
general definition best meets the purposes of this chapter: a
gene
is “any portion
of chromosomal material that potentially lasts for enough generations to serve as a unit of
natural selection.”
Today, scientists are using powerful new tools for sequencing the genomes of entire organ-
isms, including humans. These advances are expected to improve our understanding of how
multiple genes and gene products interact with other genes and environmental factors. The
term
genomics
is often used to denote both these advanced sequencing capabilities and
a more complex model interaction. Many times researchers will use the term “genomics”
instead of “genetics,” yet “genomics” should be formally subsumed under “genetics.” What
is meant by this separation of terms?Many people associate the term“genetics”with a singular
focus on single genes along with the application of classic Mendelian principles of inheritance
in which one gene represents one trait. From this perspective, genetics is the study of single
genes and their effects, and genomics is the study of the functions and interactions of all
the genetic material in the genome, including interactions with environmental factors.
Anthropologists in general have not been concerned with the study of genes
per se
, but
rather with single or a few markers to reconstruct those biological and social processes
that have contributed to the history of human groups. Today, we find ourselves in the so-
called “genomic era,” which has brought to anthropological inquiry a tremendous explosion
in the number of available markers (hundreds of thousands), with the potential to look at the
entire genome (all 3 billion base pairs) at little cost
2
in the next few years.
GENETICS IN ANTHROPOLOGY
The use of genetics in anthropology gained traction with the early discovery of
monogenic
traits
in blood, so called because their inheritance was presumed to be due to the action of
single or very few genes. The early twentieth century saw the discovery of blood types
1
All bolded terms are defined in the glossary at the end of this volume.
2
As of this writing, it is possible to sequence a genome for as little as $1000. It is probable that in the next five
to ten years that cost will go down even further. This is astounding considering that the first low-resolution
draft of the human genome came in at a final cost of $3 billion!
