Biology Reference
In-Depth Information
Population Relationships, Past and Present
How are individuals buried at a single site related to each other? How are individuals
buried at one site related to those at another site? What if those burial sites date to very
different time periods? Biologically speaking, could we argue that they are from the same
or a similar population? An early and iconic set of papers addressing these questions
come from Anne C.
Stone's 1996
dissertation work on the Norris Farms #36 site located in
the U.S. state of Illinois (
Stone, 1996; Stone and Stoneking, 1993, 1998
), though many others
have since followed suit (e.g.,
Ottoni et al., 2011
, among others).
Ultimate Origins
Questions about ultimate origins concern the initial appearance of new species: for
example, studies on the origins of Neandertals and their relationship to modern humans
(are they a different species from
Homo sapiens
?) abound. The direct analysis of Neandertal
DNA has brought tremendous insight into this question, as mentioned in the introduction
to this chapter (
Green et al., 2010; Reich et al., 2010
).
Migration/Colonization
Another kind of origins question relates to the migration of populations within species
into new geographic areas. An often-debated migration case study is the peopling of the
Americas: From what continent(s) did the populations inhabiting the Americas prior to
the arrival of Europeans in the fifteenth century come? How long ago? How many groups
of people moved to the Americas, and did they come from different parts of the world?
What routes did they travel? While modern DNA analyses have informed many of these
debates, ancient DNA analyses have provided key pieces of evidence. Most recently, an
ancient DNA study of an individual dating to 10,300 years ago from
On Your Knees
cave in
Alaska demonstrated the presence of a novel mitochondrial genetic founder lineage, indi-
cating that the early American colonizers were more genetically diverse than was previously
thought (
Kemp et al., 2007
).
Disease
Disease is an unfortunate but integral part of life. Disease can be inborn (due to a genetic
mutation present from birth) or infectious (caused by viruses, bacteria, fungi, protozoa, and
parasites). All these disease-causing agents involve DNA and can be targeted in an ancient
DNA analysis. Researchers have been looking for the degraded molecular remains of such
pathogenic agents as tuberculosis (
Donoghue et al., 2004; Wilbur et al., 2009
) and leprosy
(
Haas et al., 2000
). For a good recent review of ancient disease studies, see
Drancourt and
Raoult (2005)
, and Smith (Chapter 7), this volume.
Genetic Sex
Osteological techniques for estimating the sex of a skeleton are well established for modern
populations as well as for those from the contemporary past. However, as Moore (Chapter 4),
this volume, points out, application of these techniques to more ancient populations becomes
problematic. Additionally, there are no accepted gross morphological methods to estimate sex
osteologically in subadults, present or past; genetic techniques of sex estimation could provide
