Different forms of a single gene are known as alleles. Alleles of genes that occur close together on a chromosome, unlike those of genes farther apart, tend to remain associated, to be passed along through the generations much as if they were a single unit; such tight associations are known as haplotypes. We often can tell who are related because they share the same haplotype. We can even study ancient migration patterns by looking at the present-day distribution of the haplotypes.
A somewhat different twist is a recent study of the modern and
prehistoric distribution of a haplotype found in 10,300-year-old human remains from a
cave in an island off the coast of southern Alaska. Individual native Americans from
such diverse places as California, Ecuador, and the southern tip of South America share
the haplotype. Obviously, the descendants of the population to which this early man
belonged have spread far and wide. What does this have to do with us? Among the modern
individuals who have inherited these alleles are some within our own Chihuahuan
Tarahumara.
Contributor: Arthur H. Harris, Laboratory for Environmental Biology, Centennial Museum, University of Texas at El Paso.
Desert Diary is a joint production of the Centennial Museum and KTEP National Public Radio at the University of Texas at El Paso.
Dalton, R. 2005. Caveman DNA hints at map of migration. Nature 436:162.