Modern man is said to have evolved until about 100,000 years ago and then
to have stopped evolving. Evolution since that time, it is claimed, has
been "cultural and social evolution." Biological evolution is unknown
among humans in historical times.
There is evidence that humans have evolved in the last several thousand
years and continue to evolve.
Analysis of variation in the human genome indicates that genes
associated with brain size have evolved over approximately the last
37,000 years and 5800 years (Evans et al. 2005; Mekel-Bobrov et
al. 2005).
Sickle-cell resistance has evolved to be more prevalent in areas
where malaria is more common.
Lactose tolerance has evolved in conjunction with cultural changes
in dairy consumption (Durham 1992).
Some humans have recently acquired mutations which confer resistance
to AIDS (Dean et al. 1996; Sullivan et al. 2001) and to heart
disease (Long 1994; Weisgraber et al. 1983).
Genome-wide sequencing shows evidence of much more positive selection
as well (Sabeti et al. 2006). There is some evidence that human
evolution has accellerated recently, since humans dispersed from
Africa and developed agriculture (Hawks et al. 2007).
References:
Dean, M. et al. 1996. Genetic restriction of HIV-1
infection and progression to AIDS by a deletion allele of the CKR5
structural gene. Science 273: 1856-1862.
Durham, William H. 1992. Coevolution: Genes, Culture, and Human
Diversity. Stanford, CA: Stanford University Press.
Evans, Patrick D. et al. 2005. Microcephalin, a gene regulating
brain size, continues to evolve adaptively in humans. Science 309:
1717-1720.
Hawks, John et al. 2007. Recent acceleration of human adaptive
evolution. Proceedings of the National Academy of Science USA 104:
20753-20758.
Long, Patricia. 1994. A town with a golden gene. Health 8(1)
(Jan/Feb.): 60-66.
Mekel-Bobrov, Nitzan et al. 2005. Ongoing adaptive evolution of
ASPM, a brain size determinant in Homo sapiens.
Science 309:
1720-1722.
Sabeti, P. C. et al. 2006. Positive natural selection in the human
lineage. Science 312: 1614-1620.
Sullivan, Amy D., Janis Wigginton and Denise Kirschner. 2001. The
coreceptor mutation CCR5-delta-32 influences the dynamics of HIV
epidemics and is selected for by HIV. Proceedings of the National
Academy of Science USA 98: 10214-10219.
Weisgraber K. H., S. C. Rall Jr., T. P. Bersot, R. W. Mahley, G.
Franceschini, and C. R. Sirtori. 1983. Apolipoprotein A-I
Milano. Detection of normal A-I in affected subjects and evidence for
a cysteine for arginine substitution in the variant A-I. Journal of
Biological Chemistry 258: 2508-2513.
