Complexity Digest 2003.26 - 17
Senescence In A Bacterium With Asymmetric Division, Science
Excerpts: Senescence (or aging) is a deterioration of function with age manifested as a drop in survival and reproduction (1). A fundamental question about senescence has not been settled: Which organisms should be senescent, and which should be potentially immortal? We present evidence for senescence in a bacterium with asymmetric division, supporting the notion that asymmetry is the key condition for senescence to evolve (2). The molecular processes underlying senescence are genetically determined. Why then is senescence-which imposes a cost on the individual-not eliminated by natural selection? For most organisms, selection against senescence is weak.
- Source: Senescence In A Bacterium With Asymmetric Division
[ http://www.sciencemag.org/cgi/content/full/300/5627/1920 ], Martin Ackermann, Stephen C. Stearns, Urs Jenal, Science Jun 20 2003: 1920