Viruses scout evolution's path
Morell, V.
Science 278(5343): 1563-1564
1997
ISSN/ISBN: 0036-8075 PMID: 9411777 Document Number: 472664
At a meeting of the European Society for Evolutionary Biology in Arnhem, the Netherlands, in August, Lin Chao of the University of Maryland, College Park, noted that the fast-evolving viruses he uses to test theories about the evolution of sex suggest a possible resolution of a decades-old debate about the trajectory of evolution. During the 1930s, R. A. Fisher of Cambridge University proposed that evolution is like a staircase, on which organisms develop through a sequence of small genetic steps leading to a higher level of fitness, unless a major shift in the environment compels them to start scaling a different set of stairs. In contrast, Sewall Wright, working at around the same time at the University of Chicago, thought that in addition to environmental forces, genetic changes could derail the evolutionary process and envisioned evolution as occurring on a landscape of many peaks and valleys. Chao's virus cultures indicate that both metaphors could be valid.