Leigh Van Valen

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Leigh Maiorana Van Valen (born August 12, 1935 in Albany , † October 16, 2010 in Chicago ) was an American biologist at the University of Chicago . His main areas of work were evolutionary biology and biological systematics .

life and career

Van Valen became known especially for his formulation of an ecological species concept. The aim of this proposal is to define species by the niches they inhabit . At Van Valen, a niche is to be understood as a complex conjunction of living conditions, so that ultimately exactly one species can be assigned to each niche. Even if the ecological species concept can still be said to be topical, it could not establish itself as a general concept. One problem is that a sufficient description of a niche itself has to fall back on species, so that a complete definition of the term species through the niche term would be circular .

Van Valen's evolutionary red queen hypothesis , which states that a species must constantly become more efficient in order to maintain its current position , also became influential . According to Van Valen, the reason is as follows: An increase in performance of one species usually leads to disadvantages for another species. This must consequently also carry out an evolutionary increase in performance in order to be able to maintain its position. This dynamic can lead to an evolutionary "upgrade" from which no species takes advantage. An example: A tree in a forest has a great advantage if it grows taller because it receives more sun rays. At the same time, it hides the sun for other trees, which consequently have to get taller themselves. This can lead to a growth in height of trees, which ultimately does not give any type an advantage - possibly even only disadvantages.

In his paleontological work on the adaptive radiation of mammals in the early Cenozoic , Van Valen used names from JRR Tolkien's novels to name fossil species, see Quirky Scientific Names from Biology and Medicine .

Web links

swell

  1. ↑ Leigh Van Valen (1976). Ecological species, multispecies, and oaks. Taxon 25 : 233-239
  2. ↑ Leigh Van Valen (1973). A new evolutionary law. Evolutionary Theory 1 : 1-30
  3. ^ Leigh Van Valen (1978). The beginning of the Age of Mammals. Evolutionary Theory 4 : 45-80
personal data
SURNAME Van Valen, Leigh
ALTERNATIVE NAMES Van Valen, Leigh Maiorana (full name)
BRIEF DESCRIPTION American biologist
DATE OF BIRTH August 12, 1935
PLACE OF BIRTH Albany
DATE OF DEATH October 16, 2010
Place of death Chicago