Court jester hypothesis


The court jester hypothesis is used in reference to the idea that abiotic forces, rather than biotic competition between species, function as a major driving force behind the processes in evolution which produce speciation. In evolutionary theory, the court jester hypothesis contrasts the Red Queen hypothesis.
The term "Court Jester hypothesis" was coined by Anthony Barnosky in 1999 in allusion to the Red Queen hypothesis. In a 2001 paper on the subject, Barnosky uses the term without citation, suggesting that he is the one who coined it. Westfall and Millar attribute the term to him in a paper of their own from 2004. Michael Benton also credits Barnosky with coining the phrase.
Since 2001, many researchers in evolution have started to use the term "Court Jester hypothesis" to describe the view that evolution at a macro scale is driven by abiotic factors more than the biotic competition called the Red Queen hypothesis. One example of a Court Jester dynamics is the correlation between global temperatures and diversification rates in birds.

Content of hypothesis

The court jester hypothesis builds upon the punctuated equilibrium theory of Stephen Gould by providing a primary mechanism for it. The 2001 paper by Barnosky that is one of the first to use the term appropriate for the Court Jester side of the debate: the Stability hypothesis of Stenseth and Maynard Smith, Vrba's Habitat Theory, Vrba's Turn-over pulse hypothesis, Vrba's Traffic light hypothesis and Relay Model, Gould's Tiers of Time, Brett and Baird's Coordinated Stasis, and Graham and Lundelius' Coevolutionary Disequilibrium theories.
Barnosky's 2001 paper that was one of the first to introduce the term, explains what the Court Jester hypothesis means, describing it as one side of a debate over:
The Red Queen hypothesis and Court Jester hypothesis both influence coevolutionary switching in host-parasite interaction. Barnosky acknowledges in the 2001 paper that the Court Jester hypothesis is not necessarily inconsistent with the Red Queen hypothesis:

The Red Queen Hypothesis

The Red Queen Hypothesis is a term coined by Leigh Van Valen, in 1973, in a reference to the Lewis Carroll book Through the Looking Glass. It refers in evolution theory to the arms race of evolutionary developments and counter-developments that cause co-evolving species to mutually drive each other to adapt. There is dispute over how strongly evolution at the scale of speciation is driven by these competitions between species, and how much it is driven instead by abiotic factors like meteor strikes and climate change, but there was not an artful metaphor to capture this alternative until one was coined by Anthony Barnosky.