The Laupala Cricket Variation
The brief in question is related to crickets:
Tamra C. Mendelson & Kerry L. Shaw. 2005. Sexual behaviour: Rapid speciation in an arthropod. The likely force behind an explosion of new Hawaiian cricket species is revealed. Nature 433, 375-6, and Supplementary Info.
http://www.lehigh.edu/~inbios/pdf/Mendelson&Shaw_Nature05.pdf [broken link]
Even the subtitle indicates that such publication was a “likely” speculation, proven to be wrong by their current 2006 paper!
In the original one page long brief we can read that:
"Females prefer pulse rates of their own species [Mendelson, T. C. & Shaw, K. L. Genetica 116, 301–310 (2002), see below], so divergence in male song reduces the chances of interbreeding between species."
Because those crickets are able to interbreed in the lab producing fertile offspring, those crickets are not an example of ‘speciation’ but of variation.
Even in their original 2005 Nature's brief it does not says that the interbreeding between them is impossible, the different song-preference, it is theorized, only may be reducing the “ability of interbreeding between divergent populations.” However, their recent publication has demonstrated that such is not the case:
Mendelson, T.C. and Shaw, K.L. 2006. Close-range acoustic signaling and mate choice in Hawaiian crickets. Behavioral Ecology and Sociobiology (PDF). [Broken link]
“We predicted that females would exhibit a shorter latency to mating with hybrid males whose pulse rates were more similar to the conspecific pulse rate of the female. However, neither hybrid by L. paranigra nor hybrid by L. kohalensis pairings showed significant differences in latency to mating among females mating with the slower singer, the faster singer, or both...
"...the hypothesis that the premating barrier between L. paranigra and L. kohalensis is maintained by the female’s preference for a conspecific male’s song at close range was not supported by the present study. When females were presented with male hybrids exhibiting a wide range of pulse rates, no relationship was detected between male pulse rate and either the frequency of, or latency to, mating. Rather, females of both species accepted males with pulse rates several standard deviations outside their respective conspecific ranges, indicating broad female preference functions for pulse rates at close range. Therefore, we are unable to reject the null hypothesis that the pulse rate of male “courtship” song has no effect on behavioral barriers in close-range interactions.”
“The two species do not overlap geographically, nor does available evidence suggest a cost to hybridization (i.e., a reduction in hybrid fitness).”
“Matings between L. paranigra and L. kohalensis result in viable and fertile offspring, and the second generation of hybrids (F2) provide a genetic and phenotypic mosaic of parental types. Thus, although individual males are characterized by a particular pulse rate, the population of F2 males exhibited a broad range of pulse rates against a recombined genetic and phenotypic background... Males were second-generation hybrids resulting from a L. kohalensis grand-dam and L. paranigra grand-sire, and several F1 intercross parents.”
“In close-range encounters, aspects of chemical signaling may be important to mate recognition within species and may further reduce the probability of interbreeding among divergent lineages. The nature and strength of this barrier is yet unknown.”
“Results of our study demonstrate that while strong behavioral barriers exist between these two species, variation in the pulse rate of male calling song did not predict female mate choice at close range. These results suggest a more complex architecture to mate recognition in Laupala than previously hypothesized” [from the Abstract]
“Females did not exhibit a preference for either slower or faster hybrid pulse rates... As with mate choice, latency to mating was not correlated with hybrid male pulse rate.”
The Hawaiian cricket, Laupala [broken link]
I posted at ARN that “I can see again and again that varieties are deliberately and conveniently confounded with species...”
"If two different animals can interbreed producing fertile offspring, they are just varieties, no matter if science classifies them as different species or even genera (as the living fertile example of the product of a false killer "whale" x dolphin)"
[photo taken by Bill Mull]
Note: However, with all of this evidence demonstrating that variation within compatible animals is what is going on in nature, the journal Science was erratic enough to include the very same article of 2005 (presented at the beginning of this posting), proven in 2006 to be a living example of variation within compatible and fertile offspring producers (F2 crickets), but not of 'speciation', however Science presented it as:
Breakthrough of the year: Evolution in Action. By Elizabeth Culotta and Elizabeth Pennisi. Science 23 December 2005: 310(5756)1878-79.
However, earlier both Andrew Rowell, and Casey Luskin debunked those calculated deceptions published in Science. The right title of that promotional published by Science must be Microevolution In Action. While I presented The Fraud of Evolution: Variation sold as Speciation.
Update (Jan 20):The response to the above mentioned Insect Systematist can be read at: Chronicles for The Laupala Cricket Variation.
Some of the other broken links rescued:
This was my preliminary compilation of compatible organisms:
And this is a compilation of references:
The inspiring article:
Additional compatibilities explored in my blogs are:
[I noticed that somebody copied my previous link information and posted it in the Wikipedia: http://en.wikipedia.org/wiki/Hybridisation_in_shorebirds]