Research on Intelligent Design

To put together scientific advances from the perspective of Intelligent Design.

Friday, January 27, 2006

The Maggot (Rhagoletis Fly) Variation

The Lonicera fly (Rhagoletis pomonella), a new natural variety, product of interbreeding between the blueberry maggot (Rhagoletis mendax) and the snowberry maggot (Rhagoletis zephyria.)

In the public discourse of this finding, or at least in the first abstract presentation on the subject, the use of the word 'speciation' was not even used at all by its authors:

The other hybrid bridge - Hybridization between specialist insects facilitates host shifts. 2004. Dietmar Schwarz, Bruce McPheron. [Tuesday, August 3, 8:00 AM to 11:30 AM. The Ecological Society of America (ESA), Portland, Or.]

However, almost a year later, evolution and its 'speciational' discourse and politics were evident, together with its fallacies and its non-sense, let's see (remember to replace the senseless word of 'speciation' with the more accurate word of variation (as well as to replace here 'species' with the accurate word variety) as we are dealing here with variation within compatible organisms):

Schwarz D, Matta BM, Shakir-Botteri NL, McPheron BA. Host shift to an invasive plant triggers rapid animal hybrid speciation. Nature. 2005 Jul 28;436(7050):546-9.

From Nature's the Abstract:
"An alternative speciation route is homoploid hybrid speciation (1) in which two ancestral taxa give rise to a third, derived, species by hybridization without a change in chromosome number.

Although theoretically possible it has been regarded as rare (1) and hence of little importance in animals.

On the basis of molecular and chromosomal evidence, hybridization is the best explanation for the origin of a handful of extant diploid bisexual animal taxa (2, 3, 4, 5, 6).

The frequency of homoploid hybrid speciation in animals may therefore be higher than previously assumed." [Note: The reference's numbers in the original]
Now, let's see how the evolutionarily biased media presented it:

New animal species evolved in an instant, Bob Holmes. news service. 18:24 27 July 2005.
"A new species of insect may have arisen in an evolutionary eye-blink as a result of cross-species mating. The discovery suggests that hybridisation - well known to be an important force in producing new plant species - may also be widespread in animals."

"...The researchers are not yet willing to declare the honeysuckle maggot has completed this process [of a speculated and non-existent evolutionary 'speciation'], Schwarz says, because they have not ruled out the possibility of a low level of interbreeding with at least one of the parent species."

"If hybridisation often leads to shifts in host preference, it could be much more important in animal evolution than anyone had suspected, says Schwarz. After all, many - perhaps even most - animal species on Earth live in tight association with a particular host. "It makes one think it is possible for hybridisation to be important in generating biodiversity," says Thomas Dowling, an evolutionary biologist at Arizona State University in Tempe, US."

My comment: In January 15 2005 my paper on Intelligent Design to Generate Biodiversity was posted at ISCID. Directed hybridisation will indeed still be "important in generating biodiversity"

See how the 'evolution-avid' distorters of reality from National Geographic presented it:

Evolution Revolution: Two Species Become One, Study Says. By James Owen for National Geographic News. July 27, 2005.

In the picture for this article we read the next legend:
Rhagoletis pomonella (Photo: Guy Bush)

"The newly discovered Lonicera fly species arose through hybridization, a new study says. Two other fly species mated and formed a hybrid, a combined form that cannot mate with its fellow hybrids. Given a separate niche in which to evolve—in this case, an alien huneysuckle imported to the U.S. — a hybrid animal can become a full-fledged new species, according to researchers."

So, here the National Geographic bullies are affirming that the new variety of maggot is "a combined form that cannot mate with its fellow hybrids." However, we just read in the other "proevo-promo" that the original researchers "have not ruled out the possibility of a low level of interbreeding with at least one of the parent species."

So, in their 'little' ideological extreme, National Geographic is affirming an evolutionary fairy tale or fallacy not even subscribed by the scientists that did the study themselves!

Then, National Geographic declares that
"George Turner is a professor of evolutionary biology and biodiversity at the University of Hull in England. He agrees that animal evolution through hybridization may be much more widespread than previously believed."
Remember, here we are in reality dealing with variation within compatible animals. A new variety fully fertile and fully able to interbreed with the other varieties of the group.

Then, there we have National Geographic again declaring that:
"Hybrids that aren't sterile may have the opportunity to become a full-blown new species."
That we know must be corrected to better reflect reality as: >"Hybrids that aren't sterile may have the opportunity to become a full-blown new VARIETY."

Finally, Schwarz said. "In animals there has been so far only limited information on this mode of speciation."

In this mode of what? In this mode of VARIATION! You got it!

The first author of that paper declares:
Dietmar Schwarz. Postdoctoral Scholar, Entomology, PSU. Diplom Biology, Christian-Albrechts University Kiel, Germany. Ph.D. Entomology, Penn State.
"I study the natural hybridization of Rhagoletis mendax and Rhagoletis zephyria, which is associated with a host shift to introduced honeysuckle, Lonicera spp."
And he also declares
:"My research focuses on the evolutionary and ecological consequences of hybridization - especially its role in speciation - in host specific insects. The system that I am using is the Lonicera Fly, a newly discovered population within the Rhagoletis pomonella species group. The Lonicera Fly is an independent population that arose by hybridization between two native taxa, R. mendax and R. zephyria, and hybrid origin genotypes are only found on introduced species of the Lonicera tatarica complex. This system represents a unique example for a combination between hybridization and a recent host shift in a host specific animal."
In the personal statement of Dietmar Schwarz we have the evidence that his work is done in "a newly discovered population within the Rhagoletis pomonella," which is "an independent population that arose by hybridization between two native taxa, R. mendax and R. zephyria." This is variation within compatible organisms, plain in simple. This is not the evolutionary graal for "the origin of species", this is not the speculative 'speciation' at all, this is not "macroevolution" at all!

For academic purposes, let's conclude with the basic references presented by the author in his original thesis:

Natural Hybridization And Speciation In Rhagoletis (Diptera: Tephritidae) 2004 Dietmar Schwarz (Full PhD Thesis in PDF).
"During speciation by introgressive hybridization, hybrid offspring do not become immediately reproductively isolated, but can still interbreed with the parental taxa to some extent. This results in the formation of a “group of recombinant individuals” (Dowling, T. E., and C. L. Secor. 1997. The role of hybridization and introgression in the diversification of animals. Annual Review of Ecology and Systematics 28:593-619), which may evolve reproductive isolation from its parents. Well-documented examples for introgressive hybridization are rare both in animals and in plants (Dowling, T. E., and B. D. DeMarais. 1993. Evolutionary significance of introgressive hybridization in cyprinid fishes. Nature 362:444-446; Rieseberg, L. H. 1997. Hybrid origins of plant species. Annual Review of Ecology and Systematics 28:359-89). It is unclear whether speciation by introgressive hybridization is a mode of speciation that occurs only rarely in nature or whether it is just difficult to document (Dowling and Secor 1997). Unlike polyploidization, it does not leave a characteristic signature in the hybrid species’ genome.

The mechanisms by which animal hybrid swarms become reproductively and ecologically isolated are poorly understood. The literature contains only three examples
of speciation by introgressive hybridization in animals. They comprise three fish
(DeMarais, B. D., T. E. Dowling, M. E. Douglas, W. L. Minckley, and P. C. Marsh. 1992. Origin of Gila seminuda (Teleostei: Cyprinidae) through introgressive hybridization: Implications for evolution and conservation. Proceedings of the National Academy of Sciences of the USA 89:2747-2751; Salzburger, W., S. Baric, and C. Sturmbauer. 2002. Speciation via introgressive hybridization in East African cichlids? Molecular Ecology 11:619; Smith, P. F., A. Konings, and I. Kornfield. 2003. Hybrid origin of a cichlid population in Lake Malawi: implications for genetic variation and species diversity. Molecular Ecology 12:2497-2504) and one mammalian example (Wayne, R. K., and S. M. Jenks. 1991. Mitochondrial DNA analysis implying extensive hybridization of the endangered red wolf Canis rufus. Nature 351:565-568). These studies provide morphological and genetic evidence that make a hybrid origin the most likely explanation for the origin of an extant species, but do not report empirical data on potential mechanisms of speciation. In all four cases the authors explicitly or implicitly state that allopatric speciation is the most likely mechanism by which these animal hybrid taxa became isolated.

In plants, the work by Rieseberg and coworkers provides the best-documented example for speciation by introgressive hybridization (Rieseberg, L. H., C. Van Fossen, and A. M. Desrochers. 1995. Hybrid speciation accompanied by genomic reorganization in wild sunflowers. Nature 375:313-316; Rieseberg, L. H., B. Sinervo, C. R. Linder, M. C. Ungerer, and D. M. Arias. 1996. Role of gene interactions in hybrid speciation: evidence from ancient and experimental hybrids. Science 272:741-745). These authors showed that certain species of sunflowers formed by hybridization between two parent taxa with the same chromosome number. By experimental studies Rieseberg et al. (1995 and 1996) showed that, although the hybrid taxa had the same chromosome number as their parents, they were distinguished by chromosomal reorganizations from the parent taxa that serve as a reproductive barrier. Rieseberg (1997) uses the term “homoploid” to distinguish examples like the hybrid sunflowers from “polyploid” hybrid species. Dowling and Secor (1997) propose a parallel term for animal hybrids that originated by introgressive hybridization. They term such taxa “diploid, bisexual hybrid species.”
Which are “Diploid, bisexual hybrid VARIETIES!.” So, here we have seen that such examples, no matter how frequently are chanted as examples of 'speciation', are just examples of variation within compatible organisms, as is the case for the cichlids and as is the case for the red wolf, already seen.

So, my dear student, once again "Don't be fooled by the evolutionary establishment and by its deceiving press releases"!


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