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Posted by HerpNut on January 19, 2002 at 01:05:41:
In Reply to: Re: Exasperatum, or Horridum? posted by Marty on January 18, 2002 at 12:52:58:
The fallowing was copied and pasted from a herpetologist document.
Genetic analysis of Beaded Lizard
THE BIG PICTURE: While the Mexican beaded lizard's true status in the wild is unknown, this species is well represented in U.S. collections. Several Mexican institutions hold this animal as well. The American Association of Zoos and Aquariums (AZA) Lizard Advisory Group (LAG) wishes to manage these captive animals by grouping individuals from like localities, which would allow for greater genetic exchange between institutions while maintaining the genetic integrity of different populations. Towards this end a studbook was published in March, 1995.
Unfortunately, most captive beaded lizards are of unknown origin. Currently four subspecies are recognized but it is unclear whether they are all valid. The characters used to distinguish between the subspecies overlap considerably; therefore, they cannot be grouped by physical or morphological similarity. Thus, a more accurate method must be employed to determine subspecific identity.
To eliminate this taxonomic dilemma, genetic analysis of DNA from blood samples from a wide range of captive and wild beaded lizards from known localities is being performed. This will allow managers of this species to make better decisions about proper grouping of animals (based on genetic similarity) for future breeding. In this manner we may ensure the beaded lizard's future in captivity and help clarify its taxonomic status.
THE PROJECT: Approximately .1ml of blood from designated lizards is drawn and placed in vacuum containers filled with EDTA as a preservative. Subsequently the mitochondrial DNA and electrophoresis are performed in the laboratory. Once all samples are analyzed, taxonomic groups can be rearranged and recommendations for breeding these animals can be made.
WHO: Craig Ivanyi & Janice Perry, ASDM Department of Herpetology. Genetic studies are being conducted by Dr. Scott Davis, Texas A & M University.
WHEN: Ongoing since the summer of 1996.
WHERE: Texas A & M University.
FUNDING: Provided in part by the American Association of Zoos and Aquariums Lizard Advisory Group.
NOW REGARDING OUR PREVIOUS CONVERSATION
HerpNut: "When are you guys going to realize that A Sub-species is not about pattern or color???"
Marty: Except, that in many cases subspecies were and have been described based soley in those characters. You have to look no further than H.s.suspectum and H.s.cinctum for an example.
Yes, understand that Taxonomy is a branch Biological Science and like any science it is changing contineously
HerpNut: "A sub-species it is not a sub-species just because it looks different. Or because it inhabits a certain locale."
Marty: True, because subspecies will not follow the characters used to descibe it 100% of the time. Part of what makes then subspecies and not species.
>>>> Just exactly is a subspecie?
PRONUNCIATION: sbspshz, -sz
NOUN: Inflected forms: pl. subspecies
A taxonomic subdivision of a species consisting of an interbreeding, usually geographically isolated population of organisms.
HerpNut: "Do you guys think that a herpetologist did DNA test to descrive H. s. cintum???"
Marty: No, cause if he did, the distrubution of H.s.cinctum would likely be very diffrent.
>>>> "Distbution" As of Geogaphy Range...
>>>> As we know it H. s. suspectum is a decendent of H. s. cintum. True H. s. cintum is found north of the Geographycal Species Range. True H. s. suspectum is found south of the Geographical Species Range.
>>>> What we find in the middle is nothing more that H. suspectum ssp. They are not really H. suspectum suspectum nor H. suspectum cintum. Why? Because the Geographical Subspecies Range is contineous and the specie is in evolutionary change.
HerpNut: "What is the difference between Suspectum and Cintum??? Is it the bands??? Or, is it the spots???"
Marty: Or an artificially contrived convienence.
>>>> I could not agree with you more on this one.
Marty: Yes, please don't make it sound as if subspecies are cut and dry. If subspecies were so apparent, would there be as much taxonomic revision as there is?
>>>> There is a lot of Taxonomic Revision because many subspecies where described without throughly research. Understand that some animals were described long time ago. Some animals were descrived many times.
Just look at Heloderma species and subspecies...
Heloderma horridum ssp.
Common name: Beaded Lizard
Trachyderma horridum WIEGMANN 1829: 421
Heloderma horridum - WIEGMANN 1829
Heloderma hernandesii WIEGMANN 1834
Heloderma horridum - SUMICHRAST 1864: 497
Heloderma horridum - SMITH & TAYLOR 1950: 193
Heloderma horridum - WERMUTH 1963: 1
Heloderma horridum - STEBBINS 1985: 169
Heloderma horridum - LINER 1994
Heloderma horridum - KÍHLER 2000: 51
Heloderma horridum horridum
Heloderma horridum alvarezi
BOGERT & MARTIN DEL CAMPO 1956
Heloderma horridum exasperatum
BOGERT & MARTIN DEL CAMPO 1956
Heloderma horridum charlesbogerti
CAMPBELL & VANNINI 1988
Heloderma suspectum ssp.
Common name: Gila Monster
Heloderma suspectum COPE 1869: 5
Heloderma suspectum - SMITH & TAYLOR 1950: 193
Heloderma suspectum - WERMUTH 1963: 2
Heloderma suspectum - STEBBINS 1985: 169
Heloderma suspectum - LINER 1994
Heloderma s. cinctum Banded Gila Monster
BOGERT & MAR═N DEL CAMPO, 1956
Heloderma s. suspectum Reticulate Gila Monster