# Hybrid?



## Doritoinmontucky (Oct 18, 2011)

I was wondering if anyone has heard of cross breeding tortoises? If so what breeds and what would you call the outcome? I'm just curious if anyone had ever heard of this. I have never read a book that says anything about it. any info would be greatly appriciated. Thanks.

-Derrik


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## dmmj (Oct 18, 2011)

One of our members (N2torts) I believe has some sulcata and leopards crosses.


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## Tom (Oct 18, 2011)

Yes it happens. I don't think it should.


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## Doritoinmontucky (Oct 18, 2011)

Does it cause Defects that are not healthy for the hatchling tort?


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## Tom (Oct 18, 2011)

Not that we know of. It just dilutes/pollutes a finite gene pool.


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## Doritoinmontucky (Oct 18, 2011)

True, I didn't really think of it like that...


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## GBtortoises (Oct 19, 2011)

"Yes it happens. I don't think it should."---_Ditto_

"It just dilutes/pollutes a finite gene pool."---_Ditto again_


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## N2TORTS (Oct 19, 2011)

Wonder what the human gene pool would be if "stuck" to our "own breed" ? ........

EX: French , English , German .....and Race ...... Not so pure eh ?


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## Yvonne G (Oct 19, 2011)

N2TORTS said:


> Wonder what the human gene pool would be if "stuck" to our "own breed" ? ........
> 
> EX: French , English , German .....and Race ...... Not so pure eh ?



Not the same thing. We're all human species. Tortoises don't come in "breeds," and are different species.


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## GBtortoises (Oct 19, 2011)

Humans did stick with their own breed last I knew.


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## Madkins007 (Oct 19, 2011)

Many species of animals naturally crossbreed under certain conditions- similar enough species that they can confuse courtship signals, close proximity, usually a fringe area so fewer choices in their own species, often some other sorts of pressure to sort of force them together- like loss of habitat.

I am not aware of any examples of this in wild tortoises, although there is some evidence in the DNA that it happens with Red- and Yellow-foots. It could happen in other areas, I just don't know about it.

Captivity often simulates the above conditions, and some keepers try to cross-breed. The result is generally referred to as a cross and the species name is written with both names and an 'x', as in _Chelonoidis carbonara x denticulata_

My personal opinion about crossbreeding is that if we had a big gene pool to play with, a rock-solid knowledge of breeding and incubation needs, and had a breeding plan to improve the hobby (smaller, hardier, etc.), it would not bother me, but I personally am really troubled by 'cosmetic' cross-breeding and by casual cross-breeding- but again, this is just my opinion.


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## Doritoinmontucky (Oct 19, 2011)

Thanks for the opinions!


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## GBtortoises (Oct 19, 2011)

There are examples of cross breeding having taken place in the wild between _Testudo marginata_ and _Testudo ibera_ although extremely limited. It has also always been accepted that _Testudo hermanni_ and _Testudo horsfieldi_ can successfully breed in captivity although I've never seen resulting offspring.

"My personal opinion about crossbreeding is that if we had a big gene pool to play with, a rock-solid knowledge of breeding and incubation needs, and had a breeding plan to improve the hobby (smaller, hardier, etc.), it would not bother me, but I personally am really troubled by 'cosmetic' cross-breeding and by casual cross-breeding- but again, this is just my opinion." 

Mark, if you don't mind I'd like to "borrow" your opinion! I could not have said it better.


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## Doritoinmontucky (Oct 19, 2011)

Having two different backgrounds may have effects on behavior as well. A tort with two backgrounds might feel confused...out of place. Lol I wouldn't like that...


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## N2TORTS (Oct 19, 2011)

emysemys said:


> N2TORTS said:
> 
> 
> > Wonder what the human gene pool would be if "stuck" to our "own breed" ? ........
> ...



Yvonne....actually ~ A species is often defined as a group of individuals that actually or potentially interbreed in nature. In this sense, a species is the biggest gene pool possible under natural conditions.That definition of a species might seem cut and dried, but it is notâ€”in nature, there are lots of places where it is difficult to apply this definition.Also, many plants, and some animals, form hybrids in nature. Hooded crows and carrion crows look different, and largely mate within their own groupsâ€”but in some areas, they hybridize. Should they be considered the same species or separate species?There are lots of other places where the boundary of a species is blurred. Itâ€™s not so surprising that these blurry places existâ€”after all, the idea of a species is something that *we humans invented for our own convenience!*

Heterosis ( hybrid vigor ) is a scientifically proven reality that minimizes the likely hood of genetic disease and boosts over all health, vigor, even size. A magnification of the gains had by incorporating divergent lines within breed. That said, it is no magic bullet. Crossing breed lines wonâ€™t make two dumb dogs smart, nor two cowardly dogs brave. Garbage in will get you garbage out; albeit healthier, possibly more soundâ€¦garbage. 

As far as breeds are concerned ....
A breed can be defined as "a homogeneous grouping of animals within a species, developed by humans, a line of descendants perpetuating particular hereditary qualities." 

JD~






Madkins007 said:


> Many species of animals naturally crossbreed under certain conditions- similar enough species that they can confuse courtship signals, close proximity, usually a fringe area so fewer choices in their own species, often some other sorts of pressure to sort of force them together- like loss of habitat.
> 
> I am not aware of any examples of this in wild tortoises, although there is some evidence in the DNA that it happens with Red- and Yellow-foots. It could happen in other areas, I just don't know about it.
> 
> ...



Very well said Mark ! 

~


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## GeoTerraTestudo (Oct 19, 2011)

N2TORTS said:


> Yvonne....actually ~ A species is often defined as a group of individuals that actually or potentially interbreed in nature. In this sense, a species is the biggest gene pool possible under natural conditions.That definition of a species might seem cut and dried, but it is notâ€”in nature, there are lots of places where it is difficult to apply this definition.Also, many plants, and some animals, form hybrids in nature. Hooded crows and carrion crows look different, and largely mate within their own groupsâ€”but in some areas, they hybridize. Should they be considered the same species or separate species?There are lots of other places where the boundary of a species is blurred. Itâ€™s not so surprising that these blurry places existâ€”after all, the idea of a species is something that *we humans invented for our own convenience!*
> 
> Heterosis ( hybrid vigor ) is a scientifically proven reality that minimizes the likely hood of genetic disease and boosts over all health, vigor, even size. A magnification of the gains had by incorporating divergent lines within breed. That said, it is no magic bullet. Crossing breed lines wonâ€™t make two dumb dogs smart, nor two cowardly dogs brave. Garbage in will get you garbage out; albeit healthier, possibly more soundâ€¦garbage.
> 
> ...



Some inaccurate statements there (and btw, no need to shout).

Although it is true that the concept of a species is artificial, it does reflect a reality. As was stated above, tortoises do not come in breeds, only species, subspecies, and regional variants. Breeds are varieties that have undergone artificial selection (human-induced evolution) from a single-species origin, often a single subspecies or race. Natural selection, on the other hand, can occur over longer periods, and can ultimately result in bigger genetic differences (although not necessarily bigger morphological differences).

Some closely related species or subspecies of turtles can hybridize in nature (e.g. box turtle subspecies; leopard tortoise subspecies; occasionally Russian and Hermann tortoises). These may occur in natural zones of intergradation, or may be more rare occurrences, depending on how closely related they are and where they're located.

Bottom line, if two animals are closely related enough, they may readily hybridize and have healthy offspring. In captivity, though, a lot of animals may be lacking for mates, and so might mate with a partner with whom they would not choose in nature. This is a problem because:

- The offspring may be unhealthy, or have partially or completely reduced fertility.
- Even if healthy, the animal may not be as well-adapted to the environments from which each parent species originated.

If you view pets as merely pets, then as long as the animal is healthy, you might not consider this to be a problem. However, if you view captivity as a kind of "Noah's Ark" for animals that may be threatened in their natural habitat, then you would not want to hybridize them, because that can negatively impact their survivability in the event that they are to be rewilded.

Humans interbreed all the time because we are all members of the same subspecies (_Homo sapiens sapiens_), with only clinal (regional) differences. Different box turtle subspecies are known to hybridize in zones of intergradation, as are leopard tortoises. Dogs can mate between breeds because they are all members of the same species, their breeds having diverged quite recently in history.

But different naturally occurring species have been reproductively isolated from each other for hundreds of thousands to millions of years. Leopard tortoises are not very closely related to sulcata tortoises, and yet people have been hybridizing them in captivity. I disapprove of this practice, because it artificially yields animals that are intermediate between their parents, and therefore lack their adaptations. In my opinion, this should not be done. Hybridization between closely related subspecies or races may be acceptable under some circumstances, but in general we should try to maintain close to the kind of genetic diversity that animals would be encountering in nature. Shrinking it may result in inbreeding depression, and enlarging it may result in infertility. Best to try to follow Mother Nature's lead in most cases.


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## dmmj (Oct 19, 2011)

don't most hybrids end up sterile? what is it that a horse and donkey make, mules? aren't they sterile?
I would be interested to know if the leocattas will end up sterile.


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## fbsmith3 (Oct 19, 2011)

Well, scientists have said:
-a hybrid between a human and a Chimpanzee can produce fertile offspring.
-While a hybrid between a human and a gorilla will most likely not produce fertile offspring.

Either way itâ€™s a very cool concept, I still would NOT want to marry a chimp or a gorilla. Just because something can be done or is interesting does not mean it should be done.


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## GeoTerraTestudo (Oct 19, 2011)

dmmj said:


> don't most hybrids end up sterile? what is it that a horse and donkey make, mules? aren't they sterile?
> I would be interested to know if the leocattas will end up sterile.



I wouldn't be surprised if "leocatas" (they have a name?) are sterile, but I don't know.

A lot of hybrids do have partially or completely reduced fertility, yes. This results when the parent species have a different number of chromosomes. Horses (_Equus ferus caballus_) have 64 chromosomes and donkeys (_Equus africanus asinus_) have 62. The resulting offspring (a mule or a hinny) has 63 chromosomes. This causes problems during meiosis, or the special type of cell division that produces sperm and egg cells.

Interestingly, Przewalski's wild horse (_E. ferus przewalskii_) has 66 chromosomes, but they not only form fertile hybrids with domestic horses, they are also considered to be merely a different subspecies within the same species! This is because they have undergone a Robertsonian translocation in the relatively recent past, which split up two of their chromosomes into four. However, this did not change the genetic information very much, so the divergence was slight.

Some hybrids have reduced fertility, even with the same number of chromosomes. Wolves/dogs (_Canis lupus_) can hybridize with coyotes (_C. latrans_) and golden jackals (_C. aureus_), but the offspring usually experience an incomplete reduction in fertility, even though all these canines have 78 chromosomes. This is probably due to a mismatch in where the genes are physically located on the chromosomes.

Lions (_Panthera leo_) and tigers (_P. tigris_) can famously form a sterile hybrid called a liger or tigon. Although handsome, these animals usually have poor health. The media doesn't report on it, but they usually die young, too. They also have unpredictable behavior, probably due to the social behavior of lions and the solitary behavior of tigers. 

Bringing it back to turtles, I wouldn't want to subject a tortoise to the kinds of problems that hybrids in other animal groups face. From infertility to cardiovascular disease to confused behaviors, I don't think hybrids from distantly related species have a particularly high quality of life. Like I said, best to perpetuate healthy animals that come from the same source population, or if inbreeding depression is evident, outcross with another population from the same species, or maybe another subspecies at the furthest. But not another species. That would likely be problematic.


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## dmmj (Oct 19, 2011)

Personally I prefer liger


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## GeoTerraTestudo (Oct 19, 2011)

dmmj said:


> Personally I prefer liger



Well, they do have magical powers. 

Actually, the convention on hybrid nomenclature states that the first half of the portmanteau name comes from the father's species, while the second half from the mother's. So, if the dad is the lion and the mother the tiger, the offspring is a liger. If it's the other way around, the offspring is a tigon.


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## N2TORTS (Oct 19, 2011)

Some inaccurate statements there (and btw, no need to shout)
Who's shouting ? 

Inaccurate?....
"But different naturally occurring species have been reproductively isolated from each other for hundreds of thousands to millions of years. Leopard tortoises are not very closely related to sulcata tortoises...." 
There not ? Do you have proof of that ? Although living on the same Continent for those millions of year? Iam not here to get into a " ***** match " on the net . I didnt hatch these but very proud to own them , and maybe shed some light in years to come . Like I mentioned " WE" created the names for the species in a few years , while evolution has been going on for millions with out a " specific name " 

Best to try to follow Mother Nature's lead in most cases.= I agree 
" Its Not Nice To Fool Mother Nature" 








dmmj said:


> Personally I prefer liger



^5 ... me too!


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## GeoTerraTestudo (Oct 19, 2011)

N2TORTS said:


> Who's shouting ?



In netiquette, using all-caps or enlarged, bold-faced fonts often signifies shouting.



> Inaccurate?....
> "But different naturally occurring species have been reproductively isolated from each other for hundreds of thousands to millions of years. Leopard tortoises are not very closely related to sulcata tortoises...."
> There not ? Do you have proof of that ? Although living on the same Continent for those millions of year? Iam not here to get into a " **** match " on the net . I didnt hatch these but very proud to own them , and maybe shed some light in years to come . Like I mentioned " WE" created the names for the species in a few years , while evolution has been going on for millions with out a " specific name "



Yes, I do have proof of that. Please refer to the two attached articles: Le et al. (2006), and Fritz and Bininda-Emonds (2007). Although both of these tortoises are large grassland species, they are actually fairly distantly related. So much so, that the genus _Geochelone _has been revised. It turns out that, based on both mitochondrial and nuclear gene phylogenies, the closest relatives of the African sulcata tortoise are the Indian and Burmese star tortoises. The leopard tortoise, meanwhile, turns out to be more closely related to the three southern African _Psammobates_ species, but is distinct enough to have its own genus, _Stigmochelys_.

So, it turns out that sulcata and leopard tortoises are not very closely related at all, and yet people have taken to hybridizing them, presumably because they are both large, African grassland tortoises that do well in captivity. But this is not a good reason. If anything, the sulcata might hybridize more readily with star tortoises, since it is more closely related to them ... but of course, I am certainly not advocated that, either. Distinct tortoise species should be maintained and perpetuated as such, in order to avoid problems in the interspecific (and even intergeneric) hybrid generation.


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## Kristina (Oct 19, 2011)

I am also against hybridization, but I have to admit, a high-domed, Sulcata sized tortoise with star markings would be incomparably freaking cool.


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## N2TORTS (Oct 19, 2011)

GeoTerraTestudo said:


> N2TORTS said:
> 
> 
> > Who's shouting ?
> ...





Despite previous research, phylogenetic relationships
within the family Testudinidae have remained controversial
(Caccone et al., 1999a; Crumly, 1982, 1984a; Gerlach,
2001, 2004; Meylan and Sterrer, 2000; Parham et al.,
2006). One of the perceived problems, voiced by several
authors, concerns the high level of morphological
convergences suspected for some traditionally used characters (AuVenberg, 1974; Bramble, 1971; Pritchard,
1994). In addition, all testudinid molecular studies to
date have been limited in terms of taxonomic sampling
because they addressed speciWc questions of relationship
within smaller subsets of the family (with the possible
exception of Cunninghamâ€™s (2002) study, but this has not
yet become available). These studies included relationships
within the genus Gopherus (Lamb and Lydeard,
1994), origin and relationships of Malagasy tortoises
(Caccone et al., 1999a), origin of GalÃ¡pagos tortoises
(Caccone et al., 1999b), origin of Indian Ocean tortoises
(Austin and Arnold, 2001; Austin et al., 2003; Palkovacs
et al., 2003), relationships within the genus Indotestudo
(Iverson et al., 2001), and relationships within the genus
Testudo (Fritz et al., 2005; Parham et al., 2006; van der
Kuyl et al., 2002).

Come on now ........


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## GeoTerraTestudo (Oct 19, 2011)

Kristina said:


> I am also against hybridization, but I have to admit, a high-domed, Sulcata sized tortoise with star markings would be incomparably freaking cool.



Might be neat-looking, but we still shouldn't breed them. BTW - I'm also opposed to the hybrid "parrot cichlid" fish and other such artificial crosses.






N2TORTS said:


> Despite previous research, phylogenetic relationships within the family Testudinidae have remained controversial (Caccone et al., 1999a; Crumly, 1982, 1984a; Gerlach, 2001, 2004; Meylan and Sterrer, 2000; Parham et al., 2006). One of the perceived problems, voiced by several authors, concerns the high level of morphological convergences suspected for some traditionally used characters (AuVenberg, 1974; Bramble, 1971; Pritchard, 1994). In addition, all testudinid molecular studies to date have been limited in terms of taxonomic sampling because they addressed speciWc questions of relationship within smaller subsets of the family (with the possible exception of Cunninghamâ€™s (2002) study, but this has not yet become available). These studies included relationships within the genus Gopherus (Lamb and Lydeard, 1994), origin and relationships of Malagasy tortoises (Caccone et al., 1999a), origin of GalÃ¡pagos tortoises (Caccone et al., 1999b), origin of Indian Ocean tortoises (Austin and Arnold, 2001; Austin et al., 2003; Palkovacs et al., 2003), relationships within the genus Indotestudo (Iverson et al., 2001), and relationships within the genus Testudo (Fritz et al., 2005; Parham et al., 2006; van der Kuyl et al., 2002).
> 
> Come on now ........



Hey, you wanted proof. 

Even if they were sister species, I still wouldn't want to hybridize them. Hermanns and Russians are closely related, and I don't think we should hybridize them, either.


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## Kristina (Oct 19, 2011)

GeoTerraTestudo said:


> Kristina said:
> 
> 
> > I am also against hybridization, but I have to admit, a high-domed, Sulcata sized tortoise with star markings would be incomparably freaking cool.
> ...



I am absolutely on the same page - although I did once own an adorable miniature mule


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## ALDABRAMAN (Oct 19, 2011)

N2TORTS said:


> emysemys said:
> 
> 
> > N2TORTS said:
> ...





...


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## Weda737 (Oct 19, 2011)

I know it's not really that relevant, and I'm not supporting either argument. Just an interesting note though, that corn snakes (red rat snakes) and black rat snakes hybridize naturally around here. I've even seen a few myself that I suspect are hybrids. Just thought it was neat.


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## Doritoinmontucky (Oct 19, 2011)

WOW! I got alot more info about this than I thought i would. Thanks everyone, realy interesting stuff. I think i learned more in the last few minutes than i have in a while. And just an opinion the parrot cichled is derived from the Red Devil cichled and a Gold Ceverum, yet a parrot reflects niether. They are confused fish(dont know weather to kill or Flee i think.lol). Like was said two spices of tort would probably rear a really psycologicaly tormented animal.

-Derrik


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## N2TORTS (Oct 20, 2011)

Weda737 said:


> I know it's not really that relevant, and I'm not supporting either argument. Just an interesting note though, that corn snakes (red rat snakes) and black rat snakes hybridize naturally around here. I've even seen a few myself that I suspect are hybrids. Just thought it was neat.



Very relevant....and EXACTLY correct...... funny how people think this wouldnt included tortoises living in the same area ....


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## GeoTerraTestudo (Oct 20, 2011)

N2TORTS said:


> Weda737 said:
> 
> 
> > I know it's not really that relevant, and I'm not supporting either argument. Just an interesting note though, that corn snakes (red rat snakes) and black rat snakes hybridize naturally around here. I've even seen a few myself that I suspect are hybrids. Just thought it was neat.
> ...



Yes, it is very relevant. The corn snake (_Pantherophis guttatus_) comes in two subspecies: _P. guttatus guttatus_ and _P. guttatus emoryi_. These are known to hybridize along a zone of intergradation (the way different subspecies of box turtle do).

This, however, is very different from the situation with the sulcata and leopard tortoises. Not only are these two species now thought to belong in different genera, but they also do not come into contact in nature. Both species are African, but sulcatas are from the Sahel just south of the Sahara, while leopard tortoises come from the savannas of eastern and southern Africa. In the wild, these two species would never meet.


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## Madkins007 (Oct 20, 2011)

Weda737 said:


> I know it's not really that relevant, and I'm not supporting either argument. Just an interesting note though, that corn snakes (red rat snakes) and black rat snakes hybridize naturally around here. I've even seen a few myself that I suspect are hybrids. Just thought it was neat.



As I said, where you have two similar-enough species 'forced together' in some way, you are more likely to see natural crossbreeds. Here around Omaha, a lot of Eastern and Western species and subspecies overlap, and we see quite a bit of this as well. I'm not a frog person, but I understand that our cross-bred subspecies of Leopard frogs is semi-famous, sort of like the black phase fox squirrels we have.



GeoTerraTestudo said:


> N2TORTS said:
> 
> 
> > Weda737 said:
> ...



To use some different tortoises as an example...

Red- and Yellow-foot tortoises share some habitat, experience pressures that isolate and concentrate them, and the Red-foot has a rather weak courtship/mating signal. There is DNA evidence of interbreeding... although not much visible evidence- but that may be due to the resulting tortoise looking like a Red-foot. These two share a very common DNA and are thought to only have split apart a few million years ago.

On the other hand, Red-foots and Chacos overlap in the Gran Chaco region- often found very close to each other, experiencing pressures, etc.- but there is no evidence I am aware of that they crossbreed. Different DNA, different mating rituals, different appearances. 



N2TORTS said:


> [
> 
> Yvonne....actually ~ A species is often defined as a group of individuals that actually or potentially interbreed in nature. In this sense, a species is the biggest gene pool possible under natural conditions.That definition of a species might seem cut and dried, but it is notâ€”in nature, there are lots of places where it is difficult to apply this definition.Also, many plants, and some animals, form hybrids in nature. Hooded crows and carrion crows look different, and largely mate within their own groupsâ€”but in some areas, they hybridize. Should they be considered the same species or separate species?There are lots of other places where the boundary of a species is blurred. Itâ€™s not so surprising that these blurry places existâ€”after all, the idea of a species is something that *we humans invented for our own convenience!*



Species and taxonomy in general is our attempt to codify what we observe happening in nature. We made up the words, but the rules are based on what we see and can measure. We are not perfect at it, but we are working towards a better understanding. 

The examples mentioned are perfect examples of how we can see that there is some rule being followed there. We just are not sure how it fits in with the other rules.

In some ways, the science of taxonomy is like a person watching an unfamiliar game or sporting event in another language. We can see the evidence of the rules going on, but trying to tease out all of the nuances and 'reverse engineer' the rules is tough.


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## Doritoinmontucky (Oct 22, 2011)

Wow thanks everyone, this has been great. I almost wonder if it should have gone into debatible topics tho...


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## dmmj (Oct 22, 2011)

So the 2 african species never come into contact, I wonder if in a natural setting would they mate? or did they only mate because they were in the same enclosure to produce the leocattas?


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## Doritoinmontucky (Oct 22, 2011)

Hmm, if one or the other managed to cross the sahara, and it was breeding season they might.


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## Raymo2477 (Oct 26, 2011)

Well there not tortoises...but I know of natural hybrids in box turtles with ornate/desert, ornate/eastern, ornate/three toed etc. They only happen where species overlap also where I live there are natural hybrids of the eastern and midland painted turtles.

I know it's not scientific but I really see these more as morphs of the same species instead of distinct subspecies.


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## Neltharion (Oct 26, 2011)

Madkins007 said:


> Species and taxonomy in general is our attempt to codify what we observe happening in nature. We made up the words, but the rules are based on what we see and can measure. We are not perfect at it, but we are working towards a better understanding.
> 
> The examples mentioned are perfect examples of how we can see that there is some rule being followed there. We just are not sure how it fits in with the other rules.
> 
> In some ways, the science of taxonomy is like a person watching an unfamiliar game or sporting event in another language. We can see the evidence of the rules going on, but trying to tease out all of the nuances and 'reverse engineer' the rules is tough.



I like this explanation.


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## GeoTerraTestudo (Oct 26, 2011)

Raymo2477 said:


> Well there not tortoises...but I know of natural hybrids in box turtles with ornate/desert, ornate/eastern, ornate/three toed etc. They only happen where species overlap also where I live there are natural hybrids of the eastern and midland painted turtles.
> 
> I know it's not scientific but I really see these more as morphs of the same species instead of distinct subspecies.



Yes, these animals are closely related to each other. Much more so than sulcatas and leopard tortoises.

What about _Testudo_ hybrids? I know Russians and Hermanns have been known to hybridize in captivity, and indeed they do form a clade within the genus _Testudo_. Have Greeks ever been known to hybridize with Egyptians or marginated tortoises? Or indeed, despite being a little more distantly related, has anyone ever heard of Greeks hybridizing with Hermanns or Russians?


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## N2TORTS (Oct 26, 2011)

This may have some info ...
- Tortoise Protection Group 
Hermanns tortoise/Herman's tortoise: ... Hybrid: The progeny from a breeding between two species which are not of the same genus i.e. offspring that is a cross ...
www.tortoise-protection-group.org.uk/site/98.asp 


Thought this was interesting too............

GC News: February 3, 2010 
Team of Veterinarians Prepare Hybrid Tortoises for Release on Pinta Island in 2010 
In November 2009, a group of veterinarians, working with the Galapagos National Park (GNP), prepared 39 hybrid tortoises slated to be the pioneer group to initiate the return of tortoises to Pinta Island. Project Pinta is a multi-year project aimed at the restoration of the island following the successful eradication of goats on Pinta in 2003. While complete island restoration will require the eventual repopulation of Pinta with a reproductive tortoise population, scientists and managers are awaiting the final results from genetic analyses of a massive sampling of tortoises before making the final selection of which tortoises to use. To initiate the return of tortoises, critical ecosystem engineers during this important period of vegetative recovery, a special group of tortoises will be released onto Pinta. To ensure that this group of hybrid tortoises will not compromise any future efforts to reestablish a reproductive population, veterinarians sterilized them.


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## GeoTerraTestudo (Oct 26, 2011)

N2TORTS said:


> GC News: February 3, 2010
> Team of Veterinarians Prepare Hybrid Tortoises for Release on Pinta Island in 2010
> In November 2009, a group of veterinarians, working with the Galapagos National Park (GNP), prepared 39 hybrid tortoises slated to be the pioneer group to initiate the return of tortoises to Pinta Island. Project Pinta is a multi-year project aimed at the restoration of the island following the successful eradication of goats on Pinta in 2003. While complete island restoration will require the eventual repopulation of Pinta with a reproductive tortoise population, scientists and managers are awaiting the final results from genetic analyses of a massive sampling of tortoises before making the final selection of which tortoises to use. To initiate the return of tortoises, critical ecosystem engineers during this important period of vegetative recovery, a special group of tortoises will be released onto Pinta. To ensure that this group of hybrid tortoises will not compromise any future efforts to reestablish a reproductive population, veterinarians sterilized them.



Yes, because humans have decimated island tortoise populations on both the Galapagos Archipelago and the Seychelles Archipelago (which includes Aldabra), restoration efforts often involve using tortoises from nearby islands when the native population/subspecies is extinct. This is similar to other restoration projects, like the one that reintroduce peregrine falcons to the Great Plains after DDT, using falcons from other locations. When the native animals are gone, the next best thing is to use the next closest relative as a replacement.

Notice, however, that the veterinarians sterilized the tortoises in the project mentioned above, so as not to compromise any future restoration efforts.

There is talk of doing similar Pleistocene Rewilding in parts of the US and Europe using modern relatives of extinct mammals (bolson tortoises, horses, camels, llamas, elephants, cheetahs, and lions). This is controversial, but again, the justification is that since the ecosystems are disturbed due to human activity, it is justifiable to use closely related proxies when the native animals are extinct. Interesting topic, and one that I am involved in, but we can save discussions on reintroducing bolson tortoises, horses, and cheetahs for a Debatable Topics thread some other time.


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## dmmj (Oct 26, 2011)

Why would they sterilize them?


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## GeoTerraTestudo (Oct 26, 2011)

dmmj said:


> Why would they sterilize them?



So they don't hybridize with full-blooded tortoises native to that island. There are some differences in these closely related tortoises from one island to another, like shell shape that effects whether they graze or browse. These restorationists have eradicated goats, which is a good first step, and are now introducing hybrid Galapagos tortoises to restore the native plant-animal cycles on the island. However, because they plan on eventually reintroducing full-blooded animals later on, they don't want these hybrids to breed with them.

Not sure I entirely agree with this approach, but if they have enough animals to work with, then it does make sense.

This is why hybrid animals cannot be used for rewilding. They lack the adaptations of their parents, so except for last-ditch efforts, they do not qualify as stock for reintroduction. This is actually the problem with bison restoration today in America. Most bison have some cattle introgression, or genes in them from cattle due to hybridization projects in the past. These animals are ineligible for introduction into national preserves or parks, like Yellowstone, which have only completely native, pure-blooded bison. Again, might be a bit too cautious in some cases, but overall a good management policy for wildlife conservation.


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## Neltharion (Oct 26, 2011)

dmmj said:


> Why would they sterilize them?



To ensure that they don't reproduce. It appears that this group of hybrids are guinea pigs to see if the island will sustain a tortoise population. Once its been established that it will, a legitimate species will be placed on there. It would appear that this hybrids are deemed to be expendable.


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## N2TORTS (Oct 26, 2011)

Why would they have to sterilize Hybrids if " they are mules" as some folks think ?


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## GeoTerraTestudo (Oct 26, 2011)

N2TORTS said:


> Why would they have to sterilize Hybrids if " they are mules" as some folks think ?



Well, remember, Galapagos tortoises are all very closely related to each other ... at the subspecies level, like different types of box turtles. Again, this is a far cry from the relationship between sulcatas and leopard tortoises, which are at least in different species, if not in different genera. Time will tell, but I would be surprised if a "lepracutta" turns out to be fertile. Galapagos tortoise hybrids may be thought of as merely mutts; it's the kinds of hybrids you find in the pet trade that may be likened to mules.


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## N2TORTS (Oct 26, 2011)

GeoTerraTestudo said:


> N2TORTS said:
> 
> 
> > Why would they have to sterilize Hybrids if " they are mules" as some folks think ?
> ...



"Well, remember, Galapagos tortoises are all very closely related to each other ... at the subspecies level, like different types of box turtles. Again, this is a far cry from the relationship between sulcatas and leopard tortoises, which are at least in different species, if not in different genera."

Even though being from the same Continent for 1,000's of years?




GeoTerraTestudo said:


> "Time will tell, but I would be surprised if a "lepracutta" turns out to be fertile."
> 
> Like Mentioned before I dont have really interest if they will be . Iam more interested in absorbing info , and seeing it " first hand" , plus the fact it was possible . If they are so distant from one another I doubt any of the eggs would have been fertile at all ...no? If there are no boundaries within a genetic link then we should be able to cross a Leo with a radi' , Or an yellow foot and a Russian right?
> Sullies and Leos are both Old World tortoise's that have evolved from at least one species , before the " so called boundry line" split ?


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## cdmay (Oct 27, 2011)

N2TORTS said:


> Why would they have to sterilize Hybrids if " they are mules" as some folks think ?



As GeoTerraTestudo (GTT) has explained, the issue isn't as simple as 'some folks think'. Not all mixed breedings result in sterile offspring-- and that is the problem. The point isn't at all whether or not two distinct populations might produce fertile offspring if crossed together. Heck, captive breeders have forced all kinds of unnatural crosses that have resulted in fertile offspring. So what? All that means is that the old, 'hybrids are all sterile' belief was wrong. The real issue is that unique and distinctive populations will become polluted as a result all of this crossbreeding, hybridizing or whatever you call it.
Added to this threat is the undeniable track record of reptile breeders in general who, in just a couple of decades, have completely ruined most of the captive populations of Boa constrictors, corn snakes, kingsnakes and so many other reptiles that they 'work with'. Just try and find a captive produced Boa constrictor or corn snake that doesn't possess numerous mutations or genes from multiple unique wild populations in its DNA. It's nearly impossible because of all the mixed breeding and wanton crossing just to spread albino and other mutant genes...all for the sake of making a quick buck. Now all of these captive animals are genetically tainted thanks to those numbskulls. 
The Galapagos tortoises that are of mixed heritage that are being released onto Pinta Island by the CDRC have been sterilized for good reason. Those people know what they are doing and realize that the tortoise populations have been screwed up enough. Incidentally, the tortoises are being released on Pinta because the lack of the island's large but slow moving herbivore--the extinct Pinta tortoise-- has disrupted the native plant systems. It is hoped that the released 'mutts' will at least serve some useful purpose by restoring that balance.


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## N2TORTS (Oct 27, 2011)

I was waiting for you to pip in ....
excellent info Carl~
"As GeoTerraTestudo (GTT) has explained, the issue isn't as simple as 'some folks think'. Not all mixed breedings result in sterile offspring"..... 
Coming from YOU and GTT theres proof right there about alot of assumptions and misbeliefs that hybrids are mules right ?


Also isn't it true that ......Sullies and Leos are both Old World tortoise's that have evolved from at least one species , before the " so called boundry line" split.... correct?


I find these threads interesting and peoples views about genetics and the " naming of species" of animals we discover in current times.
Thanks for the opinion.

JD


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## cdmay (Oct 27, 2011)

I was waiting for you to pip in ....
excellent info Carl~
"As GeoTerraTestudo (GTT) has explained, the issue isn't as simple as 'some folks think'. Not all mixed breedings result in sterile offspring"..... 
_Coming from YOU and GTT theres proof right there about alot of assumptions and misbeliefs that hybrids are mules right ?_

Hybrids of higher animals (the example of lions crossed with tigers and then actual mules has already been discussed) usually are sterile. 
Reptiles and other 'lower' life forms are different. So very often hybrid reptiles are not sterile. But that doesn't in any way mean that is is OK to start producing hybrids. If anything, it makes the intentional production of hybrids even more irresponsible and reckless.

_Also isn't it true that ......Sullies and Leos are both Old World tortoise's that have evolved from at least one species , before the " so called boundry line" split.... correct?_

They may have come from a common ancestor but so what? That was eons ago and now they are clearly very different animals. Why muddy the limited genetic waters by using the common ancestor excuse? A hybrid tortoise can live a very long time and may pass from one owner to several others over its lifetime. Who is going to insure that it won't be bred by someone who doesn't realize it is a hybrid? 
Can you see the potential problems? That is why the CDRC took the drastic measure of sterilizing those mixed Galapagos animals--they knew the risk was too great to allow populations that are already in grave danger to become genetically crossed up.

_I find these threads interesting and peoples views about genetics and the " naming of species" of animals we discover in current times.
Thanks for the opinion._

You make a good point when you imply that the 'naming of species' is a recent event. I agree in that the whole taxonomy issue can be a mess and needs work. But I would still counter that taking animals that do not intergrade in nature, (or that live sympatrically without interbreeding) and intentionally creating hybrids from them is largely foolish and irresponsible.


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## GeoTerraTestudo (Oct 27, 2011)

N2TORTS said:


> GeoTerraTestudo said:
> 
> 
> > Well, remember, Galapagos tortoises are all very closely related to each other ... at the subspecies level, like different types of box turtles. Again, this is a far cry from the relationship between sulcatas and leopard tortoises, which are at least in different species, if not in different genera.
> ...



That's correct. Populations drift apart whenever there is some barrier to gene flow, and that could be a river, a forest, a mountain range, a strait, whatever. This is how the different types of Galapagos tortoises have evolved in different directions; each one has its own island, and no longer interbreeds with animals on other islands. Same thing for box turtles. A continent is a big place, and there are big latitudinal differences in climate. Eastern box turtles deal with different conditions than three-toed, Gulf coast, and Florida box turtles. Also, each box turtle has a home range of only an acre or two, so they do not travel very far in a lifetime. This means that over time, genetic differences will accumulate between populations, eventually resulting in subspecies. If the process continues for a longer period, and/or if there are big enough environmental differences, then you can even get speciation. This is why there are four different species of box turtle in North America (_Terrapene carolina_, _T. ornata_, _T. coahuila_, and _T. nelsoni_), and even more subspecies.






> Like Mentioned before I dont have really interest if they will be . Iam more interested in absorbing info , and seeing it " first hand" , plus the fact it was possible . If they are so distant from one another I doubt any of the eggs would have been fertile at all ...no? If there are no boundaries within a genetic link then we should be able to cross a Leo with a radi' , Or an yellow foot and a Russian right?
> Sullies and Leos are both Old World tortoise's that have evolved from at least one species , before the " so called boundry line" split ?



Well, the differences may be such that a mating can produce a hybrid that is viable, but not fertile. Again, mules are very healthy creatures, but they are almost always sterile. A little closer than that are wolf-coyote hybrids, which have reduced fertility, but are not completely sterile. Closer still are wolf-dog hybrids, which are completely fertile (as dogs are considered domestic wolves). Go farther out than mule distance, and you find animals that are not only sterile, but don't even survive: like hybrids of African and Asian elephants, for example, which die as babies. Any farther out than that, and the embryo doesn't even survive long enough to be born.

So, it is apparent that sulcatas and leopard tortoises are close enough to form viable hybrids, but that does not necessarily mean that they can form fertile hybrids.






cdmay said:


> They may have come from a common ancestor but so what? That was eons ago and now they are clearly very different animals. Why muddy the limited genetic waters by using the common ancestor excuse? A hybrid tortoise can live a very long time and may pass from one owner to several others over its lifetime. Who is going to insure that it won't be bred by someone who doesn't realize it is a hybrid? Can you see the potential problems? That is why the CDRC took the drastic measure of sterilizing those mixed Galapagos animals--they knew the risk was too great to allow populations that are already in grave danger to become genetically crossed up ...
> 
> You make a good point when you imply that the 'naming of species' is a recent event. I agree in that the whole taxonomy issue can be a mess and needs work. But I would still counter that taking animals that do not intergrade in nature, (or that live sympatrically without interbreeding) and intentionally creating hybrids from them is largely foolish and irresponsible.



Good posts. Do you think there is an ethical way to discourage reptile breeders from creating hybrids? I mean, on the one hand, the animals belong to them, and it would be paternalistic to tell them what to do with their own animals. On the other hand, as you've explained, they are damaging the gene pools of captive reptiles. So what can be done? Do you think people would think twice about making hybrids if they knew the consequences of those actions? Would educating people help them make informed choices? The choice would still be theirs, but maybe some of them would elect not to breed hybrids after all.


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## Neltharion (Oct 27, 2011)

N2TORTS said:


> I was waiting for you to pip in ....
> excellent info Carl~
> "As GeoTerraTestudo (GTT) has explained, the issue isn't as simple as 'some folks think'. Not all mixed breedings result in sterile offspring".....
> Coming from YOU and GTT theres proof right there about alot of assumptions and misbeliefs that hybrids are mules right ?



I wouldn't say that there are assumptions or misbeliefs. A better characterization would be to say that there are generally accepted truths to hybrids with rare existing exceptions. Most hybrids are sterile, that is true. On rare occasions, you will get hybrids that can reproduce. In the mule example, male mules are known to be sterile. On rare occasions females are fertile. Even among the parrot cichlids and flowerhorns, on rare occasions some of those hybrid fish are found to be fertile and capable of reproducing.



N2TORTS said:


> Also isn't it true that ......Sullies and Leos are both Old World tortoise's that have evolved from at least one species , before the " so called boundry line" split.... correct?



Keep in mind that Africa is a continent that expands across roughly 11,700,000 square miles. Where a sulcata's native range is the Sahara and the Sahel, and a Leo's range are the south eastern savannahs around Sudan down to the Cape. That's a huge gap that these tortoises have evolved across.

While you may consider then closely related because they evolved from a common ancestor. As a point of reference, we Homo sapiens and the common chimpanzee Pan troglodytes, have DNA that is 96 to 98% identical. Yet people would affirmatively say the differences are huge.




N2TORTS said:


> I find these threads interesting and peoples views about genetics and the " naming of species" of animals we discover in current times.
> Thanks for the opinion.



One thing is that Linnaeus started taxonomy and the naming of species back in 1735. Its been around and dare I say 'evolved' over close to 300 years. Certainly not anything done just in current times.



GeoTerraTestudo said:


> Good posts. Do you think there is an ethical way to discourage reptile breeders from creating hybrids? I mean, on the one hand, the animals belong to them, and it would be paternalistic to tell them what to do with their own animals. On the other hand, as you've explained, they are damaging the gene pools of captive reptiles. So what can be done? Do you think people would think twice about making hybrids if they knew the consequences of those actions? Would educating people help them make informed choices? The choice would still be theirs, but maybe some of them would elect not to breed hybrids after all.



At least among the fishkeeping communities, particularly those that keep African or Central/South American cichlids, they discourage people from cross breeding and buying hybrids. They tell keepers, if you must cross breed fish, keep them to yourself, not to sell them and not to give them away. 

I know for reptiles the situation is a little different. Since not everyone necessarily has the space to keep all of the offspring they produce. I seem to remember this topic came up in another thread too. 

As many of these less-developed countries encroach on the natural habitats for housing and other development, some cultures capture these reptiles for food, and poachers capture endangered species for the underground pet trade, there will come a point in time where the last existing populations of many of these animals will be in captivity. As hobbyists, I would argue that we have a responsibility to keep these bloodlines pure. Someday there may be breeding and release programs to try to re-establish some of these species back into the wild (I can think of the GalÃ¡pagos Pink Land Iguana as an example).


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## cdmay (Oct 27, 2011)

GeoTerraTestudo said:


> cdmay said:
> 
> 
> > They may have come from a common ancestor but so what? That was eons ago and now they are clearly very different animals. Why muddy the limited genetic waters by using the common ancestor excuse? A hybrid tortoise can live a very long time and may pass from one owner to several others over its lifetime. Who is going to insure that it won't be bred by someone who doesn't realize it is a hybrid? Can you see the potential problems? That is why the CDRC took the drastic measure of sterilizing those mixed Galapagos animals--they knew the risk was too great to allow populations that are already in grave danger to become genetically crossed up ...
> ...



Hybridizing, in of itself, is not necessarily the issue or the problem. The problem lies in what people do with those hybrids.
For example, N2TORTS has a hybrid tortoise that is a cross between a leopard tortoise and a sulcata-- OK fine. It is probably an interesting animal to maintain too and I can understand JD being excited about growing it up. So then the pressure is on JD to be a responsible keeper who maintains good records and steadfastly keeps that animal from reproducing for all of the reasons that have been mentioned above.
But suppose there are bunches of those hybrids floating around that get sold to irresponsible keepers who feel that it is within their rights to breed it to whatever they want? What about that first buffoon who hits on the grand idea of crossing a leopard tortoise with an 'ivory' or amelanistic sulcata just to eventually come up with ivory or albino leopard tortoises? Don't laugh--this is exactly how there are now all kinds of hybrid albino Boa constrictors that stemmed from a couple of Colombian animals that uneducated breeders then bred to Peruvian, Surinam, Guyana and every other distinct type of Boa constrictor. Now the entire captive gene pool of Boa constrictors consists mostly of mutts. 
What is the long term outcome for the tortoises...besides a colossally screwed up captive gene pool, I mean? As this is already the case with many captive hatched reptiles I sure do not have faith in the captive breeders.
Ideally, reptile breeders would have been like orchid breeders who maintain very, very detailed records of every registered cross between known orchid species. I think that the American Orchid Society (AOS) even has a database that can be accessed to see just what parentage is involved with each new hybrid. In addition, orchid growers have religiously maintained pure species and subspecies, as well as regional variants for many generations and so there is little danger of them becoming lost to future generations. Also, orchids can now be cloned through tissue culture which also aids is preserving pure species for the future.
Sadly, reptile keepers have demonstrated that very often ego and greed are the driving intrests when it comes to reptile husbandry and it all becomes about the $$.


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## dmmj (Oct 27, 2011)

Reptile keepers have egos? I am shocked.


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## N2TORTS (Oct 27, 2011)

Carl ...and GTT ... thanks for all the valuable info , and the time to share with everyone , including me. Once again I did not breed these myself ( not that it matters) , but simply a trade I made 2 years back for a fresh insight for myself with a breed/hybrid ( or whatever ya wanna call it ) that I have never worked with or owned. I have no intentions actually on breeding them at this point that would be years down the line anyhow, but along with all my torts, keeping very accurate records and watching visual changes as they develope. Thus far, I must say they are both really neat lil' torts with tons of personality , very active , healthy and happy. 
I myself enjoy the time spent with them too~
Also as long as the debates are civil I think they are an important part of learning from each other , as we all have had different educations/ life experiences and opinions that just adds to the " Great Book Of Knowledge" 
JD~


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## cdmay (Oct 27, 2011)

N2TORTS said:


> Carl ...and GTT ... thanks for all the valuable info , and the time to share with everyone , including me. Once again I did not breed these myself ( not that it matters) , but simply a trade I made 2 years back for a fresh insight for myself with a breed/hybrid ( or whatever ya wanna call it ) that I have never worked with or owned. I have no intentions actually on breeding them at this point that would be years down the line anyhow, but along with all my torts, keeping very accurate records and watching visual changes as they develope. Thus far, I must say they are both really neat lil' torts with tons of personality , very active , healthy and happy.
> I myself enjoy the time spent with them too~
> Also as long as the debates are civil I think they are an important part of learning from each other , as we all have had different educations/ life experiences and opinions that just adds to the " Great Book Of Knowledge"
> JD~



That is a neat looking animal that should become a very interesting adult... I would just hate to see a lot of them getting spread around.


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## wildak (Oct 28, 2011)

I can see benefits to cross breeding . Learning what species can cross and reproduce could save species in the very near future. 
If there's only a handfull of a type of tortoise you could then cross it to another species and after several generations and many years later have a whole new bloodline that's a 100% pure blood.
If you have one extremely rare male tortoise you could possibly breed it to an endless amount of females of another species. Like Lonesome George, they have been attempting to get him to breed to save his genes. If he breeds we could save his species.

Heck I heard talk of cloning a Mammoth from recently found viable dna in the ice. They would cross it with an African Elephant and after many generations could have a 100% pure Mammoth. Now that's some crazy #%@#. Though it is thought that mankind is the reason they went extinct. So should we do it to fix what we screwed up ?


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## GeoTerraTestudo (Oct 28, 2011)

wildak said:


> I can see benefits to cross breeding . Learning what species can cross and reproduce could save species in the very near future.
> If there's only a handfull of a type of tortoise you could then cross it to another species and after several generations and many years later have a whole new bloodline that's a 100% pure blood.
> If you have one extremely rare male tortoise you could possibly breed it to an endless amount of females of another species. Like Lonesome George, they have been attempting to get him to breed to save his genes. If he breeds we could save his species.
> 
> Heck I heard talk of cloning a Mammoth from recently found viable dna in the ice. They would cross it with an African Elephant and after many generations could have a 100% pure Mammoth. Now that's some crazy #%@#. Though it is thought that mankind is the reason they went extinct. So should we do it to fix what we screwed up ?



*Re: hybrids and conservation*
I think that, because Lonesome George is literally the last of his subspecies of Galapagos tortoise, we should allow him to hybridize with another Galapagos tortoise subspecies, provided that those progeny are treated as the new representatives of his kind, and not his mate's kind, meaning that they are not allowed to interbreed with other subspecies of Galapagos tortoises. It would be easier if the last of a race is female, since then the male from another subspecies would still be available for his own kind, but that is not the case. An inter-generic hybrid like a lepracutta would have to be a really desperate attempt at conservation, like if there were only one sulcata and one leopard tortoise left in the whole world (which is, thankfully, not at all the case). Other than such last ditch efforts as these, there's really no reason for it. And as I've said, it can actually interfere with conservation efforts because you can't release hybrids back into the wild, partly because they will created "genetic pollution" with existing full-blooded animals, and partly because they might not be as well adapted to the environment as either parent species.

*Re: cloning and rewilding*
I'm all for cloning mammoths (even though it's a long shot, at best) because, as you say, they probably went extinct due to over-hunting by humans in the first place. I am generally a proponent of the "you broke it, you bought it" approach to restoration. If animals have become endangered due to human activities, then it's up to us to help them. And if they have become extinct, then assuming we have the technology, we should try to bring them back. I am also a proponent of introducing closely related animals from other areas if and only if the native subspecies is extinct. Again, if we caused the damage, then we should try to repair it. Otherwise, not only is it none of our business, but it would actually be meddling for us to try to change things that came about independently of our actions.


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## wildak (Oct 28, 2011)

I totally understand where your coming from GEO and agree that hybrids must never be allowed back to the wild, in fact they should be put down first. 
That being said I think we should explore the idea of crossing extremely rare turtles and tortoises in order to see if the hybrids are sterile or not and to have future genetic lines. It would have to be done with conservation in mind and not pet trade. Possibly a hybrid microchip plan could help identify % of genetics in the case of human error.
I just think if we don't explore the idea until there's a natural or man made disaster certain species could be S.O.L. since some species are limited in captivity.
Food for thought.


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## Doritoinmontucky (Nov 1, 2011)

It is good for people to have a place to express there views without verbal abuse, or put downs. I believe that Hybrids should not be sought after, but the fact that spieces dieing out should raise some attention to the fact that we should have some more programs for there conservation. Methods of Hybriding could unlock questions that scientists have. But i bieleve it should be done in a controlled enviorment. 

-Derrik


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