Tortoise, Hybrids, Genetics, and Such

[GGboy17]

Question 1: So, recently I saw a video of a Sulcata x Leopard tortoise hybrid. That made me wonder, that is the tortoise was relatively the same size as each other, and had similar husbandry could they mate, and have hybrid babies?

Question 2: Are all tortoises in the same Genus?

Question 2/3: If all tortoises are NOT in the same Genus can tortoises with different Genus mate and have hybrid babies?

P.S- Can somebody go into more detail about what a genus is. I have a somewhat hold of it, but still Don't completely get it. So, being fairly new to reptiles, and tortoises please keep the explaining relatively basic. THX!

 

[Markw84]

by classic definition, "species" is the highest grouping of animals that can successfully produce fertile offspring. And also by classic definition, "genus" groups animals as the level above species, and these animals can interbreed, but cannot produce fertile offspring. The best example is a mule. An interbreeding of two different species - the horse and donkey, both of the genus Equs but the offspring - the mule - is infertile.

Sulcatas and leopards until very recently were in the same Genus - Geochelone. As such, they could interbreed but not produce fertile offspring. Now they have split the leopard tortoises into a different genus - Stigmochelys. So, if that is correct, they should not be able to interbreed by classic definition. But don't tell them that!

Now the classification of genus is much more dictated by DNA and lineage as the chief criteria. They must show "monophyly and validity as a separate lineage".

In any case, it seems the offspring - they are calling leopracatas now - should not be fertile.

 

[Tom]

Question 1: So, recently I saw a video of a Sulcata x Leopard tortoise hybrid. That made me wonder, that is the tortoise was relatively the same size as each other, and had similar husbandry could they mate, and have hybrid babies?

Question 2: Are all tortoises in the same Genus?

Question 2/3: If all tortoises are NOT in the same Genus can tortoises with different Genus mate and have hybrid babies?

P.S- Can somebody go into more detail about what a genus is. I have a somewhat hold of it, but still Don't completely get it. So, being fairly new to reptiles, and tortoises please keep the explaining relatively basic. THX!

1. They can, but they shouldn't. Different species should not be housed together, much less allowed to breed.
2. No.
2/3. See number one.

More info:

 

[GGboy17]

Thanks Guys!!!

 

[Kapidolo Farms]

Within my life time the means to make determinations and what those determinations are have changed a great deal. As you look through various web sources to expand on this topic be sure to make the "American Museum of Natural History" top of the list. They are a major contributor to how these things change, and have IMO relatively easy to understand definitions and explanations.

http://www.amnh.org/shelf-life/episode-02-turtles-and-taxonomy as an example, almost Sesame Street simple, but still as up to date as it gets.

If you want heavy reading then I can offer some suggestions. Factors that go into 'relatedness' are genetics, morphology, and geography(paleo).

Chelonians have a good fossil record which also helps drive the determination in relatedness.

The two poles of perspective are that every individual is unique - to the idea, we all (all known life) share only four proteins that determine what we grow to be. The idea of species and genus make it so we can talk about units of animals that are related and common to each other, and unique and uncommon to other units/groups. Groups themselves have different levels of relatedness. "Species" an artifact of science required so studies can be made that characterize "like individuals".

The one thing we all share is uniqueness. Mull that over a bit.

 

[Alaskamike]

Great question. One would think simple explanations would flow from labels & definitions - but the more we study the more we learn in genetics & " relatedness"

At one time I did a fair amount of research into evolutionary biology ( till I changed my major to psychology - science is hard lol )

Tortoises ( like humans & other animals ) share a common ancestor. As the branches deprecated & moved into varying climates the various branches became ( over 100ds of 1000ds of yrs) more & more unique till at some point the two branches could no longer produce viable offspring. This is what happened to torts as evolutionary time marched forward.

With the Sulcatas & Leopards , their common ancestor is not as far back in evolutionary terms as say a Redfoot & a Sulcata. Not only that , they share overlapping territories on the com tenant of Africa. So it is possible they have occasionally bred in the wild.

The step before complete incompatibility between branches is sterile offspring.

 

[Bambam1989]

I think nature is random and strange things happen.... I once had a bunny-kitty..

 

[Taylor T.]

I once had a bunny-kitty..

I have a very strange image in my head now.

 

[Tidgy's Dad]

The taxonomy of living things is a very complicated and quickly evolving (forgive the pun) discipline. I should know, I'm writing a book on the subject and the goalposts are constantly changing, both due to new discoveries from the fossil record, new taxonomic systems being proposed, genome analysis and the dividing of species/ subspecies etc for other reasons such as conservation.
1. Size is not really the issue, it depends on genetic compatibility. The definition of a species can be done in many different ways, the simple definition of if an animal is capable of producing fertile offspring with another animal, then it is of the same species is flawed. Firstly, with extinct organisms you can't possibly test this, so in palaeontology, especially where DNA does not exist, morphology is of prime importance. Secondly, someone used the example of the horse and donkey of the same Genus Equus, another example would be the lion and tiger, both of the genus Panthera. These can produce offspring; a mule (male parent a donkey, or a hinny (male parent a horse); or a liger (male parent a lion) or a tigon (male parent a tiger). However, very rarely these hybrid offspring can produce fertile young themselves when mated with a pure animal. So it gets difficult and we could say the definition should be changed to if the organisms can produce viable offspring most of the time.
To return to size, it can be a problem, of course, for example with a male tiger and a lioness, the size difference can cause the foetus to abort.

2. No.
Tortoises are currently grouped into about 16 living genera, there are also extinct genera.
This classification is constantly under revue.

3. Some can, see other answers above, not sure we should be experimenting with this.

A genus is a taxonomic unit used between species and family and is important in the standard binomial classification system, so for example we are Homo sapiens. (wise man ). Note only the genus is ever capitalized. The definition of a genus is just as complicated as that of a species, but roughly speaking, is determined by monophyly, that is that all in the genus share the same common ancestor, sensible compactness; that the taxonomic units shouldn't be split to suit individuals trying to save subspecies or groups of animals in a particular region, for example (sorry, guys). Organisms can show great variety and difference in their geographical range, but still currently be of the same genus; and the other determining factor is the individuality of the group of organisms in the genus, how different they are from others in evolutionary terms.

 

[wdbyrd]

by classic definition, "species" is the highest grouping of animals that can successfully produce fertile offspring. And also by classic definition, "genus" groups animals as the level above species, and these animals can interbreed, but cannot produce fertile offspring. The best example is a mule. An interbreeding of two different species - the horse and donkey, both of the genus Equs but the offspring - the mule - is infertile.

Sulcatas and leopards until very recently were in the same Genus - Geochelone. As such, they could interbreed but not produce fertile offspring. Now they have split the leopard tortoises into a different genus - Stigmochelys. So, if that is correct, they should not be able to interbreed by classic definition. But don't tell them that!

Now the classification of genus is much more dictated by DNA and lineage as the chief criteria. They must show "monophyly and validity as a separate lineage".

In any case, it seems the offspring - they are calling leopracatas now - should not be fertile.

There are folks with leopardcatas that say they are in fact not infertile and have breedes them successfully with Sulcatas.

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I think the folks that do these classification should investigate these claims as they should be easy to verify if they are valid.


This would mean leopard and Sulcatas are the same species.

 

[wdbyrd]

1. They can, but they shouldn't. Different species should not be housed together, much less allowed to breed.
2. No.
2/3. See number one.

More info:
View attachment 210978

It's obvious that the classification is wrong. They are improperly classified in different Genus, and if the claims of these so called hybrids not being infertile are validated then they are improperly classified as being a different species.

 

[Shelled]

Not necessarily so. That species in the same genus can interbreed, but not produce fertile offspring, and species in different genera can't interbreed, is not how species and genera defined by most species concepts. There are several different species concepts, and none manages to capture all possibilities which exist in nature. There are individuals within the same species which interbreed for example. A good example of that are circumpolar occurring gulls. Herring gulls in Europe can breed with the subspecies to the east in Asia/Siberia, which can breed with those in Canada. But those in Canada can't interbreed with those in Europe. Same species, there is geneflow, but they can't interbreed.
Unless good evidence is found of them interbreeding in the wild I would think it's OK they're in different genera. But who knows what evidence taxonomists in the future will find to lump them again in the same genus. Taxonomic classifications aren't rigid, and can change with advances in knowledge.

 

[ZEROPILOT]

I see combinations of Redfoot, Cherryhead Redfoot and Yellowfoot pretty often.
Some are crossbred on purpose for a certain color or size I suppose. That make them more valuable for retail. Some are mixed due to incorrect keeping or just laziness. I'm not aware of any of them being infertile. But these are closely related species. Especially in the case of Redfoot and Cherryhead.
In fact, I currently own two mixed that were given to me.
They won't be breeding.
This is just my particular preference.

 

[ZEROPILOT]

Not necessarily so. That species in the same genus can interbreed, but not produce fertile offspring, and species in different genera can't interbreed, is not how species and genera defined by most species concepts. There are several different species concepts, and none manages to capture all possibilities which exist in nature. There are individuals within the same species which interbreed for example. A good example of that are circumpolar occurring gulls. Herring gulls in Europe can breed with the subspecies to the east in Asia/Siberia, which can breed with those in Canada. But those in Canada can't interbreed with those in Europe. Same species, there is geneflow, but they can't interbreed.
Unless good evidence is found of them interbreeding in the wild I would think it's OK they're in different genera. But who knows what evidence taxonomists in the future will find to lump them again in the same genus. Taxonomic classifications aren't rigid, and can change with advances in knowledge.

Nice assessment.
I've also read that in the regions where Redfoot and Yellowfoot could and probably do interact with one another, there is no evidence of cross breeding in those areas in the wild.

 

[wdbyrd]

Not necessarily so. That species in the same genus can interbreed, but not produce fertile offspring, and species in different genera can't interbreed, is not how species and genera defined by most species concepts. There are several different species concepts, and none manages to capture all possibilities which exist in nature. There are individuals within the same species which interbreed for example. A good example of that are circumpolar occurring gulls. Herring gulls in Europe can breed with the subspecies to the east in Asia/Siberia, which can breed with those in Canada. But those in Canada can't interbreed with those in Europe. Same species, there is geneflow, but they can't interbreed.
Unless good evidence is found of them interbreeding in the wild I would think it's OK they're in different genera. But who knows what evidence taxonomists in the future will find to lump them again in the same genus. Taxonomic classifications aren't rigid, and can change with advances in knowledge.

It may not happen in the wild due to lack of proximity to each other. I'm still learning. So if it is verified that the offspring of a leopard and Sulcatas torroise is fertile and can have offspring themselves would it be evidence that these two types of tortoise should be viewed as the same species? That is what is being claimed. That the offspring of a leopard and sulcata had offspring itself. Are you saying that even if this is true they can still be classified as being different species?

 

[ryan57]

It may not happen in the wild due to lack of proximity to each other. I'm still learning. So if it is verified that the offspring of a leopard and Sulcatas torroise is fertile and can have offspring themselves would it be evidence that these two types of tortoise should be viewed as the same species? That is what is being claimed. That the offspring of a leopard and sulcata had offspring itself. Are you saying that even if this is true they can still be classified as being different species?

Rhinos are evolving smaller horns in response to poaching

In the 2006 animated feature film Over the Hedge, we see what happens — albeit through a fantastical lens — when wild animals are pushed into close proximity with humans. As humanity continues its encroachment on the natural world, transforming wild habitats into homogenized human settlements...

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There are examples where Rhinoceros have "evolved" in the past 10 years (yes, only 10 years) to have no horn. Not smaller... NO HORN.

Look, the established timeline of evolution is completely wrong and if organisms can breed then they are the same "kind". The fact that traits can affect change in 100 years even means that the falsely established timeline is mathematical folly.

Go back 250 years. Look at what has changed in 250 years. Even if the exponent of change is at a statistical extreme, it is absolutely impossible that this talk of billions of years is accurate. At all.

Climate change, nice... the oldest almanac is younger than this country and we didn't have recorded temperatures or even an thermometer to accurately measure temperature until around 2000 years ago at the absolute earliest so we're basing millions of years on a sample size of 2000? Huh? That is not scientific.

Thermometer - Wikipedia

en.wikipedia.org

4,600,000,000 years old and 2000 is the sample size at a maximum? 1/2,300,000th to draw a conclusion? Nonsense.

I wouldn't want these people even calculating the size of timber to use for a shed that I don't go in.

 

[loving homes]

Question 1: So, recently I saw a video of a Sulcata x Leopard tortoise hybrid. That made me wonder, that is the tortoise was relatively the same size as each other, and had similar husbandry could they mate, and have hybrid babies?

Question 2: Are all tortoises in the same Genus?

Question 2/3: If all tortoises are NOT in the same Genus can tortoises with different Genus mate and have hybrid babies?

P.S- Can somebody go into more detail about what a genus is. I have a somewhat hold of it, but still Don't completely get it. So, being fairly new to reptiles, and tortoises please keep the explaining relatively basic. THX!

It is possible for these two tortoises two breed and have babies but it is not none yet if the babies can breed after sulcata to a leopard as been done I've been trying it the other way round if you look at kamp kenan on YouTube he had some given to him they are beautiful but have not had babies yet I have seen my 6 year old leopard on my female sulcata so it just a waiting game and at the end of the day in the wild if these two meet up they would breed

 

[Tom]

It is possible for these two tortoises two breed and have babies but it is not none yet if the babies can breed after sulcata to a leopard as been done I've been trying it the other way round if you look at kamp kenan on YouTube he had some given to him they are beautiful but have not had babies yet I have seen my 6 year old leopard on my female sulcata so it just a waiting game and at the end of the day in the wild if these two meet up they would breed

They don't meet up in the wild. Their ranges do not overlap.

Species should never be mixed. Its bad for them in so many ways to be housed that way.

 

[Rwchambers62]

It may not happen in the wild due to lack of proximity to each other. I'm still learning. So if it is verified that the offspring of a leopard and Sulcatas torroise is fertile and can have offspring themselves would it be evidence that these two types of tortoise should be viewed as the same species? That is what is being claimed. That the offspring of a leopard and sulcata had offspring itself. Are you saying that even if this is true they can still be classified as being different species?

They can breed to each other but doesn’t mean same species. As far as fertile and non fertile. Time will tell on this. Jut like Neanderthal and Homo sapiens bred to each other and had children that were fertile. There may come a time that nature will produce fertile offspring.

 

[Shelled]

It may not happen in the wild due to lack of proximity to each other. I'm still learning. So if it is verified that the offspring of a leopard and Sulcatas torroise is fertile and can have offspring themselves would it be evidence that these two types of tortoise should be viewed as the same species? That is what is being claimed. That the offspring of a leopard and sulcata had offspring itself. Are you saying that even if this is true they can still be classified as being different species?

If you apply the biological definition that if 2 animals can produce fertile offspring, then yes. But most species would hold up under multiple species definitions, and these wouldn't.
Then, there is also the good practice of keeping populations pure, and these two rarely, if ever, cross-breed in the wild, even if they occur in the same area, so why force it in captivity?

See for example what happened with Green Tree Pythons. Used to be one species, with lots of localities. Regularly localities get mixed in captivity. Now they split the Green Tree Pythons from Papua New Guinea in 2 species (Morelia viridis and M. azurea), the latter of them with 3 subspecies. So people might have been mixing not just localities, but species.