# Tortoise, Hybrids, Genetics, and Such



## GGboy17 (Jun 22, 2017)

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!


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## Markw84 (Jun 22, 2017)

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.


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## Tom (Jun 22, 2017)

GGboy17 said:


> 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?
> 
> ...



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:


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## GGboy17 (Jun 23, 2017)

Thanks Guys!!!


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## Kapidolo Farms (Jun 26, 2017)

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.


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## Alaskamike (Jul 10, 2017)

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.


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## Bambam1989 (Aug 18, 2017)

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


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## Taylor T. (Aug 19, 2017)

Bambam1989 said:


> I once had a bunny-kitty..


I have a very strange image in my head now.


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## Tidgy's Dad (Aug 19, 2017)

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.


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