giraffe subspecies

[Yassa]

This is a super interesting discussion, thank you very much to all involved.

I have a couple of questions to the topic of giraffe genetics & species/subspecies, maybe you can help me:
1) What species/subspecies are the giraffes in Queen Elisabeth N.P. in Uganda? Rothschild? Is it correct that the rothschilds are down to a couple of hundred free ranging individuals?
2) Some time ago I found a genetic study of rothschild and reticulated giraffe in US zoos and the result was that they were all mixed up. Just the massai giraffes in the US were genetically distinctive and their pattern matched those of wild massai giraffes.
Is this correct? Or is there newer research to conterdict this?
3) Is there any genetic research to confirm if the european zoo populations of rothschilds and reticulated are mixed up like in the US, or is there hope that they are more or less purebred?
4) Last - a few years ago, the so-called west african giraffes in french zoos were found to be antiquorum and not peralta. I tried to understand the underlying research, but found the data about where the founders of this zoo population came from very confusing. Is it confiremed through genetics that the giraffes in (mainly french) zoos are indeed purebred antiquorum? Or is it possible that the zoo population is actually a mix between antiquorum and peralta (I hope not...).

Thanks a lot if someone can help me.

 

[Jurek7]

Hi, I just wanted to be clear that forms of giraffe are very much worth conserving as are Sumatran Tigers, Amur Leopards etc, but as subspecies, not species.

I learned that DavidBrown you are apparently involved directly in conservation, so congratulations for this work and more success.

 

[DavidBrown]

Jurek we can go on and on forever. I think that you are interpreting the data wrong or not reading the paper thoroughly. Yes, there is some mitochondrial evidence that Masai giraffes and reticulated giraffes had some introgression, but there is no introgression in the nuclear DNA between the few individuals showing a history of mtDNA introgression. These individuals are at the frontier of where these groups meet and the nuclear genetic pattern shows that the hybridization shut down hundreds of thousands of years ago.

The microsatellite genetic differentiation data is completely consistent with the morphological subspecies boundaries. There are patterns of genetically localized differentiation within subspecies, but these are nested within the pattern of genetic differentiation between subspecies. I don't understand your statement: "At higher resolution, most microsattelite patterns groups to single localities (giraffes in each locality are different, same race or not)." All of the giraffes within each of the genetically differentiated localities are part of the same subspecies.

There are no Angolan giraffes mixed in with the West African and Rothschilds giraffes. West African and Rothschilds giraffes form monophyletic groups, as do the Angolan giraffes. Depending on how one builds the tree you are correct that the Masai giraffe clades are sometimes paraphyletic with respect to the South African giraffes, but the network analysis shows them as being monophyletic groups. There are a couple of reticulated giraffe individuals with haplotypes that are paraphyletic with respect to the Rothschild's giraffes. We interpret these to be ancient haplotypes that predate the split of the Roths and the retics and have persisted in the retic population. The underlying pattern (with the above caveats) as shown in the mitochondrial network analysis is that the six groups are monophyletic with respect to mitochondrial DNA.

All of the groups are monophyletic with respect to nuclear DNA.

The patterns of reciprocal monophyly in nuclear and mitochondrial DNA indicate that these populations are reproductively isolated. The patterns of differentiation in spot pattern between these groups is also congruent, to the degree that the spot patterns have been quantified. Contrary to your statement: "I don't understand why you claim on this basis that giraffe subspecies are distinct and don't interbreed, when the data show precisely the opposite", I think that the data very strongly supports that there are speciation level differences between the giraffe subspecies.

You are of course welcome to your opinion, but I do not think that your critique here has any factual basis.

At some point hopefully someone will do full genome analysis of multiple individuals of the different giraffe groups and provide comoletely unambiguous evidence that these groups are reciprocally monophyletic. In the meantime I think that we did a pretty thorough job with the available genetic tools that we had when this study was done, and the results are completely consistent with the results done by the French group (Hassanin et al.) and my friend Russ Seymour who extracted DNA from 100+ museum samples.

Hi DavidBrown,

You given a link to research paper. Figure 1 on the paper shows that within Reticulated giraffe diversity are nested West African, Rotschild's and some Angolan giraffes. Within Masai giraffe diversity are nested all South African giraffes.

West Africans and Rotschilds are closer related to each other than some Reticulated to other Reticulated and some Masai to other Masai.

Microsatellite locii show similar incomplete pattern. At higher resoultion, most microsattelite patterns groups to single localities (giraffes in each locality are different, same race or not).

Also, this paper states that mt DNA clades are "largely" that is not fully consistent with phenotypes (races defined by spot shapes etc).

I don't understand why you claim on this basis that giraffe subspecies are distinct and don't interbreed, when the data show precisely the opposite.

 

[DavidBrown]

Hi Yassa,

The giraffe (sub)species in Queen Elizabeth NP were Rothschild's. The wild giraffe populations in Uganda were unfortunately mostly wiped out in the 1970s except for Murchison Falls NP, where a free ranging population still persists. There have been attempts to reintroduce giraffes to Kidepo NP, and possibly Queen Elizabeth NP, but I don't know what the status of that is. My colleague Zoe Muller who studies the Roths in Kenya may know. Her webpage is girafferesearch.com.

2. You are correct that the genetics research on the U.S. zoo population shows that the Rothschilds and the reticulated giraffes have interbred. The Masai giraffes still have a mostly unhybridized gene pool. The giraffe populations in U.S. zoos are now managed as a Roth-retic hybrid gene pool and a Masai gene pool. To my mind these populations exist primarily as conservation ambassadors for their wild cousins rather than stock material for any possible reintroductions, which would never happen from Western zoos anyway as there are still intact populations for all of these groups in their range states that would serve as reintroduction stock.

3. I really don't know anything about the European giraffe gene pool or to what extent it has been analyzed. Does anybody here know? Has this data been published anywhere and if so could you please direct us to it?

4. There is a paper by Hassanin et al. that does discuss this some, but I honestly don't know the particulars of the French zoo giraffe program. Here is a link to the Hassanin et al. paper: Mitochondrial DNA Variability In Giraffa camelopardalis: Consequences for Taxonomy, Phylogeography and Conservation of Giraffes In West and Central Africa (Alexandre Hassanin) - Academia.edu

This is a super interesting discussion, thank you very much to all involved.

I have a couple of questions to the topic of giraffe genetics & species/subspecies, maybe you can help me:
1) What species/subspecies are the giraffes in Queen Elisabeth N.P. in Uganda? Rothschild? Is it correct that the rothschilds are down to a couple of hundred free ranging individuals?
2) Some time ago I found a genetic study of rothschild and reticulated giraffe in US zoos and the result was that they were all mixed up. Just the massai giraffes in the US were genetically distinctive and their pattern matched those of wild massai giraffes.
Is this correct? Or is there newer research to conterdict this?
3) Is there any genetic research to confirm if the european zoo populations of rothschilds and reticulated are mixed up like in the US, or is there hope that they are more or less purebred?
4) Last - a few years ago, the so-called west african giraffes in french zoos were found to be antiquorum and not peralta. I tried to understand the underlying research, but found the data about where the founders of this zoo population came from very confusing. Is it confiremed through genetics that the giraffes in (mainly french) zoos are indeed purebred antiquorum? Or is it possible that the zoo population is actually a mix between antiquorum and peralta (I hope not...).

Thanks a lot if someone can help me.

 

[DavidBrown]

Hi, I just wanted to be clear that forms of giraffe are very much worth conserving as are Sumatran Tigers, Amur Leopards etc, but as subspecies, not species.

I learned that DavidBrown you are apparently involved directly in conservation, so congratulations for this work and more success.

Jurek, I appreciate your comment re: conservation. You seem to keep arguing that there is no genetic evidence that the giraffe subspecies are reproductively isolated. I am arguing back because I spent many years gathering and analyzing the genetic data to answer this question. The analysis has been vetted and peer-reviewed. Your claims that the paper are flawed are of course how science works, but this work was not done carelessly and the claims that I make re: potential giraffe speciation are not made lightly and definitely not for the purpose of "taxonomic inflation" as you seem to be suggesting.

 

[Pertinax]

The giraffe populations in U.S. zoos are now managed as a Roth-retic hybrid gene pool and a Masai gene pool.

3. I really don't know anything about the European giraffe gene pool or to what extent it has been analyzed.

That is very interesting and I had not realised that. In Europe there has been a lot more emphasis in recent years on promoting 'pure' herds, particulary of Rothschilds and Reticulated. In the UK for example, many of the 'A & B list' zoos have developed groups of pure(?) Rothschild's, while the known hybrids/generic Giraffe they kept formerly have largely been moved to 'B or C List' zoos and wildlife parks. At the same time and for some years(known) purebred Reticulateds were totally absent in the UK but have now reappeared-imported from European stocks, at a few locations, but there are far still less of them than the Rothschild's groups.

I don't know if any analysis has been done regarding the exact purity of any of these animals though.