DNA samples of Bengal tigers polluted by genes of the Siberian Tiger - Printable Version +- WildFact (https://wildfact.com/forum) +-- Forum: Information Section (https://wildfact.com/forum/forum-information-section) +--- Forum: Terrestrial Wild Animals (https://wildfact.com/forum/forum-terrestrial-wild-animals) +---- Forum: Wild Cats (https://wildfact.com/forum/forum-wild-cats) +----- Forum: Tiger (https://wildfact.com/forum/forum-tiger) +----- Thread: DNA samples of Bengal tigers polluted by genes of the Siberian Tiger (/topic-dna-samples-of-bengal-tigers-polluted-by-genes-of-the-siberian-tiger) Pages:
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RE: DNA samples of Bengal tigers polluted by genes of the Siberian Tiger - Pckts - 06-25-2015 (06-25-2015, 08:07 PM)'sanjay' Wrote: Contributing to the twist, Here is the documentary. Its long and untold story of Indian govt that kept his secret for long. Makes total sense, and thats why its the only tiger not to be pure bengal dna in india. Sad that it was shot, it should of never been released to begin with. They seem to do this often, not enough research on the cats they intend to release in the wild. Like Sariska where they release a tigress who has never bore cubs and males that are most likely her siblings and who have never been fathers. You would think that such a huge task would be far more researched. RE: DNA samples of Bengal tigers polluted by genes of the Siberian Tiger - Shardul - 06-26-2015 (06-20-2015, 04:24 AM)'Kingtheropod' Wrote:(06-19-2015, 08:58 AM)'GuateGojira' Wrote: In fact @sanjay, Bengal and Amur tigers are/were of the same size and weight, in old and modern records. The fluctuations in weight came from the size of the samples and the reliability of the records. Most of the statements that the Amur tigers were larger came from the reports of Baikov and another few about "giant" specimens, but now those are considered unreliable. How is it possible for one tiger in one isolated reserve to pollute an entire population? In fact, Dudhwa National park and Katarniaghat wildlife sanctuary are not even contiguous, even though both are part of the Dudhwa tiger reserve. The Bengal tiger population is not one metapopulation, it is split into a lot of smaller sub populations that are isolated from one another. Please explain how can "siberian gentics" from one mixed tigress from Dudhwa pollute tiger gene pool from other reserves in the Terai like Corbett, Chitwan, Bardia and Rajaji? It seems like some people have decided that 'Siberian genetics' only can result in large tigers. RE: DNA samples of Bengal tigers polluted by genes of the Siberian Tiger - Pckts - 06-26-2015 (06-26-2015, 01:04 AM)'Shardul' Wrote:(06-20-2015, 04:24 AM)'Kingtheropod' Wrote:(06-19-2015, 08:58 AM)'GuateGojira' Wrote: In fact @sanjay, Bengal and Amur tigers are/were of the same size and weight, in old and modern records. The fluctuations in weight came from the size of the samples and the reliability of the records. Most of the statements that the Amur tigers were larger came from the reports of Baikov and another few about "giant" specimens, but now those are considered unreliable. Couldn't agree with you more. Welcome btw. RE: DNA samples of Bengal tigers polluted by genes of the Siberian Tiger - Shardul - 06-26-2015 (06-26-2015, 01:39 AM)'Pckts' Wrote:(06-26-2015, 01:04 AM)'Shardul' Wrote:(06-20-2015, 04:24 AM)'Kingtheropod' Wrote:(06-19-2015, 08:58 AM)'GuateGojira' Wrote: In fact @sanjay, Bengal and Amur tigers are/were of the same size and weight, in old and modern records. The fluctuations in weight came from the size of the samples and the reliability of the records. Most of the statements that the Amur tigers were larger came from the reports of Baikov and another few about "giant" specimens, but now those are considered unreliable. Thanks, Pckts. RE: DNA samples of Bengal tigers polluted by genes of the Siberian Tiger - GrizzlyClaws - 06-26-2015 According to the recent phylogenetic classification for the tiger subspecies, Amur and Bengal might not even consider as two different subspecies, but rather two different clades within a same subspecies known as the Mainland tiger. They are just as different as the South African lion and East African lion, and given that Bengal to live in the colder climate, they would also develop the fluffy coat like the Amur tiger. The tone about "Bengal's gene pool being polluted by Amur" is a bit too heavy, since we cannot say that the Serengeti lion's gene pool would be polluted if they mix with the Kruger lion. RE: DNA samples of Bengal tigers polluted by genes of the Siberian Tiger - Pckts - 06-26-2015 (06-26-2015, 06:21 AM)'GrizzlyClaws' Wrote: According to the recent phylogenetic classification for the tiger subspecies, Amur and Bengal might not even consider as two different subspecies, but rather two different clades within a same subspecies known as the Mainland tiger. Technically they have 2 different DNA strands, so they are different genes. Thats why you are able to distinguish the two, but in terms of "polluting" or not, that is unknnown since we don't know what the amount of time is needed to start evolutionary changes from area to area. I think over time, you could drop a amur in india and its blood line would eventually turn back into bengal. But who knows how long it would take. Thats just a theory obviously RE: DNA samples of Bengal tigers polluted by genes of the Siberian Tiger - GrizzlyClaws - 06-26-2015 Amur and Bengal are the two variations within a common tiger subspecies which known as the Mainland tiger. However, if we compare Bengal and Javan, then these two belong to two different subspecies. Just like the lions, African and Asian belong to two different subspecies, while all African lions belong to a common lion subspecies. RE: DNA samples of Bengal tigers polluted by genes of the Siberian Tiger - Pckts - 06-26-2015 (06-26-2015, 10:55 PM)'GrizzlyClaws' Wrote: Amur and Bengal are the two variations within a common tiger subspecies which known as the Mainland tiger. agreed, but still different genetic sequences. I am far from a genetic expert, just know they are genetically different. But I seriously doubt if both are pure bred, neither would "pollute" the others gene pool with such a minimal number of specimens introduced. I'm sure they have interbred here and there. But what does that mean, is a different story. RE: DNA samples of Bengal tigers polluted by genes of the Siberian Tiger - GrizzlyClaws - 06-27-2015 Historically, Bengal did overlap its territory with both Chinese tiger and Indochinese tiger, so these two tiger groups were the ones who commonly interbred with Bengal. The Chinese tiger is quite interesting as they did overlap with Bengal in the Southwest China and with Amur in the North/Northeast China. Also, the Sumatran tiger is the natural hybrid between the Indochinese tiger and the Javan tiger which is a true crossover between two different tiger subspecies. If tigers wanna interbreed, then just let them be. That's why I believe that the population of the Bengal tiger is the last hope for both Chinese tiger and Indochinese tiger. The survival for the Chinese tiger can only depend by breeding with Bengal, and the Indochinese tiger is also quite vulnerable. And the only hope to restore the Chinese tiger is to introduce the Bengal population. As for Bengal, they need to first re-boom their own population back to 10000, then we can talk about to borrow their gene pool for other tiger groups. RE: DNA samples of Bengal tigers polluted by genes of the Siberian Tiger - GuateGojira - 06-27-2015 Even if we consider the idea/theory of Dr Kitchener, that all mainland tigers are in fact one "subspecies", the true is that the Bengal and the Amur tigers are the LESS related of all the groups. Both Bengal and Amur tiger populations born from the original population of Indochina at about 15,000 years ago, the Bengal ones invaded India about 12,000 years ago, while the Caspian-Amur invaded the center and west of Asia about 10,000 years ago (the largest the distance, shorter the time), the definitive separation of the Amur group was just about 200 years, surely caused by the human intervention, just like the separation of the Sundarbans tigers from the mainland Indian population. These two tiger groups, although represent the largest specimens of the species in the Holocene, are very different morphologically speaking, specially in the skull. In fact, it will be more plausible to mix a Bengal with an Indochina tiger than with an Amur one. It is also interesting that there was probably an intermix between the Amur and the South China tiger, even Mazák was not sure of the clear "separation area". Besides, very few specimens were collected in the south of Manchuria (popularly know as territory of the South China tiger). Interestingly, the largest tiger from the Central part of China was a male of 190 cm in head-body and 190 kg, which is as large as an average Amur tiger. Sadly, there are to few skulls to get a conclusion here. Finally, the case of Tara, like I said before, is very old and that supposed DNA mix is already finished. Other thing, like @Shardul said, India is not a metapopulation, but a group of "islands" of tigers surrounded by an ocean of people. A young tiger traveling across this ocean had an impossible task and most of those young ones end dead. RE: DNA samples of Bengal tigers polluted by genes of the Siberian Tiger - GrizzlyClaws - 06-27-2015 The Chinese tiger is closer to the original tiger population of the pre-Toba eruption era, but keep in mind that they were also intermixing with both Amur and Bengal for thousands of years. So the original archaic features of the Wanhsien tiger could be diluted in process. Also, P. youngi is probably the synonym of the Wanhsien tiger, and many modern scientists did not recognize it as a valid species, but either a tiger or a leopard. By judging its size, it is definitely more likely being a tiger. RE: DNA samples of Bengal tigers polluted by genes of the Siberian Tiger - GuateGojira - 06-27-2015 Agree, and I most add more. South China tiger DNA analyzed by Dr Luo and her team found that in fact, it had a primitive origin, probably the true original Holocene tiger and direct descendent of the Wanhsien tiger. Remember also that, according with our theory, the surviving population of North Indochina tigers, after the Toba eruption, were in fact Panthera tigris acutidens, the original mainland tiger, so the genes of this large subspecies are still living in all modern tigers. So, in this case, what we have now is just a group of modern "changes" between populations, just like between humans. Check how different are the skulls of humans from Europe to those of Africa, America or those from Australia, but still we ALL are Homo sapiens. The more I read, the more I am agree with Dr Kitchener in this point: it seems that there is only one mainland tiger subspecies with clinal differences and the modern "subspecies", identified by few genetic differences are just the blame of humanity, not a true differentiation caused by the nature. Finally on the Panthera youngi issue, Dr Herrigton classified it as "leo", and all modern books quote him, but the BIG problem is that just this study was made, and clearly ignore the results from Dr Hooijer, which clearly clasify it as "tigris" or at least "tigris like". In one occasion I hypothesized that probably Panthera youngi was the last descendent of the Panthera zdansky, and now I see that @tigerluver and you are following the same way. It seems plausible, after all, ALL the great cats disappeared from the area, except the tiger and the leopard (although this last one had a latter arrival, from Africa). RE: DNA samples of Bengal tigers polluted by genes of the Siberian Tiger - AndresVida - 04-05-2021 (06-19-2015, 08:58 AM)GuateGojira Wrote: However, this is a size also reached for Bengal tigers and in this last case, we do have reliable records of tigers that have exceeded 300 kg.RELIABLE records of tigers who exceeded 300 kgs? I thought the largest reliable tiger ever measured was 271 kgs, c. 260 kg empty. Where did you get the reliable 300+ kg tiger records considered reliable? RE: DNA samples of Bengal tigers polluted by genes of the Siberian Tiger - GuateGojira - 11-15-2021 (04-05-2021, 12:40 PM)LoveAnimals Wrote: RELIABLE records of tigers who exceeded 300 kgs? I thought the largest reliable tiger ever measured was 271 kgs, c. 260 kg empty. That post is from 2015, so you must understand that many things changed since then. A reliable record is not necesary a scientific one. The heaviest tigers recorded by scientist are in fact two males of 272 kg+ recorded in Chitwan, Nepal. Now, in hunting records we have two Bengal males that surpassed the 300 kg, one from India of 318 kg and other of 320 kg in Nepal. However these are exeptional specimens and that is why I don't include them in my tables. Other things, tigers of those huge weights were cattle killers or had some stomach content, which suggest that they probable weighed as low as 280 - 290 kg empty, but this is just speculation. At the end, we have reliable-scientific records of male tigers between 250 - 272 kg from India/Nepal and Russia. Anything over that is exceptional and should be taked with caution. |