How distant are Siberian tigers from other nearby subspecies (North Chinese tiger?) in years since divergence vs. say the lion?
Photograph by Joel Sartore, National Geographic
Published September 17, 2013
The first sequenced tiger genome shows that big cats evolved to kill.
Scientists mapped the genes of the endangered Siberian tiger (or Amur tiger), both to understand the genes that make big cat species distinct from one another and to aid efforts to preserve genetic diversity in wild tiger populations. (Also see "Isolated Tigers Travel Surprising Lands to Find Mates.")
The largest tiger subspecies, Siberian tigers weigh as much as 660 pounds (300 kilograms) and grow to some ten feet (three meters) in length. Only about 450 Siberian tigers exist in the wild, and around 4,000 tigers total are thought to remain in their natural habitats. (See a National Geographic magazine interactive of big cats in danger.)
"We looked at this very large tiger first to see what made it distinctive from other cats," said genome expert Jong Bhak of South Korea's Personal Genomics Institute in Suwon, a co-author of the Nature Communications study reporting the mapping of the Siberian tiger genome.
Bhak and colleagues sampled genes from a nine-year-old male tiger at the Everland Zoo in Korea, and compared them with gene map information from the Bengal tiger, lion, and snow leopard. (See tiger pictures.)
Natural Born Killers
"Genetically all the cats are very close, so we need close genetic mapping to find the small differences that make them distinct," Bhak said.
Some gene differences are apparent in the mapping, such as two genes likely involved in adaptation to high altitudes and thin air in snow leopards and white fur in white African lions.
But overall, the cat family seems to rely on a narrow set of 1,376 genes linked to strong muscle fibers and digestion of protein, the study shows, seen widely across the study species. The genes likely originated in large part with the earliest common ancestor of big felines some 11 million years ago, the study authors suggest.
"I take this to indicate that [big cats] have evolved to fill a very particular carnivorous niche in the environment that is predicated on the advantages in hunting these genes provide," said Bhak.
Domestic cats also have many of these same genes, he said. "All the cats are unparalleled hunters, and here we are seeing some of the genetic reasons."
Simply mapping the tiger genome represents a significant advance for researchers, said forensic geneticist Thitika Kitpipit of Thailand's Prince of Songkla University, who led a team that recently completed a map of the maternal genes, or mitochondrial DNA, of tigers.
With more wildlife officials debating the introduction of some big cats to preserves in a bid to diversify wild populations, a gene map is a first step in understanding the genetic landscape of big cats, Bhak said.
Wildlife officials from 13 nations agreed in 2010 at a Tiger Summit in St. Petersburg, Russia, to work toward saving the tiger in the wild amid increasing reports of poaching and declining wild populations in Asia.
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yes, all the cats are very similar. Ever seen a cat stalking a mice? Its exactly the same a tiger stalks its prey.
Hi Dan, thanks for this interesting news. I'm now doing an awareness campaign for tigers that leads me through 31 Asian countries in 6 months. I speak with a lot of scientists and the discussion about reintroducing tigers comes up most frequently.
I would like to ask you to give your opinion about the correlation between the existence of proven 'killer' genes and possible success with reintroducing tigers.
Thanks in advance!
Hello Dan, that's interesting. I'm now doing an awareness campaign for tigers through 31 Asian countries and talk with a lot of scientists.
The discussion of breeding and reintroducing tigers comes up a lot. However, I can't understand why the two subjects are connected in any which way. Can you explain to me?
Some biologist out there, answer this please. I heard of the subject epi-genitics, even though the genes sequenced look identical, there is some bit of a diffrence still. On and of genes, did the scientist who sequenced the genes take that to account?
NATURAL LIMITS TO EVOLUTION: Only micro-evolution, or evolution
within biological "kinds," is genetically possible (such as the
varieties of dogs, cats, horses, cows, etc.), but not macro-evolution,
or evolution across biological "kinds," (such as from sea sponge to
human). How could species have survived if their vital tissues, organs,
reproductive systems, etc. were still evolving? A partially evolved
trait or organ that is not complete and fully functioning from the start
would be a liability to a species, not a survival asset. Plants and
animals in the process of macro-evolution would be unfit for survival.
For example, “if a leg of a reptile were to evolve (over supposedly
millions of years) into a wing of a bird, it would become a bad leg long
before it became a good wing” (Dr. Walt Brown, scientist and
creationist). Survival of the fittest actually would have prevented
evolution across biological kinds! Read my Internet article: WAR AMONG
EVOLUTIONISTS! (2nd Edition).
What about natural selection? Natural selection doesn't produce biological traits or variations. It can only "select" from biological variations that are possible and which have survival value. The term "natural selection" is a figure of speech. Nature doesn't do any conscious selecting. If a variation occurs in a species (i.e. change in skin color) that helps the species survive then that survival is called being "selected." That's all it is. Natural selection is a passive process in nature, not a creative process.
The real issue is what biological variations are possible, not natural selection. Only limited evolution, variations of already existing genes and traits, is possible. Nature is mindless and has no ability to design and program entirely new genes for entirely new traits.
Evolutionists believe and hope that over, supposedly millions of years, random genetic mutations caused by environmental radiation will generate entirely new genes. This is total blind and irrational faith on the part of evolutionists. It's much like believing that randomly changing the sequence of letters in a romance novel, over millions of years, will turn it into a book on astronomy! That's the kind of blind faith macro-evolutionists have.
Visit my latest Internet site: THE SCIENCE SUPPORTING CREATION .
I discuss: Punctuated Equilibria, "Junk DNA," genetics, mutations, natural selection, fossils, dinosaur “feathers,” the genetic and biological similarities between various species, etc., etc.
Babu G. Ranganathan*
Author of popular Internet article, TRADITIONAL DOCTRINE OF HELL EVOLVED FROM GREEK ROOTS
*I have given successful lectures (with question and answer period afterwards) defending creation before evolutionist science faculty and students at various colleges and universities. I've been privileged to be recognized in the 24th edition of Marquis "Who's Who in The East" for my writings on religion and science.
I was surprised at the 4 animals studied, one was a white african lion, one a white tiger. Where is the conservation value in that? Wouldn't it have made more sense to study other wild subspecies, rather than genetic mutants? (bbc.co.uk article earlier)
Great article. I agree mankind should be more concerned with protecting themselves from danger of any kind rather than hunt & take their land from them.
Oh really- cats were made to kill?? Amazing -I never imagined that!!
Now how would anyone have known this without a full genome sequence?
How can someone save a Tiger by knowing its genome???
I think thanks by knowing it's genome big corporations can make more money....
I should note that Dr. Kitpipit did offer two cautions on the study; one was that it was only one tiger sequenced and she would like to see more, the other was that she would like more assurance that some already-identified mitochondrial DNA sequences weren't inadvertently counted as nuclear DNA in the new study.
What an awesome creature! Its truly a shame that mankind threatens the very existence of this and other amazing species. I hope conservation efforts are as successful as possible in order to save these big cats.
@Don Bose , i think some species look and do it much better though. I have a bengal cat and you can just see his shoulders going while he prowls. Some domestic cats just dont it have it like that
@Ahmad Cerial Epigenetics actually involve the coiling of DNA around objects called histones. This wrapping is caused by methyl groups but do not affect the on/off switching of the DNA but rather the scanning of the code during protein synthesis, so epigenetics shouldn't have an effect on the sequencing
@Babu Ranganathan Quite an answer Babu. But what does this mean for the non-scientists among us?
last I looked those creatures with wings had some very valid and functional two *hind*legs which might have taken some of the pressure on having good *front*legs off of them - at least when they were using their hindlegs to walk and when we look at species with two sets of *legs*. I do believe in God, but Im rather certain he is not Micro managing Gene Pools of m(b)illions of species.
@Babu Ranganathan As the saying goes 'people who don't believe in evolution don't really understand how it works'...
I may not be an expert but I know enough to reply to this: "A partially evolved trait or organ that is not complete and fully functioning from the start would be a liability to a species, not a survival asset"... Wrong - in a world of no eyes (to quote one far more erudite than myself) , half an eye is better than no eye at all.You might consider (as I have, before you say it) the principle of 'seeing what you look for'...
@Crissie Tiger I don't think there was a white tiger. Where did you see that?
@Crissie Tiger I agree. Why not a studiy on the almost extinct South China tiger, that can only be found in zoos and in Africa, as an reintroduction experiment. Dan, can you reply?
@Deborah Morgan It's not an easy issue Deborah.
@Shomita Mukherjee My reaction also. If they had not had that ability they would have been one or the other: vegetarians or extinct.
@Christina Reddy So what has Justin Bieber has to do with tigers? Is he finally becoming a hero by supporting the survival of this majestic cat?
@Ibrahim Arslan Agree. I want to do something about it. Make them pay for what they used. Companies like Heineken (tiger beer), Maybank, Tiger Airways and others have benefitted enormously from the tiger image and what they they do in return?
@Mitra Ramkissoon Hello Mitra, I'm now doing an awareness campaign for tigers that leads me through 31 Asian countries in 6 months. I speak with a lot of scientists and the discussion about reintroducing tigers comes up most frequently.
Conservation efforts can only improve if there is more money available and if the political will is there to protect them. The discussion is always about jobs (tigers live mostly in areas that are rich for what's in the ground or on the ground. And almost all countries are developing countries so they need jobs and money.
So the choice for destroying tiger habitat is easily made.
It means that Babu is a religious zealot who knows exactly zero about biology, except for a few technical terms that he misuses to make it sound like he's smarter than he is.
It means Babu is a religious zealot who knows absolutely nothing about biology other than a few technical terms that he then misuses.
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