New international research on the genomes of big cats, including tigers, lions and snow leopards, gives scientists clues as to how these endangered species evolved to become superior killers, National Geographic reports, and reveals that tigers share 96 percent of their genes with the common house cat.

In order to further conservation efforts towards protecting the genetic diversity of big cats and understand what makes them distinct from one another, a group of scientists mapped the genes of the endangered Siberian tiger (also known as the Amur tiger), which can weigh up to 660 pounds and grow to ten feet tall in length.

"We looked at this very large tiger first to see what made it distinctive from other cats," genome expert Jong Bhak of South Korea's Personal Genomics Institute in Suwon, and co-author of the Nature Communications study reporting the mapping of the Siberian tiger genome, told National Geographic. Bhak and his team sampled genes from a nine-year old male Siberian tiger named Taegeuk at Everland Zoo in South Korea, comparing them with those of the Bengal tiger, lion and snow leopard, according to BBC News.

"Genetically all the cats are very close, so we need close genetic mapping to find the small differences that make them distinct," Bhak said. Big cat species share around 1,376 genes for strong muscle fibers, keen sense of smell and the ability to digest protein, though certain genetic traits vary, such as two genes found in the snow leopard that are likely involved in surviving high altitudes.

"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. "All the cats are unparalleled hunters, and here we are seeing some of the genetic reasons."

Conserving big cats, especially tiger populations, is of utmost importance to scientists, as currently wild tiger populations have dwindled to about 4,000 individuals.

"Our tiger reference genome can be used as the basis for comparing all the tigers in the world, so that we know the genetic diversity of tigers," Bhak told the BBC. "And we can actually have a plan of how we can breed tigers effectively [in zoos] to save the genetic diversity." He added that tigers are essentially big domestic house cats, and much closer in relation to them than previously thought.