WHILST DOGS have been hailed as probably Mankind’s most valuable and long-standing domesticated animal, a new scientific study has shown that cats were domesticated and proving their worth to humans many thousands of years earlier than believed.
Scientists have traced the ancestry of all domestic cats alive today back to just five female wildcats that lived in the Fertile Crescent region of what is now Iraq and Syria. A study of feline DNA shows that cats were domesticated from their wild cousins much earlier than previously believed and that humans must have transported them around the world from their Middle Eastern homeland.
The study analysed the DNA of nearly a thousand cats - domestic and wild - from countries as far apart as China and Scotland in an attempt to identify the closest living relatives of the pet cat, Felis silvestris catus.
Guesswork and Facts
‘There’s been an awful lot of guesswork on how one of the most interesting experiments in natural history took place,’ says Stephen J. O’Brien, chief of the Laboratory of Genomic Diversity at the National Cancer Institute in Bethesda, Maryland, USA, one of the authors on the study.
Based on morphology, scientists already presumed that wildcats - as opposed to other species such as ocelots and pumas-were the progenitors of today’s domestic cats. The controversy, Prof. O’Brien says, concerned where domestication occurred and how many times it might have happened.
Ancient Egyptian fresco of a domesticated cat guarding geese.
Wildcats are a single Old World species. Five subspecies live in Europe, sub-Saharan Africa, China, Central Asia, and the Near East. The researchers collected genetic material from 979 modern-day cats, domestic and wild, from three continents. Their analysis indicates that the common ancestors of all domesticated cats lived in the Near East some 130,000 years ago.
They were wildcats living in the Fertile Crescent - the area extending from the Eastern Mediterranean around Turkey and down into Mesopotamia -’exactly the place where humanity settled down to agriculture ten to twelve thousand years ago,’ says O’Brien.
Near Eastern Wildcat - the ancestor of the world’s domesticated cats.
The team found five lineages of mitochondrial DNA (mtDNA) in modern felines. Because of this variation, the researchers believe domestication occurred a half-dozen times or so in the Middle East.
Scientists used both the DNA from inside the cell nucleus, which is inherited from both mothers and fathers, as well as DNA from the mitochondria structures outside the cell nucleus, which is inherited only from females.
Professor David Macdonald, director of the Wildlife Conservation Unit at Oxford University and a co-author of the study, said that one of the most important findings was the discovery that domestic cats have a much older history than previously supposed.
‘In our studies of mitochondrial DNA from these cats we found five distinct lineages dating back 100,000 years prior to any archaeological record of cat domestication,’ Professor Macdonald said.
‘These appear to come from at least five female cats from the Near East whose descendants have been transported across the world by humans,’ he said.
This analysis fits with the oldest archaeological evidence for cat domestication—in 2001, scientists in Cyprus unearthed a cat skeleton that had been buried with a human 9,500 years ago. It also fits with the fact that ‘domestication of pretty much everything else in the world came from the Fertile Crescent,’ says Carlos Driscoll of Oxford University, the first author on the study, which appeared online in Science magazine’s website.
Dr Andrew Kitchener, a zoologist at the National Museums Scotland and co-author of the report in the journal Science, said: ‘This shows that the origin of domestic cats was not Ancient Egypt - which is the prevailing view - but Mesopotamia and that it occurred much earlier than was thought. The last common ancestor of wildcats and domesticated cats lived more than 100,000 years ago.
‘However, we do not know exactly when cats were domesticated, although it is likely to have been around 10,000 years ago when other animals like cattle and goats were domesticated.’
From Cat to Cult
The experts believe cats originally sought out human company, attracted by rodents infesting the first agricultural settlements. These early farmers would have found the animals extremely useful for protecting their grain stores.
Over the generations they selected the friendliest and most reliable creatures for breeding, creating the domestic cat in all its forms and forging the peculiar relationship between human and feline that has lasted to this day.
Although the first domestic cats appeared in Mesopotamia, it was the Egyptians who turned them from a working animal into a pet and then later into a god-like creature, creating a cult that was passed on to the Romans and exported around the world.
Although the domestication of the cat has been pushed back thousands of years, it still took place long after dogs were tamed. Scientists believe the first wolves and wild dogs began to live alongside hunters around 100,000 years ago.
The next puzzle, says O’Brien, is locating the genetic mutations responsible for making cats tame. Finding these ‘tameness genes’ is one of the goals of a cat genome project currently being conducted by a consortium that he leads.
The study has also identified a genetic marker for the Scottish wildcat, which is endangered because breeding with domestic cats is diluting its gene pool. Scientists will now be able to work out how many Scottish wildcats are left, although it is believed that there may be fewer than 500.