Irish American scientist leads breakthrough research that finds common ancestor for mammals

This 2012 artist's rendering provided by the American Museum of Natural History shows a hypothetical placental mammal ancestor

Dr. Maureen A. O’Leary of Stony Brook University on Long Island was a leader in a research project that published results in the journal Science this week that claims to identify the creature that was all mammals’ common ancestor.

The story also appeared on page one of The New York Times and the team could be in the running for a Nobel Prize in science for the discovery

O’Leary is the daughter of well known Irish-born Democratic party activist Stella O’Leary who is based in Washington.

The New York Times reports on O’Leary’s fascinating new discovery, which piggybacked on research that helped further prove that a comet or asteroid hit the Earth some 65 million years ago, killing off all the dinosaurs.

“I think it's fair to say, without the dinosaurs having gone extinct, we would not be here," said Paul Renne, director of the Berkeley Geochronology Center, who led the research on the dinosaurs and cosmic crash. The dinosaurs' disappearance "essentially releases the little timid mammals to become the big guys."

And it was those ‘little timid mammals’ which gave way to human life as we know it today.

"In some sense, we are a product of that opportunity,” said O’Leary of the end of the dinosaurs.

Acting as the lead of 22 researchers, O’Leary and her team examined 4,541 different characteristics of mammals both still around and extinct, and traced their DNA and their physical features back until it seemed there was a common -- and hypothetical -- ancestor.

Using their research, the team was able to envision what the common mammalian ancestor might have been. Said O’Leary, "This isn't something that is just a guess; this is something that is a result of the analysis. This thing had a long furry tail. It had a white underbelly and it had brown eyes."

Further, the common ancestor is described as roughly rat-sized weighed no more than a half a pound, and lived on insects.

The common ancestor is at the top of a specific branch of mammals, the ones that nourish their offspring through gestation.

The common ancestor, as the New York Times explains, could have “led to some 5,400 living species, from shrews to elephants, bats to whales, cats to dogs and, not least, humans.”