Sentences with word «eutherian»

To figure out how chromosomes of placental mammals have changed over time, researchers need to know what those early eutherians started with.

The researchers came up with 21 pairs of ancestral eutherian chromosomes, they report today in the Proceedings of the National Academy of Sciences.

So team member Jaebum Kim, now at Konkuk University in Seoul, and colleagues wrote a sophisticated computer program that was able to reconstruct the original eutherian chromosomes based on what parts of the chromosomes are together today in those 19 species.

Although the Portsmouth team points out that both the age and classification of Juramaia is up for debate, the overall scientific consensus still seems to give the title of oldest eutherian to the Chinese specimen.

Rat chromosomes, too, are very different than the early eutherian's, but for a different reason: Their chromosomes swapped pieces between chromosomes rather than within a given chromosome.

There are three kinds of mammals: egg - laying monotremes such as the platypus, marsupials like kangaroos and opossums, and the majority — placental, or eutherian, mammals — including humans and about 4400 other mammal species.

To do that, Harris Lewin, an evolutionary geneticist at the University of California, Davis, and colleagues compared 19 genomes of various mammals at different spots in the eutherian family tree, including several primates.

By comparing 400 morphological features, such as the shapes and numbers of teeth, in the new fossil with those in 68 other specimens, the researchers have now placed the 73 - million - year - old creature in the Eutherian evolutionary tree, an umbrella group that includes placental mammals.