Sunday, April 10, 2011


The ordinary parasite may have an additional inspiring pedigree than once consideration: Dinosaurs might have hosted the scrounging bugs, a study says. The findings, available Tuesday in the journal Biology Letters, in addition illustrate through similarity of lice that mammals and birds can have begun to grow earlier than the dinosaurs went extinct 65 million years ago. That's counter to a long-held idea that they only ascended and diversified on one occasion the dinosaurs were gone.
Parasites waste their whole lives on one species, so they develop beside with their hosts. That means their similarities can be use as a way to learn evolutionary interaction between the   Johnson, an ornithologist in the University of Illinois at Campaign. The international group of researchers looked at DNA comparison between 69 recent lineages of lice that provide for various birds and mammals. Based on this DNA comparison, the scientists were intelligent to assume how much time had agreed since a variety of lice shared ordinary ancestors.
The scientists also use fossils in construction their parasite family tree: a 44-million-year-old bird louse fossil and a 100-million-year-old book louse fossil. Based on the dinosaur’s fossils substantial individuality, the scientists were intelligent to decide wherever they fit on the family tree of the lice with the aim of had been analyze heritably. Those anchoring time points permitted them to fix dates at which further lice in the tree divided to develop into separate species. The researchers accomplished that lice began diversifying around 125 million years ago, so their hosts birds and mammals should have begun diversifying well earlier than the dinosaur die-off.
Researchers used some fossils of very old lice, including this 44-million-year-old example
Johnson said that dinosaurs may still have been the primary animals to have parasites. Reptiles have no hair or feathers against which a louse might latch, but lice could have lived on the initial feathered dinosaurs, and then sustained to do so as individuals dinosaurs evolved into birds.

No comments: