Distant Cousins: The Elephant and the Mouse

Research Shows SIZE Irrelevant When it Comes to Similar DNA

Scientists are discovering that in some cases, the building blocks of DNA are starting to resemble a pair of dice in what is turning out to be the crap-shoot of life.

Who'd have thought for example, that the dolphin and the giraffe were related? Or the majestic elephant and the tiny field mouse? And I don't mean "related" in some vague way because these are "animals." I 'm telling you these pairings have a lot in common because the father down you whittle away the DNA the more plusses you come up with as compared to minuses.

Such is the result of research completed by Professor Carlo Alberto Redi of the University of Pavia (www.unipv.it) and whose findings -after studying hundreds of mammals -- were recently published in the Journal of Molecular Evolution (www.springerlink.com)

Redi (biographical sketch at www.unipv.it) and his team of researchers discovered that different animal species have a number of similar chromosomes and have more in common than meets the eye.

According to an article posted on www.innovation.ca, "molecular evolution," is based on the premise that a comparative analysis of sequences of molecules, in particular that of DNA, can be traced to apparently different species. In other words, as two species diverge in evolution from a common ancestor, their genes will accumulate mutations. Some of these mutations will affect the function of the protein or RNA that the gene encodes, and some will be simply neutral. The longer the divergence, the more the accumulated mutations. And the more the accumulated mutations, the greater the difference between the genes. It is this difference between genes (more precisely, gene sequences) that can be used as a measure of evolutionary divergence. Getting back to the Journal of Molecular Evolution and how this ties in with elephants and mice, typically, the pattern of differences is represented by what is called a phylogenetic tree, or genealogy -- the Tree of Life. As a result, we can reconstruct past events that gave rise to the current panoply of similar and dissimilar creatures by isolating and sequencing specific genes from their DNA.