This past week’s science readings on the web look like they might well have come from the tabloid magazines. Besides all the jokes about changing a tiger into a lion or a cheetah, we have stories of giant viruses driving the evolution of microorganisms. We note that cat DNA has been found in the HIV/AIDS virus and pandas are genetically like dogs.

One exercise that upper elementary or junior high students go through when first introduced to the Life Sciences is developing an operational definition of what is ‘Life’. Sophisticated Biology students from High School to Post Graduate studies are still coming to grips with this puzzle. Now scientists are looking at giant viruses found in amoebas and the roles played as “melting pots” of microbial evolution. It will be fascinating to hear the discussions of where these giants fit into the grand scheme of life.

And then it seems that an entire cat gene has been found in the HIV virus. The gene plays a significant role in terms of human infection by the virus. According to the study, this gene helps the virus do some “fancy footwork” at the final copying process. Discovered nearly 30 years ago, it has only recently been recognized to actually come from a cat.

In a previous blog I noted that Dr. Luc Montagnier was looking seriously at the HIV virus as a vector for genetically engineering human disease. He also indicated that he thought that a lot of retrovirus DNA might be found in the human genome.

Although he did not say it, others have noted that the so called “junk” DNA may be an example of selfish DNA. Additionally, it is possible that the repetitive and noncoding DNA may act in some ways to protect the DNA code through the sheer vastness in much the same way large numbers of herbivores are safer against predators.

And then there is the release of Jingjing’s Genome. Jingjing, a giant panda, was the official 2008 Olympic Mascot. According to Scientific American, the giant panda is only the second Carnivora to be sequenced, the first being the dog. The study indicates that the giant panda genome is smaller than the human genome containing 3 billion base pairs and 21,000 genes. In spite of the small panda population, this study revealed that there are no signs of inbreeding. Jun Wang of BGI-Shenzhen in China and the University of Copenhagen remarked that there is a slow rate of evolution consistent with the notion that the panda is a “living fossil”.

The most interesting revelation in this genome is that mutations have robbed pandas of their ability to taste meat, pushing them toward their bamboo diet. Incredibly, the panda has all of the genes required to digest meat, yet none of the genes to digest bamboo. The microbes in their gut (microbiome) have become extremely important for the digestion of bamboo. The authors are confident that this genome, besides acting as a reference, will also make important contributions to make both to ecological and population studies in the future.