The importance of gene transfer among bacteria is already fully accepted. Now we learn that the rate of gene transfer can be enhanced by environmental stress. We wonder how many forms of stress will enhance horizontal transfer among bacteria, and whether eukaryotes have a version of the same mechanism.

To make the finding conform to the darwinian paradigm, the writers must suppose, "Rather than being simple, the common metazoan ancestor was genetically complex, containing many genes previously considered to be vertebrate innovations." (Nothing like this phylogeny is suggested in the fossil record.) They must also suppose that the rate of gene loss accelerates significantly on the branches leading to non-mammalian kingdoms. (Else those kingdoms would have the genes as well.)

The evolution of new features — like the ones that differentiate humans from coral — depends on the acquisition of new genetic programs. Suppose these do not arise by the darwinian method, but arrive by horizontal transfer. In this case, the presence of human genes in coral, and not elsewhere, does not create a crisis. But it is still quite interesting!

"Red coloured rain occurred in many places of Kerala in India during July to September 2001 due to the mixing of huge quantity of microscopic red cells in the rainwater. Considering its correlation with a meteor airbust event, this phenomenon raised an extraordinary question whether the cells are extraterrestrial. Here we show how the observed features of the red rain phenomenon can be explained by considering the fragmentation and atmospheric disintegration of a fragile cometary body that presumably contains a dense collection of red cells. Slow settling of cells in the stratosphere explains the continuation of the phenomenon for two months. The red cells under study appear to be the resting spores of an extremophilic microorganism. Possible presence of these cells in the interstellar clouds is speculated from its similarity in UV absorption with the 217.5 nm UV extinction feature of interstellar clouds." [Thanks, Michael Paine and Chandra Wickramasinghe.]

photo by B. Stedman

My initial interest was to find out more about the role of viruses in evolution. I was intrigued to learn from Luis Ruedas (n.s.) of Portland State that mice infected with hantavirus live longer than uninfected mice. And Paul Turner (3) of Yale explained that viruses can generate "gene transfer agents" that contain host genes only — no viral genes. When the cell dies these may be released into the environment for possible incorporation into other genomes.

But my primary lesson was that the world of viruses is huge and mostly unknown. In this regard, Forest Rohwer (4) of San Diego State University observed that the number and variety of viruses in seawater are ten times those of the next-most abundant life form, bacteria. And by his estimate, less than .0002% of the bacteria-infecting viruses have been studied!

In the past decade, we have become aware of dozens of examples like this one in which a new genetic program or subroutine was acquired by horizontal transfer. However, for providing new functions, this process should be much less frequent than the mutation of sequences inherited vertically, according to the darwinian paradigm. If so, by now scores or hundreds of new examples illustrating that process — new genes written by mutation — should have been published. Where are those articles?