A New Wave of Science Blogging?
7 hours ago in Labs
"I know that most men, including those at ease with problems of the greatest complexity, can seldom accept even the simplest and most obvious truth if it be such as would oblige them to admit the falsity of conclusions which they have delighted in explaining to colleagues, which they have proudly taught to others, and which they have woven, thread by thread, into the fabric of their lives."How are we testing this assumption? By looking for evidence (at the molecular level) of how selection has shaped the processes that cause recombination. There are three such processes, but two of them, conjugation and transduction, can be easily shown to cause recombination only as side effects of genetic parasitism by plasmids and phages respectively. That leaves natural competence (DNA uptake) and its genetic consequence (transformation), which is what we work on. Transformation itself arises when the so-called recombination machinery in the cell acts on DNA the cell has taken up. But this machinery exists not because of selection for making new combinations of genes using DNA brought in from outside, but because of selection for the ability to repair and replicate the cell's own DNA. Because transformation itself is an unselected side effect of the replication and repair machinery, we concentrate on understanding how natural selection has acted on natural competence (the DNA uptake process).Leo Tolstoy