What history tells us XXXVI. Reverse transcriptase and Lamarckian scenarios of evolution.

Abstract

The discovery in 1970 of reverse transcriptase was considered as a blow to the Central Dogma of molecular biology. But there was more in this discovery : the possibility to generate scenarios in which the genome would be modified (by insertion of reverse transcripts) following a functional adaptation of the cells (and organisms) to variations in their environment ; i. e. a lamarckian mechanism of evolution. Howard Temin, one of the discoverer of reverse transcriptase, was the first to explore this possivbility, without success. In 1988, John Cairns proposed a similar scenario to explain the rapid occurrence of adaptive mutations in bacteria. After some years of a hot debate, other, non-lamarckian, mechanisms were proposed to account for these observations. I try to explain the recurrence of these heterodox models.