Reverse transcriptases were discovered by Howard Temin at the University of Wisconsin-Madison in RSV virions[REF] and independently isolated by David Baltimore in 1970 at MIT from two RNA tumour viruses: R-MLV and again RSV [REF].
The idea of reverse transcription was very unpopular at first, as it contradicted the central dogma of molecular biology, which states that DNA is transcribed into RNA, which is then translated into proteins.