Thursday, April 20, 2017

The last molecular evolution exam: Question #4

More than 90% of our genome is transcribed when you add up all the transcripts from various cell types and various times of development (= pervasive transcription). Many biologists take this as evidence that most of the DNA in our genome is functional. What are the counter-arguments? Who do you believe and why?

Question #1, Question #2, Question #3, Question #4, Question #5, Question #6

1 comment :

  1. A transcript is only evidence for transcriptase activity, not the activity of the transcript itself. Leaky RNA transcriptase activity can transcribe junk DNA and lead to non-functional RNA trascripts. Also, recently formed pseudogenes can produce a large number of non-functional RNA trascripts if the gene promoter is still operational.

    Therefore, the null hypothesis is that transcripts are non-functional. You need evidence for function outside of the mere existence of an RNA transcript.