Random sequences rapidly evolve into de novo promoters
How new functions arise de novo is a fundamental question in evolution. We studied de novo evolution of promoters in Escherichia coli by replacing the lac promoter with various random sequences of the same size (~100 bp) and evolving the cells in the presence of lactose. We find that ~60% of random sequences can evolve expression comparable to the wild-type with only one mutation, and that ~10% of random sequences can serve as active promoters even without evolution. Such a short mutational distance between random sequences and active promoters may improve the evolvability, yet may also lead to accidental promoters inside genes that interfere with normal expression. Indeed, our bioinformatic analyses indicate that E. coli was under selection to reduce accidental promoters inside genes by avoiding promoter-like sequences. We suggest that a low threshold for functionality balanced by selection against undesired targets can increase the evolvability by making new beneficial features more accessible.
Almost like biochemical activity is common and easy, and systems governed by stochastic electrosteric interactions are lousy with easily evolved near-misses.
It definitely is. I’ve referenced it numerous times on this forum(such as here), in discussions concerning the relationship between non-coding DNA, junk-DNA, and de novo gene birth.
It ties in really well with the concept of noisy, spurious, or so-called pervasive transcription providing the source materials for potentially selectable open reading frames evolving into bona fide protein coding genes.
I completely agree, and I love that he is very into science at this stage in his life! I’m just not going to bring up ID, should we ever have the chance to meet
Dating myself a bit, but I saw him in concert when I was a senior in high school. Vanilla Ice was supposed to be the opening act, but he cancelled. Oh, those were the days. Please Hammer . . . don’t hurt 'em.
