3 ms·

DNA is discrete. It can be precisely represented symbolically.

• rcthompson 12y ago
  DNA is a lot less discrete that you might think. There's epigenetic factors and population proportions, for example. But even considering DNA as just a 4-letter language with discrete characters, my point is that many, even most, small sequence changes to a genome (e.g. single-nucleotide variants) have small effects or no effect at all, which gives evolution a smooth enough gradient to optimize things over time. That's what I mean by continuous in this context. The opposite would be, for example, a hash function, where any change, no matter how small, completely changes the output. Hence you couldn't "evolve" a string with a hash of all 7s by selecting for "larger proportion of 7s in the hash function", because hash functions are completely discontinuous by design. But you can evolve a bacterium that includes more of a given amino acid in its proteins by selecting for "larger proportion of that amino acid in protein extract".