[jack6e]

In another story popular on HN yesterday/today about DNA [0], some of the commenters discussed epigenetics, and the fact that the DNA sequence is simply the "hardware" that encodes what is possible for cells to produce, but there is "software", if you will, above that which determines how sequences of DNA are actually expressed.

In these cases of analyzing really old DNA where only the DNA remains, I wonder how researchers make decisions about selecting what they want to express between varying attributes? I.e., the example used in the article about representing "Cheddar Man" - did they have some basis for selecting the traits to visualize or was it arbitrary?

[0] https://news.ycombinator.com/item?id=16589412

[laretluval]

I'm not sure the hardware/software analogy is useful. It's more like DNA is source code with a bunch of if statements that depend on the chemical environment the cell is in.

[jack6e]

Sorry if that is wrong, I'm just repeating the metaphor used by the more educated people in that other thread to the best of my understanding.

[jccooper]

Epigenetics can sometimes influence pigmentation, but expression of human skin and hair colors is pretty explicitly genetic, so you can expect the same results from the same genes a mere several thousand years apart.