[__loam]

It's easy to forget how grounded in physics biology is. When I was in college, we had an issue where our stem cell lines were differentiating into bone. Turns out, the hardness of the environment is a signal stem cells can transduce, and the hard dish was telling them they were supposed to be bone cells.

[praptak]

Hmm, this mechanism can only add more bone to existing bone, right?

So how do the first bone cells know to start becoming bone?

[empiricus]

probably a transient signal (in the rna-protein soup) that happens during embryonic development.

[__loam]

Which came first, the chicken or the egg?