Even that isn’t really clear in practice as I understand it. The genetic drift from proto chicken to chicken likely means that there is no single instance of proto chicken birthing chicken, even if you could fully sequence the DNA of every proto chicken. It’s kind of an inconvenient issue with DNA taxonomy, because if we really did have that full DNA history, there would likely be several different populations with overlapping genetics and we might actually choose to draw that line for a number of different mutation combinations when they start statistically creating certain traits, instead of a single mutation. But oh no now we are back to descriptive taxonomy so let’s just move on.
The reality is that we haven’t really observed speciation in a controlled setting, so the current framework almost requires us to sample the evolutionary timeline at long intervals, or it starts to get sloppy.
Even that isn’t really clear in practice as I understand it. The genetic drift from proto chicken to chicken likely means that there is no single instance of proto chicken birthing chicken, even if you could fully sequence the DNA of every proto chicken. It’s kind of an inconvenient issue with DNA taxonomy, because if we really did have that full DNA history, there would likely be several different populations with overlapping genetics and we might actually choose to draw that line for a number of different mutation combinations when they start statistically creating certain traits, instead of a single mutation. But oh no now we are back to descriptive taxonomy so let’s just move on.
The reality is that we haven’t really observed speciation in a controlled setting, so the current framework almost requires us to sample the evolutionary timeline at long intervals, or it starts to get sloppy.