>Darwin's generation was around the last who could have a full understanding of all branches of science
And
>Not really no. A single person can no longer know, grok even the whole of biology, or even the whole of molecular biology.
have always struck me as odd statements to make.
Not to get pedantic, but that's more of a commentary of our classification of knowledge than the kind of tasks they had to deal with. They were presented with the same living beings that we have today (well, those that aren't extinct anyway). No more, no less.
They had plenty of chances to get overwhelmed with what was in front of them, regardless of what their contemporary science had figured out already.
Put another way, not knowing how things work didn't make their jobs any easier. The way things work doesn't change no matter how many branches of science you throw at it.