Charles Darwin Question

[caelestis]

Hello,

I'm having a lot of trouble with this statement and was wondering if someone could help clarify or give me a brief explanation of Darwin's conceptual gap??

It reads "Charles Darwin presented ideas on the causes of organismic change through time.
A primary conceptual gap existed which left his theory open to criticism."

I have tried endless hours searching the web for more information and reading through my textbook but had still no luck...

Thankyou I would really appreciate your help.

[mith]

Darwin never addresses how. That's where genetics comes in.

[Darby]

If the changes are small and gradual, then it's hard to explain where "jumps" come from - no one knew of mutations or how protein properties could change radically with a small coding alteration, or duplicate.

[alextemplet]

People must have known something about variation at that time didn't they? After all, selective breeding of domestic species had been a well-established practice for millenia. Not exactly the same as genetic science but it's something.

[Darby]

The issue was that with just the variation shifts they saw, it was hard to explain scales becoming feathers, or fins becoming legs. You needed a mechanism that could produce fairly dramatic shifts.