I suspect the biologists presumed their invitees would follow the biologists' methodology of fitting new observations into established theory (dogma, in effect) - even if it must be kluged to fit. But to physicists science is all about the theory. And mathematicians require proof, not dogma.
As H.H. Pattee said:
I have wondered for some time now about the late, great Ernst Mayr's seeming insistence that biology is so separate from physics, that it needs to declare itself a "sovereign" discipline of the natural sciences, that at once requires all "intelligent" people to bend the knee to Darwinian evolutionary theory, while at the same time maintaining that Darwinian evolutionary theory isn't a straightjacket on human thought.
The late, great Mayr evidently did not consider possibilities other than evidence that can be gathered from direct observation, direct perception.
I wonder what he is perceiving now. R.I.P. Tricky problem there. I don't think he solved it. Much to his rue as I imagine.