Natural selection is an inadequate metaphysical basis for biology because it lacks teleology, a goal, direction or purpose.
This means that the potential for meaning - for knowledge - is excluded. It is too small a frame - it leaves so much out that is so important that what is left is not even a coherent subject.
This is revealed in its incapability of understanding the meaning of life and it origins, major transitions and categories. Without teleology, biology is net-destructive.
Indeed - without teleology we cannot know. I mean we cannot explain how humans could have valid knowledge about anything.
If Natural Selection is regarded as the bottom-line explanation - the fundamental metaphysical reality (as it is for biology, and often is with respect to the human condition) then this has radically nihilistic consequences.
Because natural selection is at best - when correct - merely descriptive of what-happened-to-happen. There was no reason why things had to be as they actually were, there is no reason why the present situation should stay the same, there will be no reason to suppose that the future outcome is predictable.
There is no greater validity to what-happened-to-happen compared with an infinite number of possible other things that might have happened - so there is no reason to defer to what-happened-to-happen, no reason why what-happened-to-happen is good, true, just, powerful or anything else - what-happened-to-happen is just what led to greater differential reproductive success for some length of time under historical (and contingent) circumstances. Nothing more.
Therefore - if humans are nothing more or other than naturally-selected organisms - then there is zero validity to:
or science - including that there is no validity to the theory of evolution by natural selection.
In sum - Without teleology, there can be no possibility of knowledge.
(This is not some kind of a clever paradox - it is an unavoidable rational conclusion.)
None of the above have any validity - because they all what-happened-to-happen.
If and only if biology includes direction and purpose, is the subject compatible with the reality of knowledge.