Eugene Koonin has written a paper on the origin of life in which he acknowledges that, given what we know, the odds of any system capable of replication of genetic material and translation (replication and translation: R&T) into proteins of that genetic material arising by chance are exceedingly close to zero.
That being so how can we account for the appearance and existence of life? We must certainly increase the odds somehow, but there are really only two ways of doing that - either introduce intentionality (Intelligent Design)or postulate a near infinite number of worlds in which chance operates.
Koonin explicitly wants to avoid the former so he embraces the latter and plunges himself into the very metaphysical speculation he wants to avoid:
I only discuss here what is often called "weak" anthropic principle and is the only acceptable scientific rendering of this concept. The so-called "strong" anthropic principle is the teleological notion that our (human) existence is, in some mysterious sense, the "goal" of the evolution of the universe; as such, this idea does not belong in the scientific domain.
Having discarded an explanation because he considers it metaphysical and unscientific he then adopts a second hypothesis that is itself metaphysical and unscientific.
He argues that the universe is really a multiverse, infinite in extent, containing every possible kind of universe consistent with the laws of physics (I'm not sure why he adds this qualifier since there could certainly be universes which are inconsistent with the laws of physics, at least as we know them). If that is so, and given that a universe in which R&T occurs by pure chance is a possible universe, no matter how unlikely, such a universe must exist and we're in it. In other words given enough trials anything that is possible to happen, no matter how improbable, will happen. Since our universe is a possible universe, given an infinite number of worlds and an infinite amount of diversity, our universe must exist.
This is a wonderful piece of metaphysical legerdemain. Simply postulate the existence of a near infinite number of worlds, never mind about adducing evidence for them, stir in the tacit but crucial assumption that those worlds would be infinitely diverse, and presto, a world with life in it just has to exist.
Koonin's goal in writing this paper is, as he makes clear, to allow his fellow materialists to avoid the despair which results from having no answer to those pesky Intelligent Design people. He writes:
A final comment on "irreducible complexity" and "intelligent design". By showing that highly complex systems, actually, can emerge by chance and, moreover, are inevitable, if extremely rare, in the universe, the present model sidesteps the issue of irreducibility and leaves no room whatsoever for any form of intelligent design.
Perhaps, but at what cost? After all, if we are to accept the assumption that in an infinite number of worlds all possibilities consistent with the laws of physics become actual (and they must do so an infinite number of times) then it follows that there must be an infinite number of worlds that are intentionally designed since that is certainly a possibility consistent with the laws of physics.
But set that aside and note the implicit admission in Koonin's words. Unless there are an infinite number of worlds representing all possible biological histories the idea of Intelligent Design becomes very difficult to avoid.
Note, too, that Koonin purports to be advancing a legitimate scientific hypothesis even though it's full of metaphysical speculation. Yet Intelligent Design is condemned by the scientific establishment because it has metaphysical implications.
Koonin's paper is very learned, but it's really an act of learned desperation.
RLC