It seems the more we learn about biology the less plausible any naturalistic account of living things becomes. Science has discovered that living cells, for example, are filled with tiny protein machines that are constructed just like machines in the macro-world. The amazing functions and complexity of these machines strongly suggests intentional, purposeful engineering and only someone with an apriori commitment that permits only materialistic, naturalistic causes could insist otherwise.
One of perhaps thousands of such machines in living things is the tiny motor in the cell's mitochondria that produces, or synthesizes, ATP from ADP. ATP is a molecule that provides energy for myriad tasks within the cell, and copious quantities of it are necessary for the cell's vitality. The motor that churns it out, called ATP synthase, is illustrated in this short video:
One can believe that this device came about as a result of blind, purposeless, random processes like genetic mutation. One can believe that such things happened in a land faraway in the far, far distant past, but one would be hard-pressed to show how impersonal forces produce such marvels in any other sphere of human experience.
In other words, when we see machines like this we understand them to have been designed purposefully by an intelligent agent or agents. We have a "uniform experience," to borrow Hume's term, that machines do not result from the mindless activity of natural forces and processes but require the intentional activity of a mind.
It's not logically impossible that such contrivances could come about apart from intelligent agency, I suppose, but it takes a blind, irrational faith in chance and nature to think that they actually have.
