Your statement, "Every scientist working on this problem agrees it was a natural process." is baseless conjecture.
If you actually do your research you will find a very large question mark about life. It cannot be analyzed, quantified, duplicated or created. Existing life can be modified. But that is all we know except for this. Psalm 36:9 just tells us God is the source. That is all anyone knows. Period.
The Bible tells us after the earth was cool enough for a world ocean God started the process of preparing the earth for being the home of us humans. How much time that took is unknown. Billions of years? The Bible just breaks it up into six creative days. And to make matters more interesting, those days overlapped in cases.
God of the gaps? What gap are you speaking of? Maybe you are referring to the totally erroneous view of those who style themselves as creationists? If so, know this. The Bible does not back up their claim.
All we know is the human family was created a little more than 6,000 years ago.
How long will humans live on earth? Here are two places in your Bible to check.
Psalm 72:7 tells us until the moon is no more. At its present rate of pulling away from earth, the moon will cease affecting out tides in about 3 billion years. That is close to the time when our sun will run low on hydrogen and start fusing helium and become a red giant.
But is that all? Look here...
"25 Long ago you laid the foundations of the earth,
And the heavens are the work of your hands.+
26 They will perish, but you will remain;
Just like a garment they will all wear out.
Just like clothing you will replace them, and they will pass away.
27 But you are the same, and your years will never end.+
28 The children of your servants will dwell securely,
And their offspring will be firmly established before you.” (Psalm 102:25-28)
Bottom Line
By the time entropy (heat death) makes the universe "wear out" and need to be replaced, man will still be. And when the replacements are ready, man will still be. But no matter what assignments we have throughout the universe or how many people live, the earth will always be our ancestral home. That will be tru even if the planet no longer exists.
Any more questions? Go here for answers.
http://www.jw.org/en/bible-teachings/questions/