Re: Shall we get rid of our junk?

One of the main practical goals of the biota is to quickly recover from
catastrophic extinction events. Understanding this is essential to
understanding the function of "junk" DNA.

Suppose a meteor impact caused the extinction of all mammals on this
planet except for two populations of mice: 1) A populations of mice on
the euroasian continents that have there "junk" DNA intact and: 2) A
populations of mice in the Americas that had been alterred by
scientists such that all of their "junk" DNA was erased.

What might we expect to observe as these populations of these two
continents evolved over thousands of years? (Everybody should consider
themselves invited, or even compelled, to provide their own answer to
this question.)

This is my answer to this question:

At first, let's say 10 years after the extinction event, we'd see
rapid exapansion of mouse populations on both continents. No
difference from one continent to the next. But if we came back in
10,000 years we'd find, IMO, a big difference between the biota on
these continents. On the euroasian continent there'd have been rapid
evolution. New species would have evolved from the original mouse
populations and would have begun to repopulate the niches that existed
before the extinction event! In stark contrast, in the Americas at
this same point in time, you'd see a continent filled with mice and
slight variants thereof. IOW, the mice that lacked "junk" DNA would
prove competitively incompetent. Eventually, maybe sooner rather than
later, some of the species from the Euroasian continent would gain
entry and rapidly come to dominate the Americas, and this would
probably cause the extinction of the American mice.

Junk DNA is not junk. It is the primary strategy that Gaia employs to
achieve its greedy goal to maxmize the probability that life will
survive into eternity.

Jim


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