Setchell based his claim on a basic temperature testing of the Yellowstone Park waters in which various bacteria masses were multiplying so successfully that they could be easily seen by the naked eye of a three year old child attracted to colorful strands in the water.
In other words, this was not a natural event that scientists could not study until technology had advanced much further ; this was junior high Bio 101.
The real problem was that in 1903 and for a long time there after, all scientists (well almost every scientist respected by other scientists) simply knew that Life was organized in an absolute hierarchy of complexity, with the educated White Man at the very top and the 'primitive' microbe at the very bottom.
Any suggestion that microbes had superior genes that allowed them to live in deeper, higher, colder, hotter, under greater pressure, more acidic or more basic conditions than Man-the-Conquerer was simply not on.
For simply suggesting that creatures at the very bottom of this hierarchy of Life were superior to the creatures at the very apex threatened to pull down all the human hierarchies it indirectly supported : those of man over woman, whites over colors, urban over rural, new over old, well do to do over the poor, adults over children, protestant over all others, anglos over dagos etc.
Science, I never tire of repeating, is not based on cooly examining the facts, but on examining facts after filtering them first through the immense prism of the scientists' social consitioning, at a particular place and point in time.
(Skip that particular place bit - scientists are such a globally minded lot, they all move in unison, based on their collective conditioning at particular points in time.)
WWII, with its unexpected death-dealing Auschwitz & Hiroshima produced by the most civilizied of men and its unexpected triumph of life-saving Penicillin produced by primitive microbes, was needed to change those social conditioning.
A process that led to Setchell's lost work being discovered and re-valuated, sixty plus years later, by a few other scientists, but long after he was already long dead and buried.
So, whenever you hear the word "DNA Testing" ,think of Setchell because that hot water pond slime he found all those years ago -and the scientific world ignored - is today the source of the heat-resistant enzyme that makes it all possible.
Crucial stuff yes - but nowhere in a billion years as important as the intellectual sea change his discovery should have produced - one that could have done much to reduce all the horros huaman inflicted on other humans and upon all lifeforms.
Seventy five years later after his death, a hundred years after his discoveries, I still insist that he is a scientist to whom serious attention must finally be paid....