Blog dedicated primarily to randomly selected news items; comments reflecting personal perceptions

Monday, August 29, 2016

Primal Fire

"We realized that the discovery of controlled fire must have caused a significant shift in the way humans were interacting with each other and with the environment [factors known by scientists to drive the emergence of infectious diseases]."
Rebecca Chisholm, biologist, University of New South Wales, Australia

"I hope these studies [primal emergence of humans controlling fire and consequences therefrom] will spur us to think more about fire, and take it in all the different directions it can go."
Caitlin Pepperell, professor, University of Wisconsin-Madison

The first evidence of early humans using fire dates back to more than a million years, but the practice did not become routine until about 650,000 years later, the latest research indicates. Photo: Reuters
When early man understood the function of fire pertaining to its practical domestic use, it became the most valuable commodity available to enterprising humankind, seeking above all to fulfill the obligation that nature blueprinted all her creatures with: striving to succeed with the imperative to survive. Basic human ingenuity even in its primitive form enabled humankind to understand the function and facility of crude tools to make life just a trifle easier; tools to prevent carnivores other than man from their own destiny, to destroy so they too could survive.

Tools to help manipulate early hominids' environment in any way that could prove to be helpful; defence, offence, carving, skinning, cutting and slicing. But only fire had a range of valuable and practical purposes that no other element gave promise to; it could help fend off attacks by other wild animals who feared fire, it could warm those close to it during cold, dark nights, it could illuminate and give light during the night hours, and above all, it could roast and cook meat for much easier consumption.

Tending a fire, seeing it would never be extinguished must have been a very important task, until it was understood that flint and dry mosses could help initiate new, controlled fires. So that when males went out hunting, with their superior physical strength and their sharpened flint-and-sinew-and-stick weapons to bring down the day's slaughter, women could be left at the hearth to tend the fire and look to the welfare of the hugely dependent young.

The immense evolutionary advantage conferred on humankind with the discovery that fire could be a volatile, but sometimes-obedient pet to add huge quality to life, is legendary; a gift from the gods -- or the one called Gaea. But science is never content to sit on its laurels, hypothetical or proven, and other theories are always waiting in the wings to be expressed.

One such is a study published by scientists who identified a genetic mutation in modern humans, one that permits us to metabolize certain toxins, smoke among them, at a safe rate so that we would not be overwhelmed completely unless that inhalation was too severe. No other primates shared that same newly-detected genetic sequence, not even Neanderthals and Denisovans. These researchers feel that this was a genetic adaptation to our supreme advantage.

In response to breathing in smoke toxins, which would be commonly the case when early humans lived in caves and built fires in them with smoke resulting and circulating in the near proximity to be breathed in by whomever would be there, a slow process of selection in response to the smoke toxins occurred since the risk of respiratory infections, the suppression of the immune system and disruption of the reproduction system would have completely negated the progress realized by fire's use.

This mutation, it is hypothesized, granted 'modern' humans (homo sapiens), an evolutionary head-start over Neanderthals, according to Gary Perdew, professor of toxicology at Pennsylvania State University, one of the paper's authors. The mutation theory, if correct, may have been the enabler to allow modern humans to become inured against adverse effects of fire; a bit of serendipity not shared by other species.

Another study recently published in Proceedings of the National Academy of Sciences makes the suggestion that profound new damage accompanied the advantages to humans with the use of fire. It might have initiated the spread of tuberculosis through bringing people in close contact with one another in early groups that assembled for mutual protection, and shared in close quarters all the advantages they had, including fire.

The most natural reaction to smoke infiltrating one's breathing apparatus is to involuntarily cough to clear passages. Incessant coughing as a result of ongoing and prolonged exposure to smoke would have the effect of damaging lungs. Biologists Rebecca Chisholm and Mark Tanaka from the University of New South Wales simulated the manner in which ancient soil bacteria could have evolved as infectious tuberculosis agents when fire and the heat it produced helped tuberculin bacteria to evolve.

As for gender-assigned roles, it is entirely feasible that these became set in the minds of inherited generations from the time that men took their superior strength and their hunting tools out to the fields and forests to bring home the raw meat to be cooked over the fires that women were left to tend, along with their offspring.

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