rationalskepticism.org

Jayjay4547 wrote:

zoon wrote:

Jayjay4547 wrote:..
What’s this Cito? Sweat glands? Actual things with functions? Tell me more!

Are you saying here that in your view, sweat glands have a function: to help regulate the temperature of the individual?

Yes

Jayjay4547 wrote:

zoon wrote:If this is your view, then what difficulty do you have with the view that they evolved through natural selection? A chance mutation in one gene of one individual made that individual slightly more likely to have damp skin and stay cooler in the heat, so that individual survived and had more descendants with the same mutation, and the mutation is eventually carried by most of that population. Over hundreds of thousands of years further chance mutations which improved thermoregulation appeared, and again gave the individuals carrying those mutations a better chance of surviving and passing on those genes. This process is not self-creation, since nobody's creating anything, but it does lead to the appearance of functionality. It's also a process without apparent purpose, since the functionality appears with no need for any guiding intelligence.

Your outline says how but it hides “why” in the phrase “improved thermoregulation”.

Jayjay4547 wrote:
Does a “damp skin and stay cooler in the heat” improve thermoregulation if it comes at the cost of losing up to 14 litres of water per day? (Wiki entry on perspiration). I read as a child that a damp skin hobbled the dry land evolution of amphibians. If the damp skin is so advantageous, why don’t other African mammals have similar skins to ours? This short-changing of why enables you to use how as springboard for claiming no apparent purpose and then, no guiding intelligence in human evolution.

Jayjay4547 wrote:Your explanation is the first data point in this my attempt to show how atheist ideology has messed up the human origin story. I need to say that in the face of others alleging that I have “no data”.

Jayjay4547 wrote:
Other data come from this Smithsonian Mag article by science writer Jason Daley: https://www.smithsonianmag.com/science- ... 1xo4mme.99
After dismissing “the aquatic ape theory (it “hasn’t received much support from the fossil record and isn’t taken seriously by most researchers”), Daley writes:

“A more widely accepted theory is that, when human ancestors moved from the cool shady forests into the savannah, they developed a new method of thermoregulation. Losing all that fur made it possible for hominins to hunt during the day in the hot grasslands without overheating. An increase in sweat glands, many more than other primates, also kept early humans on the cool side. The development of fire and clothing meant that humans could keep cool during the day and cozy up at night.”

This explanation adds “why” to your “thermoregulation” but in doing that it raises credibility issues. When our ancestors came to the hot grasslands, what competitive edge did they bring to the cohort of hunters who were already reaping the full crop of herbivores? A damp skin? Primate smarts? They weren’t the only primates with smarts, nor were other grassland lacking in smarts when it came to killing.

Jayjay4547 wrote:
Just as a major problem with the aquatic ape theory lies in its disrespect for animals that actually do live in water, so this thermoregulation story as presented here, disregards the great excellence in what competing animals of the hot grasslands can do. The imagined scene where humans are adapting, is effectively scene unpopulated except for resources as a stage with one actor on it. What is missing is a sense of the environment acting on the pre-human actor, in the form of other hunters with no taboo against eating primate flesh. When that is fed that into the model, what is striking about our ancestors on the hot grasslands, is their lack of natural equipment displayed by other species, that impose caution on animals that want to eat them: no fangs, no hooves, no horns and no claws These all pose existential threats to predators. The picture of our ancestors in their natural context, including thermoregulation, comes sharply into focus when we suppose that when they moved out of the cool shady forests, they were already habituated and proficient at defending themselves using hand held weapons: sticks and stones. When the fight came to them they needed to be formidable, without necessarily being proficient as hunters themselves.

Jayjay4547 wrote:
When you sharpen focus this way, the thermoregulation story does not go away, but it is also transformed. An animal that while it is alive, keeps prospective predators at a distance, doesn’t need a skin so resistant to puncture, abrasion and tearing. Without that constraint, it can use precious perspiration more efficiently that say a horse can, that also sweats. According to the Wikipedia article on perspiration, animals like dogs (predators) cool themselves by passing air through the oral cavity and pharynx. Well our ancestors filled their skull with too large a brain to leave a big oral cavity and pharynx, or a carotid rete such as buck use for cooling.

Jayjay4547 wrote:
So, when you bring other competing animals into the explanation as important parts of the model, our ancestors come into sharper focus as having satisfied the particular environmental criteria that led to them flowing BY NATURAL SELECTION into an innovative solution to a universal inter-species problem on the hot grasslands. And the model itself start to tingle messages for more exploration. Our ancestors appear hugga-mugga with the other animals, in a way well represented in the Australian Aborigine origin narratives.

Jayjay4547 wrote:
Science seems to have gone backward here. In 1925 Dart proposed that Australopithecus, that unexpected missing link, used its hands for “offence and defence”. After that brilliant exposition Dart pursued the thread of offense, which went through some pretty torrid times as the hunting hypothesis at the hands of Robert Ardrey, and now appears in anodyne form in Daley and your stories. When science goes backwards that deserves to be examined closely.

I have to break here in discussing your most interesting post.