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Author Topic: Could discovery of fire led to humans loss of tapetum lucidum?  (Read 1807 times)

Offline AndroidNeox

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It occurs to me that once our distant ancestors discovered fire, some physiological changes might have been in order. I've suggested in this forum that maybe that's why humans lost our fur (if you sleep next to a fire you don't need fur and it can be dangerous). Recently, I was imagining humans at night watching for predators. If they sat around their fire with their backs to the light, they would see the eyes of any approaching animals by the glow of their eyes... reflected from the tapetum lucidum. Humans lacking a tapetum lucidum could approach without their eyes glowing and revealing their presence.

Personally, I strongly suspect that the discovery of fire drove quite a few physiological changes in our ancestors.


 

Offline RD

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Looks like our predecessors did not have this feature ...

Quote from: wikipedia.org/wiki/Tapetum_lucidum
... some animals lack a tapetum lucidum and they usually are diurnal. These include most primates ...
http://en.wikipedia.org/wiki/Tapetum_lucidum#Classification
 

Offline sebology

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Opening this question up to changes in physiology from our ancestors experience of fire:

I suffered quite a serious burn about a year ago on my arm and face which healed remarkably quickly with no scarring; I wonder if the same had happened to an animal with skin similar to humans but had never evolved around fire, whether they would be able to heal in the same way.

 
 

Offline CliffordK

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Possibly.  However, forest fires have naturally occurred forever.  They're greatly feared by animals, but some undoubtedly have been scarred by fires, recovered, and managed to pass on their genes. 

Healing, of course, is a natural part of all animals, and in the wild, it occurs without stitches, salves, or other medical intervention (of course some animals also die of inflicted wounds).

I have seen humans with serious burn scars, either leaving permanent scarring, or perhaps requiring years of reconstruction, especially if the skin has contracted.

I don't know about eating hot food.  For example tolerance for drinking beverages just below the boiling point.  Can animals drink a good hot drink?

I have gotten heat induced blisters, but I do have a fair amount of heat tolerance in my hands, and in the past have been known to occasionally pick out a piece of spaghetti from a pot with a rolling boil with my bare hands QUICKLY.

I suppose one might consider that one has two general types of skin.  "Thick Skin" is found on the palms of the hands and the bottoms of the feet.  Then you have the rest of the normal skin over the rest of the body.  However the evolution of the thick skin would have occurred long before humans and would be related to the pads on animal feet.  But, one does have a bit better heat tolerance with the thick skin on one's fingers.
 

Offline alancalverd

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if you sleep next to a fire you don't need fur and it can be dangerous

Try telling that to a cat or a dog. Anyway most animal fur is self-extinguishing. I've been given a thick, pure wool cloak to wear in a smelting plant.
 

Offline AndroidNeox

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Thanks for the replies... good info and good thinking
 

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