[_ Old Earth _] Common Heat Reduction Techniques within Differing Species

[Barbarian]

The same glands involved in sweating are in all terrestrial mammals, just modified to different ends. Apocrine glands, for example, are mostly involved in releasing odors, hence signalling.

Sweating as a cooling mechanism in small animals is a bad use of water, and is never, AFAIK, the primary mechanism, as it is in humans and horses.

But it's like color. We don't think that bears and horses are related, even if some have evolved the same coloring.

 

[Blue-Lightning]

The same glands involved in sweating are in all terrestrial mammals, just modified to different ends.

That's true and we should remember those glands are arranged in a variety of different combinations and varieties on different organisms - for example, ear wax is just a modified substance coming from what are essentially sweat glands.

What I've been trying to bring to attention though are the similarities in the structure of sweat glands in various creatures - that is what I find startling.

Sweating as a cooling mechanism in small animals is a bad use of water, and is never, AFAIK, the primary mechanism, as it is in humans and horses.

To clarify that just a little more, it is never the secondary mechanism, as it is in humans and horses. The primary is blood circulating radiation.

But it's like color...

Mmm, I think it's a little more complex than that. As you know, the more complex a structure or mechanism, the more unlikely it is that it will show up in a variety of different, unrelated* species. Color on the other hand is something that every object has and there are just so many colors something can be - two items being brown isn't very significant.

Now if you find a bear with a mane and a pinto patterned coat...

BL

 

[M82A1]

Don't you roll your eyes at me, young man... or lady.... or elderly person... oh, you get the idea.

Young Man would be the correct term. :wink:

What disagreement among scientists? Give me an example.

 

[Barbarian]

It's not more complex than color. There are a number of possible forms sweat glands take, and we see different ones used in different mammals. Likewise, there are a limited number of pigments in mammals, and they are distributed differently in different mammals. It doesn't mean that polar bears are like white horses with black noses, even though polar bears are white with black noses. They just have the same distribution (or lack thereof) of pigments.

The genes are still there in all mammals for all these glands, but they are modified by other genes. I suspect that when some genes are suppressed, you will see that it was done differently in different orders of mammals, much the way we see suppression of the vitamin C gene in different orders of mammals.

 

[Blue-Lightning]

It's not more complex than color.

Well, what I am referring to as not being very complex are the actual colors of animals in that any object must have color, not every object but have sweat glands. However, if you are referring to pigmentation being a similarly complex process, then yes, I would most likely agree that the way in which organisms pigment themselves is quite complex and very interesting.

The genes are still there in all mammals for all these glands, but they are modified by other genes. I suspect that when some genes are suppressed, you will see that it was done differently in different orders of mammals, much the way we see suppression of the vitamin C gene in different orders of mammals.

And to be honest, that's something that would be over my head in gene mapping - I understand genetics, but I wouldn't be able to disect that information without someone first "translating" it for me.

However, I do think that if we look at the similarity in the modifications of sebacious (sp?) glands that we will find a remarkable similarity. I'll take a look next time I get a chance to see if I can find any sweat gland diagrams of different mammals.

BL

 

[Barbarian]

If that impresses you, then the fact that eyes in vertebrates and arthropods are governed by the same genes should really be impressive.

But it doesn't mean that eyes had a common origin in insects and vertebrates. It merely means that the particular genes had the potential to produce eyes, and do so in certain circumstances. There is also evidence that vertebrate body plans are simply inverted arthropod body plans, from a common ancestor.