Re: selection criteria for obesity

From: Paul Crowley (slkwuoiutiuytciuyik_at_slkjlskjoioue.com)
Date: 12/23/04 

Date: Thu, 23 Dec 2004 21:44:26 -0000

"Pauline M Ross" <pmross@ross-software.co.uk> wrote in message
news:masls0dd3tce519hchimt3i55dqgiq46q7@4ax.com...

Thanks for the post, which I don't remember
seeing before. I've stored it for permanent
reference.

On this point however:

> a) Insulation after loss of fur: this says that we lost our fur (for
> some reason) and needed some compensating insulation.

That's a poor way of expressing it. The
argument must be that, in the hominid
niche, fat was a more effective insulator
than fur. (It's foolish to say that they
lost hair first -- during the switch they
probably had both.)

> This makes no
> sense at all: in terrestrial environments, fur is the optimum method
> of temperature regulation under any conditions

Not so. Fur is _worse_than_useless_
when it regularly gets wet and has to
dry in air. It will drain massive amounts
of energy from the animal under such
conditions, and not be an insulator at
all. Persistent showers of rain (in the
rainy season) cause distress to most
animals in Africa, including chimps.

> and even if it had
> already been lost, the most effective means of insulation would be to
> regrow it (unless the reasons for losing it were overwhelming).

Sure -- and all you have to do is to
identify the terrestrial conditions in
which hominids lived.

Consider other animals with similar
anatomies (i.e. pigs, especially the
Babirussa).

Try camping on the ground in the
open. Then imagine putting a small
infant on such ground. Think of
emulating fur on the infant -- perhaps
covering it with some woollen
clothing. Would that help if it was
continually raining, or if condensation
was a problem -- or if the infant was
peeing a lot?

Paul.

Relevant Pages

  • Re: Cold Blooded Dinosaurs
    ... are used as insulation? ... is that body coverings followed the ... evolutionary development of endothermy. ... Now, as I pointed out, endothermic animals do not ...
    (talk.origins)
  • Re: Cold Blooded Dinosaurs
    ... the catalyst for the development of feathers. ... bald bird species if insulation were the only factor. ... The fur on mammals serves more than one purpose. ...
    (talk.origins)
  • Re: Sweating hominids
    ... > The insulation provided by the pelage does not protect the animals ... > against hyperthermia resulting from diurnal activity, and, indeed, ... Thermal insulation cannot protect any animal ... "Mosquitoes transmit many of the diseases most important to ...
    (sci.anthropology.paleo)
  • Re: selection criteria for obesity
    ... Fur loss is about Homo rather than about hominids. ... Some mammals have no fur & no SC fat layer, eg, elephants. ... If SC is for thermo-insulation, ...
    (sci.anthropology.paleo)
  • Re: Cold Blooded Dinosaurs
    ... The observations support the notion that insulation ... is used by animals that maintain a body temperature ...
    (talk.origins)
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