Re: Miss, there's an ape in my soup!

Pat Dooley (
23 Dec 1994 02:48:59 -0500

> In article <3d2vu1$>
> (Pat Dooley) writes:

>>> In article <3cttee$>,
>>> (Phil Nicholls) writes:
>>> << deletions>>

>>>Your constant emphansis on convergence ignores that fact that it
>>>is not all that common and is certain not the driving principle
>>>of evolution.

>> Sometimes you betray a woeful ignorance of evolutionary theory.

>Interesting. I had reached more or less the same conclusion
>about you. Let's see, shall we?
>> To quote one sentence from Dawkins' The Blind Watchmaker:
>> "Australia, South America, and the Old World offer numerous
>> further examples of multiple convergence".

>> His chapter "making tracks through animal space" has many
>> wonderful examples of convergent evolution, including
>> vertebrate eyes and Octopus eyes.
>You know, Pat, some of us have explored evolutionary theory a
>bit more extensively that Dawkin's writings. I just keep
>forgetting that your not one of them.

So, you set yourself up as a better informed evolutionary biologist than
Richard Dawkins. Sir, I salute your presumption though I doubt you're

>I did not claim that convergent evolution was a myth. I said
>that it was not the driving force of evolution that you seem
>to believe it to be. Morphological similarity due to common
>descent (homology) is much more common than similarity due to
>common environmental stressors (homoplasy). A failure to
>provide an explanation citing convergence is therefore not a
>valid critique.

The driving force of evolution has nothing to do with convergent
The driving force is adaptation to the environment. It is just that Darwin
and the people that followed him observed that similar environments
produce similar adaptations.

>> If a zoologist is investigating a feature and wants to explain
>> how it evolved then she or he is very likely to look for
>> similar features in other species. Evolution is very good at
>> filling niches with good designs; not surprisingly, the same
>> designs get reused.

<< deleted some stuff>>

>>Since convergences can arise in different, unrelated lineages
>>they are useless in terms of reconstructing the evolution of a
>>particular feature. Explanations that stress function over
>>form are less rigorous and often end up as untestable

Ever heard of a non sequiter? You just gave us a good example.
>> Is hairlessness an example? I think so
>> since evolution has never had any use for it in land-based
>> animals.

>What about armdillos? Elephants? Rhinos? All of
>these are land-based animals in that that is where they feed,
>mate and sleep.

Armodillos have made a trade-off between armour and hair. Like the
naked mole-rat, they are also burrowers. The elephant and rhino are
very large animals filling some of the niches left by dinosaurs. A
reasonable case can be made for the elephant having had an
aquatic ancestry. They are good swimmers, as a recent TV ad
demonstrated, and their ancestors came from a swampy North
I haven't checked Rhinos, yet.

>Your argument proceeds as follows:

>Q: Why are humans hairless?

>A: Because they evolved from an aquatic or semi-aquatic

>Q: What evidence supports this hypothesis of aquatic ancestry?

>A: Humans are hairless.

Oh dear. Is that what I argued? Silly me. I got it all wrong.
Actually, I think my line of reasoning was a little different from the
straw-man argument put up by "Chris".

Q. Why are humans hairless?

Q1. Are there any hairless savannah mammals?
Q2. How does hairlessness help you survive savannah heat?
Q3. Hows does it help you survive frosty savannah nights?
Q4. Does it improver protection from solar radiation.

etc. etc. so I end up asking, what use is it? No other primate,
savannah or otherwise has gone down that evolutionary
route. The only reasonable answer seems to come
from convergent evolution.

>Q: What evidence supports this hypothesis of aquatic ancestry?

The eccrine/accropine gland ratio is crazy.
Aquastic mammals are low on the latter.
Bipedalism is an unlikly evolutiuonary development,
whethger on the savannah or in the jungle. The behaviour of some primates
suggest a wading explanation.
Human babies can swim before they can walk. Other
apes babies sink.
Humans are much, much fatter than other apes,
especially at birth.
etc. etc.

>It's a nice little circle but the only purpose it serves is to
>exasterbate those who try to reason with you

I think you were trying to write "exasperate". You can't have meant
"exacerbate" since the sense would be incorrect. Perhaps you meant
some other mammaliam activity but ex'ed out the first letter..

>Philip "Chris" Nicholls Department of

Merry Xmas to all you naked apes out there.

Pat Dooley