Posted on 12/16/2002 6:21:39 PM PST by dennisw
How about turning a perfectly friendly breed of domesticated dog into a pit bull? Close enough?
Speak? Why?
I can't prove it, but I believe the first man was a woman.
Modern science has used mitochondrial DNA to track human origins back to a single female. This is the so-called Eve hypothesis.
I believe that this was the first fully human Homo Sapiens. A girl was born with a genetic "defect" in her mitochondria. The mitochondria control the enzyme activity in the cell. This change affected her metabolism at a deep cellular level.
The first human had an altered metabolism that manifested itself in a suite of gross differences:
She lacked vibrissae, the sensory whiskers common to all other mammals.
She had full lips, not the thin line at the rim of the mouth typical of other species.
She was weak, compared to others of her kind.
Her features retained a more child-like appearance as she grew up.
But, the two most critical differences were a lack of body hair, and a monthly estrus cycle.
Why are the last two most critical?
The lack of body hair provided an interesting advantage. To understand this, let's look at cats. There is a breed of hairless cat. Instead of fur, they have a velvety skin. Their owners often comment on how affectionate their cats are. Affectionate? Not really, these cats are just COLD, they snuggle to keep warm!
Back to our first human, she sure is cuddly. She is much more desirable than her standoffish hairy sisters.
Rather than the annual fertility cycle, she is 'in heat' all of the time. Cuddly and friendly too!
Lacking muscle strength, she needed to be protected. The beginnings of love as we now understand it.
That she needed protection is deeply ingrained it the human psyche. In propaganda there are surprisingly few common themes. The enemy is depicted as snakes, spiders, octopus, and, ... and ... hairy ape-men seizing the furless women. The massive muscular King Kong is interested in the petite Fay Rae. Did you ever wonder why this resonated with the audience?
Simple. The first man was a woman...
I noticed that you put 'in heat' into quotes, suggesting that you didn't mean that literally. However, we get some folks making the oddest statements around here so I would like you to clarify the point.
Human females do not experience anything similar to going into heat as do other mammals. They can, of course, become aroused at any time. I believe this is what you meant. Correct?
Hey, this one isn't droopy yet either.
Brilliant.
Unfortunately it applies to an ever increasing majority of "purebred" cats and dogs these days too... :(
In order for this to be a valid criticism it must first be established that the effects of deliberate selection for certain traits by humans and selection by any other environmental pressures are different. You have not done so.
Right. Selection is selection. Humans select for traits that we deem desirable. Nature selects purely for survival. The criteria are different, but still, the individuals thus culled to breed the next generation are ever-so-slightly different from the general population, and pass on their qualities to their offspring. The result is a gradual change in the species (how gradual depends on the intensity of the selection pressure), with each generation being a tiny transitional link in the chain of descent. If evolution were impossible, then humans couldn't do what this group has so easily done with foxes.
Another striking example is tusk size of the African elephant. About 80 years ago was a busy time in the ivory trade. The elephants with the biggest tusks were the first to go. As a result, almost none of the modern elephants have tusks that reach the huge sizes of those in years past.
The "big tuskers" sported a feature specifically detrimental to survival, were selected against, and the elephants of today reflect the bias towards smaller tusks.
Like you said, selection is selection.
Odd, I would have thought that you would first have to prove the above concept before I would attempt to disprove it.
Perhaps it's just that I'm less willing to take evolutionary evidence on faith.
We'd known for a while that if you bring up wolf cubs in a domesticated setting, you get an animal that looks and acts something like a dog but is much more dangerous. You lose thousands of years of selective breeding for domesticated behavior when you bring in the wild wolf genes.
Still true, but it apparently doesn't have to take thousands of years to go a good bit of the way from scratch. Thirty to thirty-five generations did the job in the silver fox case. They even look a lot different.
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