Earliest Animals Were Sea Sponges, Fossils Hint

Based on chemical signatures inside sedimentary rocks, Love and colleagues think the sponges likely grew in colonies that blanketed areas of the ocean floor. Back then the supercontinent Rodinia, which had been Earth's dominant landmass for at least 350 million years, was in the process of breaking up, and the climate was extremely cold worldwide. Sponges evolved in shallow ocean basins, because the deeper seas did not yet contain oxygen, a necessity for almost all life. Although the environment was harsh at this time -- about a hundred million years before the evolutionary growth spurt known as the Cambrian explosion -- a lack of predators made life easier for the sponges... Love and colleagues were able to date the sea sponges because the animals' chemical traces were found in rocks beneath glacial deposits from an ice age that ended about 635 million years ago. The scientists cut away the outer surfaces of the rock, cleaned the remaining core with solvents, and crushed what was left behind into a powder that could be chemically separated into its component parts... Kevin Peterson of Dartmouth College and his colleagues had independently hypothesized that sponges lived about 650 million years ago based on biological clues in the genes of modern sponges.

We don't really know that ~ we just surmise that since we don't have any matching mitochondrial DNA lineages that demonstrate that such a thing could have happened.

As it turns out there are several ways you can "adjust" your reproductive schedule to improve your chance at surviving an environment.

One of them is to "twin" ~ like in West Africa where the Twa people have a very high twin birth rate. It keeps them even with the opportunity for disease to kill them.

Similarly our friends the Neanderthal must have defeated the Four Ice Ages they lived through in Europe through the simple expedient of having more twin births ~ or maybe even more. Their women were large ~ having triplets would have been nothing to them.

However, they'd needed more nipples for larger loads, so let's say you had these large women with four breasts, and the guys over the hill there, the Cro Magnon just fresh in from wintering over in Uzbekistan, are looking around for "daes".

They have a choice ~ women with two breasts, or women with four breasts (BTW, the Cro Magnon have better jobs with higher pay, so yes, they do have this choice).

Now just what do you expect these bad boys to do? Are they going to "date" the ladies with four breasts who have triplets, or the ladies with two breasts who have'em mostly one at a time?

I think we all know the answer, and there goes the Neanderthal mitochondrial lineages.

Now, regarding the guys, I think it worked out a bit differently. Cool guy, a bit shorter, flashing blue eyes, red hair with streaks of platinum, and he's show'n the gals his stuff with a spear bringing down a Saber Toothed Tiger with ONE HAND.

I think that y-chromosome lived in eh!

Now just what do you expect these bad boys to do? Are they going to "date" the ladies with four breasts who have triplets, or the ladies with two breasts who have'em mostly one at a time?

Unfortunately, reproduction is not too logical. For example, would a typical male be more comfortable mating with a two-breasted woman, or one with four breasts? The fact that inherent guidelines to judging the quality of a mate forces the individual to avoid drastically altered mating partners. I'm not talking about race, because it falls within the gambit of the emphasis individuals put on genetic stock that is, to a limit, potentially differentiated enough to allow the dominance of healthy traits. Four-breasted ones will be looked down as mutants with uncertain genetic guarantee.

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