It’s the same with most every creature you know. Make up a different life-pyramid for each one and you’d find that the few unique things that make them their own specific type of creature are essentially add-ons, extremely minor alterations on top of the ponderous weight of older traits.
Evolutionary “refinement” also sometimes involves a certain amount of letting-go. The horse’s mammalian ancestors, for instance, jettisoned reptilian scales, and all mammalian lineages since then demonstrate this loss. Horses and other equines even gave up toes – plural – for the single toe represented by each hoof.
But those ancestors kept a great number of the core physiological traits of reptiles, amphibians and even fish – hearts, brains, lungs, tails, and so much more – that are evident today.
Species that fit into collections of near-identical pyramids as the horse, donkey and zebra are startlingly common. Well-known pets and farm and zoo animals are frequently part of a connected set of species, and every creature in each set pursues a strategy for survival very similar to every other. Horses, dogs, cats, cattle, sheep, bears, camels and dolphins are only a few of the familiar creatures which have numerous and varied close relatives. In each of these closely-related groups, tiny capstones of difference rest on massive bases of absolute sameness.
Dogs, wolves, foxes, coyotes, all the canines in the world, look fairly similar. Show a five-year-old a wolf or coyote and he will instantly recognize the “doggie.”
Domestic cattle are only one type of bovine, all of which have very similar body plans and strategies of survival. All bovines eat grass and digest it with multiple stomachs, have the same number of toes, possess horns (except for certain domestic breeds of hornless mutants), and have a significant number of other traits so similar that even non-scientists can easily see their relatedness.
Housecats are only one type of feline. All felines have the same type of sharp fangs in their mouths, the same number and type of claws on their feet, all stalk and kill other animals and eat raw meat of necessity. Yes, there are noticeable differences – cheetahs, for instance, break the rule about having retractile claws – but all members of the felid family are easily and immediately recognizable as felines. Cats.
By now, I hope you’ll have a fairly good idea of what I mean by this pyramid illustration. It’s not that any modern day creature is in any sense a pinnacle of evolution, the crowning end result of 3.5 billion years of some sort of mystical “striving for excellence.”
If anything, it’s probably the reverse. Sooner or later, every species either dies or is subsumed into something else – if it’s lucky, it becomes a layer in the life history of its descendents. But those descendents are decidedly not creatures standing alone on a featureless creationist plain, with no trails leading to or from their perfect uniqueness.
Instead, they stand out only as pyramid peaks do, tiny capstones on massive bases, small newnesses atop overwhelming evidence of gone-befores. Their very bodies bear witness, in every muscle and bone, every organ, every cell, that they are NOT unique creations. Every creature alive is only the most recent rewrite – with very slight editing – of a tale of life billions of years old.
Less Than Human
Let’s look at another of these pyramid-collection lineages, the apes.
The ones we’re most familiar with, of course, are the orangutans, gorillas and chimps.
Just as with the equines, we could track them to their origins by going back to the beginning of Life. We could start with single cells and build a pyramid up and up, layer by layer, with informed speculation in the early stages, but with more certainty later.
But we really don’t have to do this, because most of this ape pyramid would be identical with that of the equines, until well into the late Cretaceous.
It was only at some point fairly recent in mammalian history, fairly high on the pyramid, that the two lineages went their separate ways. Only here would we begin adding on new and unfamiliar layers.
Somewhere up near the top of this ape pyramid, we’d arrive at a slice of monkey-ness. On top of that would be a slice of primate-ness, and above that would be the little capstone which identifies the chimpanzee.
Just as with the horse, most of what you see when you look at a chimp is not specifically Chimp. Chimpanzee teeth, for instance, are fairly direct copies from earlier primates – who adapted them from yet earlier mammalian ancestors, who cribbed them from reptiles, who plagiarized them from amphibians, who stole them from fish.
Chimpanzee ears are little different from the ears of any other primate. Chimpanzee fingers are obvious forgeries of earlier monkey fingers. Chimpanzee knees are shameless borrows from non-chimp ancestors. To say nothing of hearts and lungs, livers and lips.
Okay, here’s the part you probably already guessed: The collection of familiar-ape pyramids includes a fourth member: Us. And just as with the others, whose pyramids are totally identical except for a little pip of a capstone, so too is the pyramid for H. sapiens.
At the crest of our own 500-foot-tall, massive life-pyramid, somewhere up there above that layer of primate-ness, is the inches-high capstone that is specifically us. Only a tiny vertical pip at the top of our own pyramid represents that specific body of traits which are exclusively human.
Barring this little bit of late-added human uniqueness, the tiny bit of tweaking of the more basic nature that added the human touch, our brains are primate brains, based on blueprints many millions of years old. Our elbows are reptile elbows, our lungs are amphibian lungs, and to be comical and crude about it, our asses are fish asses. And all of those things, in every part of us, shouts the legacy of our single-celled ancestor.
When you look at yourself in the mirror, most of what you see is not human.