Posts of late are straying from my Biological roots. This post is designed to restore the balance, somewhat. However, if my readers are expecting a detailed and rich explanation concerning the evolution of those Pesky Pisces, they are going to be sadly disabused. The following is not without informational content. With that said, there is much errant intellectual meandering without coherent purpose or relevant direction. I make no apologies for this screed. Honestly, I can state with sincere intent/content that my effort was the result of the Muse, which is oft sitting upon my shoulder, spewing a diatribe that defies editing or mediation/moderation. Enjoy.
This morning, I propelled myself at an age-appropriate, sedentary pace along the path of a local country lane. This morning ritual is sometimes referred to as 'running'; however, I prefer to call the ambulatory process/progress Dotage Dodering. Anyway, I'm starting to wander/wonder off the path/page. During the forward momentum, I was destined to pass over a small brook. This insignificant water course is usually of no interest to me. But on this occasion, for reasons not immediately discernible, I decided to stop and peer over the low parapet. My unprompted curiosity was promptly rewarded. As my eyes focused on the lightly 'tea-stained' babbling water, I espied a denizen, not a troll, close to the bridge edge. An eel had emerged from its burrow within the bank. And it was big. Its shovel-shaped head measured nearly the span of my hand, and I estimated that about 2 feet of its sinewy black form was visible, hinting at a total length immeasurable extending within its dark, dank den. The swart eyes impressed upon its sleek dorsal form stared back into mine. Something was unsettling and outre about that unblinking, steady gaze. I moved slowly to the opposite bank, and the head of the eel followed my movement without falter. I got close and peered into the water. The eel stood fast and, with its soulless, dead eyes, latched onto mine. As if by cue, it slowly opened its maw, hinting at fathomless depths of infinite shade. I expected long fangs ready to rend flesh and tear sinew, but instead I was met with two rows of small peg-like protusions, barely discernible. At the termination of the eel's unremarkable dental display, it slowly retreated to its lair. The spell was broken, and the reverie that had held me in thrall dispelled.
As I continued my forward perambulation (no, I didn't throw the baby in the water), my normally cluttered, chaotic mind pondered my recent experience with uncharacteristically cold precision and logic. In addition, I noted that my nipples were experiencing light but significant chafing. When younger, this might reflect minor arousal, but at 70, it was a nuisance. This is particularly pronounced as I have been 'sported' with a minor congenital abnormality termed in the medical community as a teritary or accessory nipple. Thus, I am doomed not only by 'runner's chafed nipple x2', but in my case, I have to suffer the indignity of 50% more irritation. Note to self: apply extra vaseline, not nipple rouge, to three redundant anatomical appendages. My brain retreated into the archives and dredged through the meagre knowledge concerning mouths, and in particular, jaws and teeth. I sourced a scant snippet (redundant, double positive) on the evolution of said anatomical features and recalled that jaws first emerged in fish and that the jaw evolved from a bony gill arch. My interest stirred, I turned on my heel and hurried home as fast as my arthritic bipedal appendages could bear. Once showered, I entered my inner retreat/den/office/sanctum and placed the 'Bugger Orff' sign on the door. Suitably encounced, I scoured the internet, absorbing knowledge like a man demented.
What follows, after this rather dilatory and particularly irrelevant introduction, are the labours of my rather incoherent and not particularly focused research. Unfortunately, I became distracted by sites concerning the sexual stimuli of applied nipple rouge. Naughty Flaxen!
Think back to 600 million years ago (Edicaran Period). Life, albeit simple, abounded in the shallows of endless seas. The land was a barren place, and life of any degree had not evolved sufficient sustaining features to allow exploitation and colonisation. Thick mats of bacterial blooms dominated the sea floor. Strange blob-like animals lie supine and inactive on the bacterial drugget. Nutrients from prokaryotic growth drift into the mucus covering of primitive animals by osmotic processes and natural gradient equalisation. The squat, irregularly shaped creatures are devoid of the features that would subsequently evolve and define and dominate the Cambrian Explosion to come. But as yet, animals lack a gut, skeletal structure, and organised neural collective complexity. And importantly, no means of sensing or moving in a direction. They are bound to where they lie and only move to the tune and whim of currents and powerful physical forces to which they can neither react nor resist. This is a time of bacterial abundance. There is no halt to their remorseless growth, and they dominate and carpet the seabed without check. But this would change.
Now we move toward the end of the Edicaran. Animals have evolved; some continue their sequestered existence. However, evolution has moulded other creatures to exploit a loophole. The predator is born. By 558 million years ago, we see the emergence of active predators (of sorts). They have developed reactive senses that supply information about their environment. They respond, and as the gut evolves, they can graze on the bacterial expanse and finally actively digest the cells.
During the early Cambrian, we see the development of the notochord, a rudimentary backbone in what would become the bony fish. These early fish were devoid of jaw and fins and propelled themselves by whip movements of their sinuous body. Their mouths were but gaping holes, and feeding was achieved by sucking up bottom detritus. The Cambrian was a dynamic period for evolution, and during this time fish evolved jaws, from gill arches, fins, bony protective plates and eventually teeth, possibly derived from dental skin plates. Fish had moved from being the prey of the boneless mollusc-like critters to being their predators. The combination of jaws, teeth and rapid movement became a formidable formation. This formula became the dominant mode of life for prey and predator alike. Humans are direct descendants of the first bony fish. The evolutionary development of the fundamental anatomical features described was already present in fish by the late Cambrian.
Fins would become lobes, allowing fish to tentatively invade the land. Amphibians would be the result. A phyllum betwixt the two mediums, but master of none. With the evolution of reptiles, animals would finally divorce themselves from the seas and become permanent residents and eventually masters of the land. But that's a story for another day. But only if I can be Arrrsed!
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