http://www.brentrasmussen.net/uti/node/79
"My grandfather wasn't no monkey!", "You think we came from slime?!", and "man, if you want to believe your great^100 grandpa was a rock, be my guest...but it's STUPID!".
....
Great to the 100th? Well, yes, that would be pretty stupid. A monkey? Slime? Rocks as ancestors? Clearly you don't have an adequate grasp of either the actual concept of evolutionary ancestry or of the significant time factors involved.
I figure at 20 years per generation, 100 generations of grandfathers would equate to twenty centuries. That means the grandpa you're talking about was a contemporary of rabba Yeshua bar Yosseff just 2,000 years ago. Not quite an adequate evolutionary time-scale and certainly far from the mark when talking about the origin of life on Earth. But even 100 years ago, 16 years per generation was more the norm as it was with my grandparents and many of their ancestors. That would have put your great^100 grandpa in the time of another wildly exaggerated hero, King Arthur, in about the 5th century of the common era.
Increasing the multiple, your great^1,000 grandpa would have had even shorter generation gaps, being about 14 or 15 years apart on average. He would have been a Paleolithic nomad in about 13,000 BCE, just shortly before the foundation of the most ancient cities like Jericho and Damascus. He still would have been fully human and already a member of the only surviving human species, Homo sapiens.
Your great^10,000 grandpa and grandma would have been everyone else's great to the Nth grandparents too. (Everyone alive today that is) He would still have been definitely human and visibly different from his Neanderthal neighbors. Whether he would be considered Homo sapiens yet 140,000 years ago or still classified as H. antessesor or heidelbergensis doesn't really matter. All are still obviously people and no more ape-like than any of the more isolated aboriginal primitives still around today.
Your great^100,000 grandpa might now be called Homo ergaster or erectus having lived some 1.3 million years ago, reconstructed by a forensic artist below.
And his great^10,000 grandfather would have been called Homo habilis or rudolfensis. Any or all of them would have appeared to be a bit more ape-like than the most monkey-faced modern guy, but he still would have been definitely human, especially when compared to the other fully bi-pedal apes that were wandering around a million and-a-half to a couple million years ago. If you were to put your erectine or habiline grandpa on a crowded pew in your church, he would have looked like an ape-man. But if you saw him amongst his natural neighbors, the paranthropines, you would have seen him as nothing less than a man. However, the generations would be shorter, now being something like 13 or 12 years apart on average.
Your great^1 million grandpa on the other hand is quite a leap away from Homo erectus. A lot can happen in 900,000 generations and the world was much different 10 million years ago. There were no definite humans yet, but there were other hominids even though none of them could walk on two legs for very long. There were creatures similar to modern gorillas, chimpanzees and orangutans, but they were different than the ones we have today. One of the orangs for example stood as much as 8 feet tall. And the space between generations would have been only eight to ten years and much less as time goes on in reverse.
At six or seven years between generations, your great^10 million grandpa would have been barely recognizable as a primate, looking almost as much like a squirrel. And he might have witnessed the demise of the dinosaurs, or he would have grown up in the harsh wasteland that was the wake of the KT impact for so many years. Now the generation gap really begins to close. For most of the Mesozoic era and a long time before that, the age difference between father and son would only be about a year.
Your great^100 million grandpa was a shrew-like mammal darting through the Jurassic underbrush 170 million years ago. The amniotic sacs his children were born in didn't have quite the same integrity that his grandfather's birth-sacs had. Although leathery and easily torn, they would still have been considered egg "shells" much like some snakes are born in today. This grandpa would have been mammalian, but not yet placental.
Your great^1 billion grandpa would have lived under water along with everything else, including trilobites and some really alien beasties a few hundred million years ago and at least a couple hundred million years before the first dinosaur. The generation gap is now a monthly rather than yearly division. But for most of the last half-billion years of our genealogy, that wasn't the case. In 400 million years, your ancestors went from toothy swimming worms like conodonts and pikia and became crossopterygiian fish and then tetrapoidal amphibians, synapsid reptiles and even amniotic proto-mammalian cynodonts. But the generations before that were infinitely less interesting.
The world of your great^10 billion grandfather wasn't much different from that which was already described, although there were a lot fewer trilobites then. And he wasn't a swimming worm yet. He would have been a roundworm, if he would have been considered a worm at all. He may have looked more like a jellyfish with a sense of direction. Before that, he may have been something even simpler, like a microbial sponge, but still definitely a metazoic animal even if he wasn't really a "he" in the sense of discernible gender anymore.
Your great^100 billion grandfather may not have been an animal yet, but a sort of co-op of bacteria living inside a single membrane: The mitochondrion, Golgi apparatus, nucleus, and other bacterial endosymbionts, all of which have their own individual ancestry.
Your great^1 trillion grandfather would have been various bacteria before they learned to cooperate in a single eukaryotic cell.
And your great^10 trillion grandfather would have been bacterial too.
Your great^100 trillion grandfather may have been an even simpler chemosynthetic protien in an inhospitable world unrecognizable as Earth. Even earlier, with 'generations' now coming every few minutes and represented by chemical hypercycles, your 'ancestors', for lack of a better word, would have been macromolecular cycles in which the end result of a given chemical reaction is the constituents to fuel the next leg, which ultimately circles back around to any one reaction. This is the earliest we can go back in terms of proto-biology (Abiogenesis) and it's chock full of speculation at that. We are now at just over 4 Billion years ago.
Those substances in turn came from the smaller planetoids and dust grains which formed the earth itself starting five billion years ago.
Although the concept of 'ancestors' and 'generations' no longer has meaning, your ancestral molecules can be found in volatile ices and hydrocarbon tars making up cometary bodies in the Solar Nebula before the earth congealed. And much of the material in your body, the minerals for example would have been present in the solar nebula as "just rocks".
The material which condensed into a disk to form our solar system including the earth was a combination of interstellar hydrogen and heavier elements such as nitrogen or oxygen. These heavier elements, each and every atom, were cooked up inside a large star[s] and released in a super nova. You are made of stardust.
The primordial elements Hydrogen and Helium which made up the first massive stars themselves? That was produced in the Big Bang in a process called Big Bang Nucleosynthesis.
No comments:
Post a Comment