I’m interested in some sciences, in an amateurish way, and I enjoy finding out that everything is not as neatly tabulated as scientists want us to think.
I used to believe that the theory of evolution best explains the development of animal and plant life on our planet. But it doesn’t. The role of astronomical and geological events has also to be considered; and this still leaves some mysteries to explore.
The big brain
About two million years ago human predecessors experienced massive climactic, dietary and environmental change associated with the last ice age. During this period they also underwent a remarkable and sudden anatomical change, the development of bigger and more complex brains.
A theory in anthropology goes like this. The big brain in human predecessors developed too suddenly for the species to adapt physically through evolution. Humans today still have not done so. Unlike many other mammal species, protohumans couldn’t be born already equipped to survive, as the female pelvis was not wide enough to allow the baby to leave her body when its large skull was fully developed.
The solution was to make all births in effect premature, with the baby skull still unformed and growing. This led to offspring dependance on parental care to an unprecedented extent, which led in turn to pair bonding and shared parentage to an extent uncommon in animal life forms.
This, it is supposed, led to the development of language, concepts, technology, tribe bonding and the role divisions behind civilisation. All these developments were compensations for the early birth of a not fully formed infant.
No one so far has accounted for the sudden origin of the big brain. Its development was early in human evolution, prior to the emergence of Homo sapiens. Big brain development was counter to the theory of evolution, but vital as it turned out for the rise of human culture.
“In summary, then, rapidly increasing brain size was a key feature that set humans apart from the walking apes that lived before 2.5 million years ago. Since then our brains have trebled in volume. This increase was not gradual and steady: most of it came as a doubling of volume in Homo erectus 2 million years ago. In other words, the greatest acceleration in relative brain size occurred before 1.5 million years ago, rather early in our genus, and then gradually slowed down”. (Stephen Oppenheimer, Out of Eden 2003).
A wide birth passage capable of allowing full development of the fetus in the womb would have restricted female mobility and made mothers vulnerable to predators. But production of only partially developed and helpless infants, and consequent pair bonding, also restricted mobility, of the tribe, and made the group vulnerable to predators. Neither alternative was environmentally advantageous. We are dealing with, not evolution, but evolution+.
The “sudden” development of the big brain has to do with scarcity of fossil evidence though. We should discount theories that credit brain implants grafted on likely ape men by super intelligent ETs marooned for some reason in the Pleistocene era.
Yet despite a false perspective due to lack of evidence for all the stages of human development, there is something unusual here. Why did our ancestors develop a big brain so quickly, instead of slowly adapting to changed environments as evolutionary theory posits?
One consequence of ice ages, as far as we can tell, is species diversification. Under threat, life seems to send out a wide variety of adaptations, and they spread randomly over new environments created as the ice moves. Has there been a comparable decrease of species at other times?
The ideal place to look for this would be among the most prolific species, bacteria and other microorganisms, but there is no record available of fluctuations in their numbers.
In the 20 billion years since the Big Bang, nuclear reactions formed stars and galaxies, including our sun and what became its solar system 4.5 billion years ago. Widespread nuclear reactions filled space with cosmic dust, newly formed elements, and solidified matter that frequently collided. This pattern of collision continued after the earth was formed, and affected the way life evolved there. As well as direct impact, cosmic matter would have affected the atmosphere, climate and ocean levels on earth.
Five major events, and many less eventful ones, have been identified which affected plant and animal life on earth since its emergence 3 billion years ago.
About 450 million years ago about 70% of all observable life forms disappeared. This happened again 360 million years ago. About 250 million years ago 70% of land animals and 96% of sea animals perished. About 200 million years ago up to 75% of all species vanished, leaving the dinosaurs the dominant life form. About 70 million years ago 75% of all species vanished, leaving mammals the dominant life form. These are all estimates, because the fossil record is not complete, but it does give the idea that massive changes in life forms, as much as their successful adaptation to environments, was the way life evolved on this planet.
Possible causes were asteroid collisions, temperature variations, changes in sea levels and erosion of feeding habitats. On the scale of four billion years from formation of the earth to now, it seems like the slow adaptation of life to its environment was given a shake every now and then, and cosmic and global upheavals remodelled the environment of earth and the life forms evolving upon it. It’s as though nature was practising genetic engineering. What purpose could this serve?
Biological self censorship
Our genes must still be adapted to these sudden changes. It might explain some of our odd behaviour, such as cruelty, and indifference to their pain, towards members of our own species, and determination to harm our own environment, both behaviour patterns seen only in humans (unless the dinosaurs also terminated themselves). We might have a need to cull ourselves for the good of the species (and of the planet). Whether with a concentration camp or gulag, or a Big Mac and a TV set, we may be readying ourselves for our next major adaptation, extinction.
One of the major factors in our species’ drive towards extinction is religion. It’s an odd fact that most religions posit mankind as basically evil, and doomed. Unless that is they adore the right saviour and follow the correct doctrine. All too often in our history when confronted with major disasters we have done little but pray. For many natural disasters that was all we could do, but what about disasters caused by disease, such as the Black Death? Its cause was sin. Wasn’t it?
Humans seem adapted to think the worst. Religious folk see sin all around them and have a great time cursing the evil doers. Atheists are blinded by greed and wreak reckless destruction for a quick dollar. Superstitious folk, who don’t believe in god and who haven’t the energy for the profit motive, believe in phenomena such as ESP and the Millennium Bug. Well meaning folk hand the planet in their care over to incompetent politicians in return for meaningless rhetoric. Paranoid schizophrenics (as we all tend to be at times) worry about conspiracies and alien invasions but do nothing else. The rest of us forget to practise biodegradable consumption, and can’t read the list of ingredients on food packages because the print is too small (the specials are much more clearly marked). Nobody wants to be the last man standing.
What’s this propensity of the species to practise collective Russian Roulette for? Can’t have recourse to the Bible for an answer. There an angry god drives mankind from Eden, drowns all life forms like unwanted kittens because they disappoint him, then dies on the cross, still striving to change humans for the better. Does god know something we don’t?
Perhaps humans don’t belong on the planet after all, and are best gone. We once found the oxygen in the atmosphere poisonous. Our huge digestive system is designed to filter out all the poisons in available food. Our immune systems battle a continual onslaught of poisonous microbes. We see things naturally upside down till the brain corrects our vision. Perhaps we and our big brain came from somewhere else?
That’s evolution for you. Scratch evolution and you uncover anatomical adaptations like the big brain, which seem to have nothing to do with evolution. You find widespread species destruction which seems to serve no useful purpose; and an inbuilt species self destruction which might be explained by our common awareness of being a stranger in a strange land.
The big brain might have given us intelligence, the ability to adapt to change. But that adaptability, that intelligence, might be temporary, and might evolve away.
Darwin wanted evolution to explain all animal development, but it has to be radically adjusted to explain planetary development and the place of humans on that planet. It’s evolution+.
©2017 Original material copyright Phillip Kay. Images and other material courtesy Creative Commons. Please inform post author of any violation.