How Humans Stopped Evolution Forever

Hey Thoughty2 here. In 1978 paleoanthropologist Andrew Hill was throwing shit at his colleague when he discovered one of the most important pieces of evidence to ever support the theory of evolution. Hill and his colleague were avoiding doing work by throwing elephant dung at each other at an archeological site in Tanzania. Hill dove towards the ground to narrowly avoid a large dung projectile hitting him in the face. As he slammed into the ground he noticed something peculiar within the dirt of the excavation site, a trail of footprints. These incredible footprints that had been perfectly preserved by hardened volcanic ash were found to be 3.6 million years old. They had been made by some of the very first upright-walking hominids. Up until Hill's chance discovery the oldest human footprints we had found were only tens of thousands of years old. 3.6 million years ago when these footprints were made, our ancestors looked remarkably similar yet so very different, than modern man. Australopithecus is the name science has given to the specimens found from this period of human's evolutionary timeline. Australopithecus looked profoundly more apelike. Compared to modern day humans, they had far smaller brains, a protruding large jaw and stubby nose. The progress mankind has made physically, in what is relatively, a very small amount of time, is mind-blowing. If evolution carries on at this rate I should have superpowers in no time. Where's my x-ray vision and superior hindsight? But along the way something happened and evolution was stopped in its tracks. Human evolution has progressed so remarkably fast, Earth is 4.5 billion years old and in only a tiny 7 million years, which equates to just 0.15 per cent of Earth's history, humans have evolved from a primitive apelike ancestor to a walking, talking, intelligent being. Well, most of us anyway. But this rapid physical and mental change within our species was caused due to immense environmental pressures. For the vast majority of humankind's history and our ancestor's, we have not been predator's like we are today, but prey. Only with the advent of weapons and technological advancement have we risen to the top of the food chain. Many early fossilised human remains have been found all over the globe that have fatal wounds made by animals, such as tigers, leopards, and even by an eagles' talons, as was found to be the cause of death of the 2 million year old "Taung Child" skull. So both physical and mental adaptation was necessary for our species' future survival and prosperity. Rapid changes had to be made so we were better equipped both mentally and physically, to fend of predators and find food. And so evolution showed no signs of stopping. But then we went and ruined it all by saying something stupid like "let's build a homogeneous civilisation." In 3100 BC Mesopotamia was built, the first human civilisation. Huge advances were made in farming and humans no longer needed to forage or hunt to survive. As the centuries have passed we have, on average, all become wealthier, better medicated and gained easier access to food. The pressure to adapt to our environment disappeared and so did the rapid evolutionary progress. Today not only the fittest and strongest pass on their genes to the next generation, but everybody does. This is especially true in the West, with modern medicine and food at our fingertips whenever we desire it, even the most stupid and weakest members of society will pass on their genes and that they most certainly do, even if said individuals don't know exactly who's genes they have passed on, one only needs to watch five minutes of Jeremy Kyle to understand what I'm talking about. So in developed countries at least, there is no natural selection anymore. Sir David Attenborough himself said that "We are the only species to have put a halt to natural selection, of its own free will.” Attenborough predicts that physical evolution in humans will eventually cease completely and we will instead go through a process of cultural evolution, in which we will evolve mentally. So whilst survival of the fittest may no longer hold true, survival of the intelligent certainly does. As each generation builds upon the wisdom of those before them, intellectual growth will speed up exponentially. Today a person's survival depends not on whether they can effectively hunt prey but whether they can secure a good job to buy food for themselves and their family. It has thus become more important than ever that people are more intelligent and more creative than their peers. There are only so many jobs in the world and this fierce competition to be the best, climb the ladder and steal more prestigious jobs from others has put an evolutionary pressure on our minds. The Flynn effect is the observation that over time average IQ levels have increased, substantially. Since 1904, when IQ tests were first used, the average IQ level across the globe has increased every single year, in a linear fashion. Every few years IQ tests are completely re-written and intentionally made harder so that the global average always remains at 100. If you were to take an IQ test from 80 years ago you would find it significantly easier than a modern day test. Human evolution has not stopped, far from it, but it's goals have changed. Mental acuity is now the next target of natural selection. So it looks like that X-Ray vision might have to wait, shame. So we're evolving culturally, although that's very hard to believe looking at the current state of contemporary music. But what about physically? Is this really all we're getting? Has humanity peaked ascetically and mechanically? Well, that may not be entirely the case. It's generally accepted that evolution has been slowing down since the dawn of human civilisation. But we shouldn't be so quick to put a definite end on physical evolution, after all, mutations don't occur overnight, they take tens, sometimes hundreds of thousands of years to take hold. And, if we look really closely, we have actually changed physically, in recent times. Despite getting more intelligent, over the past 30,000 years our brains have shrunk, from an average of 1,500 cubic centimetres to 1,350 cubic centimetres. Blue eyes are a prime example of evolution, until just 10,000 years ago, blue eyes did not exist, everyone had brown eyes. But 10,000 years ago some unknown patient zero near the Black Sea developed a genetic mutation that turned their eyes blue. They passed down the blue-eyed mutation to many others and very soon blue eyes became extremely popular, for an unexpected reason. Blue eyes were an early form of paternity test. Men would often prefer female partners with blue eyes because the man would know that if his wife had a blue-eyed baby then it was probably his. If the baby had brown eyes, then someone had been a little naughty. Studies have shown that most men find blue eyes more attractive than brown and it's thought that this unreliable historical paternity test could be the reason. Of course we now know that eye colour genes can be passed down through several family generations and even if both parents have blue eyes, it's still possible for them to give birth to a brown-eyed baby. So I imagine throughout history a lot of unlucky women were incorrectly accused of cheating. But surely one of the best ways we have evolved in modern times is that humans have become naturally more resistant to diseases. Even when we have food on the table and good healthcare there is one environmental pressure that hasn't left us alone since the dawn of time. One of the world's biggest killers, malaria. Over one million people die from malaria each year, mostly in sub-saharan Africa. But in 2007 a study found a group of 1,800, previously undiscovered genes that have only become prevalent in humans in the past 40,000 years. These genes make us more resistant to various diseases, such as tuberculosis, leprosy and even malaria. And it's predicted that these genes will only become stronger and more prevalent within the human race in the future. Evolution has conquered hunger, and within the next few hundred millennia we may even conquer disease, for good. Thanks for watching.