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A new study has discovered a powerful force that is now driving evolution on Earth.

How will humans change in the next 10,000 years, from their appearance to their minds and personalities?

The unexpected result of 4 billion years of evolution is humanity.

Evolution formed us from self-replicating chemicals in Archean seas to eyeless fish in the Cambrian depths, to mammals racing away from dinosaurs in the dark, and then, surprisingly, ourselves.

Organisms reproduced in a haphazard manner. Mistakes in gene copying occasionally made them more adaptable to their circumstances, so those genes were more likely to be passed down. More reproduction and blunders ensued, with the process repeating itself over billions of generations. Homo sapiens came at long last. But the storey doesn't end here. Evolution will not end with us, and we may be developing at a faster rate than ever before.

It's difficult to forecast the future. The world will most likely shift in unexpected ways. We can, however, make educated assumptions. Surprisingly, looking back at the past and believing past trends will continue in the future is arguably the greatest way to predict the future. This hints to some unexpected aspects of our future.

We will most certainly live longer lives and grow taller, as well as becoming more light-weight. We'll presumably be less aggressive and polite, but our brains will be smaller. We'll be nice and jolly, but maybe not as intriguing as a golden retriever. At the very least, that's one scenario. But first, let's look at biology to see why I think that's plausible.

Is natural selection coming to an end?
Some experts believe that the emergence of civilisation halted natural selection. Selective pressures that dominated in the past - predators, hunger, illness, and warfare – have mostly vanished.

High-yield crops, fertilisers, and family planning helped to put an end to famine and starvation. Despite, or perhaps because of, modern militaries with nuclear weapons, violence and war are less common than before. The lions, wolves, and sabertoothed cats who stalked us in the dark are now extinct or endangered. Vaccines, medicines, and clean water tamed plagues that killed millions — smallpox, the Black Death, and cholera.

But evolution didn't halt; now it's driven by other factors. It's not so much about survival of the fittest as it is about reproduction of the fittest in evolution. Even if nature is less likely to kill us, we still need to find spouses and nurture children, thus sexual selection has become more important in human evolution.

And, if nature no longer has influence over our evolution, the unnatural environment we've built — culture, technology, and cities – creates new selecting pressures that are very different from those we encountered during the ice age. We're not well accustomed to this modern environment, so we'll have to change.

And the procedure has already begun. We evolved genes to help us digest starch and milk as our diets altered to incorporate grains and dairy. Disease resistance mutations spread as congested urbanisation created conditions for disease to spread. Our brains have also shrunk for some reason. Artificial selection results from unnatural surroundings.

To forecast where this will lead, we'll look back in time, examining trends throughout the last 6 million years of evolution. Some trends will persist, particularly those that occurred in the last 10,000 years, after the invention of agriculture and civilization.

New selective forces, such as lower mortality, are also present. We can't learn from the past, but we can learn from how other species responded to similar challenges. Domestic animals' evolution may be particularly significant — we're arguably evolving into a kind of domesticated ape, but one that we've tamed ourselves.

I'll utilise this method to make some forecasts, however not all of them will be accurate. That's what I'm going to guess.

Lifespan

Humans will almost probably evolve to live far longer lives than they already do. Life cycles change in response to mortality rates and the likelihood of being killed by predators and other hazards. Animals must reproduce young or not reproduce at all when mortality rates are high. It's also pointless to evolve mutations that prevent ageing or cancer because you won't live long enough to benefit from them.

The opposite is true when mortality rates are low. It's preferable to wait till you're sexually mature. Adaptations that lengthen longevity and fertility, allowing you more time to reproduce, are also beneficial. That's why animals with few predators, such as those that live on islands or in the deep ocean, or simply those that are large, have evolved longer lifespans. Greenland sharks, Galapagos tortoises, and bowhead whales are all late-maturing species that can live for hundreds of years.

People were exceptional among apes in having low mortality and long lives even before civilisation. Hunter-gatherers with spears and bows could defend themselves against predators, and food sharing kept them from going hungry. As a result, we evolved delayed sexual maturity and lengthy lifespans ranging from 70 years to 100 years.

Even still, child mortality was high, approaching 50% or more by the age of 15. The average lifespan was only 35 years. Even with the rise of civilisation, child mortality remained high until the 19th century, when plagues and famines reduced life expectancy to 30 years.

Then, in the last two centuries, improved diet, medicine, and hygiene lowered youth mortality in most developed countries to less than 1%. Globally, life expectancy has risen to 70 years, with 80 years in affluent countries. These increases are attributed to better health rather than evolution, but they do pave the way for evolution to lengthen our lives.

There's no need to reproduce early any longer. The years of training required to become a doctor, CEO, or carpenter, on the other hand, incentivize procrastination. Adaptations to extend lifespan and child-bearing years are now advantageous because human life expectancy has doubled.

Given that an increasing number of people are living to be 100 or even 110 years old - the current record is 122 years - there's reason to believe that our genes will change until the typical person lives to be 100 years old or even longer.

Dimensions and strength

Animals such as tyrannosaurs, whales, horses, and primates - including hominins - have all evolved bigger sizes over time.

Australopithecus afarensis and Homo habilis were early hominins that stood four to five feet (120cm-150cm) tall. Hominins such as Homo erectus, Neanderthals, and Homo sapiens became taller as time went on. In the past, we've continued to grow taller, owing in part to better diet, but genes appear to be changing as well.

It's unclear why we grew so large. Size evolution may be influenced in part by mortality; growth takes time, so longer lives mean more opportunities to expand. Human females, on the other hand, prefer tall guys. As a result of decreasing mortality and increased sexual desires, humans are likely to become taller. Today, Europe, lead by the Netherlands, has the world's tallest people. Men are on average 183cm (6ft) tall, whereas women are 170cm tall (5ft 6in). Most people may one day be that tall, or even taller.

We've become more gracile as we've grown taller. Our skeletons have become more lightweight over the last 2 million years as we have depended less on physical power and more on tools and weapons. As farming caused us to settle down, our lifestyles became more sedentary, resulting in a loss in bone density. These trends are likely to continue as we spend more time behind desks, keyboards, and steering wheels.

Humans have also lost muscle mass in comparison to other apes, particularly in the upper body. This is likely to continue. Our forefathers had to kill antelopes and dig roots before tilling and reaping the crops. Working with people, words, and code is becoming increasingly important in modern jobs; they require brains rather than muscle. Even for manual labourers like farmers, fishermen, and lumberjacks, machinery like tractors, hydraulics, and chainsaws now do a lot of the heavy lifting. Our muscles will continue to diminish as physical strength becomes less important.

Our jaws and teeth shrank as well. Plant-eating hominins possessed massive molars and mandibles that were used to chew fibrous foods. Jaws and teeth reduced when we transitioned to meat and later began cooking. Because modern manufactured foods, such as chicken nuggets, Big Macs, and cookie dough ice cream, require even less chewing, our jaws will continue to shrink, and we will likely lose our wisdom teeth.

Beauty

Deserts, oceans, mountains, glaciers, and sheer distance divided humanity's far-flung tribes after individuals departed Africa 100,000 years ago. Differing selective forces — different climates, habits, and beauty standards – caused human appearance to evolve in different ways in different regions of the world. Tribes developed distinct skin tones, eyes, hair, and facial characteristics.

These populations were reconnected with the emergence of civilisation and new technology. Conquest wars, empire building, colonisation, and trade – including human-to-human trade – all changed populations, causing them to interbreed. We're now connected by road, train, and air. We'll trek 4,000 miles to locate a partner, whereas bushmen would walk 40 miles to find a partner. We're becoming more and more one global population, mixing freely. This will result in a world of hybrids — light-brown-skinned, dark-haired Afro-Euro-Australo-Americo-Asians with skin colour and facial traits that are similar to the worldwide average.

The evolution of our look will be accelerated through sexual selection. Mate selection will become more important as most forms of natural selection cease to exist. Humans may become more appealing, but their appearance will become more consistent. Globalized media may also result in more consistent quality standards.

Globalized media may also lead to more uniform beauty standards, pushing all people toward a single ideal. If the ideal is masculine-looking males and feminine-looking women, however, sex differences may be emphasised.

Personality and intelligence

Finally, our brains and minds, which are the most distinguishing characteristics of humans, will evolve, possibly radically. Hominin brain size has almost tripled in the last 6 million years, implying that tool use, sophisticated communities, and language have all favoured huge brains. This tendency may appear to be unstoppable, but it is unlikely to do so.

Our brains, on the other hand, are shrinking. Brain size reached 10,000—20,000 years ago in Europe, right before humanity established agriculture. Then the brains shrank. Modern humans have lower brains than our forefathers or even mediaeval folks. It's unclear why this is the case.

It's possible that when we switched to farming, fat and protein became limited, making it more expensive to create and maintain huge brains. Brains are also high-energy consumers, burning roughly 20% of our daily calories. A large brain could be a liability in agricultural communities where starvation is common.

Perhaps hunter-gatherer life was more taxing than farming. You don't have to outwit lions and antelopes or memorise every fruit tree and watering hole within 1,000 square miles to live in civilisation. Making and wielding bows and spears also necessitates fine motor control, coordination, and the capacity to track animals and trajectories — and it's possible that the regions of our brains responsible for these functions shrank when we stopped hunting.

Alternatively, perhaps living in a huge society of experts necessitates less mental effort than living in a tribe of generalists. Hunting, tracking, gathering for plants, producing herbal medicines and poisons, crafting tools, waging battle, making music, and magic were all abilities that stone-age humans learned.

As members of huge social networks, modern humans undertake fewer, more specialised functions, taking advantage of division of labour. We specialise in one trade in a civilisation and rely on others for everything else.

However, brain size does not equal intelligence: elephants and orcas have larger brains than humans, and Einstein's brain was smaller than average. Neanderthals possessed brains that were comparable to ours, but more of the brain was devoted to vision and bodily control, implying that they had less capacity for language and tool use. So it's unknown how much the reduction of brain mass affects overall intelligence. Perhaps we lost some abilities while gaining others that are more useful in modern life. It's likely that having fewer, smaller neurons has allowed us to maintain processing power. Still, I'm concerned about what happened to the 10% of my grey matter that was missing.

Domestic animals, strangely, have lesser brains as well. Sheep lost 24% of their brain mass after domestication, whereas cows lost 26% and canines lost 30%. This opens the door to an unnerving possibility. Possibly, like a domesticated animal, being more inclined to go with the flow (and perhaps even thinking less) has been bred into us, as it was for them.

Our personalities must also be changing. Hunter-gatherers had to be aggressive in order to survive. They killed over partners, hunted huge beasts, and fought with neighbouring tribes. We buy meat from a store and settle disagreements with the help of the police and the courts. If war hasn't vanished entirely, it is presently responsible for fewer deaths per capita than at any other point in history. Aggression, which has become a maladaptive trait, may be bred out.

Changes in societal patterns will have an impact on people's personalities. Humans live in far bigger groupings than other apes, forming hunter-gatherer tribes of roughly 1,000 people. However, in today's globe, people live in large cities with populations in the millions. In the past, our partnerships had to be limited and typically lasted a lifetime. We now live in seas of people, travelling frequently for employment and developing thousands of ties, many of which are transient and more virtual. This world will force us to become more outgoing, open, and tolerant individuals. However, traversing such broad social networks may necessitate a greater willingness to adapt - to be more conformist.

This existence does not suit everyone's psychological needs. Our inclinations, wants, and anxieties are primarily those of our stone-age forefathers, who found purpose in hunting and foraging for their families, fighting with their neighbours, and praying in the dark to ancestor-spirits. Modern society does a good job of meeting our physical wants, but it falls short of meeting the psychological needs of our primal caveman minds.

As a result, an increasing number of people are experiencing psychological problems such as loneliness, anxiety, and despair. To cope, many people turn to alcohol and other narcotics. Selection against these disorders' sensitivity could improve our mental health and make us a happy species. However, this may come with a cost. Many great minds struggled with depression, including politicians like Abraham Lincoln and Winston Churchill, scientists like Isaac Newton and Charles Darwin, and artists like Herman Melville and Emily Dickinson. Virginia Woolf, Vincent Van Gogh, and Kurt Cobain were among those who committed suicide. Substance abuse devastated others like Billy Holliday, Jimi Hendrix, and Jack Kerouac.

A worrying concept is that problematic minds will be purged from the gene pool, but this may come at the expense of eradicating the spark that produced visionary leaders, brilliant writers, artists, and musicians. Future humans may be more well-adjusted, but they will be less fun to party with and less inclined to start a scientific revolution if they are steady, cheerful, and boring.

Is there a new species?

There were nine human species once, but today we are the only ones left. Is it possible, however, for new human species to emerge? We'd need separate populations subjected to different selecting forces for it to happen. Although distance no longer isolates humans, selective mating might theoretically produce reproductive isolation. Different populations, even species, may arise if individuals were culturally isolated – marrying based on religion, class, caste, or even politics.

H.G. Wells imagined a world in which class separated species in his novel The Time Machine. The upper classes evolved into the lovely but useless Eloi, while the lower classes evolved into the hideous, underground Morlocks, who revolted and enslaved the Eloi.

Religion and lifestyle have historically produced genetically diverse groupings, as shown in Jewish and Gypsy populations, for example. Politics divides us today, but may it also split us genetically? Liberals now prefer to associate with other liberals, while conservatives prefer to associate with conservatives; many on the left will not date Trump supporters, and vice versa.

Could this result in the emergence of two species, each having innately opposing viewpoints? Most likely not. Still, to the extent that culture divides us, it has the potential to drive evolution in many ways, depending on the individual. Human genetic variety may be preserved and increased if civilizations grow more diverse.

New Strange Possibilities

So far, I've largely looked backwards from a historical standpoint. However, the future may be very different from the past in certain aspects. Evolution has progressed.

Directed evolution is one of the most extreme options, in which we deliberately govern the evolution of our species. When we choose partners with attractive appearances and characteristics, we are already breeding ourselves. For thousands of years, hunter-gatherers arranged marriages for their daughters, looking for good hunters. Men were supposed to seek the approval of the bride's parents even when children picked partners. Similar customs can still be seen today in other parts of the world. To put it another way, we have our own children.

And in the future, we'll be able to do it with considerably better awareness of what we're doing and greater control over our progeny's genes. We can currently detect genetic disorders in ourselves and embryos. As with crops, we could be able to select embryos for favourable genes. Direct altering of a human embryo's DNA has been demonstrated - but it appears morally repulsive, effectively turning youngsters into medical experimentation subjects. However, if such technologies are proven to be safe, I can see a future where it would be considered a poor parent not to provide your children with the best genetics available.

Computers also introduce a whole new level of selection pressure. We are outsourcing judgments about what the future generation looks like to computer algorithms, who recommend our possible partners, as more and more matches are made on smartphones. Digital code now influences what genetic code is passed down to future generations, just as it influences what you stream or buy on the internet. This may sound like something out of a grim science fiction novel, yet it's really occurring. Our DNA, like our playlists, are curated by computers. It's difficult to say where this will lead, but I'm not sure it's wise to entrust the future of our species to iPhones, the internet, and the firms that power them.

The majority of discussions on human development are backward-looking, as though the greatest achievements and problems occurred in the distant past. However, as technology and culture evolve at a breakneck pace, so will our genes. The most fascinating aspects of evolution, according to some, aren't life's origins, dinosaurs, or Neanderthals, but what's going on right now, in the present, and in the future.

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