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The energy a chimp burns while covering 3,000 meters sees a human through to around 12 kilometers! The human torso, by contrast, is largely immobile when we walk. So it’s unsurprising that they just don’t travel very far – usually no more than two or three kilometers a day. If a chimp walks upright, it ends up waddling from side to side because its legs are so far apart.
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Walking on two feet turned out to have distinct benefits. Our ancestors had to cover even greater distances if they wanted to eat. It was an age of intense climate change.ĭroughts had become increasingly common. That’s exactly what was happening when humans bid adieu to chimps. The first boon of walking upright was efficiency.Īs we just saw, adaptation occurs during periods of rapid environmental changes. That said, there were some important advantages too. So you can see that our evolutionary divergence from chimpanzees had some drawbacks. That’s astonishing given how small it is compared to a human! We’re weaker, slower and less agile than our jungle-dwelling relatives.Ī chimpanzee isn’t just twice as fast as a human, it can also lift objects twice as heavy as even the strongest man or woman could manage. Two percent might sound like small change, but it makes a big difference. We share 98 percent of our genes with them. Embracing our new two-footed existence meant forfeiting other abilities. That’s what made us the dominant species on earth.īut change didn’t come cheap. Our evolutionary path began the moment our ancestors stopped scrabbling around on all fours and started walking upright. What sets us apart from the rest of the animal kingdom – is it, for example, our large brains or perhaps our unique opposable thumbs? These help both the original organism and its offspring thrive.Ī good example of a large-scale environmental change which triggers this kind of evolutionary adaptation is climate change.Īnd that’s Darwin’s theory of evolution in a nutshell! In the following book summarys, we’ll dig a bit deeper and explore how the history of the human body fits into all this. This describes how an individual develops new heritable traits that help it adapt to new surroundings. Well, when dramatic environmental changes occur, natural selection uses a different tool – adaption. Organisms without significant new heritable traits come out on top. Negative selection, therefore, favors the status quo. That’s because, like humans with hemophilia, these organisms would be less likely to survive – if it weren’t for modern medicine! These traits lower chances of reproductive success.Īn organism with negative traits is less likely to produce offspring than competitors which don’t have them. A good example in humans is the genetic disorder hemophilia. That’s when an organism has “negative” heritable traits. Natural selection is usually driven by negative selection. That’s a mouthful, right? What it means is that different organisms will produce a different number of offspring that go on to reproduce in their turn. Then there’s differential reproductive success. Every organism passes genetic traits on to its offspring. By that Darwin meant that each individual organism is different from other members of the same species. Natural selection can be broken down into three separate – but interlinked – components.įirst, there’s variability. Because of that, they survive and go on to reproduce. This simply means that the best-adapted members of a particular species are “selected” by nature. Centuries of religious ideas about the history of humanity were turned on their head.Īccording to Darwin, the driving force behind evolution is natural selection. Between its covers was a theory that shook the world.
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Obesity, diabetes and osteoporosis are on the rise in the wealthiest and most advanced nations. That’s created a mismatch between our prehistoric bodies and the modern world we inhabit. Today, life is an embarrassment of riches.
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The development of the human body is a story millions of years in the making.īut social history and deep biological time stopped moving in tandem during the age of industrialization. It measures time in millennia rather than centuries.