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Course: 23andMe > Unit 1
Lesson 1: Human prehistoryHuman prehistory 101: Prologue
Award winning video introduces human prehistory starting over 200,000 years ago. Who were our first human ancestors? Where did they live? Created by 23andMe.
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What is 23andMe and what is its relationship with Khan Academy? Does it have anything to do with Sal's involvement with Big History? http://www.bighistoryproject.com/ Thank you in advance for your answers.(41 votes)
Yes, the research was done and khan academy was able to use the info to put into video form.(1 vote)
- I'm just wondering, if evolution actually happened shouldn't that mean that there should be people around nowadays halfway through the evolutionary cycle? I mean, shouldn't monkeys still be turning into people? Feel free to call me stupid for this, but I just don't understand. Why didn't all monkeys become people? That's probably the main thing I don't understand about evolution. IF evolution happened, why didn't all monkeys evolve?(11 votes)
A common mistake, not addressed in these other answers, is to think that evolution has some sort of "goal", and that human intelligence is somehow the ultimate pinnacle of evolution. If you make that assumption then you will easily become confused, since that would make it reasonable to expect other great apes to develop similar intelligence.
However, that's not the case. Evolution has no purpose other than to let living things survive and reproduce. Different species have different ways of doing this, and they're all pretty great at whatever niche they've got going. See, apes are good at being apes and it would make no sense for them to evolve into humans as long as they can get along by being apes.(21 votes)
- if all of us evolved from a common group of primates in africa, why are we so different? yeah, you might say, some migrated to other parts and faced different conditions, but what may have caused them to separate? why would primitive humans decide to leave the familiarity of their habitat and... well, move... sort of?(8 votes)
People also probably followed herds of animals for food and clothing.(11 votes)
- One part i missed. Who (or what) is our common ancestor? Because you said Human-Chimps= Common Ancestor but who (or what) is our common ancestor?(6 votes)
- We don't know for sure as we do not have an abundance of those fossils. Fossilization is actually an extremely rare event for many types of organisms because conditions often need to be near perfect for it to happen. The only reason scientists have so many total fossils is because there has been life on the planet for so long. The odds of an individual animal fossilizing are astronomically low and then you have to factor in the odds of human scientists finding it. They get only just a little bit better when you talk on the species level, but even then it is rare. There are species we know to have existed only from digging up one tiny tooth or toe bone from one individual.(7 votes)
I may be perceived as crazy for asking this, but I've always wondered about aliens, or extraterrestrials. What does 23andMe or KhanAcademy think about the idea that we were.. well.. Engineered. It may be a completely ridiculous idea, but I have always been curious.(3 votes)
The problem with the idea of alien/extraterrestrial engineering as well as with panspermia is that these ideas just kick the question of the original appearance of life back a planet or two - the question of life starting from a mix of non-living chemicals remains. Note that I accept a materialistic answer to where life on Earth came from. At least we have the example of life having occurred on Earth, so is makes more sense to explore how that could come to be based on the Earth's history than to kick the question to some other planet that we know far less about. Admittedly, the laws of chemistry will be the same on any planet, but why not tackle trying to find an explanation for life appearing on Earth first.(8 votes)
For all the people who question whether evolution is real by asking why apes are not evolving into humans, consider that what you are asking is almost exactly like saying: Why aren't Norwegians evolving into Chinese people? (or vice versa for that matter) This actually is a more valid question bc Norwegians and Chinese people are much more closely related (obviously). But consider the original question again - Norwegians should be getting darker and darker hair, right? And they should be getting shorter, right?
Anthropologists remind us that while we might think we are the best animal on the planet, evolution doesn't prefer us over squirrels, snakes or cockroaches. IOW, apes don't have the ambition of becoming more human-like any more than cockroaches aspire to become squirrels.(6 votes)- The adaptation of people or other animals to their environment takes much longer than the time suggested in the question. Apes are not going to evolve into humans because both humans and apes share a common ancestor long ago (millions of years) Both humans and apes diverged from this common ancestor and no one can predict what the future holds for either species.(2 votes)
For the sake of this experiment, practical biology should be ignored because it would yield disastrous results for our potential test subjects. If a black (or white population) moved into an area of high or low UV light so that the amount of UV light was drastically different from the amount their ancestors were subjected to, would skin colour ever change? (This experiment relies on inbreeding which would means that it would only work in theory) If a mutation began to occur, how long would it take?(3 votes)- If a low-melanin population moved to a high UV area then there would be probably be immediate selection pressure for higher melanin because those individuals would be less prone to skin cancer. Still, it would take many generations for the population as a whole to start to show a significantly higher average amount of melanin.(4 votes)
I have some questions for any evolutionists. How did the atoms that started the Big Bang originally get there? How did consciousness arise from non-matter? How come the Big Bang happened when it did, and not a million years before-hand(ie. what defined when it happened)? If natural selection is true, and humans are the apex of evolution, then why didn't all animals evolve to be humans? Why are humans the only rational creatures, since it would greatly increase any animals chance of survival?
Every year half a millimeter of dust falls on the moon. If the moon is millions of years old then there should be 20 feet of dust up there, but when Apollo 11 landed they only found a couple inches. Why? There is no wind, and dust is dispersed evenly throughout the cosmos.
Why is evolution not happening today? Why can we not go outside and see different "links" in the evolutionary chain? Why did it stop? Why would humans evolve without an opposable toe since it would greatly help us?
Imagine a house. If left to itself, the house will degrade and fall apart. No matter how long you leave it, it will never start to rebuild itself. It will never develop a brain or any form of locomotion. It will eventually disappear and leave no evidence of it ever existing. Why is this true? What is the difference between now and when evolution started happening?
For evolution to begin, DNA and RNA would need to be present. The probability of a DNA or RNA strand randomly appearing out of non-matter is approxamently 1/10^1,000,000,000. That is like randomly dropping scrabble letters on a board and coming up with a perfect sentence from Shakespeare's Hamlet. And even if that did happen what do you have? One DNA strand. To create life, you would need a couple billion strands of DNA. That would be like randomly throwing a quadrillion scrabble letters into a Olympic pool and have them sink to the bottom in perfect order, spelling out all of Shakespeare's plays and Webster's Complete World Dictionary to boot. How on earth did that happen?
Now imagine that somehow a billion strands of DNA did appear. The whole bundle would resemble what would happen if you put a frog in a blender. But no matter what you do to that mass of guts and flesh, it will never turn back into a frog. Experience tells us that. We could heat it, let it sit, expose it to a million volts of electricity, but it would just rot and disappear.
If all humans and animals are the result of random chance, then why are humans the only ones that are rational? Why did we evolve manners? And politeness? None of those in any why help our survival. Why aren't we savages like all other animals?
So to any evolutionists out there, how did evolution happen?
I love debating, so please ask any questions.(4 votes)- u mean that human evolve from apes and god did not created man i have a confusion please help me out ??????????????????????????(0 votes)
The idea the humans were created by God is really a belief based on ancient traditions. The world is incredibly complex and hard to understand, so most of us find comfort in believing that God exists and that He created everything. The invention of many gods was the first attempt to explain the natural world by ancient cultures. Eventually, religions that tell of there only being one God arose, and today we have Christianity as the largest religion in the world.
However, we've found fossils left by the remains of our ancestors and each fossil can be dated according to its surrounding geology and other methods, such as radiocarbon dating. We can also analyze the physical structure of different fossils to determine the likely position of a particular species on our lineage. So, with this data, we can use these fossils to build a sort of family tree of all the extinct species and subspecies that lead to the evolution of modern humans. The oldest fossils of modern humans are only around 200,000 years old. We also use genetics to observe the relationship between humans and current apes. All this evidence lets us piece together a natural history of our species and our ancestors. As a result, we know as a fact that humans are apes and that we share a common ancestor with the modern chimpanzee that lived 6 million years ago.
Regardless of whether or not you believe in God, you cannot deny the evidence that shows how humans actually evolved from the ancestors of chimpanzees. Science provides no evidence of God nor the role of God, but at the same time it doesn't provide evidence of the absence of God. You can continue believing God created man if you wish to do so, but realize that science shows us there was a process of natural selection that doesn't require the presence of God to directly design man and a lot of what happens in nature is due to chance and a given set of ecological conditions. Science and religion are ultimately just two radically different ways of viewing the world, and as a result, a few in the Christian community feel threatened by it. However, you don't have to let that concern you because in the end of the day science does not disprove religion.
Science only calls into question the literal interpretation of the Bible. It is obvious that the world was not created in 7 days, that the world and the universe is much older than 6000 years, as it may appear to be if you follow biblical history, and life was not created all at once in its present form.(16 votes)
- At0:19, why did we call one of our ancient ancestors Lucy?(2 votes)
When she was discovered, "Lucy in the Sky with Diamonds" was a new pop song by the Beatles. It was being played a lot at the dig.
BTW, it is not known whether she was a direct ancestor, but she is most likely to be a very close relative, at least.(4 votes)
0:19Video transcript
Your personal ancestry story begins with the shared story of our human ancestry. You and your distant cousin, the chimpanzee, have a common ancestor. which lived about 6.5 million years ago. We can learn about this common ancestor by noting what makes us similar to chimps. But many things also distinguish us from chimpanzees, like our big brains, which enable abstract reasoning and the development of complex languages. And our anatomy, adapted to up-right walking, these human traits developed gradually over millions of years. The fossil record reveals a long and eventful parade of human ancestors. During some periods, several of our ancestors co-existed. Gradually, they became more efficient up-right walkers. And later, developed skulls with larger brain cases devoted more to thinking and less to chewing. Our knowledge of the exact relationships between these ancestors is incomplete. And often, is revised, because of new fossil finds. Some of them were our direct ancestors, some of them were distant cousins, who became evolutionary dead ends. But by 200,000 years ago, we're on firmer ground. We find the bones of people in Africa, who looked something like us, not exactly like us, but close. They built fires and flaked stone into spear heads, knifes, and scrapers. They were physically strong, and still depended on their muscles, not their technology for much of their survival. Here, in addition to fossils, we have genetics to help us find our prehistoric kin. All of this, living today, inherited our DNA from this small group of ancient people in Africa. Over time, they began to look more and more like us. And by 100,000 years ago, their skeletons weren't so different from ours, but these early Homo sapiens shared the planet with two of their distant cousins. By this time, as a result of previous migrations, Homo erectus was living across Asia, and had been for 2 million years. Homo erectus had a big brain, some made hand axes, some do fires, and some may even have worn clothing. At the same time, Neanderthals lived across Europe, and western and central Asia. They had even bigger brains. They made spears and stone tools, similar to those found in Africa, and we suspect they had strong social relationships. They cared for the sick, and infirm, and buried their dead. Not so very different, culturally, from early Homo sapiens, it seems that our human anatomy developed before our complex human culture. But things were about to change. Today, we live in all climates, all over the world; and are unique, in our dependence on our cultures for survival. How we got from there, to here, forms the next chapters in our human story.