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Human prehistory 101 part 1: Out of (eastern) Africa

Second in a series of videos that introduces human prehistory, this video describes how our human ancestors spread throughout Africa and then into other regions such as Australia and Europe. How did they reach Australia so early on? What happened when our ancestors encountered Neanderthals? Created by 23andMe.

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  • starky tree style avatar for user Daniel H.
    how did our ancestors in Africa turned out to look like Asians, Canadians, and so on?
    (3 votes)
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    • piceratops ultimate style avatar for user Ksenia
      The environment changed thus there were changes in organisms and adaptations. For example white skin evolved in Norhern Europe through
      1)lack of sunlight
      2) insuffiicient vitamin D and lack of melanin causes skin to loose its dark complexion
      3) selection as lighter skin was preferred in Europe for reasons asides from sexual attraction, predominant reason being that your off spring had a better chance at survival in cold temparatures
      It is thought that blonde hair and blue/green/grey eyes evolve in the ice ages, same reasons as white skin developed..evolved due to environment..
      different body types is probably a combination of diet and environment, for example south east asians are still very petite because of diet and tropical conditions where it is an advantage to carry less fat
      stocky bigger boned Scandinavians are this way for the opposite reason, needed more body fat to survive cold conditions..
      asians have different shaped eyes...apparently because all east asians have ancestry from Mongolians, Mongolians originally developed, as did Inuits and native Americans who were descendants of Mongolians, their eyes are lie that because of harsh weather conditions caused their eyes to evolve with extra fat on the eyelid and a less open eye to protect their eyes, same reason for their wide prominent cheek bones, a protective evolvment for weather conditions..
      well nose shape is unknown for why it developed into different shapes
      there are the basics
      (20 votes)
  • female robot grace style avatar for user Scho
    What about Pangea and it's possible effects on facilitating transcontinental travel?
    (4 votes)
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  • male robot hal style avatar for user projectearth
    How come Neanderthals were not as equip at making tools, while they had bigger brains than the homo sapiens?
    Keep in mind the neanderthals also had a body that were better adapt to their environment, yet there were still overtaken by the homo sapiens.

    Ill assume it may have something to do with, the environment in Africa may have been less harsh. Thus giving them more leisure time to, refine their arts and technology. Not quiet sure. Maybe someone can chime in?
    (4 votes)
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    • primosaur ultimate style avatar for user Lucas Muehleisen
      cranial capacity is far from the only determining factor in how successful you are in an evolution sense. Other tools such as communication are just as vital, if not more so than cranial capacity. for example agriculture was only invented in about 7 different places around the globe, the rest of humanity found out about agriculture through communication from other people. Coming back to neanderthals, it has been shown that their larynx (vitally important for speech) was shaped differently than ours and not as efficient. This is one reason why we may have prevailed over the neanderthals. Even though on a person per person basis they may have been more intelligent, they were hampered by other biological issues that made it hard for them to communicate their achievements.
      (7 votes)
  • leaf green style avatar for user Tushar
    How did our ancestors reach Australia?
    (4 votes)
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  • male robot hal style avatar for user Michael Zero
    While we aren't quite sure if early Homo Sapiens bred with Neanderthals and Homo Erectus, if it turns out to be true, would that mean that some humans today have HS+Neanderthal, some have HE+HS, and some have only HS lineage? Could this account for differences among modern humans?
    (2 votes)
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    • piceratops ultimate style avatar for user Just Keith
      The differences amongst humans is very minor. We're not only of the same species, but the same subspecies. It is not likely that either the latter erectus had much to do with current sapiens DNA.

      While sapiens does have erectus as an ancestral species, it wasn't the latter population that early sapiens co-existed with. The current evidence strongly suggests that both sapiens and neanderthals independently evolved from homo heidelbergensis, which in turn evolved from erectus about 600,000 years ago, possibly earlier.

      The reason that I doubt the latter populations of erectus could have had any influence on distinct populations is because sapiens appear to have gone through a bottleneck some 70 thousand years ago (give or take a few thousand years), possibly due to the Toba supervolcano eruption (there's a good Wikipedia article on that giving both the pros and cons of the Toba catastrophe theory). If this theory turns out to be true, then the various populations of sapiens occurred from a small group that existed after the extinction of erectus.

      There are better data suggesting that there may have been some inbreeding between neanderthals and sapiens in Eurasia. There are articles both in favor of and against significant human-neanderthal hybridization. So, at this time, this is an unresolved issue. Genetic studies currently under way on neanderthal DNA may help solve this question in the next few years.
      (4 votes)
  • leaf orange style avatar for user Ajay Chandra
    How did the Neanderthals disappear and why at the time of the video ?
    (2 votes)
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    • mr pants teal style avatar for user Jacob Bechtel
      There are a number of hypothesis.
      One is they were wiped out as a species of humans, perhaps by competition with homo Sapiens, maybe just by an in ability to adapt to a dramatically changing climate.
      Another is they interbred with homo Sapiens and didn't die out, but disappeared as a distinct sub-species as they were absorbed into homo Sapiens.

      But long story short, we don't know but as we gather more evidence we may narrow it down to a most-likely scenario.
      (3 votes)
  • duskpin ultimate style avatar for user Aysis
    what is the function of an appendix?
    (2 votes)
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    • aqualine seedling style avatar for user SpinosaurusRex
      The function of the appendix is unknown. One theory is that the appendix acts as a storehouse for good bacteria, “rebooting” the digestive system after diarrheal illnesses. Other experts believe the appendix is just a useless remnant from our evolutionary past.
      (1 vote)
  • piceratops ultimate style avatar for user Vincent Jiang
    What song is playing in this video?
    (1 vote)
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  • aqualine sapling style avatar for user SmithEvaMarlena ♥
    Don't you pronounce Neanderthals with a th?
    (1 vote)
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  • piceratops tree style avatar for user davidantao01
    When did religion start?
    (2 votes)
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    • piceratops ultimate style avatar for user AegonTargaryen
      Religion seems to be about as old as humans. But how far it does back kind of depends on your definition of religion. We have evidence of humans burying their dead from tens of thousands of years ago, some animals (notable elephants)bury their dead in a similar manner.
      (1 vote)

Video transcript

For tens of thousands of years, Homo sapiens lived throughout Africa, but only some of these people were our ancestors. By 60,000 years ago, our ancestors were on the move, and their expansions started to have staying power, we don't know how fast, or how far they traveled. Today, hunter-gatherer groups move, on average, about 1 km a year, it's about half mile. But it's not always consistent--what we do know is this, as their descendants moved into new environments, they became more isolated from one another, setting the stage for the high level of genetic diversity that we see in Africa today. By 50,000 years ago, people started making more sophisticated tools, and creating a lot more art. Did new language abilities spark this burst of innovation? Maybe a genetic change in a population allowed some people to express more complex concepts through language, and so to out-compete those who couldn't, no one really knows. Around 50,000 years ago, small groups of travelers crossed into Asia, possibly as few as a hundred people in all. Everyone alive today who has any non-African ancestors is probably descended from these travelers. Within a few thousand years, climatic conditions became drier, and the Sahara desert expanded, making it harder to turn back, the intrepid travelers and their descendants followed a coastal route, eastward in Asia, reaching present day Malaysia within a few millenium. Did they meet Homo erectus along the way? By 45,000 years ago, people were living in parts of Australia and making their mark. In order to get there, they had to cross the 90 km--that's about 50 miles--of open water which separates Australia from the nearest islands of present-day Indonesia. Just how this was done, no one knows. It's amazing to think that people reached Australia and Europe at around the same time. Traveling eastward and southward along the coast of Asia, people didn't experience big and hard environmental changes; but hitting northward, into Europe, they faced extremely harsh, cold climates and tough terrain. As humans moved into Europe, they also ran into the Neanderthals, who'd been living there for hundreds of thousands of years. The Neanderthals were stocky, and physically better adapted to the cold climates, but the newcomers proved to be very skilled at shaping natural materials into useful and attractive objects. Though the Neanderthals may have acquired some of their neighbors' advanced technologies, they soon found it hard to keep up. Humans' success might have meant the Neanderthals' downfall. The two populations coexisted, even interbred, for a few millenium, but by 35,000 years ago, Neanderthals were confined to the southwest corner of Europe, and soon thereafter, they had disappeared, another unsolved mystery, yes, our story is full of them. Homo sapiens outlasted their cousins, and expanded their reach across Africa, Eurasia, and Australia; but soon times got tough for everyone, how would our ancestors cope with the extreme temperatures of the ice age.