Primates and Homonids

in this video, we're going to briefly discuss primates, which includes organisms such as ourselves and some of our more closely related organisms such as the chimpanzees. And so primates are really just a group of mammals that are characterized by very specific features such as large brains and sophisticated visual systems. And in fact in the back of our heads, there's a region of our brain called the occipital lobe, which controls our complex visual systems. Now, primates are also characterized by features such as having good parental care, meaning that they take good care of their offspring, and they are also characterized by having complex social behaviors. Now, some primates have opposable thumbs, which is really just a non digit finger, such as our thumb that is going to allow for grasping in the utilization of tolls as well as fine motor skills. And so a fully opposable thumb is one in which the thumb is able to touch the front of the fingertips for each of the four digits. And so humans have fully opposable thumbs, but so do gorillas. And chimpanzees also have opposable thumbs as well now, which will notice is that the given uh it does have this thumb as you see here, however, it is distant from the fingertips uh is pretty great in comparison to the chimpanzee gorilla and homo SAPIEN. Uh And again, the homo SAPIEN is the human hand. And so what you'll notice is that because there's such a great distance here, uh they do not have fully opposable thumbs that allow them to touch their thumb to the front of their fingertips. And what you'll notice is the tar sierra over here is also going to have more primitive like features where it is not going to have a fully opposable thumb. Now in general, these primates can be broken up into two major groups and those two major groups are the pro simians and the anthropoid, or the simians. Now the route pro and prosimian is a route that means before. And so pro simians are going to be a group of primates that are more similar to early primates and that's where the pro comes into play again. Pro means before. So you can think early or earlier primates and uh the pro simians include lemurs and lorises and also the tar Sears. And so notice down below, we're showing you this image of a lemur which again is a prosimian and it is going to have features that are more similar to early primates. Now, the other major group of the primates are the anthropoid or the simians and these are going to be bigger brained primates that are going to include monkeys and apes and humans and chimpanzees. And so notice down below, we're showing you this image of these chimpanzees that are showing these complex social behaviors. And so those are going to be an example of the arthur points or the semites. Now, these are three points or simians can be further grouped into what are known as hominids. And so hominids can be defined as these arthur points uh and the hominids are also sometimes called great apes. And so the hominids include gorillas, chimpanzees, bonobos, humans, and orangutans. And so if we take a look at this image down below, which you'll notice is we're showing you the skeletal structure of these different primates and we can use this image to introduce this term bipedal ism. And so the term bipedal ism refers to the ability to walk only on the two hind limbs. And so basically it's saying the ability to walk on two ft. That is what bipedal ism is. So, humans are fully bipedal as adults And uh which you'll notice is that many of the great apes are actually not fully bipedal. And so the great apes here are going to include humans, but humans are the only ones that are fully bipedal. They're the only ones that can walk on two ft predominantly. Now the chimpanzees, gorillas and orangutans, they are great apes, however, which you'll notice is that they can use their hands and they tend to use their hands for a lot of emotions and movement. Uh and a lot of their arms. Uh you can see the bone structure for their arms are much longer and very extended and their posture has been so that they can more conveniently use their hands in addition to their feet in order to move around. Now, the given, on the other hand over here is not actually a great ape. It is an arthur point, but it is not a hominid. And so the gibbon here also has the long extended skeletal structure in its arms, and so the gibbon is going to walk more using all four of its limbs, so it is not going to display that bipedal ISm. And so this here concludes our brief introduction to some of the features of primates and some of the groups of these primates. And I'll see you all in our next video.

Australopithecus is a genus of hominids that lived from about four million years ago to about two million years ago. And this the organisms in this genus played an important role in human evolution. Over here you can see the reconstruction of the skull of an Australopithecus species Australopithecus, af friends ISS, which you can see that name printed on this map over here. And also, if I jump out of the image really quick, you can see that name printed behind where my head waas So that is the species name. And next to that skull, we have a reconstruction of that organism. Um what people think it might have looked like this is based on a partial fossil. That's our partial fossils that have been uncovered. So you know it, Z, there's some artistic license being taken here. But this eyes is thought to be the ancestor or an ancestor of modern humans. Australopithecus afarensis. And, uh, this particular organism is known commonly as Lucy um, which is Theo con name given to a particular skeleton of the species that was found? No, As you can see in this map, there are many different species of straehle. A pith acas, and they're found all over Africa. And Australopithecus is indeed native to Africa. And there were a bunch of different species, uh, in that genus. Now, from that genius arises this a new genus Homo. That's the genius that we belong. Thio. And it's thought that theme, the homo genus of hominids, evolved from possibly from Australopithecus af Arends iss. And it's thought that the homo genus arose around two million years ago. So let's actually take a look at some of the species in the homo genus now, uh, early early species in the homo genus is homo habilis and that I'm abbreviating the name here just to be clear. So a Chablis is short for homo habilis and basically this, um, this name just means handyman, and these organisms were named for their tool use. Uh, there, you know, early humans, very early humans and some people, some scientists actually believe that they're better classified in the Australopithecus genus rather than the homo genus. So, um, you know that line? That distinction is not super clear cut, right? It's not super explicit, you know, there's it's ah, you know, a vague enough transition that some people even classify this homo habilis is Australopithecus hapless, for example. Now, uh, another early species is homo erectus, and also Homo or gaster. These early humans originated in Africa, but they actually emigrated from the continent. And here in this map, behind my head, you can see the path taken by early humans. And we're actually looking at three different species. And in yellow, that's thedetroitbureau shin of Homo erectus. So you can see they were found in Africa. But they also crossed over, Um, you know, via the Sinai Peninsula there, uh, to the Arabian Peninsula. And they also, um, you know, made it into the Indian subcontinent, Southeast Asia. However, it was homo Neanderthal, uh, Neanderthal insists that made it into up into Europe. Right. So those, uh, those guys are colored in in this orange color, and you can see that they were found, uh, you know, really, like, all across Europe, into the Bactrian region, all around the black, and cast me and see. And even on the island of Albion, or as we know it today. England. Um, now, uh, these guys, these homo Neanderthal insists these air what we often commonly referred to as Neanderthals, right? Who? Sometimes we also call them caveman. Um however, when we say Neanderthal in science were actually referring to this particular species or potentially subspecies, there's actually some argument there as to whether Neanderthals are a species or subspecies, uh, of human. And it's worth noting that they do share 99.7% of their DNA with modern humans, which, to put that into perspective, chimpanzees share about 98.8% of their DNA with modern humans. So this is like a full percentage point closer to modern humans. So very similar DNA. Now, humans are known as homo SAPIENs, which means Wiseman and Homo SAPIENs air. Actually, what we call, uh, anatomically modern humans. People living today are thought of as a sub species. We actually call ourselves Homo SAPIENs. SAPIENs, right. So are subspecies of modern humans. Just tax on an extra SAPIENs. Right? So we're h SAPIENs SAPIENs. Little redundant. So we're not wise man, But wise, wise man, like super extra smart, I guess. Um and you can see that Homo SAPIENs have inhabited the whole planet. Where are trajectory? Here is shown in red. We spread over Africa, made it up into Europe. Asia, Russia crossed the bearing straight into Alaska. Um, you know, down into the Americas, uh, colonized all of the self Pacific region Oceania, if you will, um, you know, even went up into the Arctic region. So, uh, you know, we our ancestors, I should say I shouldn't take credit. Our ancestors colonized the whole planet, so you know they're there. Four bears, the Neanderthals, Homo erectus. They got out of Africa, but they didn't make it nearly as far Azaz our ancestors did. Now, another term I wanna briefly mentioned is Crow Magnin. Uh, Cro Magnons man. Right. Cro Magnons people, Those air, actually, just early European, European homo SAPIENs. So those are technically humans. Those are our, uh, direct ancestors. In essence. Now, uh, in addition to this map, I also have this other cool chart that shows basically the the presence of various species of Thehuffingtonpost genus on and their distribution. And also like when they were populating Ah, a certain area. So you can see we have homo gaster and homo erectus. Um, and you can see that homo erectus started in Africa, right? Spread out into Asia. So I know this chart might look a little confusing. Hopefully, you can kind of get the idea. I don't expect you to draw any terribly important conclusions from it. It's just their toe, you know, add a little color to this story. Now, one thing I do want to point out, though, is that there is overlap between Homo, Neanderthal, Insys and Homo SAPIENs. That is to say that Neanderthals and home of SAPIENs were contemporaries. They lived at the same time. However, there are no more Neanderthals, right? Those guys disappear it some point. Homo SAPIENs are everywhere now, And, you know, there's a lot of and also, you know, if you look at this, um, figure you notice that the Neanderthals break off way before Homo SAPIENs break off. So they just they represent distinct lineages. Right? So what happened to the Neanderthals? That's a really big question. Where did they go? They were contemporaries with homo SAPIENs. Now there are none there. Many different theories as to why this is, um including, uh, you know what they call assimilation? Essentially Neanderthals. Inter bred with Homo SAPIENs. And now we're all just kind of one species. They were essentially Neanderthals. were absorbed into Homo SAPIENs, which would give credence to the idea that they're actually just a subspecies, not, um, a distinct species. Some theories go into places that are a little darker. I mean, for example. For example, some people, uh, piggyback off the idea that there's a Nen Herron violence in human nature, right, that humans are innately violent organisms. And so people think that, uh, those old homo SAPIENs may have actually carried out genocide against the Neanderthals that they they actually wiped them out. And that's why they disappeared. So, uh, there's a whole range of explanations. I don't pretend to know enough Thio, you know, weigh in and say that I believe one is more likely than another, though I do think they're very interesting. And I highly recommend that if you're interested in this, you go check out some of those explanations because it is fascinating stuff. That's our history, right? So that's all I have for this video. Hopefully, this tickled your imagination a little bit, tickled your fancy, and I'll see you guys next time