Anatomical Differences between Human and African apes, Biedalism - Grade 12 Life Sciences

Hello there wonderful matrix. Welcome to Educate. Today we'll be doing bipedalism as well as the anatomical differences between African apes and humans as part three of our human evolution video and stay tuned. So basically what is bipedalism? Bipedalism is the ability to walk on two legs. So in short bipedalism is just walking on two legs just like us humans we walk on two legs we don't use four right and then the ones that use four legs are known as quadrupedal organisms. So quadrupedalism is walking on four legs just like African apes. Remember I've already told you guys that African apes such as chimpanzees, gorillas, orangutans all of them they walk on four legs okay compared to us as humans but it is more advantageous to walk on two legs than to walk on four legs. Okay so the animals that walk on four legs they've got some bit of a disadvantage as compared to us who walk on two legs. Starting with this one the movement for us who walk on two legs it is easier and it is energy efficient. So basically for us to move it is very simple for you to move on two legs than to move on four legs. Imagine that guys that a moving with four legs you need to take your time and you need to spend a lot of energy all right but as humans we are walking on two legs so it make it becomes easier becomes energy efficient right that is why most of the times humans are able to run faster than dogs. Dogs are walking on four legs right but humans are walking on two so we are able to run faster than the dogs. So basically a bipedalism has got this advantage it is easier and it is more energy efficient it saves energy all right it saves energy you don't spend too much energy in moving all of those four legs. One of the other advantages of bipedalism it is the that the hens are free to pick or carry food as well as using tools. Basically you know that these orangutans these gorillas these chimpanzees they have got four limbs basically they've got four limbs or they've got four hens okay you can say they've got four legs okay so those four legs they use them to also pick because they can work as hens you see when a gorilla is trying to a to climb the tree it uses these the it uses two of the legs to be able to grab the tree and move from branch to branch so out of those four legs it uses two to be able to work as hens but it works on all of them but as for us humans we have got a two upper limbs which is our hens then we've got two legs which is the lower limbs right so the hens are free to pick because we are only working on two legs even when you are walking the the hens are free to pick or to carry food to carry stuff you can carry different objects at the same time you are walking but a gorilla cannot walk and carry something in the hand because the same hand is used to walk you get the sense right so it is an advantage to be a bipedal organism just like as humans it is an advantage to be a human because you are able to walk at the same time carry or pick a food a carry or pick objects such as tools and whatnot one other advantage of bipedalism is that you stand upright and standing upright gives a better and a wider view of the surroundings when you are a human and you are standing upright you are standing erect or you are standing upright you are able to see all a bigger view a wider view you are able to see a bigger area okay so this is this is actually making it easier for you to avoid predators let's just say someone is trying to attack you you can see them from a distance okay but if it's a if it's a monkey okay let's just say if it's a if it's a gorilla the gorilla is a is using four legs to walk and it is not so it cannot even see what's in front of it right it can only see what is just a closer to it but not a wider view so standing upright if you're a bipedal or by organism you'll be able to stand upright right and walk on those two legs so standing upright it's an advantageous it's an advantage okay it's an advantage because we're able to get a wider and a better view of the surroundings so that you can escape whenever there's a predator coming to you or whenever there's an attack coming to you and then one of the other bipedalism advantages or significances is that in courtship behavior the male sex organ is readily displayed okay this one is interesting because basically when you're standing upright you are actually exposing your sexual genitals simply means that the sex organ is readily displayed for everyone to see but this doesn't this definitely doesn't apply to us humans because we wear clothes right we wear trousers but basically standing upright it exposes that genital so that's one of the best courtship behaviors as well in animals not us as humans so these are the advantages of a bipedalism or the advantages of walking on two legs now look at this there are differences there are anatomical differences there are differences in the structures of the body between humans and apes now let's clear this one more time remember that when i'm talking about african apes what am i actually talking about we have got chimpanzees these are examples of african apes we have got chimpanzees these african apes right we have got orangutans orangutans and then we have got gorillas we have got gorillas and then lastly we have got bonobos something like this so these are the four that are being referred to when you say that we are comparing the anatomical differences between humans and african apes the question can come and say that you are comparing differences between humans and chimpanzees or differences between humans and orangutans it is still the same thing guys because all of those things are african apes okay these are african apes we say these are african apes so whenever you make a comparison just remember that all of these differences that you're gonna do right now these are the differences between all these african apes and us humans so now remember that we've already said that us humans are bipedal we walk on two legs right whereas the african apes are quadrupedal they walk on four legs so due to this bipedalism certain structures of the body between humans and apes will definitely be different because we are walking on two legs it means that our skeletons are adapted to walk on two legs right and the african apes have got skeletons adapted to walk on four legs so we are going to look at those parts of the body those anatomical structures that are different between humans and african apes due to bipedalism the first one is the position of the foramen magnum the foramen magnum is basically the hole in the base of the skull where the spinal cord leaves or enters the skull basically if you didn't know that your skull basically this skull here it is connected to your body through the spinal cord so there's a spinal cord that runs here at the back at the back here the spinal cord is the spine that you can feel right so basically there is a hole where the spinal cord enters the skull all right it's just a hole this is a hole here is a hole whereby the what whereby the spinal cord it actually enters up the what the skull or it leaves the skull you can say enter or leaves the skull so this hole is at different positions when we compare between humans and african apes basically in humans the foramen magnum is in a more forward position allowing for us to walk upright to walk a with bipedalism to walk on two legs basically so here you can see that the foramen magnum which is the hole that i'm talking about it is more in a forward position if you compare it to this one of an african ape quadrupeds or african apes they've got their foramen magnum in a more backward position what do i mean look at this this is a chimpanzee skull this is a human skull so this hole for a chimpanzee you can see it is almost found at the at the end of the skull it is at the back part it is in a backward position of the skull but in a human the foramen magnum is in a more forward position so the fact that our foramen magnum which is the hole where the the spinal cord enters or leaves the spine the skull it makes us to be bipedal it makes up to makes us to be able to walk a on two legs to be able to stand upright and walk on two legs so basically you can see that this is the skull basically you can see that the skull here it is connected to the foramen magnum but as for apes this foramen magnum is in a more backward position it is more backwards so that is why you can see that the skull here the the spine the spinal cord here it is connected at the back of the skull because the hole that is connecting the spinal cord and the skull it is in a more backward position in a what in an african ape remember african ape is chimpanzee orangutan then gorilla that's why here you can see this is a chimpanzee skull so this hole known as the foramen magnum for humans it is in a more forward position but for african apes it is in a more backward position so being in a more forward position it allows our spine to actually enter vertically so that we can stand and walk on two legs but but for these african apes it is in a more backward position so the skull will enter in such a way that it will okay the this spinal cord will enter here at this point in such a way that you will have a posture that is bent like this basically the african apes they don't actually stand upright that much okay they stay there guys you get what i'm talking about here all right so now we are still here at the bipedalism due to bipedalism as well there is another difference between humans and african apes it is the spinal cord or the spine itself right let's just say the spine is so basically in humans the spine is curved the in humans the spine is s-shaped the shape of the spine the human spine is an s shape it looks like s okay so here if you look at this human here he is standing upright and you can see that here this skull this is okay this is the spine i mean so this spine here the spine it is s-shaped it almost look like an s so this actually causes the upper body to be directly above the pelvis resulting in a vertical posture so the fact that this spine is an s-shaped it causes the body to be just on top of this this this thing known as the pelvis the pelvis just this region so basically the upper body is directly on top of the pelvis causing you to stand upright like the weight of the body is distributed directly okay i'm not trying to be a physical science teacher for now but basically i'm talking about here the spine being s-shaped it allows the upper body the upper body to be directly on top of the pelvis causing you to to stand upright grade 12 so that's for humans so whenever you're answering this question you're going to say that humans have got an s-shaped spine okay but what about apes african apes have a less curved so you can say that they they are their spine now okay their spine not the spinal cord their spine is less curved and particularly the shape almost looks like a c it looks like a c shape a c all right so when it stands upright the weight will just pull it down all right so basically a an african ape cannot stand upright like as humans okay it can try to stand upright but its its position is just unsteady you can see that this is an african ape it is trying to stand upright but you can see that this c-shaped spine this c-shaped spine here this is this c-shaped spine it is causing this upper upper body weight to pull it down so eventually it will always be in this posture this is the right posture for an african ape so that's why african apes they walk on four legs that's why they are quadrupedal all right they are quadrupedal because of their spine being c-shaped their spine is less curved so basically a that spine is actually pulling down it's pulling it down so that and it ends up walking on four legs but as for us humans our spine is s-shaped so it is causing the weight to be vertical so that you can walk on two legs and stand upright or erect we look at the third difference due to bipedalism as well another thing that causes us to be bipedal as humans is that our pelvic gaddle our pelvic gaddle or our pelvis it is short and wide so the pelvis of a human being is short and wide compared to that one of an african ape so it is able to support vertical weight so if you are looking at this this is the pelvic gaddle okay this is the pelvic gaddle for a what for a human being it is short and it is wider specifically in females for for for human for humans in females and the pelvis is more wider than in males because remember that females have to give birth right but we are not there we as we are comparing here humans and african apes humans must have a pelvis normal a pelvic gaddle that is what that is short and wider when compared to that of african apes african apes have got long and narrow so their pelvic gaddle or their pelvis let's just say their pelvis is long and it is narrow if you can look at this diagram here is the pelvis of an african ape it is long indeed and it is narrow I don't know guys you get this is it's long and it's narrow but when you see a human one it is wider it has got a bigger width and it is shorter but this one it is longer but it has got a smaller width or it is narrower you get the sense right so this is the third difference due to bipedalism so now let me give you a trick when you're answering questions what causes bipedalism in humans what causes humans to be bipedal or what causes bipedalism if they say this is a six marks question explain what is causing bipedalism all right so you talk about bipedalism you have to talk about those three things you talk about the foramen magnum's position okay what causes bipedalism in humans you first talk about the foramen magna the foramen magnum's position remember I've already told you guys that that hole in the skull it is in a more forward position for us humans all right so here you have to say that humans have a humans foramen magnum humans foramen magnum is in a more forward position foramen magnum is in a more forward position that's one mark in a more forward position so the foramen magnum in humans is in a more forward position so what is the advantage of having a foramen magnam in a more forward position remember it allows the spine to be able to enter vertically okay so this allows the spine to enter vertical allows spine to enter vertically so when the spine enters vertically you already know that the human being will stand upright because the spine it is the one that is controlling your back right basically if it enters vertically so that is two marks here for this okay so you talk about the what the foramen magnum's position this is the first reason this is the first reason oh yeah this is the first reason for having bipedalism in humans the second reason that we are bipedal as humans we talk about what we talk about the spine shape the shape of the spine okay so humans have an s-shaped spine humans have an s-shaped spine or you can say that their spine is more curved you can say it's an s-shape or it is more curved and when it is s-shaped what does how does that allow bipedalism so it allows so it allows vertical weight vertical weight of the upper body of the upper board to be directly to be directly above the pelvis to be directly above the pelvis so this is the second reason that we are bipedal as humans according to our structure right so basically humans have got a spine that is s-shaped so this allows vertical weight of the upper body to be directly on top or directly above the pelvis so this is the second difference between humans and apes due to due to these walking styles bipedalism and quadrupedalism and then the third one what else causes humans to be bipedal it is this one that we are on humans have got a short and wide so short and wide short and wider pelvis okay short and wider pelvis than African apes so this short and wider a pelvis it allows or it supports vertical weight which supports vertical weight as we've already explained that a which supports vertical weight so this is how this is how you get your six marks so these six marks question can just a you know pop up and be like give a reason why humans are bipedal right give a reason why humans are bipedal you have to talk of these three things but these are also differences between humans and African apes these are differences due to bipedalism these differences are actually causing us to have two different walking styles it's causing humans to walk on two legs causing African apes to walk on four legs right hey Lapo I know that you've been enjoying this wonderful video and most likely you've been enjoying watching this handsome face in front of you but sorry ladies I'm taken I just here to tell you that educate is on the road to 100,000 subscribers by the end of 2025 so please click the subscribe button and click the notification bell so that you get notifications whenever I post new videos I want you guys to pass okay so if you make my dream true I reach hundred K subscribers I will make your dreams come true I will even get you to varsity I will get you with seven distinctions yes now let's go to other differences between humans and African apes these ones are not connected to bipedalism in any way so let's talk about the first one the brain or the cranium size let's talk about the difference in the skull this is the skull of a chimpanzee this is a skull of a human being okay so there are notable differences between the skull of a human being and the skull of a chimpanzee so basically the cranium size or the brain size is bigger in humans so humans have put a larger cranium the cranium remember it is this a this this this bone here basically it is this bone here this bone here it is the one covering your brain right it is known as the cranium cranium right so humans have got a larger cranium size no matter if got a larger cranium than chimpanzees remember that I can say chimpanzees or I can say orangutans or African apes all of it is the same thing guys at the same thing here so here humans have a larger cranium size if you look at the cranium size of a chimpanzee it is way smaller when you compare it to the one of a human being so humans have got a larger cranium size so this larger cranium size what does it actually indicate a larger cranium size it indicates a larger brain all right basically the cranium houses the brain I've already told you that the cranium is the one protecting the brain so if you've got a bigger cranium or if you've got a bigger head then it means you've got a bigger brain simply that so simply here the humans have got a larger cranium size than chimpanzees so since this these humans have got a larger cranium since the cranium is the one that is a housing the brain or it is the one that is enclosing the brain so a larger cranium indicates a larger brain size how can you have a larger brain how can you have a larger brain in a smaller head how can it even fit guys doesn't make sense so the fact that the cranium size is bigger in humans it means that humans have got a larger brain than what than chimpanzees and having a larger brain what does that suggest a brain is the one that processes everything remember that the brain processes everything right so brain leads to intelligence so humans are more intelligent than African apes there are guys where humans were more intelligent than African apes why is that is because we've got a larger cranium size normally we've got a larger brain size that is why as humans were able to make tools as humans were able to make phones as humans were able to teach just like the way I'm teaching you African apes cannot do that because they've got a smaller brain size a smaller cranium with a smaller brain they do not have that much intelligence when you compare it to humans so that's one of the anatomical differences between humans and African apes right we also have got brow ridges the brow ridge is just a bone that protrudes here on top of the eyes so here look at here this is the brow ridge this is the brow ridge so it is just a bone that is that is found on top of the eyes it's a bone that is supposedly here at this position but in humans it's definitely not so much visible right it's very small or it's so much it's not it's not visible it's just a bone that is supposed to be on top of the eyes but for chimpanzees the brow ridge you can see that it is very very very very visible so chimpanzees have got a well-developed brow ridge okay they've got a well-developed brow ridge humans have got very small or they do not have any brow ridge dear my mind I cannot even feel a brow ridge here I cannot even see it I don't even see that there's a bone on top of a on top of my my on top of my my eyes okay so this is the eye of a human being the brow ridge is supposed to be here but you can see that the brow ridge is not there for us humans so for us humans the brow ridge is either very small or there is no brow ridge at all but chimpanzees have got a well-developed so we say it is well-developed in chimpanzees but in humans it is very small or it is not there at all alright so that's one of the anatomical difference in the skull or in the head guys always read the question so that you understand which differences do they want we have differences due to bipedalism those three which I've already mentioned they can ask them to be specific to say give differences according to bipedalism here these are the differences in the head or in the skull between a human skull and the chimpanzee skull so make make sure that there's a difference there we also look at what else okay now after that we look at the dentition yes we look at the dentition dentists whenever you hear the word dentish the dentist or dentition basically you're talking about the teeth okay so the teeth of human beings are different from the teeth of African apes right they're different from the teeth of chimpanzees different from the tips of the teeth of a gorillas orangutans all of those so the differences is that the jaws let's start with the jaws basically chimpanzees have prognathous jaws where is the jaw basically the jaw we are talking about here this a this region is known as the jaw just above your teeth this is a jaw so basically in African apes the jaw it is prognathous it is protruding it is well developed it is just protruding out so in this case you can see that this is the jaw it is so visible it is protruding it is very visible when you compare to the position of the eyes do you see where the eyes are but the jaw is very very very very far from the eyes so you can see that this jaw or these teeth actually protruding but don't say teeth it is the jaw okay but for us humans you can see that the position of our eyes and our nose and our jaw is not so much protruding it is just a bit protruding as well okay so chimpanzees have got a more prognathous the word prognathous it just simply means that the jaw it is a protruding out normal it is get the sense guys you get the sense words cannot describe the love I have for you that's what you yeah that's how you lie when you when you do things right so this this I cannot even describe this in words you can see that guys this jaw of this African ape it is protruding English is not Englishing but it is protruding but for humans it is less prognathous it is not that much a pro protruding it is not that much a it is not that much developed I think I'm cool in a sense so basically the jaws of chimpanzees are prognathous but humans have got less prognathous jaws humans have got less prognathous jaws and then the canines as well so basically the chimpanzees have got large and pointed canines chimpanzees have got can I remember the canines are the teeth that are used to cut meat if I'm not mistaken you've learned this in grade 11 at some point but basically the canines are these teeth here you've got four of them in your mouth in total two in the upper jaw two in the lower jaw basically those teeth these canines in African apes they've got larger canines they've got larger tooth teeth teeth size is bigger in in what it is bigger in an African apes but humans they've got very small you can see that here this is a chimpanzees a mouth this is a chimpanzees mouth this is a human mouth here so you can see that these are the canines these these teeth here the canines of chimpanzees are so large they are so big and they're so sharp they are so pointed all right they are pointed they are sharp they are larger but when you look at the canine of a human being this is the canine of a human being getting this one this is the canine this one this one this is also a canine I don't know a this mouth I don't recognize it but basically this is a canine this is a canine if you compare the canines of chimpanzees and human beings basically the the canines of chimpanzees are large and they're pointed I remember that chimpanzees here is the same thing as just African saying African apes right so basically they've got a larger pointed canines why do they have got larger pointed canines it is because a they eat raw meat okay they tear raw meat they eat and they tear raw meat basically chimpanzees they don't eat cooked food they don't eat soft food they eat raw meat okay they eat raw meat maybe they can just take a cat and eat it raw without cooking it it is rough guys if you don't cook meat it is rough you have to cook it first for you as a human but for chimpanzees for African apes they've got they've got these large pointed cow canines so that they can just tear down the meat so that they can just chew the meat and just eat perfectly in a sense all right but humans they've got very small canines and these canines have got small gaps basically in chimpanzees the teeth have got large gaps they've got large spaces between them gaps like I'm a gap like literally gaps but for humans our teeth they don't have those they don't have that much gaps okay the teeth are closer to one another and they are very small they're not so big they don't really need to be so big because humans have adapted to eat softer cooked foods humans are now eating softer and cooked food I remember that we've evolved from the same ancestor from a common ancestor with these African apes we are coming from a common ancestor with these things that have got these large teeth so it means that humans as humans we have moved from having those large teeth it means at some point as humans we used to have large canines we used to eat raw food okay at least according to what they're saying here we need we used to do that but because we have adapted to softer food to cooked food then our our canines became very small they became smaller all right and they became smaller and they got adapted to eat softer cooked food maybe in the near future our teeth will end up disappearing because llama cultures always say that if you don't use it it will become smaller smaller and this end up disappear disappearing so same thing here with the canines right all right we also have got the palate the palate is the roof of the mouth the palate is the roof when you take your thing and you put it on in your mouth right the roof the top part of your mouth the roof of the mouth is known as the palate just put your finger here practical you hate put it there's what there is a palate so the shape of the palate in chimpanzees is different from the shape of the palate you know what in humans the chimpanzees or the African apes have got longer they have got a rectangular palates their palates are rectangular in their long but for us humans we've got smaller we've got round palates smaller and round palates when you look at this one if you look carefully here you can see that here this is the palate this is the roof of the mouth for a chimpanzee because it's opening its mouth like ah okay so this is the roof you can see that the shape of the palate here it looks like a rectangle it's a bit rectangular okay and it is long when you look at the mouth of a human being it is more like a round shape and it is shorter it is smaller it is rounded so the palate shape is different one more difference that you would have noticed here in the faces right basically the face of a human being it is more like flat okay it is a flat face if you can just put a line on it it is not so much protruding but you can see that here this face of the chimpanzee okay of the chimpanzee you can see that it is more like protruding too much so here basically here we can just say it's a flat face I don't know how they structure it just check for you but basically a that's that's one of the difference and also you have to also observe here the size of the brain the brain size for a chimpanzee average is 350 cubic centimeters that's the volume then for a human is an average of 1450 so you can see that in these facts are actually for a zillion the fact that humans have got a larger brain as compared to African apes right now let's look at the last part which is still part of dentition is still connected to teeth in the skull right now we are connecting them together now so the cranial ridge is one of the things that a that exists or that existed before for some species right so the cranial ridge is a ridge that is running across the top of the cranium remember I've already told you that the cranium it is the head itself this bone here that is covering the brain the bone where your your hair is growing the bone where my beautiful hair is growing that's the cranium so in the cranium there is a ridge that is a on top of it and it's known as the cranial ridge it's known as cranial ridge because it's on top of the cranium right so the cranial ridge it serves as an attachment of muscles involved in chewing so when you are chewing food there are muscles that are coming from your teeth the ones that are chewing from your mouth basically and they are connected to the cranial ridge on top let's look at the cranial ridge this is the cranial ridge this is the cranial ridge this is a cranial ridge so the cranial ridge is just found here on top of the of the cranium it's just a ridge that is found across the cranium and this is where the muscles coming from your mouth the muscles involved in chowing food are connected. They are connected here at the top. So that whenever you are eating, the muscles that are involved in chowing food, they are connected at the top of this cranium, at the cranial ridge. If you look at humans, modern humans, they've changed to a cooked food diet. Remember that at some point we shared the same ancestor with these things, with these apes, but modern humans such as me and you, these modern humans have changed to cooked food. We eat cooked food. We do not eat raw things, guys. An average human being, it's cooked food. Unless if you guys are starting to be animals these days, as an asthma 2000, we used to eat cooked food. We still eat cooked food. Maybe you guys are eating some other things, but basically modern humans, they've changed to cooked foods. So they've changed to cooked foods. So basically humans, they do not have a cranial ridge. As humans, we do not have a cranial ridge. Guys, I've been pointing here at the cranium. Have you ever seen a ridge here? There's nothing. We do not have this thing here. This cranial ridge is only available or it is only present in these African apes because the African apes, remember that they've got larger canines. They chew a lot of things. Okay. They chew a lot of, they grind raw meat. They eat, they grind raw meat, all of that. It develops the cranial ridge. So basically to us humans, we are eating cooked food. So we don't really have those much muscles for chewing, right? Okay. Because the cranial ridge is associated with the muscles that are chewing food. So due to that change that we went through, because at some point as humans in the past, we used to have the cranial ridge, but it became smaller. Basically what became smaller? The jaws became smaller. Starting with the jaws of human beings. Remember the jaws, remember I was talking about this is the jaws. This is the jaw, right? This is the jaw, just on top of your mouth. So at first we had jaws like this. We've got, we had bigger jaws, just like these African apes, but because we have shifted to a diet of cooked, soft food, grade 12, right? We started, the jaws started disappearing. According to Lamarck, we were no longer using them that much because we were eating soft cooked food and the cranial ridge also disappeared because we're not chewing anything that much, right? We're not chewing those big chunks of food. We are just eating soft cooked food. Maybe in the next generation we'll be eating, we'll all be eating pureed or something like that. So thank you so much for watching this video, great house, as long as it is. Don't forget to subscribe to the channel. Tell your friends to also stay tuned.