If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

Main content

Why reproduction (Intro)

Let's explore why most living things reproduce. Created by Mahesh Shenoy.

Want to join the conversation?

Video transcript

most living beings reproduce humans make new human babies monkeys make new monkey babies and dogs well they make new dog babies or puppies so basically reproduction is where organisms make new organisms which look very similar to them right that's what reproduction is but what I want to do in this video is think a little deeply about why is reproduction necessary I mean think about it do you think reproduction is necessary to keep a living being alive I don't think so I don't need to reproduce to stay alive this dog doesn't need to reproduce for it to stay alive right I'm pretty sure you agree with this so let me just write that down it's important so reproduction is not not needed not needed for individuals for individuals to stay alive right okay and another important point is on top of that reproduction is it takes a lot of efforts if you take humans itself for example you might know right like the mother has to carry the baby in her belly for nine months and then even after the baby is born both parents have to spend so much time and effort to bring up that baby so clearly reproduction takes a lot of efforts and it's not needed for Hindus to stay alive then why do we do it that's the big question I want to try and think about so can you pause the video at this moment and think a little bit about why do you think is reproduction necessary well if you're given it some thought here is the answer or at least here is one of the answers although it is not necessary for individuals to stay alive turns out reproduction is needed or it is necessary for the species for the species to stay alive or we can say for the species to survive now the very first question you might have is hey what's the species let me just write that a little bit better what exactly is a species well for now we can just say species think of species as we can say if organisms look similar and they have the ability to reproduce then we will say they belong to the same species for example all humans look very similar in their body structure and everything and we can reproduce so all humans belong to one species all dogs belong to another species or cats belong to another species so if you want that species itself to stay alive we will see reproduction is super important and of course if you want to learn more about species in great detail we have a separate video called species so you can always go back go there and check that out but anyways let me try and clarify this with an example ok so let's consider a group of deer maybe in a forest now let's think about reproduction over here individually each deer they don't need to reproduce to stay alive reproduction doesn't help them to stay alive let's see what what happens if these deers don't reproduce what do you think will happen well clearly as time passes by the deers might get old and they will all die now even if we forget the whole aging thing even if these deers we're immortal meaning they could never age just just think about even if they could never age they can still die because there are so many predators around for example lions like to eat these deers maybe so Lions hunt the deer so that's one way that these deers can die another way could be natural calamities some deers might just get sick so it's just a matter of time all living beings just a matter of time eventually they will die and so if these deers do not have our have the ability to reproduce then they will be gone and not only will it affect the deers because they're no longer deer so that species is gone but it'll also affect these guys right and so you can see the whole ecosystem gets affected not only those species but also the species that are dependent on them the whole thing gets affected and so how does the reproduction help well let's see if the deers are able to reproduce then they can make more and more deers so with reproduction they have the ability to grow in number to grow their population and now even if the deers keep dying they keep getting hunted and even if there are natural calamities in some part of the world whatever it is because of the sheer number even if the few deers are dying it's fine because the species can stay alive because they have the ability to just make more and more copies of themselves so this is how a species can stay alive by reproducing so again let me just write that down how does it ensure survival of species well it allows the population to grow that's important it allows the population to grow so the population grows and because the reproduction gives them a chance to grow their population they can counteract the population dying they can counteract their organisms dying and as a result they can make their population stable so this will lead to stability without this the population without the reproduction the population will keep on reducing and eventually it'll it'll just become extinct now guess what there is another reason why a reproduction is important super-important you know why because it's even it's eventually we will see it's the reproduction that leads to evolution now of course evolution is a topic that we will explore in great detail in a separate chapter all together we'll talk about that in separate videos all together but just to give you an idea of how reproduction is linked to it you might know that when when individuals reproduce their offsprings that the children they don't look exactly like their parents for example you and I don't look exactly like our parents right we'll talk more about why that happens in detail in future videos but this is what we call variation going in reproduction the offsprings are not exactly similar to their parents and as a reason what happens well when these offsprings grow and they make there they they reproduce and make their children again there will be more differences right and so as more and more reproduction happens there will be more and more differences so every new generation will have more and more differences more and more variations we say and eventually if you now consider millions of years or millions or million millions and millions of generations we will eventually see the difference it will be so huge that eventually we will see new species all together will arise that's basically what we call as evolution ok it's a broad overview and in fact this is how we believe you know we in right now we have so many different species in our world because of evolution of course who talked more about that in future videos but you can now see what a big deal reproduction is for all living beings right all right so just to summarize what did we learn we learnt why reproduction is important it's not needed for individuals individual beings to stay alive it's not an essential life process however it is needed for the species as a whole to stay alive and how does it do that because reproduction allows the species to grow in number to grow in population because of this they can ensure that even if some of their organisms are dying due to various reasons the population number won't reduce the population will remain stable and we saw just we got just a glimpse of another reason why reproduction is important because as you reproduce we find that the offsprings will have some changes and then if you consider this over many many generations the changes accumulate and that's how new species are born altogether and that's how we believe that so many species that we have in the world today we all came from this idea of evolution and so without reproduction evolution would be impossible