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All right, let's get started.
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Hello, everyone.
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My name is depanga parham.
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I will be your teacher today and we will be talking about species.
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Firstly, we're going to define what it is.
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Second, we are going to look at what it means to be a species and what are some of the requirements to be a species.
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And then we're going to talk about why it's so hard to define.
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So i think the first thing we should discuss is what is a species because you, of course, cannot say why it's difficult to define.
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A species without acknowledging first what a species is.
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So the question specifically we're answering today is, explain how each of the following makes it difficult to clearly define a species, and we have variation within species, geographically isolated populations, asexual species, and then fossil organisms.
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So let's first start with what it is.
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So a species is defined as as any organism or group of organisms that have similar individuals, which have the opportunity or are capable of exchanging genes.
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And usually this is done through sexual reproduction.
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Let's scoot this over for a second.
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Can you see it properly.
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Let's move this to the center.
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So we have officially defined what a species is.
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So it's a group of organisms and they have to be similar individuals and they have to have the opportunity to exchange genes via sexual reproduction in order to create offspring or what is known as interbreeding.
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So species coming together to make the next generation.
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So let's start with this first one.
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So a variation.
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Within species.
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So let's get this text.
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Okay, so a, so if we have a variation within species, so let's type this, variation within species.
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So if we have a variation within species, why do you think it would be difficult for a scientist to be able to pinpoint exactly what that species is.
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Well, if we look back at our definition, we have a group of similar individuals.
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And if there's a variation within the species, then it's not possible for you to have similar individuals because those things vary.
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So let's just do a quick example.
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So my drawing's not the best, but we're going to try.
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So let's do blue.
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All right.
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Let's just do black.
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Perfect.
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Okay.
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So let's say we have a bird.
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So we have this one bird and that's a horrible bird.
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But that is okay.
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There is grace and i majored in biology, not art, but that's okay.
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So we have one bird, and that's one species.
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And then let's say that there's another bird who has a different variation within the species.
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So the two birds are in the same family, so they're both birds.
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They both lay eggs.
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The only difference between these two birds, let's say, is the color.
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So we can't say that this group of birds are similar individuals because they have variations within their species.
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So then this would be its own species.
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So we're going to do bird number two.
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So that's one species.
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And then, of course, bird number one is its own species.
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So it's really hard to define what specifically a species is within a group of species.
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When it varies so drastically because you don't want to lump a species with another species, if there are certain variations that you're able to pinpoint that makes it different, right? that would be a disservice to trying to understand the species and doing research and stuff like that.
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It just makes things complicated.
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So that's one reason why it's very difficult for scientists to be able to define what a species.
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Is even if it's very similar species and they only have slight variations, it's really hard for them to say, should this be one species or should this be a separate species by itself within its own category? so a little long -winded.
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I definitely hope that i answered that question.
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If not, i can definitely go back or make clarifications.
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But let's go to the second point.
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So the second point that it asked is why is it difficult for a scientist to clearly define species if you have geographically isolated populations? geographic isolation.
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So looking back at the definition, so it says that a species has to be similar individuals and they have to have.
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Have the opportunity of exchanging genes.
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So i know you might be asking.
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So if that's the case, why would geographic isolation be difficult if the species can just be together? and they can complete this definition just fine.
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So i'm going to give another example, a visual example representation, just so you can see.
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Thank you for bearing with me.
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We'll get through this together.
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So let's say, let's do the bird example again, except we're going to have birds that love sitting on black trees.
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And then we're going to have birds that love sitting on blue trees.
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Okay.
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So you have the population.
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Oops.
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Made a little mess up.
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That's okay.
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Just to simply erase.
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We can keep it moving.
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All right.
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So you have this population.
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Bird a, and they are all together.
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They are happy.
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I'm going to draw these dots as the birds, just to simplify things.
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So we have all of these birds in this one population, and they are loving on each other and having the best time ever in their tree.
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And then we have bird population b, and same thing.
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So bird population b.
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And we're going to continue to have all.
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All these birds, having a good time eating fruit flying around, breeding with one another.
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And so you can see that these are two separate locations.
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So you have species a, the black birds and the black trees, and you have species b, the blue birds and the blue trees.
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So if they're geographically isolated, they can brood with one another.
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They're similar organisms.
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So how is that hard? well, with the changing earth and migration and changing environments, what if, just maybe, a bird from species a and then a bird from species b came together and had a baby that had the traits of bird a and the traits of bird b.
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So this is a baby bird.
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This is a little chick from species a and species b.
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Well, now do you consider this one species? is it still two? because they're able to breed.
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And if they're no longer geographically isolated, how do you define what the species is of their offspring? or how do you define the characteristics within the genes are? are happening.
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So it's possible that let's say even if scientists did think that this was one species, right? well, what if other problems occur? so for example, when you mix a horse and a mule, i mean, when you mix a horse and a donkey, you get a mule.
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Mules aren't able to reproduce asexually because, i mean, sexually because they're sterile.
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And so then that's hard.
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To define them as a species because that breaks the definition.
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So what's possible that a mix of bird a and b could produce a sterile species? who knows? or let's also say that again going back to the first example, you might have a variation within these species.
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So then it's very hard to say, well, should we group it as one species? should this be two separate species? and if more than one pair of birds start to come together, and now they're no longer geographically separated, but they're all together.
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These once two different birds that were in species a and species b, well, now they can change.
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They can change and they can have the ability to have children together.
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And over years and years and years of that occurring, you're able to have the interchanging of genes which produces similar individuals.
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So now you no longer have two species.
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But then you have a fusion of these species and it becomes one.
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So now you can really see the problems with defining what a species is when there's geographic isolation or there's geographic changes in general.
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So you can either have two specific species but animals don't always stay in the same place and there's deforestation and hurricanes and different things that can cause geographic changes.
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And so based off of these changes, you're going to have a change in definition of what a species is.
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And species, to define a species, it's never going to be the exact same thing.
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It will always continue to change, right? and so that's why the second reason as to why it's really hard to define what that is.
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Now we're going to move on to the second point.
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So the third reason why it's hard to define what a species is is because asexual species.
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So i think it's important to understand, well, what is an asexual species? so an asexual species are species that do not reproduce sexually...