Term 1 Science 10 | Lesson 11: VARIATION, HEREDITY, ISOLATION, ADAPTATION | MATATAG Curriculum

0:01 Okay. So, hello grade 10. Welcome to our next lesson. So, we are almost finished with the term one lesson. What is it? So, just one more lesson and then it's term two . So, hopefully we learned a lot this term one. What is it? Okay. So, this time we will discuss several concepts which are related in the theory of or in the word evolution. So we have the following words like variation, heredity, isolation, selection and adaptation. So let's look at what these words help with in the word evolution or how does it affect evolution. So I am Sir Wawi, your ever curious science buddy. Don't forget to like, share, and subscribe so

0:49 you can always be updated on our next science lessons. Okay. So for our learning competence, discuss in small groups important concepts in the theories of evolution such as variation, heredity, isolation, selection and adaptation. Okay. And for the learning objectives, explain the basic concepts in the theories of evolution. Differentiate the words variation, heredity, isolation, selection and adaptation. And then discuss how these concepts contribute to evolution. collaborate in small group discussions. Appreciate the importance of evolution and biodiversity. Okay, so let's start. There you go. So let's have a quick review. So look at the

1:35 examples below. Discuss with your seatmate or group and answer the question. Why do you think these living things are different from one another? Okay, so we have a sample here. People have different eye colors, heights and hair types. Then gamels can survive in hot deserts better than polar birds. And then birds on different islands of different weak shapes. So what difference do you notice? And then why might this happen? So people have different traits like eye color, heights and hair types. Okay. So what difference do you notice the traits or physical traits? Why might this happen? Okay? So traits are basically inherited from our parents. And individuals vary what and vary among individuals. Okay?

2:22 There is diversity. It can't be okay if his traits are exactly the same as mine or we're identical. Okay? Even if we say we have different parents. No, that's not like that. So um heredity is not like that or the process of heredity is not like that. It causes or it creates rather it creates a variation and of course variation is very important in evolution. So we'll see later what he's doing okay with the theory of or the word evolution. Next, camels can survive in hot deserts better than polar bears. So why do camels have a greater chance of survival

3:08 in the hot desert compared to polar bears? So camels are adapted to hot climates. So all polar bears are adapted to cold climates. So let's remember, children, all organisms or animals adapted their environments to survive. So if we take the camel to, uh, let's say Antarctica, it's possible that it won't be able to adapt either. Is it okay because it's super cold? Okay. So it's not immediately possible to change his physical traits. Okay? Because we say evolution happens for a very long period of time through generations. So birds on different islands have different big shapes. This is it. So one of the best examples here is the finches

3:54 introduced by Charles Darwin. Even though the finches are the same species . Okay. Through time, the shape of their beaks changed. It's because of the environment or their food source . Some have long beaks, some are quite large and hard. Okay. It depends on the food source which they adapt through time. What? His characteristics have changed through time. Birds adapted to different environments and available food. There you go. So again, what is evolution? So when we say evolution, living things on earth are not exactly the same as they were millions of years ago. So if we can see , if we're going to go back in time, okay, and we will compare the organisms, okay, in the past and then

4:39 the present, the difference is huge. Okay. The magnitude of the change is really big because okay, all things here on earth constantly change. Changing. Something can't really stay completely the same, so evolution occurs in all organisms, even in humans. Okay? Even in other animals. Okay, but that particular change is not uh part uh did not happen overnight. It takes slowly gradually, okay, through generations. So over long periods of time, organisms gradually change. Some develop traits that help them survive better in their environment. So these helpful traits may

5:26 be passed on to the future generations and then this process is called evolution. Okay. So evolution helps explain why living things are diverse and why organisms are adapted to their in or adapted to the different environments. Okay? So change over time. So you just tell me if this is an example of evolution or not. The first one, a species of birds slowly develops different weak shapes over many generations. Is it an example of evolution? Yes. What? A boy grows taller as he gets older. Is it evolution? No. Because growing taller is a natural process in humans. We really do get older as we get older, don't we? So some bacteria become resistant to antibiotics after many

6:12 generations. Yes, it's an evolution. It seems that there have been changes in the traits of the bacteria which are passed from the parent to the next generations. Polar bears develop thick fur to survive in cold places over time. As time goes by, it is said that the fur of polar bears becomes thicker so they can survive in cold places. Okay? A dog learns a new trick from its owner. you taught the dog to turn around with commands it's not evolution it's a skill you taught the dog what so sig ayan so theory of evolution so scientists have studied living things for many years and noticed that organisms do not stay the same forever not really okay over time species can

6:58 change adapt to their environment and sometimes even form new species to explain this changes scientists develop at different theories of evolution These theories help us understand how and why living things change, how they adapt to survive and how new species can appear. Okay? So we will provide various words or concepts that affect the word evolution or have had an influence rather in evolution. Okay? So these are the concepts we have. First one variation. So differences in traits among individuals of the same species helps evolution. Heredity, the passing of traces from parents to offspring through genes. It also helps evolution

7:45 because all the good traits for example, okay, uh when we discuss the concept of natural selection, okay, in the concept of natural selection, if in the same organism, we have the best trait there. The best three, those with possible or high chances of survival. So through uh heredity those good days will be passed on to the next generations. So next isolation. When groups of the same species are separated and not interpreted leading to different changes over time. Okay? A better example here in Batangas is Tawilis. Okay? Another process where individuals with helpful traits are more likely to survive and reproduce. Okay,

8:30 this is a selection. Okay, we've discussed natural selection. So, I hope you have an idea about this. Adaptation, a trait that helps an organism survive and live successfully in its environment. For example, our giraffes developed or lengthened their necks over a very long period of time . It's an example of adaptation. Okay, next, let's start with the first one. Variations. Okay. So, how can we explain this concept? What is the word variation? So, variation, as we said, is differences that make each living thing unique. Okay. Variation refers to the differences in traits among individuals of the same species. That's the difference. Okay. So, think about it. If there were

9:17 no variation, all living things would look the same. It seems the same when there really is no variation. But in nature, differences help species survive. and adopt. Did you know that in our environment diversity helps us survive? Okay? For example, okay, in humans, if the level of our immune system is the same, we are all the same. Okay? It's possible that if a virus comes along, we could be wiped out entirely. But if our levels are different, yes, some will die but some will survive. Okay? Variation helps. in the survival of a particular species. Example in humans. In a classroom

10:03 different heights, eye colors, hair types and skin tones even though they are all humans, they are not exactly alike. Okay? And that is an example of variations. That helps. And then example number two, in animals, some rabbits have white fur while others have brown fur. Okay? So variation is all around us. It makes the word colorful, interesting, and full of life. So, how does it help evolution? How does variation contribute to evolution? Evolution cannot happen if all organisms are exactly the same. Let's remember, variation creates different traits within population. Some of these traits may be helpful for survival. I will give an example. Let's say imagine 100 rabbits. We have 100 rabbits. Some

10:49 are white, some are brown. Some are white, some are brown. Okay? Because they are different. Their far colors are different. Nature can choose what surrounds us, it can choose which traits are most useful. Okay? So for example, these brown and white rabbits live in a particular place. Like for example in a snowy area, which of the rabbits do you think is possible or has a high chance of survival? Of course those are white rabbits because they have the ability to blend in the environment. Mostly the ones that are likely to be wiped out are the brown rabbits because their color is very visible. Okay? So look,

11:34 if you're all brown, it's possible they'll wipe you out. But because of variation, there are organisms that remain. Okay? Getting it. Next, heredity. Okay. So, traits are passed from generation to the next. Heredity is the passing of traits from parents to their offspring through genes. Okay? Children often resemble their parents because traits are inherited. Example in humans, mother with Carly hair. Our father has brown eyes. So our child has inherited Carly hair and brown eyes in animals. Let's say parents one golden far. Our parent two has brown fur. Our poppy inherits a spar color from its parents. Okay? So let's remember how does heredity work? Parents have traits controlled by genes. Genes

12:21 are passed from parents to their offspring. The offspring receives a mix of these genes. These genes determine the traits they have. Let's remember, key points traits are passed down through jeans. Offspring may look like one of or both parents. Heredity is one reason why living things are similar within families. Let's remember, genans are like tiny instructions passed from parents to children helping them grow, helping them grow, look and act in certain ways. What is it? So how does it help? How does it help evolution? So let's remember. Okay. Helpful trades are only useful for evolution. If they can be inherited by offspring possible. That upspring has a high chance of survival. For

13:08 example, if a rabbit has thick fur, that helps it survive in cold weather. Its babies may inherit the same thick far. Okay? And there is a possibility or a high chance of survival in the next years. Generation after generation, more rabbits will have thick fur eventually. So connection to evolution son. Without heredity, beneficial traits would disappear after one generation. Well, children, through heredity. The good qualities that will be passed on to the upspring to help them survive. Okay? So if there is no heredity, no passing down of traits, it is possible that those good traits will disappear because they are not passed down. Okay? So

13:53 that's the role of heredity in evolution. Next, what about the word isolation? Okay. When distance or barriers create differences okay explanation. Isolation happens when groups of the same species become separated. When separated. That's why it's isolated. Okay. And can no longer reproduce with each other. Over time they may evolve into different species. One, one squirrels live in the same area and could meet and mate. Mate. Okay. We have spirals that only live in one place, they meet and mate. Two, a mountain form separating the two groups. A mountain was formed. Okay. The two were separated. So each group experiences different environments and changes over many generations. One is in a somewhat

14:41 tropical climate, the other is in a somewhat cold climate. Okay? They become as though they were the same as before. Okay? They are the same species but because of uh the barriers, mountains and the environments, they become so different that they can no longer reproduce that when they meet it's like or it's like a stranger. Okay? It seems like that. They are now separate species. We already have species A, species B. Okay? And it's possible that their way of survival will also be affected. Okay. So we have two types of isolation happening. Okay. The first one, geographic isolation. From the word is geographic. Physical barriers prevent groups of the same species from meeting

15:27 and reproducing. We have mountains, rivers or oceans, we have deserts, ice or glaciers. The most obvious example of this that I remember is the tawilis here in Batangas. Okay? The sardines, my children, in ancient times they were said to be sardines that live naturally in salt water. But because of geographic isolation, when the Taal volcano erupted, their place was isolated. Okay. Instead, a lake was formed. And then the herring that were trapped in the lake area. Okay? When we say lake, it's not a salt water. Okay? So it seems someone is drinking fresh water. So it seems that through time, the hermit crabs that used to live in salt water were transferred,

16:13 they were isolated down in fresh water. Okay? There are some tawils that did not survive, but there are some tawils that survived or adapted to the invasion. ronment and fired. And now they are a new species. They are called fresh water sardines. So if you introduce fresh water sardines and then their previous species, salt water sardines, they won't mate. Okay? Because they are no longer the same, even though their origins are similar, now there has been an evolution through time. So it's like they're a new species. There is species A, there is species B. So this barrier stops members of the same species from coming together to me. Another thing reproductive isolation. So even two groups meet again

17:00 they cannot reproduce because of differences. For example different mating seasons. They are the same bird, but their mating seasons are different. Let's say one is June, the other is December. Even though they are the same, even if they meet, they won't be able to reproduce because that's not their biological clock for mating. Another thing is different mating behaviors, even though they are the same species, their courtship methods are different in animals because before they mate, there are other courtship behaviors, so if their methods or behaviors are different, it is possible that even though they are the same species, they will not be able to mate. Another different body structure, same species but different

17:46 structure. You might say, "Why does this seem different?" Okay, right? Gametes don't work together. There are games like that that don't match. So these um differences prevent successful reproduction even if the two groups are in the same place. Isolation leads to fewer chances of interbreeding causing populations to change and different ways eventually become new species. They were once the same, but because of isolation, a new species emerged, which is an example of evolution. Another selection. So, we discussed the idea of ​​natural selection, kids. So uh nature chooses the best traits for survival.

18:33 Okay? So selection is the process in which organisms with helpful traits are more likely to survive and produce offspring. Okay. Let's take grasshoppers as an example. Imagine green grass with green and brown grass hoers. Birds can easily spot the brown grasshoppers so they are eaten more often. Green grasshoppers blend into the grass, survive longer and have more babies. Over time, most grasshoppers become green. Okay? It's a natural selection. Nature has eliminated organisms with ugly traits that are not suitable for the environment. Okay? So why is selection important? It helps population adapt to their environment. It increases the chances of survival. It

19:20 leads to more offspring with helpful traits. Think about it. If the environment changes, different traits might be helpful. Nature is always choosing what works best. Okay. In real life, bacteria can develop resistance to antibiotics. Those with the helpful trade survive the medicine and reproduce. Let's go back to the example, children. Let's say summer comes. The grass has turned brown again. Okay? It turned brown and dry. Okay? Then the grassper green ones. The green and brown grasser is still there. Which ones have a chance of survival? The green one or the brown one? Of course, the brown ones because they can blend in with the brown dry leaves. And the ones that birds can eat again are the green crest

20:06 hoppers. Okay? So the selection is not random. You know, nature is the one who selects. Okay? It's nature's way of choosing the traits that help living things survive and thrive. Next, adaptation. So what is this thing we call adaptation? Okay. It's a natural way of helping life survive. Adaptation is a characteristic or trait that helps an organism survive and reproduce in its environment. For example, polar bears have thick white farts and a layer of fat that keeps them warm in the arctic. This adaptation helps them survive in freezing temperatures. Example two, cact or our cactus have thick stems that stores water helping them survive in

20:51 deserts where rain is scars. Why is adaptation important? Adaptation helps living things stay alive, find food, avoid danger, and have babies that can also survive. So different environments, different challenges, amazing adaptation. So what is the trigger for the change in these organisms or adaptation? The environment. That's what triggers it. Okay. But remember the changes happen in or happen in each organism do not change over or in just a snap of time. It changes or the changes happen very slowly okay or aim through generations.

21:38 Okay. So those are the um key terms related to the word evolution. So let's proceed to the formative assessment. So, I think I've already reviewed the slides I showed . Actually, the one in our PPT is quite long. So I'm also chasing time because I'm editing the term to material. So, my recording of our discussion is very limited. So hopefully you understand that there are people who are also messaging me and I can't reply right away because I have so much work at school. But I'm trying to still update what video lectures are here. So what is evolution? So evolution is correct. Okay. Letter B.

22:23 Gradual change and organisms over time. What is variation? So when we say variation, what are the differences? So it's letter B differences among individuals in a population. Heredity is the process of correcting the passing traits from parents to offspring. What causes isolation? Okay. What causes isolation? Correct. It could be physical barriers or those of us um what do you call this? Behaviors or reproductive isolation. Okay? So physical barriers like the rivers and mountains. That's what causes isolation. What does natural selection mean? Correct. Okay. Letter C. Organism would helpful trait survive and reproduce. When we say natural selection, those are the ones

23:10 with the best traits. Those are the ones with a chance of survival. Okay. An adaptation is correct. Okay. Letter C, a trait that helps an organism survive. Which is an example of variation? Correct. It's letter B. Different eye colors in humans. Next, what happens when populations are isolated? Correct. Okay. Letter C. They evolve separately over type and become new species. Okay. Next. Which organism is best adapted to cold environments? Correct. I know letter B. Polar beer with thick for. Okay. Why do adaptations become common in a population? Yes, that's correct. Letter B, they are inherited and help for survival. Okay. So hopefully those are the key terms we can remember and we

23:57 can uh easily explain or connect how it helps evolution through time. Thank you very much, great. M.