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Hello seniors. I'm glad you're still here, listening to an exciting lesson related to life science. I'm Mom De La Soyna, and I'll be presenting to you today's amazing lesson. Are you excited? So do I. So let's make the most out of our class time. Learn while having fun.
How do species change over geologic time? A species may be a population of plants or animals which will breed to supply offspring which will then produce offspring themselves. The cause that species are populations of different organisms to arise, adapt to the environment, and become extinct is due to the process of evolution that involves a series of natural changes. These are the species of organisms that have originated through the process of biological evolution.
In this module, I will show you some very interesting topics about life that may surprise you. As we go on to the lesson, the module will also explain how populations of organisms have changed over time, showing patterns of descent with modification from common ancestors to produce the organismal diversity observed today. This module will help you explore the key concepts and topics that will help you answer the questions pertaining to the process of evolution. You will learn more about how the population of organisms has changed and continue to change over time in its evolutionary relationships. Hopefully, you will appreciate in understanding evolution that helps us solve biological problems that impact our lives. This allows scientists to choose appropriate organisms for the study of diseases.
My dear students, our lesson today is Lesson 7: The Process of Evolution. At the end of this lesson, you should be able to explain the process of evolution, identify some scientists who contributed to the historical developments of evolutionary thoughts, and compare Lamarckian and Darwinian evolution.
What is evolution? Evolution is a key unifying principle in biology. And what are the indications that show evolution has taken place in the past and is still happening today? The evidence for evolution is compelling and extensive that has been gathered supporting the theory of evolution. According to Charles Darwin, on his book published in 1859, "The Origin of Species," to identifying patterns in nature that were consistent through the evolution. Let us discover how the population of organisms change over time through natural selection. "The Origin of Species," published by Charles Darwin, outlined in considerable detail his arguments for evolution by natural selection. The theory of evolution describes a mechanism for species to change over time. There are two co-discoverers of natural selection: Alfred Wallace and Charles Darwin. Darwin is the principal theorist of the notion, whose most famous work on the topic is "On the Origin of Species" in 1859.
Evolution is the process by which organisms change over time as a result of changes in heritable physical or behavioral traits. This also allows an organism to better adapt to its environment, help it survive, and have more offspring. The genetically inherited trait that increases the survival of that species would persist through the process of evolution by natural selection. Adaptation is when the genetic trait evolves. This process increases the probability that the species would survive in a particular environment. The process in nature by which organisms better adapted to their environment tend to survive and reproduce more than those less adapted to their environment is called natural selection.
One of the examples is when wild frogs are eaten by snakes and birds. Gray wild frogs blend well in dark, hooded areas on tree bark, and green wild frogs blend in well with green vegetation found in marshes and swamps. The green wild frog on the bark of a tree is easier for a predator to find compared to a green wild frog on a green leaf. So, the green wild frogs that go into habitats where they are not camouflaged are more likely to be eaten by predators. Natural selection has favored wild frogs that live in habitats in which they are more camouflaged. Since wild frogs that have been eaten do not live to have any more baby wild frogs, this explains the distribution of gray and green wild frogs. The wooded habitat of the gray wild frog is larger and extends further north, while the green wild frog's swamp and marsh habitat are concentrated in the south. The area in which gray, green, and gray wild frogs overlap, both habitats occur but in different places.
In general, natural selection is a process that results in some plants and animals with certain characteristics being better adjusted than others to their natural environment. Those animals and plants then have a higher chance to reproduce, survive, and increase their population more than the ones that are less adapted to their environment. The better-adapted animals and plants are therefore able to pass on their advantageous characteristics to their offspring through inheritance. Adaptation is any characteristic that increases fitness, as defined because it has the ability to survive and reproduce. A characteristic that is influenced by genes and passed from parents to offspring is called heritable. Heritable adaptive characteristics become more common in a population in many generations. This process is called evolution by natural selection. Adaptation within a population leads to evolution by natural selection.
Natural selection has four phases:
One, overproduction. Example: Tarantula's egg sac may hold 500 to 1000 eggs. Some of the eggs will survive and develop into adult spiders, while some will not.
Second, inherited variation. Every individual has its own combination of traits. Going back to the example, each tarantula is similar to, but not identical to, its parents.
Third, struggle to survive. Some tarantulas may be caught by predators, such as this wasp. Other tarantulas may starve or get a disease. Only some of the tarantulas will survive to adulthood.
Lastly, successful reproduction. The tarantulas that are best adapted to their environment are likely to have many offspring that survive.
Moving on, let's solve the mechanisms of change. Mutation is a mechanism in which DNA sequence will change. The DNA sequence may mutate during cell division because of the following factors: exposure to ionizing radiation, exposure to chemicals called mutagens, or infection by viruses. The mutations happen in the eggs and sperm that can be passed on to offspring. Migration takes place when some individuals from a population might have joined another population. There is a period of animals' life cycle when animals move from one place to another. There are several reasons why animals migrate, such as reproduction, habitat deterioration of environment, availability of food supply, and even due to hormonal and behavioral changes may lead to migration of some animals. Genetic drift is a chance change from generation to generation due to survival of the strongest offspring. Again, natural selection is a process that results in some plants and animals with certain characteristics being better adjusted than others to their natural environment. And the last mechanism is adaptation. Adaptation within a population leads to evolution by natural selection. Those animals and plants then have a higher chance or aperture to survive and increase their population more than the ones that are less adapted to their environment.
That was an amazing lesson, isn't it? I hope you learned a lot in today's topic. Thank you for listening, and don't forget to take care of yourself by staying at home. See you again next time. Bye-bye.