The video talks about dinosaurs and how it was very hard for the theory of them existing to be well respected. It was not thought that dinosaurs could exist because of their immense size and that there was no mention of them anywhere in sacred stexts such as the bible. The dinosaurs that were found though were very real and later they were respected in the scientific community as a legitimate set of creatures.
The video talks about the different theories that prove evolution. One of them is vestigial structures. This theory says that certain parts of organisms can be leftover unused parts from an earlier ancestor that actually used them. The video uses the tailbone in humans as an example for these. Another theory the video uses to prove evolution is homologous structures. These are structures in embryonic organisms that are similar and prove that they have a common ancestor.
The Ted Ed video describes the five aspects of evolution. These five aspects or factors are small population size, non random mating, mutation , gene flow, and natural selection. The video says that while all five of the characteristics of evolution contribute to evolution, only natural selection contributes to adaptation, which is how organisms become better suited for their environments.
Humans as a species are rewriting the rule book that governs the concept of survival of the fittest because to survive in the life of humans it becomes more about how much money one has to have children than actually surviving. Because by nature people who can afford to have children are more likely to have them than people without the money, being able to earn money becomes important in the rule book. Instead of dying off, most of the time a bad variation such as a reduced ability to learn or a mental illness will not always result in death, but poverty or a life without having children. Therefore, the traits passed on tend to be ones that help people make money which leads to more kids, because of the development of our society that allows for people to stay alive typically even when poorly equipped with their DNA (mental hospitals etc...).
Alfred Russell Wallace was a scientist who conducted research around the same time that Darwin did about evolution. He even sent Darwin a paper with his findings. Wallace served as a way of conformation to Darwin and his theories so as he could see that others had the same ideas and thoughts. He and Darwin even worked together in a paper. Wallace's thoughts influenced Darwin heavily when creating his book, On the Origin of Species. Although he was not as famous as Darwin, Wallace is considered to be one of the leading biologists in the 19th century. Wallace also is said to be the father of Biogeography.
The experiment assumes that the organic material would bond together to form life. It does not create living organisms. Rather, it creates the building blocks of life. The experiment must have some material taken out of it to be measured as well. While the material is sampled, it must be in clear air when it is taken out. When it is in clear air, there are high chances of the oxygen in the atmosphere affecting the result in the compounds being sampled. Because earth did not have oxygen at the time, introducing the sampled substances to it would disrupt the accuracy of the experiment.
In this Three class lesson I learned the difference between codominance and incomplete dominance. Codominance is when two dominant traits are both present in offspring instead of one overriding the other. Because they are both dominant, they both appear. The reverse of this is incomplete dominance, when you have two dominant traits but instead of both being present, they combine. This is how flowers of the same species can have multiple color variations. This difference is very prevalent in nature and is an essential piece to fully understanding genetics.
The punnet square is useful for determining the probability of an organism having a certain trait. One of the many pros to using this system is that the probability is easy to calculate and the genetic equations involved are kept extremely simple. When Mendel discovered how to use a punnet square, he created laws that work with it. There are some l was that do not work with the punnet square. Codominance, multiple alleles, incomplete dominance, and polygenic characteristics. These traits of organisms do not follow the punnet square directly and are a major drawback for the system. They turn the simple system of the punnet square into a more complicated equation. Although these are a major drawback, the square is still useful for single allele traits.
In the movie The Island, the cloning shown is not realistic. We do not yet know how to copy a persons DNA so that we can make another being exactly like it and this is the main premises of the movie. The retina scanner outside of a building is fictional as well. Retina scanners are unfortunately not found on every street corner in even our most advanced cities. The growth of the clones while in the "womb" is unrealistic as people do not grow to full size inside of their mother.
The video on the lesson 4 page shows how genetics started with Mendel. Without his discoveries using his pea plants, our understanding of genetics could be different. He examined the traits in his peas using a punnet square. He also used a much larger square to show the probability of a trait appearing out of the many different types of traits. Although the square was bigger, the ratio of four to one kept true in the second generation using the lar
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AuthorMichael Tellini Archives
May 2014
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