The past couple weeks in Biology we have been discussing evolution. I’m sure that everyone has at least heard of evolution, but not everyone knows what it’s all about. Evolution is a very controversial topic but this is pretty much what I have learned about it-
Back in the year of 1801, a man named Jean-Baptiste Lamarck published The Theory of Inheritance of Acquired Characteristics. Later, a man by the name of Darwin pointed out that Mr. Lamarck was wrong. It was Lamarck’s belief that organisms were capable of inheriting acquired characteristics. In other words he thought that an organism could inherit a new or additional trait or characteristic from a parent (seems crazy right?). It was his belief that organisms could alter their behavior in response to the different changes they experienced in the environment. This would modify the individual organism’s organs, which their offspring would then inherit-- now becoming evolution. Many people agreed with Lamarck. Why wouldn’t the offspring have it if the parents did? This, for example, would be as if throughout a man’s life he did body building and lifted weights to become stronger, so when he fathered a child the kid was born with extreme strength like his father’s. Right? NO! This is exactly why there was a flaw in Lamarck’s theory. Lamarck also believed that all organisms continued evolving in an upward direction and never became extinct. He thought that organisms just continued evolving until they were perfect.
Charles Darwin, however, disagreed and stated that organisms pass on mutations, not acquired characteristics. Since organisms pass on mutations, those mutations can give the organism (and its offspring) a competitive advantage with others of its species. If these mutated organisms do have an advantage, then they have a better chance of surviving and in turn, producing offspring. These offspring have a chance of having the same mutation. If they have the same mutation then they’ll have the same advantage. And if they have the same advantage, then they have the same good chance of surviving. And if they survive, then they produce offspring. The offspring probably have the same mutation which means...well I am sure you get the idea; it just goes on and on. The point is, with more and more “mutated” organisms that are created they start taking up more room in their enviorment. This means that there is less space in the environment for the unmutated organisms. If the mutated ones have the advantage, then the ummutated ones will slowly die out and be unable to produce offspring. This makes it so that the mutated ones suddenly become the common ones. This is called natural selection. You now know the basic idea to the theory of evolution! Have you ever heard of “Survival of the fittest"? Well, ding ding ding! This is where that comes from! That phrase may not be “technically” accurate because natural selection is based on reproduction and not exactly survival. Don't get me wrong- you defiantly need survival for reproduction, but just because an organism may survive does not guarantee it offspring. That's the important part!
“Microevolution refers to evolution that occurs at or below the level of species, such as a change in the gene frequency of a population of organisms or the process by which new species are created (speciation). Microevolutionary changes may be due to several processes: mutation, gene flow, genetic drift, and natural selection.” -(New World encyclopedia) An example of this is the difference of house sparrows in North America. They were originally introduced to North America in the year of 1852 and since then the sparrows have evolved different characteristics in different locations. In the North, the sparrow population has larger bodies than the sparrows in the south. The differences in the two sparrow populations are probably, at least, partially due to natural selection- Bigger bodies are better equipped to survive in the cold temperatures. Since it is easier for the bigger bird to survive in the climates with lower temperature they have more offspring until that becomes the bulk of the bird population. That is microevolution! There are other ways in which this can occur; Genetic drift, for example. Genetic drift is all about the change in the frequency of alleles, due to random chance. Genetic drift has a larger effect within the smaller populations, because even the slightest change in the frequency can have an impact on the overall population. If the population is on the smaller side, then there is an increased chance that rare genotypes in each individual organism will not make it to the next generation. Genetic drift is pretty much saying that some random things will happen to a population to change its entire gene pool.
There is even another part of microevolution- Gene Flow! Gene flow tells you that the migration of organisms can also have an effect on the gene pool. If you have two populations sharing the same area then they will most likely end up interbreeding. If, in fact, they do interbreed then they have introduced even more genes into the gene pool for both of the populations.
Macroevolution on the other hand is a little bit different than microevolution. “Macroevolution refers to evolution that occurs above the level of species, such as the origin of new designs (feathers, vertebrates from invertebrates, jaws in fish), large scale events (extinction of dinosaurs), broad trends (increase in brain size in mammals), and major transitions (origin of higher-level phyla).”-(New World Encyclopedia). With macroevolution it’s more like focusing on the soil in which the earth worms live instead of the other way around.
There are a lot of people who believe in evolution and there are a lot of people that don’t. I believe that it is just a theory, and probably can’t be proven. Through my research I haven’t seen any solid proof that we know exactly what happened. In the Bible it says,” The LORD God formed the man from the dust of the ground and breathed into his nostrils the breath of life, and the man became a living being”, Genesis 2:7. The Bible also says, “So the LORD God caused the man to fall into a deep sleep; and while he was sleeping, He took the man’s ribs and closed up the place with flesh. Then the LORD God made a woman from the rib he had taken out of the man, and he brought her to the man.” Genesis 2:21-22. I believe that what is said in the Bible is true and that is really all that matters to me. After doing my research for this project I do believe in adaptation. Animals need to continually adapt to their environment and there is evidence that they do. Researching evolution, the backgrounds, and the theories behind it, has been very interesting to me and I now know a lot more. In my opinion the issue of evolution will never be settled but will continue to be discussed everywhere.
Back in the year of 1801, a man named Jean-Baptiste Lamarck published The Theory of Inheritance of Acquired Characteristics. Later, a man by the name of Darwin pointed out that Mr. Lamarck was wrong. It was Lamarck’s belief that organisms were capable of inheriting acquired characteristics. In other words he thought that an organism could inherit a new or additional trait or characteristic from a parent (seems crazy right?). It was his belief that organisms could alter their behavior in response to the different changes they experienced in the environment. This would modify the individual organism’s organs, which their offspring would then inherit-- now becoming evolution. Many people agreed with Lamarck. Why wouldn’t the offspring have it if the parents did? This, for example, would be as if throughout a man’s life he did body building and lifted weights to become stronger, so when he fathered a child the kid was born with extreme strength like his father’s. Right? NO! This is exactly why there was a flaw in Lamarck’s theory. Lamarck also believed that all organisms continued evolving in an upward direction and never became extinct. He thought that organisms just continued evolving until they were perfect.
Charles Darwin, however, disagreed and stated that organisms pass on mutations, not acquired characteristics. Since organisms pass on mutations, those mutations can give the organism (and its offspring) a competitive advantage with others of its species. If these mutated organisms do have an advantage, then they have a better chance of surviving and in turn, producing offspring. These offspring have a chance of having the same mutation. If they have the same mutation then they’ll have the same advantage. And if they have the same advantage, then they have the same good chance of surviving. And if they survive, then they produce offspring. The offspring probably have the same mutation which means...well I am sure you get the idea; it just goes on and on. The point is, with more and more “mutated” organisms that are created they start taking up more room in their enviorment. This means that there is less space in the environment for the unmutated organisms. If the mutated ones have the advantage, then the ummutated ones will slowly die out and be unable to produce offspring. This makes it so that the mutated ones suddenly become the common ones. This is called natural selection. You now know the basic idea to the theory of evolution! Have you ever heard of “Survival of the fittest"? Well, ding ding ding! This is where that comes from! That phrase may not be “technically” accurate because natural selection is based on reproduction and not exactly survival. Don't get me wrong- you defiantly need survival for reproduction, but just because an organism may survive does not guarantee it offspring. That's the important part!
“Microevolution refers to evolution that occurs at or below the level of species, such as a change in the gene frequency of a population of organisms or the process by which new species are created (speciation). Microevolutionary changes may be due to several processes: mutation, gene flow, genetic drift, and natural selection.” -(New World encyclopedia) An example of this is the difference of house sparrows in North America. They were originally introduced to North America in the year of 1852 and since then the sparrows have evolved different characteristics in different locations. In the North, the sparrow population has larger bodies than the sparrows in the south. The differences in the two sparrow populations are probably, at least, partially due to natural selection- Bigger bodies are better equipped to survive in the cold temperatures. Since it is easier for the bigger bird to survive in the climates with lower temperature they have more offspring until that becomes the bulk of the bird population. That is microevolution! There are other ways in which this can occur; Genetic drift, for example. Genetic drift is all about the change in the frequency of alleles, due to random chance. Genetic drift has a larger effect within the smaller populations, because even the slightest change in the frequency can have an impact on the overall population. If the population is on the smaller side, then there is an increased chance that rare genotypes in each individual organism will not make it to the next generation. Genetic drift is pretty much saying that some random things will happen to a population to change its entire gene pool.
There is even another part of microevolution- Gene Flow! Gene flow tells you that the migration of organisms can also have an effect on the gene pool. If you have two populations sharing the same area then they will most likely end up interbreeding. If, in fact, they do interbreed then they have introduced even more genes into the gene pool for both of the populations.
Macroevolution on the other hand is a little bit different than microevolution. “Macroevolution refers to evolution that occurs above the level of species, such as the origin of new designs (feathers, vertebrates from invertebrates, jaws in fish), large scale events (extinction of dinosaurs), broad trends (increase in brain size in mammals), and major transitions (origin of higher-level phyla).”-(New World Encyclopedia). With macroevolution it’s more like focusing on the soil in which the earth worms live instead of the other way around.
There are a lot of people who believe in evolution and there are a lot of people that don’t. I believe that it is just a theory, and probably can’t be proven. Through my research I haven’t seen any solid proof that we know exactly what happened. In the Bible it says,” The LORD God formed the man from the dust of the ground and breathed into his nostrils the breath of life, and the man became a living being”, Genesis 2:7. The Bible also says, “So the LORD God caused the man to fall into a deep sleep; and while he was sleeping, He took the man’s ribs and closed up the place with flesh. Then the LORD God made a woman from the rib he had taken out of the man, and he brought her to the man.” Genesis 2:21-22. I believe that what is said in the Bible is true and that is really all that matters to me. After doing my research for this project I do believe in adaptation. Animals need to continually adapt to their environment and there is evidence that they do. Researching evolution, the backgrounds, and the theories behind it, has been very interesting to me and I now know a lot more. In my opinion the issue of evolution will never be settled but will continue to be discussed everywhere.
Works Cited:
"Jean-Baptiste Lamarck." MACROEVOLUTION.NET. Web. 13 May 2011 <http://www.macroevolution.net/jean-baptiste-lamarck.html>
"Examples Of Micro". UNDERSTANDING EVOLUTION. Web. 13 May 2011. <http://evolution.berkeley.edu/evolibrary/article/_0/evoscales_0>
"Evolution". New World Encyclopedia. Web. 15 May 2011.<http://www.newworldencyclopedia.org/entry/Macroevolution>
No comments:
Post a Comment