Evolution Essay

Evolution!!!

Evolution is the change of a trait in a species over long periods of time, that causes a lot of diversity in organisms. Many people have different theories about evolution but one of the most well respected of those people is Charles Darwin. Charles Darwin had the belief that all organisms evolved over time from a common ancestry. He believed this happened using “Natural Selection”. Natural Selection is when traits become more or less common in a population based on the needs of the organisms to survive and reproduce. Natural Selection affects the phenotype of an organism or the visible traits. After a while an organism will adapt and gain certain characteristics that help with specific tasks. That trait will be more observable in the offspring of the organism. Evolution can end up changing one species into 2 differently species entirely. Charles Darwin first created his theory of Natural Selection from being on a 5 year cruise, in which he noticed a diversity in wildlife and fossils. He looked into it more and after more research, received an essay from Alfred Russel Wallace describing the same basic idea that he had about Natural Selection, and saying that he wants to combine ideas. Darwin then began examining the origin of humans, and sexual selection which determines what traits an organism gets. Darwin later published multiple books on the subject. Darwin died on April 19, 1882.

Another person well known for their research on evolution is Jean-Baptist Lamarck. Lamarck was in the military and got an award for bravery, but returned from war because of an injury. After getting back he decided to continue pursuing a career in medicine. He realized that he had an interest for botany, and wrote a 3 volume set of books about flowers. He was later appointed the position of professor of zoology. He then started studying evolution and came up with the idea of “Inheritance of acquired characteristics”. There were two basic theories behind it. One was the theory that body parts that are used grow bigger and stronger, where body parts that aren’t used slowly waste away and disappear. The other was that any changes that occur in somethings lifetime will be passed down to their children. Both of these scientists had ideas that involved the theories Microevolution and Macroevolution.

Microevolution is a change in gene frequency over a certain amount of time. Even though the number of alleles in an environment never stays the same, the frequency is usually around the same area. There are many different parts to micro evolution, and one of those factors is mutation. Mutation is a change in an organism's DNA sequence in a cell’s genome, that affects the way it looks and behaves. Mutations are caused by radiation and viruses. A lot of errors also occur during DNA Replication, during the polymerization of the second strand of DNA. Errors like these are known as mutations and can have serious affects on the phenotype of an organism. Natural selection is another part of Microevolution. Natural selection is where an organism’s phenotype adapts to the environment to help survival and reproduction. Genetic drift is part of microevolution also. Genetic drift is when there is a change in the frequency that an allele appears in a population due to random chance.This being the case, the organism will receive a random allele from the parents, so it’s almost all chance whether or not a population will be able to keep that allele. And yet another big part of microevolution is migration. Migration is when an organism moves in or out of a population. This seriously affects things because it brings in different genes that the population didn’t have before, and it also changes the frequency of the alleles of the population. Microevolution is a major part of evolution. There are other parts to evolution other than microevolution though.

Macroevolution is the part of evolution that explains changes made over an extremely long period of time. Macroevolution is on a scale of separate gene pools where as Microevolution is about one gene pool. Macroevolution doesn’t always happen all at once. It could also be gradual changes over a long period of time which is known as gradualism. However there is another theory known as punctuated equilibria. Punctuated equilibria is a way to explain long phases of stability that then change drastically. It’s kind of the change you can see over time when looking throughout history. Changes in biodiversity could be an example of macroevolution along with fossils and many other things. Macro and Microevolution are major parts of evolution.

Biochemistry can be used as even more evidence for evolution. Biochemistry is used to reveal similarities of organisms in different species. For example the metabolism of different organisms have the same basic biochemical compounds. Cytochrome C is an example of a compound found in all organisms. There are also certain proteins found in almost all organisms that prove common ancestry, because those compounds are so complex that is extremely unlikely that they developed on there own but still somehow identically. With biochemistry you can also tell that there are differences in the amino acid sequence. Knowing that you can tell which organisms are more closely related than others. And knowing that organisms are so closely related brings us to embryology. All vertebrate organisms have similar embryos but as the embryos grow, the differences in them start to become more noticeable. Studying the development of the embryos help scientists to understand evolution more. Ernst Von Baer claimed that “the more closely related any two species are, the more similar their development” even before Darwin proposed the theory of Natural Selection. And since all organisms share common ancestry, their embryos are similar. Just like an organisms embryo, a fossil can also be used to show evolution. Fossils are generally found buried in a certain order. The order an organism is, the further down it would be buried. For example fish would be underneath amphibian, which would be underneath reptile, and so on. The further down something is buried, the older it is. Because of this, you can use the fossils to witness the change in an organism over a long period of time. Transition fossils are also used because they show the transition from one organism to another. It lets you witness the changes of one species to another. Johann Wolfgang von Goethe developed the idea of comparative morphology. Comparative morphology is the study of similarities and differences in organisms to see similarities in them. This helps scientists to notice how similar different species actually are and how they might have evolved from other species.

After learning about these scientists and all of their beliefs, it’s lead me to believe that evolution definitely exists. Fossil evidence was one of the most convincing for me, along with the theory of natural selection. When I learned about them, it opened my mind up, and I started to consider possibilities that I never really believed before. The theories of Charles Darwin are what mainly convinced me that evolution exists and takes place over a long period of time. I’d have to say that I am definitely a believer in evolution now.

http://www.pbs.org/wgbh/evolution/library/04/2/l_042_03.html

http://bioweb.cs.earlham.edu/9-12/evolution/HTML/live.html

http://en.wikipedia.org/wiki/Macroevolution

http://www.allaboutcreation.org/fossil-evidence-for-evolution-faq.htm

http://medical-dictionary.thefreedictionary.com/Comparative+morphology

http://ib.berkeley.edu/courses/bio1b/labschedspring2011/labexercises/MacroevolutionHorse1_6.pdf

My Learning Experience

Throughout this year in this Biology class I have learned quite a bit about myself and my ability to learn. At the beginning of the year, as a lot of people may have noticed, I was having trouble doing my work, because I was more focused on talking to friends than i was on the task at hand. During the first semester I got a B in the class because at the end of the second quarter I quickly did all of my blog posts. I tried a lot harder the second semester though. I did most of my blog posts on time and when I was supposed too. I realized that the hardest part of the class wasn't the work, but having the motivation to actually do it. Being a procrastinator doesn't work well in a "do it yourself" kind of class, where it's up to you to do your work, and if you don't, you fail. I learned something else about how I learn though, and what I learned is that even though I get more done when I work alone, I won't understand it as well as if I work in a group. It's kind of like a double edged sword, because even though I can get more done alone, the quality of my work isn't as good. And if I work in a group, even though what I do get done is better, I won't do as much work. Around the end of this school year, I learned that when I do something, I can't just do it well enough to get by, I need to try my best so that I can reach my full potential. Next year I'm going to need to buckle down and do my work right off the bat, instead of waiting until the last minute. I need to try be more of a positive influence on the class by doing what I'm supposed to. And probably most important of all, I need to make sure I fully understand everything that I'm doing in the class. In order to do this, I'll sit next to people with which I can work well consistently and without getting off topic with. I'll make sure to ask questions when I don't understand something. And I'll tell people (Tyler) to leave me alone if they're distracting me. Other people might be able to help me stay on topic but in the end it's all on me to do my best. So even though I'm not going to promise I do better next year in Anatomy and Physiology, I can promise that I'll try my best.

DNA Structure

The first thing that you should know, and probably the most basic is that DNA is in the shape of a Double Helix.












It is however much more complex than it looks. DNA is made of 2 long polymers called Nucleotides. The two vertical strands that you see making the shape of the double helix is like the backbone of the DNA. It's Sugars and Phosphate holding the rest of the DNA together. Then you have the Middle portions of the DNA. In the picture above you can see that the DNA almost makes a latter with the red and blue connecting in the middle all the way up and down the DNA. The red and blue parts of the DNA that connect are actually hydrogenous bases, and are being held together by a weak Hydrogen Bond. The bases in the DNA are important because the sequence of bases in your DNA, defines the RNA sequence which then defines your Protein sequence, and that makes up your genetic code. Your genetic code gives you your physical traits. DNA is found in cells, and when cells divide, they have to give a copy of the DNA to each cell so the DNA goes through a process called replication. The DNA is split down the middle and the hydrogen bond is broken. Then half of the DNA goes to each of the new cells. Then replication takes place, and the other half of the strand of DNA is remade with an enzyme called, DNA polymerase. That's how the process of replication takes place.

Bacteria Transformation

This is a video I made on the Bacteria Transformation Lab that we did.

DNA Sequencing

We were studying DNA Sequencing and learned about how to read part of a DNA sequencing gel, you go from the botom of the gel, up, reading each separate band in the order that they occur. Each band is under a certain letter, and then you write the letter it's under. We practiced this by reading the sequencing gels of 3 different patients, and comparing them to someone named Norm's gel. Norm has the DNA sequence of an average person, so we found the percentage of each person's sequencing that was the same as Norm's. People who are to far off, have a good chance of disease, as compared to people who are very similar to Norm.

Norm was used as the control in this experiment. All of the people in the above graph were compared to Norm. Norm himself wasn't on the graph but the numbers shown for each person shows the percentage of their DNA Sequencing that is the same as Norms.  In order to find the percentage similar, we took the the number of DNA that was the same and divided it by the total DNA, then multiplied that number by 100 to get the percentage. We grouped the the DNA into groups of 3. They're were 33 different bases making 11 groups. Each group could then be used to determine a protein sequence.  There is a good chance that Carol has a disease because of the genetic flaw. Bob and  Abby however are similar to Bob, and have a better chance of living without a disease. Abby had the closest Protein sequence, then Bob, and then Carol had the worst compared to Norm.

DNA

DNA or Deoxyribonucleic Acid is the Nucleic acid that contains the genetic material that makes us all who we are. The strands of DNA are in the shape of a double helix. The reason it's in the shape of the double helix, is because the outside strands of the DNA are polymers called nucleotides, with sugers and nitrogenous bases running perpendicular to them and connecting between them with hydrogen bonds in the middle. It is also these bonds that make DNA replication possible. DNA is found in the structures called chromosomes. It's in cells and whenever a cell reproduces, it splits the DNA down the bond in the middle so that both cells have DNA. Then the cells copy the rest of the DNA based off of what is left of the DNA, making a perfect copy of the strand of DNA that was there before. Both of the daughter cells then have the DNA. The phosphates that are in the middle are always paired up with certain other phosphates. They have an order, and aren't just randomly paired together. That process is known as DNA Replication.

Eugenics/Baby Lab

Eugenics is the study of improving genetics in humans. They improve the genetics using selective breeding, and try to get rid of any bad genes by not reproducing them. Scientists believed that anyone with a disease that is hereditary should be sterilized as to not pass down the bad genes. Eugenics was a very big thing during the 20th century, but largely died down after world war 2. Genes are passed down from chance. For example if someone with a gene Rr has a kid with some rr, then the odds of having a kid that's Rr is 50% and the odds of them having rr is also 50%. You make a Punnett square, to determine the odds of what the kid will get. If there is the dominant trait with the recessive, the dominant will be shown. That's why eugenics is about eliminating a gene they don't want. If they only want the dominant gene then they'll sterilize anyone who has only the recessive gene, to cut down the chances of the recessive gene being spread. When did the baby lab. We looked at the traits both the parents had then made a Punnett square to see which combinations were possible, then flipped a coin to determine which trait each of the parents passed on. If both me and my parter were Cc then we'd both flip a coin, If i got heads, then I'd pass on C and if my partner got tails they'd pass on c. So the kid would have the Cc gene. Almost all of it is about chance
Eugenics was started because most people believed that the fittest and healthiest people were the ones who should have children, so in order to make sure of it, people wanted to eliminate a bad gene from the gene pool. People believed that society had already spent enough money supporting people and there diseases, and that sterilization would be a much better solution to the problem. Some people however believed that it wasn't genes that caused the problems, and that it was a person's environment that can have a big impact on their behavior and defects. At the first international congress in 1911, Punnet said, “Except in very few cases, our knowledge of heredity in man at present is far to slight and far too uncertain to base legislation upon.” He believed that we did not have enough knowledge of genetics to justify sterilizing people. In 1942, a law was passed that the involuntary sterilization of criminals was legal. Then eugenicists tried to stop interracial mariage, and believed that a white person shouldn't be able to marry someone that has any blood in them other than caucasian, however that idea was shot down.
Eugenics has had a big influence through out society, and discourages being ok with the fact that everyone is different from each other. Even Hitler, quotes Eugenicists a lot. He wanted all white, blonde hair, blue eyed people. Hitler had an thorough knowledge of eugenics and how it worked. Eugenics have had a big influence over people now a days and how they act around people that are different.

http://www.eugenicsarchive.org/eugenics/
https://people.creighton.edu/~idc24708/Genes/Eugenics/History%20of%20Eugenics.htm