Using Cladograms to demonstrate the change between species

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Displaying Evolution

Evolution is a theory that scientist have extensive research on and have many pieces of evidence to support. Scientist have made many charts tables and pictures to try and visualize the location of every species known to man. The current method of organizing all of the known species is using the Domain, kingdom, Phylum, Class, Order, Family, Genus, and Species to group all the living creatures. This method is flawed though. When it was originally created organisms were grouped using anatomical traits. This does not work for example looking at a shark and a dolphin, they look very similar but they are gnomically very different. When scientists realized this they needed to find a different method in organizing species. Now scientists are trying to figure out but first they need to figure out where each organism branched off from one another. One of the most common misconceptions is that we as humans evolved from monkeys. The truth is that we share a common ancestor and somewhere back in time humans and monkeys had some kind of isolation each supporting a different evolutionary path, humans to develop intellect while monkeys stayed in the jungle with the trees and no need to increase intelligence. Using evolutionary trait changes such as intellect for humans and monkeys scientists create Cladograms to depict changes and the beginning of a new species.

Cladograms such as the cladogram figure 1 on the next page display species and their connection to previous species. Cladograms have many “end points” for each species’ location on the cladogram. Cladograms also have some description of the change that has differentiated the two species that had a common ancestor. Using lungs as an example, the salamander is the first species to contain lungs because it is the evolutionary change that has been marked as the change from a shark. The way a cladogram works, for example, is that everything after the shark also contains lungs. A cladogram can also help figure out which characteristics changed first. Looking at dry skin and hair, dry skin developed first because it occurred on an earlier ancestor than hair. While this cladogram says that hair came first, that only means that in this lineage hair came first, in another example hair may have developed before dry skin occurred. Each change in a species is a distinct change for the survival of that new species. Cladograms can also be drawn to represent changes in DNA from one species to another showing the similarities of these species. Humans and chimps share more than 95% of their DNA. Humans and fruit flies share only 60%. Moss is not in the animal family and can be assumed to share less than 60% of its DNA with humans. Drawing a cladogram, it would look like figure 2. This figure does not go in order of complexity because all life is complex, but goes in order of how close the genomes are to humans. As each species gets closer to the right that species also gets closer to that of humans. Another way to explain this is that the closer the genomes the closer the most recent common ancestor is from each species and humans. tables are also used to display the characteristics that different species may have. For example, table 1 displays characteristics that different plants may have. The 0 represents that the species contains the trait that the ancestor would contain. 1 represents the characteristic that the species has developed. To be more specific, the pine trees do not have flowers like the ancestor. On the other hand they also have seed that the ancestor did not contain. If a cladogram was drawn to represent this data set it would look like figure 3. Assuming that evolution usually moves from less complex to more complex, figure 3 shows, in a cladogram, the changes that each species has gone through from the ancestral species to become its own new species.

Some other characteristics that can be displayed in table form are protein similarities and genetic similarities. Table 2 shows both the genetic similarities and the protein similarities of each. A cladogram for this data would display the species from right to left. The farthest right would be the least similar to humans (homo sapiens) and the farthest left (just right of Humans) would be the most similar. The chimpanzees being just to the right of Humans because they are the most similar and therefore share their most recent common ancestor.

The percentages of the genes and the proteins in table 2 are different, even though they are based off of the same genetic code. Visual and genetic changes occur from mutations of various sorts. Mutations can lead to horrific consequences that leave an individual unable to survive or produce viable offspring. While some are devastating, some mutations are unnoticeable. For instance the code that corresponds to the amino acid leucine is “UUA” or 4 other options including “UUG” which is a simple replacement mutation. In reference to the GAPDH gene from table 2, the previous explanation is the reason why the proteins that are created are the same as humans while the coding is different. Most Eukaryotes have two sets of the same chromosome. This is key for evolution. Over time many mutations occur to the genome and sometimes a mistake occurs that is not fatal and is not a change to code that codes for the same amino acid. These changes help distinguish new species. When enough non-fatal changes occur the phenotype of a specific gene can be different than that of a non-mutated organism of the same species. The differenced may lead to different strengths of an organism from the original organism that may allow it to survive and reproduce more efficiently for a variety of reasons. Success in speed of obtaining food or an increased metabolism could be positive examples of change that could over a long time change the mutated species into a new species. The genomes of these two new species are still very close, and scientist use this knowledge to find the most common ancestor.

The fossil seen in picture 1 was found by scientists. Given no information about the fossil the fossil was placed on to the cladogram depicted in figure 4. The fossil was place after vertebrates and the birds of the visible wings and vertebrae. There is no evidence though that the fossil has feathers so the assumption made is that there are none and the evolutionary change was similar to the birds but at a different time. When introduced to four genes that scientist have retrieved the original hypothesis can be tested because each gene can be checked for common ancestors and relation to other species.

Gene one is a perfect match to a chicken. This match is useful because a chicken can be placed after or along with the bird section. Whether or not wings have feathers is not present from this specific gene. The gene codes for nothing that is visibly distinct on any species. The 11th closest match on gene one is actually a sub species of alligator, called the Alligator mississippiensis. This information can be used to support that the fossil has relation to alligators. Alligators are not on the cladogram but alligators have evolved from a crocodilian ancestor (alligators and crocodiles share the same order crocodylia). Therefore the alligator’s similarity can add evidence to the resemblance of the fossil’s location. Even lower on the cladogram there is a gorilla. This 76% match can help connect the fossil to a common ancestor with the great apes, even though great apes are farther away on the cladogram they still share the ancestor.

Gene two is shared with many different variations of species of flies. This gene can be defined as a more important gene in the genome of this fossil. This is because the gene has made little change from the insects to the vertebrates. Genes that change little are genes that are required for life and if altered are more devastating than a larger change to a gene that simply changes the color of the organism. The fact that there are changes in the gene from all of the insects’(flys’) genes leads to the hypothesis the changes are not major, similar to the chimpanzee and the human gene that were different but still coded for the same protein sequence. This explains how there has been a change in time where the common ancestor had some changes in the genome but kept the same important message.

Gene three is most related to another bird, The Zebra Finch (Taeniopygia guttata). Now two out of the four are most related to birds. This is stronger evidence that points to the fossil having a closer common ancestor to birds than the crocodilians. The crocodilians are still related though. The 13th most related species is the same Alligator mississippiensis. The 86% resemblance between the alligators and the fossil shows how even though the fossil is very closely related to birds, it has close ties to the crodylia order and similarly the crocodilians. Again even lower there is a relationship to gorillas. Gorillas’ representation again shows the resemblance and the changes that occurred from the common ancestor that both the fossil and the great apes shared.

Gene four is the most related to alligators but the relationship is a little less firm with the crodylia order. The first five closest matches are all alligators with the 3rd closest being Alligator mississippiensis, the species that has been a top alligator connection in the previous genes, while the rest are crocodilian or similar sub species. This gene helps place the alligators alongside the crocodiles. This gene has no reference of birds until the score goes into the 80- 200 range. This gene shows how far the gene has mutated from the original version the common ancestor between the birds and alligators shared.

In review of the placement of the fossil in question (including distance as a factor) the fossil on the cladogram is a close evolution of a bird ancestor with some genomic ties to alligators. Alligators are closely related to crocodiles, which are mentioned on the cladogram. The alligators would come just before the crocodiles on the cladogram based on the genes 1, which the alligators have more in common than the crocodiles. Evolution happens slowly, and therefore the small changes (alligator) add up into the larger changes (crocodiles). There are only 4 genes given and from the 4 one was an alligator gene and 2 were bird genes. From this small evidence the fossil can be placed on closer to the birds. With a complete genome, more accurate placement could be possible.

Myosin is best known for its role in muscle contraction and its involvement in a wide range of other eukaryotic motility processes. According to the blast of the human gene for myosin, many monkeys that reside with the great apes also showed up. This displays how there is a close relationship between the great apes and humans. From the definition any eukaryote, using eukaryotic mobility processes would require myosin to move. This molecule developed with the ability to move, tracking it back, it would originate with the first moving eukaryotes. This would prove to be an important molecule that many eukaryotes would have in common. Only the humans’ blast was related to great apes but if there was a way to look further back in the blast there could be many more eukaryotes sharing a similar gene. The blast revealed the Humans to be the top 4 hits with decreasing accuracy of 100%, 100%,99% and 99%. After were 4 versions of the common chimpanzee all with 99% accuracy followed by more humans. This can conclude that humans are highly related to chimpanzees with their myosin gene, a gene that did not change very much from their common ancestor.