EXPLORING MOLECULAR EVOLUTION

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Results of your pairwise alignment comparing the beta globin gene in humans and in chimps:

1. Data about the alignment can be found below the blue/black alignment chart. How many nucleotides are there in the beta globin gene for:
1. The chimp? 600 bp

2. The human? 626 bp

2. A blue asterix indicates that the nucleotides in both sequences are the same, we say they are conserved. What percentage of the beta globin sequence is conserved in chimps and humans? (Don’t include the insertion at the beginning of the human gene). This percentage is often reported as a similarity “score” below the alignment.

99%

3. Would you expect the protein structure to be highly similar or markedly different in the chimp and the human? Explain.

I think similar because we have some similarities to chimps like hands and ears. So maybe the protein that has hands and ears in chips are the same in humans.

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Results of your pairwise alignment comparing the beta globin gene in humans and in chickens:

1. What is the percentage of sequence conservation between the beta globin gene in chickens and humans?

Humans and chickens have DNA sequence that is 57% alike to one another.

2. Looking at the two pairwise alignments you have performed, would you expect the beta globin protein found in humans to be more similar to that found in chickens or that found in chimps? Explain.

The beta goblin protein that is found in chickens, humans and chimps are similar. Its not surprising that the chimp and human are more similar than the chicken and the humans just by the difference in visual appearance I would expect for the human and the chimp to be more similar.

3. Do the results achieved by running these alignments support the results on evolutionary relationships determined by scientists using anatomical homology (similarities)? Explain.  

The results in the alignments supported the part of evolution that states humans are most alike to chimps and come from a line of apre ancestry. if it was stated that humans came from a line of chickens it would be less supported because only about half of the sequence were aligned.

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Results of your multiple sequence alignment comparing the beta globin gene in a variety of animal species:

1. Examine the Unrooted Tree produced.  

Record the species at the end of each branch on the unrooted tree shown below.

2. Based on the information in the unrooted tree:

1. Which two species appear to be most closely related to each other? Explain your choice.

Chimp and Human because the two branches are the closest together.

2. Which two species seem to be the least closely related to each other? Explain your choice.

Human and Goldfish because the two are on the other side of the tree.

3. Comparative evolutionary distance between species is indicated by the length of the clades they are on. Give the comparative evolutionary distance (by percentage similarity “score”) between:

1. The mouse and human: 79%

2. The wallaby and the human 61%

3. The chimp and the human 99%

Comment on the significance of these results given your knowledge of mammalian groups.

The mouse and human are extremely different because a mouse is gross but a mouse has whiskers, a tail, claws, and fur. Humans on the other hand don’t have any of those things which is why I’m confused about the percentage it has. The wallaby I don't know much about which is hard to compare the two. But if I had to guess humans jump so that might be a similarity. The chimp and human well they have hands we have hands cool, but they also have ears which are similar and the lips they have and also the teeth with the same facial structure and they walk and act they use their limbs like humans.

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Results of your Rooted Phylogenetic Tree:

1. Examine your Rooted Phylogenetic Tree and record the species at the end of each

2. Based on this tree diagram, which species is/are most closely related to:

1. The goldfish: chicken

2. The mouse: human and chimp

3. Homology is a term used to refer to a feature in two or more species that is similar because of descent; it evolved from the same feature in the last common ancestor of the species. Hence, similarity in DNA or protein sequences between individuals of the same species or among different species is referred to as sequence homology. Which two species in the tree above share greatest homology with respect to the beta globin gene? Human and chimp

4. A node is a branch point representing a divergence event from a common ancestor. Which two species have the most ancestral nodes (divergence events) in the tree above? Explain your answer giving the number of nodes leading to these species. The human and the chimp because they have a long line from the starting point, containing three nodes.

5. Looking at the phylogentic tree above, which two organisms:

1. Diverged from their common ancestor most recently?

Humans and chimps

2. Diverged from their common ancestor least recently?

Chicken and Goldfish

6. Draw a modified phylogenetic tree to show how the tree above might change if the beta globin gene for a kangaroo was added to the multiple sequence alignment.

The kangaroo would be connected to the wallaby.  the tree might change showing how the other animals are different than the kangaroo.

7. It is important to understand that the phylogenetic trees you generated using bioinformatics tools are based on sequence data alone. While sequence relatedness can be very powerful as a predictor of the relatedness of species, other methods must be used in addition to sequence homology, to determine evolutionary relationships. Briefly describe 3 other methods that you think might be used to determine evolutionary relationships.

•  Scientists could also look at the physical appearance of the organisms.

•  They could see where the animals are located.

•  They could also look at fossils found in that region to see what the past animals looked like.