Wednesday, May 18, 2011

Evolution

The Universe is a big place. It has light-years upon light-years of objects to study and to make theories about the origins of it. On earth though, we have one planet with billions of objects to study from all of time to make sense of a very controversial subject; evolution. Not stuff like “did humans come from monkeys?” but stuff like microevolution, the works of Lamarck and Darwin, and evolution in the multiple fields of science.

One of the first scientists to propose evolution formally was Charles Darwin’s grandfather, Erasmus Darwin. Erasmus wrote, these theories in Zoonomia, or, the Laws of Organic Life. He was the first to discuss about how life evolved from “a single common ancestor.” The idea was that a species evolved over a period of time through a long series of accidental changes in the genes or traits of the species. This idea was called natural selection. For as members of a species would die off, the strongest ones with the best genes would survive longer, giving them more of a chance to reproduce offspring with those traits. This continues from one generation to the next, forever improving, forever changing. Jean-Baptiste Lamarck though, had an entirely different idea.

In his theory, evolution happened because of a change in environment as opposed to a change in traits. Lamarck said that the reason anything evolved was because of its “need” to change based on the environment that it is in. Take wolves for example. If said wolves are put into a new environment with faster prey or a new predator, the population will grow stronger and become superior to the new challenges. According to Lamarck, these superior skills will be passed down to the next generation.

It is this type of change that is classified as, microevolution or “evolution on a small scale—within a single population.” In a certain population a microevolution is a change in gene frequency. These can happen in different ways or “mechanisms”, Mutation, Migration, genetic drift, and natural selection. Mutation is genes in just randomly mutating from one type to another, such as, blue genes mutating to green. Migration is a transfer of genes that are integrated from another population through either emigration or immigration. A genetic drift is when, by luck, more of one gene is reproduced than the other and each generation it changes. For natural selection see the definition in the paragraph on Darwin.

People may ask, wheres the evidence of evolution? The short answer is that you look at it everyday. Humans in general are evidence of evolution. Archeaologists all over the world have found skeletons that are almost identical to ours today. the most obvious observation is the size of human's lower jaw today compared with an anncestor from thousands of years ago. Ours it much shorter, which is why we must have the wisdom teeth removed. This would be considered MACROevolution. The facial changes happened over a very long period of time and took many generations to become distinct. MICROevolution would have seen this change in one or two generation.

Scientifically, no. Humans did not come from monkeys. But if we did, it would have been from apes. In my opinion, Darwin has the most accurate and correct theory. Evolution happens on its own through natural selection of what genes mutate and are passed to the next generation. It is not possible for a physical change due to a need for it to be passed down to the next generation, especially if it is only about the enviroment that the population is in.

bibliography:
"A History of Evolutionary Thought." UCMP, 1994. Web. 17 May 2011. http://www.ucmp.berkeley.edu/history/evothought.html
"Microevolution." UCMP. Web. 17 May 2011. http://www.ucmp.berkeley.edu/history/evothought.html.

Thursday, March 31, 2011

DNA Sequencing Activity

Protein Sequences
Norm: Met Val His Leu Thr Pro Glu Glu Lys Ser Ala
Abby: Met Val His Leu Thr Pro Val Glue Lys Ser Ala
Bob: Met Val His Leu Thr Pro Glue Glue STOP Ser Ala
Carol: Met Val His Leu Thr Val Arg Arg Ser Leu Pro
Norm was the control for this activity. Abby, Bob and Carol had their DNA sequence compared to his to find mutations. The lower the percent, the lower the similarities, the higher the mutations.
In the end, they will all be having at least some risk of developing a disease.
Abby and Bob had one base change in their DNA structure. Abby's mutation is called a Point Mutation, this particular mutation changed the type of Protein that the Codon was, from Glu to Val. The Glu is an extremely positive protein and the change to Val makes it hydrophobic, a change like this can change the entire shape of the protein and have extreme effects to the person.
Bob's mutations was a Truncation Mutation. The protein changes from a Lys to Stop. This section of Protein is now 3 codons shorter. A Mutation like this can change a person and give them bad diseases.
Carol... she has issues. 7 of the 11 codons compared to Norm have mutations. The change occurs in codon 5, one of the bases is missing, essentially moving all the other bases one to the left. Carol will either have a lot of issues or be super lucky and be normal (ya right). I know the section of DNA this is, continue reading to find out for your own. ;)

These are the DNA sequences that we used for the patients. Blast the codes here for your own data.

Norm: ATGGTGCACCTGACTCCTGAGGAGAAGTCTGCC

Abby: ATGGTGCACCTGACTCCTGTGGAGAAGTCTGCC

Bob: ATGGTGCACCTGACTCCTGAGGAGTAGTCTGCC

Carol: ATGGTGCACCTGACCCTGAGGAGAAGTCTGCCC

Saturday, March 5, 2011

In sickness and in health-Greg and Olga


Pedigree of Greg and his family.
Pedigree of Olga and her family.
Myotonic Dystrophy, autosomal dominant:
Do autosomal dominant disorders skip generations?
no, they can't. if it isn't passed on then it won't be able to continue on down the line
Could Greg or his mother be carriers of the gene that causes myotonic dystrophy?
Greg and his mother do not have the disease and will not be affected by it, thus they cannot be a carrier of the gene because MD is automal dominant which means there is a 50-50 chance of getting the disorder. There are only people that are affected by autosomal dominant genes, not carriers.

Is there a possibility that Greg’s aunt or uncle is homozygous for the myotonic dystrophy (MD) gene?
In order to be homozygous for a gene, one must have either two dominant or two recessive genes (ex: AA,aa). the only way for this to happen with the MD gene is to have the dominant trait passed on from both the mother and the father. Now, seeing how only Gregs grandma was affected by MD and his grandpa wasn't, it is not possible for his afflicted aunt or uncle to be homozygous for the myotonic dystrophy gene.

What is the possibility that Greg and Olga’s children could inherit the MD gene?
It is not possible that their children could inherit the MD gene. This is because Greg is not a carrier of the gene and Olga has no history of MD in her family.

Factor VIII, autosomal recessive:
What are the hallmarks of an autosomal recessive trait?
An autosomal recessive trait skips generation and can be carried while not affecting the carrier.This is because it is a recessive trait and can only afflict a person when they inherit two recessive traits.


What does consanguineous mean? Why is this concept especially important when discussing recessive genetic disorders?

consanguineous means that the pair in the relationship shares a common bloodline, they are from the same ancestor. (someone found that long lost relative that was twice removed after being accepted again after being removed six other times(i think anyway) http://www.biology-online.org/dictionary/Consanguineous) This concept is important because of how recessive genetic disorders require two recessive traits. If the pair mating are from the same blood line then the chances of having the autosomal recessive trait is much more likely, thus ending up with a child with the recessive disease.

What is it about the inheritance pattern of factor VIII deficiency seen in Greg and Olga’s pedigree that point toward it not being an autosomal recessive trait?

The factor VIII deficiency in Greg and Olga's pedigree point towards it being sex linked because it has only affected a few males in the family. To point towards it being autosomal recessive, it will need to have affected both males and females.

Friday, March 4, 2011

DNA Extration from Wheat germ

This lab was very simple and yet we (Michael) managed to mess up by adding in too much water. Lesson learned, beaker measurements are APPROXIMATE. Graduated cylinders are precise.... Anyway, we added one gram of wheat germ to a test tube and added "20ml" of hot water and then stirred the mixture for 5 minutes (ow..). This gave us a weird pale yellow color. After this mixing, we mixed in APPROXIMATELY -.- 1 gram of liquid dish washing detergent (DAWN). The addition of the detergent ate and destroyed the cell membrane, allowing the DNA of the wheat germ to precipitate out. this we had to mix together very carefully as to not make it foam and bubble. This was another 5 minutes of on and off mixing. THEN, the test tube was taken out of the holder and tilted to about a 45 degree angle. Slowly, ethyl alcohol was added as to not mix the mixture and layered on top. Back in the holder the wheat germ mixture was in 4 layers and after 10 minutes of waiting the DNA (should have..) was at the edge of the detergent alcohol mixture and looked like wet cotton.
Finally it was all dumped down the drain.

Friday, December 10, 2010

Bio chem

Better late than never?

Thursday, December 9, 2010

Photosynthesis Lab

Materials:
-3 beakers
-bromothymol blue (BTB)
-aquarium snail
-elodea (aquarium plant)

Procedure:
1. Acquire 3 50-ml beakers
2. Fill to 40-ml with tap water
3. Place ten drops of BTB to each beaker
4. Place the aquatic plant into one beaker
5. Place the elodea into another beaker
6. After three hours record and observe the color of all three beakers.
7. Now place the beaker with elodea in a dark area and observe the color of water after an hour or so
8. when finished with the experiment place the plant and snail in the appropriate place and clean up your work area.

Observations:
1. Water and BTB only is blue-green, this is a neutral pH of 7.
2. If the BTB plus snail is a yellow color then that shows that the snail is resperating and the CO2 changed the pH.
3.With the plant and BTB one should notice two different things happening, depending on the conditions.