Wednesday, May 11, 2011

Evolution & It's Details

Evolution and It’s Details
What exactly is evolution? I’m sure this question is in your mind. Well, biological evolution would be defined as a process that results in heritable changes in a population spread over many generations. It is important to realize that evolution does not concern simply one individual (Moran).

I’m sure you have heard many theories of how the complex human being and other species actually ended up on earth. For many years, the only explanation we could give ourselves was the theory that some higher power, like a god, created complex beings on Earth. It wasn’t until Charles Darwin came along that people could explain their existence with a science explanation, evolution.

Darwin’s theory had a total of five main points. His first point was that species are extremely fertile. They make more offspring then can actually grow to be a full adult. For example, human females have thousands of eggs that can produce adult offspring, but few of those eggs will actually make it to adulthood. His second point was that populations remain at roughly the same size. Darwin’s third observation was that food resources may be limited but they remain constant most of the time and available. From these three observations Darwin inferred that there could be a simple struggle for survival among the individuals it concerns (Huxley).

Darwin’s fourth point was that when two individuals who produce offspring sexually are not identical. Generally, they vary in many ways. His last point of the five was that much of this variation is heritable. From all these five points put together Darwin inferred that “In a world of stable populations where each individual must struggle to survive, those with the ‘best’ characteristics will be more likely to survive, and those desirable traits will be passed to their offspring.” (Huxley). These “strong” traits that survive through many generations become dominant traits. This is called natural selection. With natural selection it call also be said that these dominant traits can change a population over time, as well as creating new species.

Darwin believed that all species today derived from a single species back in the ancient times. DNA evidence also supports this idea as well.

Unlike Darwin, Jean-Baptiste Lamarck’s scientific theories were much ignored. "Lamarckism" or "Lamarckianism" is refered to today as the idea of traits being inherited (Waggoner). What Lamarck thought was much more in depth then Darwin or any other early evolutionary philosophers. He thought that changes in the environment causes changes in the organisms needs, which causes a change in the organism’s behavior. The behavioral change leads to a change in the way they use certain structures of their body. This changes the size of the structure in time. This is what Lamarck called his first law when he wrote his book. Lamarck’s second rule was that all changes in the organism were object to change by heredity (Waggoner).

Lamarck’s theory was much different from Darwin’s. Although, is presents much of the same ideas. Some of the evidence written in Lamarck’s book was evident in Darwin’s. He even states the idea of natural selection into his books like Darwin, but seems to leave this idea as less important. His ideas also differ a lot from today’s idea of evolution. He thought that evolution created perfection over a long period of time (Waggoner).

There is much more to Lamarck and Darwin’s theories then it just being a theory. Many conclusions came from their theories and people began to research. One thing that is highly researched is micro evolutionary mechanisms. Micro evolutionary mechanisms would include mutation, migration, genetic drift, and natural selection.

Mutation is explained when a random red gene is mutated into a blue gene. This can not be explained for all genetic changes but it is used for some. Migration or gene flow is when a certain gene that isn’t in an area migrates to another area. This increases a chance of the new gene combining with the gene that already exists in this area. Genetic drift is explained easily. It would be when two different dominant genes mate. The offspring gets the luck of getting more of gene then the other in the offspring. If 80% of the offspring carry one gene instead of the other, the genetic drift is shifted to the gene with the most offspring carrying it. Natural selection, which I have talked about earlier in Darwin’s theories, is when the “strong” gene survives through an amount of time within a certain species. (Caldwell).

Another level of evolution is Macroevolution. Macroevolution deals with Speciation. Speciation is the process of a single species becoming two or more species. Some biologists say that macroevolution can not occur without speciation. This level of macroevolution has been tested within plants and within 50 to 60 years the single species of the plant had became two species. Another level of macroevolution would be extinction. The reasons for extinction are numerous and it is the fate of all species. This leads into mass extinction. The last level would be punctuated equilibrium. This would be an inference about the process of species dated back to the fossil era. This says that each species will go through little evolutionary change in it’s’ history record. This leaves the sexually reproducing species in a stage called stasis.

When scientists study evolution they also study embryology. This is the study of an embryo. It includes the fertilization stage all the way to the fetus stage. This is important because evolutionary philosophers need to know what the embryo starts out at and what genes it carries. It may also be important to compare past embryos to current growing embryos to compare change.

Another thing that is very important in evolution is comparative morphology. This deals with the study of the structure of organisms. They study the outward appearance of the body such as structure. They also study the inward structure which would include things like bones. This helps include evidence for evolution because with this study, they can track physical structural changes of each species. If it changes, this gives evidence that evolution actually happens.

Another big part of evidence for evolutionary change would be the fossil record.

For 300 years scientists have been collecting fossils for evidence. This is the first record, and best, that records changes within a species over a long amount of time. Fossils provide a wide time range that scientists can study the changes of past life and compare them to current life. This gives them more time to study the differences that have evolved in each species found. Charles Darwin even used evidence from the fossil record to put into his theory.

Taking all this evidence into strong consideration, I can honestly say that evolution has a lot of scientific evidence to back up the theory. The one thing that makes me want to believe that evolution exists is natural selection. When studying DNA and how it works, I found out that the strong, dominant genes are the ones who definitely survive. If you take three genes and create offspring with the three, the strongest one will survive. Within time the weakest gene will slowly vanish. This will create a change from the past individual in the species. If you get a gene stronger then the dominant one that survived, the species will change and keep that dominant trait instead of the first strongest gene.

The second thing that makes me want to back up the theory of evolution would be the fact that Darwin and other scientists like Lamarck had so much evidence to support their theories. Darwin even used the Fossil Record for evidence. If scientists were already on a track of figuring out what Darwin’s theory proposed, then maybe what he is saying is true.

Of course, with everything, people will develop their own opinions. I don’t believe that one certain theory will ever be accepted by everyone as whole, if that would be evolution or creation from a higher being. There is evidence to support evolution and maybe their will be another evolutionary philosopher to support Darwin’s theory and make a big break in evidence to figure out the real answer of how we ended up on this lovely earth. Until then, you have to decide on your own what you honestly believe!



Bibliography

Huxley, Thomas. "Charles Darwin: The Theory of Evolution." On Truth & Reality: Philosophy Physics Metaphysics of Space, Wave Structure of Matter. Famous Science Art Quotes. Web. 11 May 2011. http://www.spaceandmotion.com/Charles-Darwin-Theory-Evolution.htm.
Waggoner, Ben. "Jean-Baptiste Lamarck (1744-1829)." Web. 11 May 2011. http://www.ucmp.berkeley.edu/history/lamarck.html
Moran, Laurence. "What Is Evolution?" 22 Jan. 1993. Web. 11 May 2011. http://www.talkorigins.org/faqs/evolution-definition.html.
Caldwell, Roy. "Evolution 101: Microevolution." Understanding Evolution. National Center for Science Education. Web. 11 May 2011. http://evolution.berkeley.edu/evosite/evo101/IVBMechanisms.shtml.
"Mechanisms of Macroevolution." Ecology and Evolution. Web. 11 May 2011. .

Friday, May 6, 2011

PCR

In honor of Mr. Ludwig's amazing video we watched in class.. I HAD to put a video in here. Without this science we would not be able to do this sort of thing! haha :D


PCR
(polymerase chain reaction)

So basically what this would be is a scientific technique in biology to take a single or few copies of DNA to generate thousands of of copies to a special sequence. This is used in the medical scene as well as the biology scene very frequent today. Suprisingly, this technique was developed in the 1980's by Kary Mullis.
The target sequence is what you want to accomplish..

In a PCR reaction it requires:
the DNA template - or a sample
DNA polymerase - the enzyme that synthesizes new strands of DNA
a Primer - complementary pieces of DNA
Nucleotides - bases A, T, C, G

PCR uses: identifying diseasing-causing viruses, a dead person, or a suspect in a crime

Cycle 1 : DNA is melted by raising the temp to 95 degrees
After the strands are seperated the temp is lowered to 60 degrees
Each primer binds with the end of the target sequence
Only DNA that has pimer attached can  be copied

Cycle 2: Same steps.
taq is thermal stable so it's not activated by this.
4 partial double stranded sequences are made

Cycle 3: Same steps.
produces 2 target molecules & 6 longer length molecules

Cycle 4: strands melted
Primers attacthed & DNA is copied
8 copies of target & longer copies produced

Cycle 5: strands melted..
pretty much same thing except
22 targets & 10 longer are produced

this grows exponentional until cycle 30 to produce billions of the sequences

:D then you have your result.



Sources:

Advice Video

Throughout the year, I can honestly say that I have learned a lot. Not just about Biology, but about workings skills and many other important skills needed in a classroom.. Here's mine & Aneesha's video of advice :D

Wednesday, April 20, 2011

Tay-Sachs Disease



TSD (Tay-Sachs Disease) 
is also known as GM2 gangliosidosis or Hexosaminidase A deficiency (lack of this protein). This causes a lack of gangliosides (chemical broken down by protein) breakdown. TSD is a autosomal recessive genetic disorder, which means that it is inherited from genetics (your parents) when you are born. This disease effects the nervous system. This disease happens directly in Chromosome 15. 


How do you get this disease?
--A child must receive the gene from EACH parent in order to have TSD. When each parent has the gene, the child has a 25% chance of getting the disease. D: If only one parent gives the child the gene, then the child becomes a carrier. Carriers don't have symptoms of the disease but the can pass it on to their children!


Who is it common in?
Surprisingly, 1 in 27 people of the Ashkenazi Jewish population get this disease. 


How bad does it get?
TSD is classified into three different parts: infantile, juvenile, and adult forms. Most people have infantile form. Which if found when they are infants and it progresses until they die around for or five years of age.
Late-onset Tay-Sachs is very rare. It's the kind of TSD that affects adults.


What about symptoms?
Since it affects the brain, your going to find symptoms like:
Slow growth
Seizures
Loss of motor skills & muscle function
Deafness
Blindness
Irritability
Delayed metal and social skills


Treatment?
If the Dr detects signs of TSD they do things like a physical exam & an eye test. As far as treating the disease to get rid of it... there is no way YET there is ONLY ways to make the patient comfortable.


So basically?
TSD is a fatal genetic disorder that you have no way of preventing. It normally occurs when the child is first born, but there are other rare forms of the disease. There is no treatment for this disease either. 


Sources:
http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0002390/





Friday, April 8, 2011

genochoice

ahaha.. the things people come up with! 

GENOCHOICE© GENETIC PROFILE FOR

Ali Davis


Behavioral CharacteristicsUpgrade Your Embryo!
percent of predispositiongenetic defect
98%Homosexuality
85%Novelty-seeking
28%Schizophrenia
25%Manic Depression
10%Addiction Susceptibility
8%Bipolar mood disorder
7%Velocardiofacial (Shprintzen) Syndrome
2%Hypernasality

Genetic DiseasesUpgrade Your Embryo!
percent of susceptibilitygenetic diseases
98%Myopia
58%Idiopathic Ventricular Fibrillation
49%Conotruncal Heart Anomaly
47%Cystic Fibrosis
33%Diabetes
10%Charcot-Marie-Tooth Disease
8%Lesch-Nyhan Syndrome
6%a-l-antitrypsin Deficiency
3%Polycystic Kidney Disease
2%Marfan Syndrome

23&ME

What are genes?

Everyone has the same set of genes.. There is actually about 20,000 in all & we are 99.5 % the same. We all have about 50 million cells in our body & each one contains unique traits about our body. These are DNA :D The letters in the DNA alphabet are A T G & C.. A's always match up with T's.. G's always match up with C's.. DNA forms ladder type structures within your cells. Chromosomes are organized into short sequences called genes. Your genes decide what you look like and things like this. You inherit genes from your mommy & daddy! Cells use genes to make proteins!

Tuesday, April 5, 2011

GATTACA!


Why do you think Vincent left his family, tearing his picture out of the family photo, after winning the swimming race against his brother?
I believe that Vincent left his family because he felt like staying there wasn't the best option for him. He wanted to prove everyone wrong by becoming what everyone said he wouldn't, and he did! 

Describe the relationship between Vincent and Anton.
 Anton was always put above Vincent. Everyone believed that since Anton didn't have the "flaw" that Vincent did, he could accomplish so much more. 

When Jerome Morrow said to Vincent/Jerome, “They’re not looking for you. When they look at you, they only see me,” what did he mean? Can you find any parallels to this type of situation in real life?
When the real Jerome Morrow said that to Vincent he was trying to explain that when they see him, they see no flaws because Jerome was supposed to be "flawless". Therefore, they wouldn't be looking for a flaw or someone else behind the scenes. In real life I would have to say that there is a lot of things like this. In many situations people want perfection, so when they see the light of perfection they don't want anything to change it.  

Choose your favorite character from the film. Explain why you choose that person. Would you want to be that person? Why? Why not?
 My favorite person would have to be the real Jerome Morrow even though I strongly disagree with some of the decisions he made. He had to be my favorite person because he didn't want perfection like everyone else did, he wanted to be normal. He was unselfish enough to give up his life & his body to someone who made something of it. Even in the end, he thought of it as Vincent lent him his dream not that Jerome gave Vincent his body. I'm not sure if i would want to be him, because in the end he did choose the easy way out, but I believe he was a good person.

At the end of the film, you are told that the Doctor knew about Vincent all along. Why did the Doctor go along with the fraud? What would you have done if you were the Doctor?
The doctor went along with the fraud because Vincent had achieved something that his son wanted so badly. Vincent cheated the system to achieve his dream, and if that's what it took I'm sure the doctor would want his son to achieve his dreams as well. If I were the doctor, I would have went along with the fraud because, in a sense, all he was doing was living his dream. Just because someone has the possible heart problem that shows in their DNA traits doesn't mean they don't have the right to become WHATEVER they want! It's like telling someone who has asthma they can't become an athlete. 
  
The technology to do what was done in the movie is definitely possible within the next fifty years. Do you think that Vincent’s world could eventually happen in America? Why?
I believe that it actually could happen, but the likelihood of that exact thing is unlikely. Maybe the pizza order video may happen (everyone has access to all of your information) but I don't believe certain things (like jobs) will be blocked off because of a possibility of a disease.   

What do you think is wrong with the society portrayed in "GATTACA"? What is right?
I believe they TRIED to make a good society and their intentions weren't bad. That would probably be what is right. Outside of that the society in GATTACA wasn't right because of the restrictions it included. Vincent is a PERFECT example that ANYONE can be whatever their little heart desires! 
   
What were the screenwriters trying to tell us through the episode of the 12-fingered pianist? Is anything wrong with engineering children to have 12 fingers if, as a result, they will be able to make extraordinarily beautiful music?
 Every person has their own talents. I don't think that people should engineer children or people to have the certain traits that they want them to. Its selfish. 

You and your spouse are having a child and are at the Genetic Clinic pictured in the movie. What characteristics would you want for your child and what would you ask to be excluded? Why would you make those choices?
I honestly wouldn't want to make ANY choices. I would want my child to be perfect in his/her own way.. not in mine!
  
Picture yourself as either Vincent, Jerome, or Anton. Would you have acted the same or done things differently if you were in the same world as them?
I would of done a lot of things different in Jerome's position. I would continued to live my life after Vincent took over his identity. There wasn't a reason to do what he did.

How does the society in GATTACA resemble the type of society America was during the height of the eugenics movement?

America wanted people to be perfect. They even sterilized people to keep them from passing on certain traits to their children. It resembles GATTACA a whole lot!


GATTACA ENDING:

Tuesday, March 29, 2011

DNA Sequencing Activity

Using DNA sequencing, it is possible to figure out which person is different from the normal, how much different, and if they have a disease because of these differences. 

ABBY - only had one difference from the normal. GAG to GTG 
This is a simple point mutation (single change in DNA)
This changes the protein in Abby to VAL (The normal is GLU)
*GLU is very positively charged, VAL is VERY hydrophobic. -- this change is caused in cystic fibrosis. 
 Therefore, the protein might not fold correctly.. or in other words she COULD have some issues with this change in her DNA.

BOB - only had one difference from the normal. AAG --> TAG
His protein went from LYS --> STOP.
(stop literarily means the end of the protein, it stops making it)
This would be called truncation mutation.  (the shortage of the protein itself)
His protein would be 3 amino acids short! :/  
This would probably cause him some problems!

CAROL - (very different from the normal, you can tell this by looking below at the graph!)
She had 14 differences, which caused a low percent similarity. 
The sequences are still there, she just had some sort of a deletion
NORMAL - ACT CCT GAG
CAROL -     ACC CTG AGG
This is called a reading frame --> frameshift mutation. 
This causes her proteins to be VERY different!!

*ALL OF THIS HAPPENS IN CELL DIVISION.
"99% of mutations have NO effect what so ever" - Mr. Ludwig


I believe the disease risk for Abby is pretty low but probably a little higher then Bob's. On the other hand, Carol will most likely have a disease risk because of how many changes she experienced!

P.S. This is probably my best post so far :D
I should work harder on this.

Monday, February 7, 2011

Eugenics

My Family Pedigree (:

Just incase you cant read the above key:
Square - Male
Circle - Female
Line between - married
Line above - siblings 
Line down - children
All shaded regions - the male or female represented tasted the strip
All clear regions - the male or female represented did NOT taste the strip
Half colored regions - the male or female represented tasted a little

During class we did a gene test to see if any of us had a certain gene. The test was to taste a strip of paper to see if you experienced the taste. I ended up tasting the strip. (btw--it was terrible!!!) A couple days later, I tested my family. My father ended up tasting the strip like i did. My mother and sisters did not, but my niece also did. Therefore, I can infer that me & my father have the same gene and it was passed onto my niece. I can also infer my mom passed her gene onto my sisters because they had the same reaction. 

So what we are looking at here is basically: what is eugenics?  Wiki defines eugenics as an "applied science or the biosocial movement which advocates the use of practices aimed at improving the genetic composition of a population" basically referring to human population. 

What were the social origins of eugenics?
       People started being curious about eugenics in the first three decades of the 20th century. American eugenics started during the reconstruction period after the American Revolution and the Civil War. As time went by eugenics seemed to be to the underlying cause of social problems, such as prostitution. Basically, they thought the sterilization of one "defective" adult could help prevent more of them. Since people had strong faith in science to fix things, they invested in eugenics. They believed the study of eugenics would solve all human flaws. 


What were the scientific origins of eugenics? 
         Eugenics came about in the 20th century by Francis Galton. He encouraged healthy people to have more kids. The first eugenic sterilization law in the United States occurred in 1907. By this time most scientists believed environments caused eugenic flaws. They believed "defectives" should be prevented from breeding!


What research methods did they use & what flaws occurred?
          Researchers attempted to trace flaws through pedigrees or family trees. They would gather medical history and other information in the pedigrees and define the dominate trait but, this presented a problem because they had to find families large enough and with enough history to research. Mendel brought the idea that each trait was governed by a pair of "factors" each inherited by the parents. They also had difficulties defining traits such as eye color, and blood group but they were more interested in mental behavior. They also had poor survey and statistical methods. False quantification was a problem because they assumed IQ tests were accurate. 


QUICK FACT: By 1924, 3000 people had been involuntarily sterilized in America!


How does this impact us today?
         Without these researchers, we would see in increase in baby deaths. Diseases wouldn't be solved and many people would still be effected. Eugenics brought tons of options to people that before had no options. So thank you eugenics! 




Information thanks to:
http://www.eugenicsarchive.org/eugenics/

Friday, January 14, 2011

Meiosis vs Mitosis

We've been learning about the differences in Meiosis & Mitosis..
So, here's what happens...

Meiosis: 
Thanks to Oscar Hertwig, we know of Meiosis. This occurs in plants, animals, fungi, and humans. During Meiosis, there are four haploid daughter cells that are produced. This process will only create sex cells (male sperm cells, female egg cells).  If you want the definition... Meiosis is a type of cellular reproduction in which the number of chromosomes are reduced by half through the separation of homologous chromosomes in a diploid cell.  The process in Meiosis is a little longer than in Mitosis. Here's what happens....  Interphase, Prophase I, Metaphase I, Anaphase I, Telophase I, Prophase II, Metaphase II, Anaphase II and Telophase II. This is a sexual type of reproduction and the cells that are produced are genetically different. During this process crossing over does happen, and the number of chromosomes are reduced by half.


Mitosis:
Mitosis was discovered by Walther Flemming. This process occurs in ALL organisms and produces two diploid daughter cells. Unlike Meiosis, crossing over does not happen here. Basically this process makes everything Meiosis doesn't (sex cells). This is the process:  Interphase, Prophase, Metaphase, Anaphase, Telophase and Cytokinesis. Mitosis is an asexual process and the cells that are produced are identical from the original cell. There is only one single division.







here's where i got my information from (: feel free to go for more info. http://www.diffen.com/difference/Meiosis_vs_Mitosis