Your Inner Fish Chapter 3 Summary

Chapter three of "Your Inner Fish" talks a lot about ZPA tissues. The story of our relationship to fossil animals is not just based on anatomy.  It can also be seen in our genes. Genes are a major part of the body and makes each of us who we are. In this chapter, Neil Shubin talks about a lab which is divided into two parts. The first part involves the study of fossils, while the other one focuses on the study of DNA and embryonic development. According to Shubin, the majority of our cells have the same copy of DNA.
So, our limbs exist in three dimensions: a top and a bottom, a pinky side and a thumb side, a base and a tip. Each bone is different from the other, and our body knows to develop in the way that Shubin describes because of chemicals produced by the cells in our our developing body. Researchers found that a certain patch of cells in the body were responsible for all of the limb development going on. If you remove that patch, no limbs develop. If you cut that patch in half, a person would end up with two limbs. All of this was tested on chickens. 

Certain geneticists began to work with flies and found a gene they called hedgehog. This gene determined which end of the fly was which, and this concept is quite similar to that of the patch of cells. Therefore, researchers began looking for something similar to this in humans. The chicken version of the hedgehog is called the Sonic hedgehog. Apparently, every creature on the planet has the Sonic hedgehog gene. This gene can be controlled by a vitamin A injection, resulting in changes in how the limbs develop. 

Researchers injected some protein that the Sonic hedgehog makes into a shark embryo. The protein was that of a mouse. Because the mouse gene was similar to the shark gene the limb development was affected the same way as if it were injected with vitamin A injection. This means that the evolution from fish fins to limbs likely involved the use of ancient genes.

"Survival of the Sickest" Chapter 6, Summary

This chapter started off by talking about how the first vaccine was the cowpox infection because it resulted in protection from smallpox. It turns out the word "vaccine" actually comes from the Latin word "vacca," and now suddenly everything makes sense! The chapter went on to talk about "junk DNA," which is 97% of the DNA in your body that, according to early scientists, don't do anything. That means that only 3% of your DNA contains instructions for building cells. We later learn that "junk DNA" isn't so junk after all. The chapter also mentions that a third of your DNA is derived from viruses. It is also brought up that humans have a total of approximately 25,000 genes. A man, Jean-Baptiste Lamark, was also mentioned. He was wrongfully accused of coming up with the theory of inherited acquired traits. This means that whatever traits a parent develops during his life will be passed on to his/her child. This theory, though not exactly right, isn't exactly wrong either. The rest of this chapter mainly talks about Barbara McClintock's evidence for "jumping genes." "Jumping genes," also known as transposons, are whole DNA sequences that move from one place to another when under environmental stress. Transposons act like "copy and paste," inserting themselves into genomes while still remaining in the same location. These "jumping genes" make up a large portion of our "junk DNA." Lastly, this chapter talks about RNA. Retroviruses are made up of RNA, an example being HIV. Using an enzyme called reverse transcriptase, retroviruses can transcribe themselves from RNA to DNA. The retroviruses that are a part of our DNA are called HERVs. They are believed to play a number of roles in human health. 

"From Atoms to Traits"

1. Mendel's experiments changed the view of heritable mutations from ephemeral and blendable to discreet entities passed from parents to offspring, present even if not always visible. His work formed the foundation of genetics. It contributes to everybody's understanding of genes, and all biological advances with genetics. If it weren't for him, genetic advancements would most likely not be possible today. 
2. 
   

This structure was discovered by James D. 

Watson and Francis Crick.

   3.  -Substitution of a single letter for another at a particular position in the polymer :                                        

     ACAAGATGCCATT -  AGAAGATGCCATT        

        -Deletion of a block of letters : ACAAGATGCCATT  -  ACAGCCATT 

        -Duplication of new letters : ACAAGATGCCATTAAA -ACAAGATGCCATTAAAAAA

        -Insertion of new letters : ACAAGATGCCATT -  ACAAGATGCCATTGTC 

        -Inversion and translocation of the letters already present : ACAAGATGCCATT -   

         AACAGAGCTATTC

   4. Evo Devo, short for Evolutionary Developmental Biology, is a field within evolutionar biology         

      that concentrates on studying the effects of changes in important developmental genes and the role 

      they play in evolution. 

  5. If a person migrates from an area where they don't consume lactose products beyond infancy to a       

     region where lactose is consumed through adulthood, it is likely that they will be lactose intolerant         

     because their body is not used to consuming lactose.     

"Does Race Exist?"

Karina Martin

Mr. Quick

A Block

10/22/13

The title of this article asks a very interesting question: “Does Race Exist?” It is interesting because when you think about it, yes, race does exist. Race has existed for years and has caused much conflict throughout the world, especially here in the United States. This article, however, is not talking about the social phenomenon that has existed for years, but the idea of race that has a biological base behind it. A person determines another’s race by looking at his or her physical features. Our features, such as our skin color or hair, are what normally make us a member of a particular race. There are other aspects that also work well in dividing us into groups, like genetically determined propensities for certain diseases.

            In this article, the question of whether genetic information can be used to determine what “group” a person is a “member” of is asked, and the answer to that is yes. As I mentioned before, we determine race by a person’s skin color and hair texture, and these signs are dictated by a handful of genes. However, how some of these “groups” are divided depends on which genes are examined; for example, a person might fit into one group based on their skin color genes, but fit into another based on a different characteristic. An example would be the “African race” in the United States. There are many people that label all Africans as from the same race. However, Africans come from different parts of Africa, which makes them very diverse, especially when it comes to looks. Over the centuries, African-Americans have mixed extensively with different groups originating from different parts of Africa. On the other hand, two people from different “groups or “races” can also share a larger genetic similarity that two from the same “race.”

            There are also medical implications of racial genetic differences that have brought many controversies among scientists. Diseases, such as sickle-cell and cystic fibrosis, result from genetic changes have risen in frequency due to being protective against diseases common in Africa and Europe. For certain diseases such as these, physicians may have to rely on background information about a person’s ancestry in order to best treat them. Some investigators say that group membership play a small role in genetic and medical studies, while others suggest that we can only understand how genetic and environmental differences among groups contribute to disease by using group membership. This dispute over the importance of group membership shows us how strongly our view of race is shaped by different social and political perspectives. 

Journey of Man

Today, we finished the video I talked about in my last post. We learned why the Y chromosome is the best place to look for genetic markers. This is because, unlike the X chromosome, the Y chromosome passes unchanged from father to son, making it the genetic marker easier to follow. The narrator of this video goes from Australia to a small Indian village and takes blood samples from them because he is trying to prove that the San Bushmen tribesmen traveled through India to get to Australia. He is taking samples from this small village specifically because the more indigenous a people are, the easier they are to connect to ancestors.

We also learned about why our skin color is different. This is because people living near the equator tend to have dark skin, while light-skinned people live nearer the poles. Also, selection on skin color depends on the UV radiation levels. In the video, we met a man named Niazov who has a genetic marker that has been inherited by 2,000 generations. Next, we met the Chuchki, a nomadic tribe, who are distant cousins of the Native Americans. They live by the Arctic Circle and have grown very accustomed to the freezing temperatures. In fact, they seem to have evolved or adapted in a way to survive int these harsh conditions. They adapted to a smaller sized body to reduce surface area in which heat can be lost. Moreover, their whole body contains body heat. The narrator finally came to the end with the Native Americans. Did you know that the first Americans to arrive on this continent arrived 13,000 years ago? It's crazy! Until next time...

WE ARE FAMILY!

In our last class, we talked about an article that we had to read for homework. The article pretty much talked about how all of us humans today are, in some way, related to each other. Weird, right? For the rest of the class, we began a video called "Journey of Man." This video is a documentary of a man who went on a journey around the world trying to discover how we are all related and where this relation started. What we have learned so far is that we all originate from Africa, from the San Bushmen tribe. The people of this tribe are the first ancestors of mankind, which lived about 50,000 years ago. These people a few major advantages: state of the art hunting technology, advanced language, and excellent tracking skills. We also learned about genetic markers, inherited mutations that write our history and are passed on from generation to generation. At some point in history, a few people of the San Bushmen tribe migrated and ended up in Australia. There is no evidence that can be found that can prove how the tribe made  it to Australia. This is because the sea levels at the time were lower than they are today, therefore, they could walk from one continent to the other. We will be finishing the video next class. Until next time!

My beautiful (not really) poem

So, remember how I said I wrote a poem about Fava Beans? Well, here it is. Think of it as a slam poem. Maybe that will make it seem less ridiculous...

Waka Flaka Fava Bean!

Can you do me a fava?

Tell me, what is a fava bean?

Fava beans are two faced fiends!

For some humans, it can help.

But for others…WELP! DEATH!

Favism, a fatal disease.

Those who have it die with ease.

Fava beans can be so mean.

If you live where they cultivate

You’re sure to feel their hate.

You’d think from spending so much time with them

They’d be your friend.

But nay! They like to slay

Those who spend time with them all day.

Fava beans aren’t the only ones who want to kill

Like Hannibal, who likes his fill.

Because they face fava beans pain

People are resistant to malaria’s reign.

Malarial parasites want to pillage your red blood cells

But G6PD gives them hell!

Evolution doesn’t fava traits

So be careful if you put them on your plates.

Because you might find out that nature

Is one of your biggest haters.

Because of all this strife

There is advancing of human life.

I am so sorry...

Hardy-Weinberg

So we did math in Bio class. It was cool, because, for once, I knew what I was doing. I actually grasped the concept of how to do a Hardy-Weinberg problem pretty quickly. Honestly, I really happy with myself. Hardy-Weinberg problems, by the way, are problems used, in some cases, to figure out the percentage of recessive and dominant individuals in a population. You can also figure out the frequencies of alleles. The equation is

Why, Pan Prior, Why?

So we were given a project where we had to research a theoretical fossil, in my case the Pan Prior, and create another theoretical fossil of the human ancestor. In other words, a transitional fossil. Fun! Most of my break was focused on this project. My partner and I split up the project, and I was given the task of planning our trip to Ethiopia to discover this magnificent fossil. It was one of the most stressful experiences of my life! I don't know how people do it! How does one sit there staring at their computer finding plane tickets, hotel prices, car rentals, etc? Maybe this was just me. I mean, our location is pretty far from EVERYTHING! It is as if no hotels exist near our location. They existed everywhere else but where we needed to go. I even asked my mother how to find a hotel because she is usually pretty good at finding hotel when we go on vacations. She couldn't do it either. It took me forever before I finally found one. Anyways, that was just me ranting. We finished, so it is now out of my life. I now live in peace. 

GENE FREQUENCIES! YAY!

We did a lab in class that involved evolution and gene frequencies. We were given a 25 red beads and 25 green beads. The red beads represented the recessive allele for no fur on a Bengal Tiger. The green beads  represented the dominant allele. We had to put all of the beads in a bag, shake them up, and pick out two beads at a time. If the bead colors we chose were green & green or green & red, then the tiger had the dominant allele. If the beads were red & red, then the tiger had the recessive allele. This means that the tiger died. 

Parent's Day!

So the classroom was a lot more crowded than usual. It was Parent's Day, which is when our parents come to our classes and see what we are learning. All in all, I'd say it was a pretty good class. At the start of it, I showed my parents a live brine shrimp from our latest lab experiment. They were pretty fascinated by it, especially with the fact that I could use the equipment in the classroom.

For the rest of the class, we talked about some...interesting stuff about physical attractiveness. We did this activity in class to determine what type of females and males we were most attracted to. It was pretty funny watching my parents do this, especially my mom because she was really getting into it and seriously wanted to know her results. The awkward part about all of this was probably the part where we had to explain the scientific reasoning behind why we are more attractive to certain females and males. Anyways, it was fun and then it was time for BREAK! Adios my people!

Do you see what I see?

We began this class period by looking at a variety of rocks and shells. Using a magnifying glass, we observed and separated the shells from the rocks. Next, we observed only the shells and separated them into categories of our choosing. My partner and I decided to separate them according to their size. When we finished, we discussed the different variations of species.

You see, the variations of a species are caused by DNA mutations. This causes different species to evolve. Some variations can be different shapes, sizes, patterns, and even color. The DNA mutations exist so that the species can adapt the their surroundings and survive. Whichever species survive can then reproduce and pass on their genes to their offspring. The offspring will continue to pass on these genes for generations. 

Then, we began the brine shrimp lab. Brine shrimp are really small, tiny actually. It is pretty difficult to see them, which is why we used our handy-dandy magnifying glass! We were given five different solutions of NaCl: 0%, 0.5%, 1.0%, 1.5%, and 2.0%.  We had to put at least 20 brine shrimp eggs in each solution to see what type of environments the shrimp could live in. Our main test was to determine how many of the brine shrimp could hatch and survive in a specific environment. As I said before, we were supposed to put about 20 brine shrimp eggs in each solution, but let's be honest: that didn't happen. They are just too small! Plus, we had to pick them up with a brush, and the brush just decided that it was going to pick up 120 eggs instead of 20. 

After we counted the eggs, we were done for the day. This lab took place in 3 days. So, the next day, we came back and counted how many of the brine shrimp were dead/partially hatched and how many were swimming. And that was pretty much it. The day after that, the last day of the lab, we counted again how many brine shrimp were dead/partially hatched and how many were swimming. We then drew a graph of our data...