Reading Review

For homework we had to read chapter six of Survival of the Sickest.  This chapter talked about genes and how they develop and change over time.  The first idea that was brought up in this chapter was the old theory of evolution that has been disproved with more recent evidence.  Originally it was thought that DNA changed randomly and mutations were sporadic and extremely rare.  This could not be true though because it could not explain how far humans have changed in a relatively short amount of time.  Knowing that mutations must be intentional geneticists realized that mutation can be caused by virus', bacteria and radiation.  DNA can change when needed based on these outside sources and other genetic factors.  These other factors are things like genetic jumping, where genes can cut and paste elsewhere or copy and show up in another area.  This is where natural selection comes in.  Genes that vary in a beneficial way are passed on because the population will want that gene.  The opposite is true for harmful genes, they will eventually be eradicated from a population if they are not helpful to have.  Genes in everything are ever changing and they always will in any species that survives for multiple generations.

Blog Quizzical

1. Explain the significance of Mendel.
 He looked at how genes move through generations by breeding peas.  
2. Draw the structure of DNA and who discovered this structure. 
James D. Watson and Francis Crick proposed the structure of DNA in 1953: The Double Helix.

3. Explain each of the five examples of variations that occur to DNA and give an example of each. 
Point mutation, insertion, gene copy number, deletion, and inversion.  Point Mutation is a single base pair change.  Insertion is the addition of another base pair.  Gene copy number is duplication of certain genes that happen during cell division.  Deletion is the absence of a base pair in genes.  Inversion is when a chromosome is flipped around.  
4. What is evo-devo? 
It is a sub-study of evolutionary biology where developmental genes are more closely examined and how they play a role in evolution.
5. Make a connection between human migration and the mutation of lactose intolerance.
Humans in America, Africa, and Europe were the only ones who after they grew up continued to use animal's milk for sustenance.  This is why people in other parts of the world are more likely to be lactose intolerant.  

Option 3: Traces of A Distant Past

I got option 3 assigned to me from Mr. Quick in this class and read the article: Traces of A Distant Past.  In class we watched a movie that discussed everything that was discussed in this paper.  The first main subject was the migration patterns of humans over millions of years.  Evidence shows that humans started in Africa and expanded to other parts of the world through slow migrations.  The evidence that proves this lies within human DNA.  By looking at the DNA strands of people in the Sans tribe in Africa, scientists can observe the y chromosomes of males and see the changes over time.  Scientists are creating a family tree of everyone in the world just because of there slight differences in DNA over long periods of time.

The article and movie have conclusive evidence of how humans got all over the planet over a relatively short period of time.  A lot of the movement was sparked by environmental changes in their environment so they moved on looking for means of survival.  Evolution was possible in humans because of this and it is why everyone is different today.  

Unit 2 Test Day

We took the unit 2 test today and I felt confident in my answers for 99% of the questions.  The genetic standards we are currently looking at are logical and easy to comprehend so it is not too complicated.  Everything is logical because it makes sense that genes will get passed down through generations, and as more branches form there is going to be more mutations/variations. UPDATE: I did well ont eh test and got a 93% giving me an A- for the quarter.  I understand what my mistakes were on the few satandards I missed and corrected them.

Dominant & Recessive Genes...NOT JEANS

In this class we looked at dominant and recessive genes and how they act over generations in a given population.  To do this everyone in the population (our class) was a Aa and they randomly selected one of someone else's genes and one of their own to show that their offspring would be that.  Although AA and Aa will show the same phenotype, we took a count of AA, Aa, and aa to find how genes change after 5 generations.  In the end of our first experiment we found that AA was 10, Aa was 3, and aa was 3.  Using the Hardy Weinberg formula we found that A showed up 57 % of the time while a showed up 43% of the time.  In the next step we took two separate populations, one of 6 and one of 10.  In the 6 population 3 were AA and 3 were Aa.  this showed us again using the formula, that A showed up 50% of the time and a showed up the other 50% of the time.  Recessive genes may rarely show on the phenotype because there has to be two present for a phenotype to show.  In Aa, only the dominant gene shows because it dominates the recessive gene.  This is is how genes work and do not confuse them with jeans this took me about an hour to figure out....

Brine Shrimp Lab

In this lab we looked at how certain brine shrimp in a given population are evolved to survive in different salinity's of water.  We placed Brine shrimp in 0, .5, 1, 1.5, and 2% concentrations of salt water.  A different amount survived in each salinity because not all brine shrimp are mutated to survive in one specific concentration.  The majority did show .5% was the most ideal environment to survive in.  It is impossible for the brine shrimp to all adapt to one salinity in as they are put in water because they are not able to adapt immediately to their situation like humans.  This would take them many generations.

Natural Selection --> Evolution

In this class we looked at natural selection and how mutations that are not good for the environment do not survive through the generations.  We did this by using 25 beads each of two colors to show how hairless Bengal tigers got wiped out.  The two green beads represented hairless tigers.  These hairless tigers were put in the killed section because they did not survive in the wild without hair.  After ten generations there was no more possibility for hairless tigers because that mutation was down to one bead which when put with a red one was no different than two red beads.  This shows how a mutation that does not survive the conditions of a creatures environment get wiped out after enough generations pass by.  This is one more point that further proves evolution.  It displays why and how species change over time and eventually evolve with mutations that let them survive, a.k.a.: adaptations.

Parents Day: Survival of The Fittest (sexiest)

On parents day we looked at what features humans look for in other humans based on attractiveness.  In men, the majority, looking at males, chose less masculine features because they saw the one of the two that was less threatening.  This leads to the decision to take on the weaker rather then the stronger. The men who chose more masculine features did this because they were more confident that they were better then the manly of the two faces.  In women men picked the less masculine faces because they were, to the male eye, more attractive mates.  In women, they picked men masculine or feminine based on what time of the month it was.  If they were going through ovulation they wanted a more manly face for mating.  If they were menstruating they wanted a more feminine face to be a care taker.  In women, they picked the more feminine faces every time because they all thought that they were more beautiful.

Evidence of Evolution Quiz

1. Explain the following picture in terms evidence for evolution.

A: This picture shows how, this land animal adapted over millions of years and generations so it would be better suited for it's environment.  

2. Which of the following continents did marsupials begin from?
1. Europe
2. Africa
3. Australia
4. South America
5. North America
   
   
   A:  e, North America

3. Comparing a dragonfly, bird, bats - explain the type of evolution that these organisms show.

A:  They evolved bones, got bigger and eventually back down to a smaller size once again.

4. Explain how the Common Descent Lab shows DNA evidence and ancestry as evidence for evolution. Include examples of Primates.

A: This lab showed how over generations species changed slowly to adapt to their environment   This slow evolution is visible due to homologous structures and similarities in Hemoglobin DNA strands.  Chimpanzees show a 97% similarity to human DNA.

5. Explain homology using some examples from your readings.
   
   
   A: Homology is the use of comparing similar structures in species. In the reading we looked a the tiktaalik which was similar to the land-fish that were before and after it's time. This is one of the key points in proving evolution.

Eleventh Class: More Transition Fossils

In this class we brought em' back.  Oh yea baby, Transition fossils.  Only this time, Adam and I got to choose which fossils we would like to look at.  The obvious choice, and the one we chose, was to examine platypus fossils and now we must create, from our IMAGINATIONS a fossil that would show transition between two already known genii of platypus.  This fossil needs to show characteristics of both genii and clearly be a step up form the last while not quite being the newer genus.  We are going to make a full research webpage for our "discovery" which will be linked in the blog later.

What does the platypus say?

Tenth Class: Tiktaalik and Evolution

In this class we looked at the extinct creature the tiktaalik.  This is a transitional fossil that adds one more important link in the long chain of evolution.  The change from fish to animals was a slow one with many holes along the way, but the tiktaalik was an important step in the process.  There is still fossils between the tiktaalik and those around it, but it did fill a gap.  This is what finding any new species does, it fills gaps so that we can explain why animals are very different from their ancestors.  For example by finding ancient horse fossils we can see how at one point, a long time ago, horses used to have three toes.  Over thousands of generations they lost two because they did not need them anymore.  Evolution like this can be seen in any animals around today.  Fossil hunting and identifying explains to humans why we are the way we are.

Tiktaalik display -- We have one in the museum!

Ninth Class: DNA Strands and Cladograms

In this class, as you can tell form the title, it was all fun and games as we examined hemoglobin DNA strands of humans, chimps, apes, and a mystery common ancestor.  looking at all the similarities between very short strands of all 4 of these DNA samples, we were able to form a cladogram showing evolution between these animals.  The common ancestor was at the very start because, it is in the name...ANCESTOR of the other three.  Next on the cladogram, branching off, was the ape because between the three remaining species it was the most similar to the common ancestor, and was the first to evolve.  After the ape were the chimps on their own branch as well, because they did not directly evolve from apes.  Finally humans fall onto the cladogram also coming off the main branch because they are very similar to chimps, but not directly down on the evolutionary chain form them.  You can see all of this in the HOMEMADE cladogram below.

Eighth Class: Test Day

In this class we took the first unit test that covered water, osmosis/diffusion, cell structure, and micro/macro-molecules.  Knowing that all these concepts are connected it is easy to figure out logical reasoning for the way one works by knowing another.  For Example, knowing that the cell wall only lets through certain molecules and wants to have equilibrium on both sides, we can figure out why osmosis and diffusion occurs.  Having connected concepts that overlap made the test a whole lot easier than memorizing a bunch of random concepts and formulas we are never going to see in our lives again.  Thanks for not making us read all of these and "memorize the material" Mr. Quick!