Q1 – Week 8 – 19-20
week 8
Week of 10/22 – 10/26
10/22 – Monday – period 7/8
Field Trip to
Long Island Horticultural Research and Extension Center (LIHREC)
https://cuaes.cals.cornell.edu/farms/lihrec/
Dress warm! Pack a bagged Lunch! Bring Your Marbled Notebook!
10/22 – Monday Homework-
Ahh Scratch the stuff below.. You guys were great!! NO HOMEWORK TONIGHT!
1. Using your notes from the marbled notebooks you are to complete 3 descriptions of research investigations that have or are ongoing at the LIHREC. Your descriptions require the following:
A: Title
B: Hypothesis
C: General procedure of the experiment
D: What was found and how it was beneficial.
I need details! So you will need to ask questions today!
End of Monday!
10/23- Tuesday – period 7 – Academic Study Hall
– period 8
1. Field trip summary – not really. Will do more Wedneaday.
2. Evolution last points, alleleA1 program
|
Mark Bridgen
Director
mpb27@cornell.edu
|
Dan Gilrein
Associate Agricultural
Program Director
dog1@cornell.edu
|
Margery Daughtrey
Plant Pathology
mld9@cornell.edu
|
Dr. Meg McGrath
Plant Pathology
mtm3@cornell.edu
|
Field trip Video:
10/23- Tuesday Homework:
1) Thank you?
2) Watch a lecture on possible cause of the 5 mass extinctions:
2) Fill the form below:
End of Tuesday
10/24- Wednesday – period 7/8
1. mass extinctions to speciation
2. Field trip review – decompress
10/24- Wednesday Homework:
Complete form after the paragraph below.
Life continues to evolve within a changing environment.
Speciation and extinction have occurred throughout the Earth’s history, and life continues to evolve within a changing environment. However, the rates of speciation and extinction vary. Speciation can be slow and gradual or, as described by punctuated equilibrium, can occur in “bursts” followed by relatively quiet periods. At times of ecological stress, extinction rates can be rapid, and mass extinctions are often followed by adaptive radiation, the rapid evolution of species when new habitats open. Scientific evidence, including emergent diseases, chemical resistance and genomic data, supports the idea that evolution occurs for all organisms and that evolution explains the diversity of life on the planet.
A species can be defined as a group of individuals capable of interbreeding and exchanging genetic information to produce viable, fertile offspring. New species arise when two populations diverge from a common ancestor and become reproductively isolated. Although speciation can occur by different processes, reproductive isolation must be maintained for a species to remain distinct. Evidence that speciation has occurred includes fossil records and genomic data.
Form:
Evolution Form:
Micro Evolution Form:
End of Wednesday..
10/25- THursdsday – period 7 – Academic Study Hall
– period 8
1. Write your notes into SHARED Google Doc from our Cornell Visitation
2. Make a second submission to last nights form.
2. Review weekend forms toughest questions, Chapter 22/23 quiz.
3. Continue with Speciation presentation.
10/25 – Thursday Night HW:
2: Please use the form as your guide to view the following videos and complete the form:
Video 1:
Video 2:
Video 3:
Video 4
https://www.youtube.com/watch?v=23mrtGCkAH8
https://www.youtube.com/watch?v=eH1s9GCqPKo
https://www.youtube.com/watch?v=svPaTOjtxJ8
https://www.youtube.com/watch?v=Ao8Q6NZqe3g
*Connections – Todays FAST PLANT Calculation Demo
Today we looked at the second generation of the of our Fast Plants and we discovered and calculated the frequency of the Non-purple Stem Color allele (q) which is a recessive allele.
We did this by recognizing that our F1 population were 100% heterozygotes, thus every individual had the recessive (q) AND the Dominant allele (p).
Have all heterozygote individuals thus ensures that our: F1 generation = q = . 5 and q = .5
We wanted to see if there was micro evolution at the Stem Color allele in the second generation.
Remember the the Hypocotyl – (stem below the cotyledons) was
Purple Or Non- purple (green)
ANL/anl or ANL/ANL anl/anl
ANL is the p anl is the q
Now we are after the q for the second generation to see if there was EVOLUTION but we had some work to do calculate the q.
NOW the jumping off point is the homozygous individuals BECAUSE WE KNOW THEIR DEFINITE GENOTYPE (q2) if we identify the expressed recessive phenotype. Homozygous and Heterozygous genotypes share the same phenotype so we cannot get allele frequencies directly from those individuals.
This was our class data for the F2 generation:
| Green Stem *Individuals/ total | 16/28 | 18 /46 | 8/29 | 43/104 | 12/21 | q2= 97/228 .4254 |
q = .65
|
q = .65 |
*We multiply both the numerator and denominator to get total alleles (each individual has 2 chromosomes)
Lets compare the 2 generations:
F1 F2
q= .5 .65
The second generation q changed!! We are not in Hardy-Weinberg Equilibrium and thus there is evolution.
Only 3 things that will cause evolution. Gene Flow, Natural Selections and Genetic Drift. Clearly there were no pollinators (bees) that had pollen from other FAST Plants fromother because we had a small population we had Genetic Drift.
 |
Using the AlleleA1 simulation, Genetic Drift of allele A1 (p) or the dominant allele LEAD to the “death of A1 alelle” after 300 generations of 400 individuals. This is due to random events in producing gametes in meiosis AND in Random fertilization. This what is meant by the drift! With no other forces working, No Natural Selection, Gene Flow, or inbreeding an allele is lost from the population. Remember we are tracking only 1 allele and that is very possible that this happening at other alleles in the genome of the species. Genetic diversity is decreasing and this population is becoming less like the populuation it once belonged to. |
Genetic Drift can lead to loss of alleles as I have shown you in the Excel Spreadsheet or the simulation that I have demonstrated for you. If these alleles are connected to ANY part of the reproductive genes then Speciation can occur as reproductive isolation will occur between different populations of the same species.
Natural Selection, Gene flow, and Genetic Drift can all lead to decreased genetic diversity in a population. These forces that cause relative allele frequencies to change at the population level can also influence the selection forces that shape them over successive generations. Remember that Evolution is not perfect and reproductive success is determined by alleles that are best favored for the current environmental conditions. These best favored alleles which are selected for due to the selective pressure by the environment of are ones that ARE THE BEST AVAILABLE alleles that the population currently has to choose from. Remember that only Natural Selection is adaptive but this adaptation occurs from what alleles are available and these available alleles are subject to change by the action of Gene Flow and Genetic Drift. So Gene Flow and Genetic Drift are not adaptive but they shape Natural Selection by providing the choices!!!!
Speciation, or reproductive isolation that occurs from the loss of alleles in the reproductive process, almost always occurs from small groups
AND the forces that make Speciation possible are the forces that make a species susceptible to extinction.
Lowering the genetic diversity through Stabilizing Selections or through Genetic Flow and Genetic Drift essentially decreases the variety of alleles that could potentially give the population the ability to survive when environmental conditions change.
THIS IS WHY MOST SPECIES BECOME EXTINCT AND THIS IS THE REASON OLDER SPECIES STILL PREVAIL TODAY.
FOR EXAMPLE: The current 3 elephant species that inhabits Africa and Asia have a distant relative in the
Manatee which is its the closest living ancestor.
What forces are at work?
Let us revisit a phylogenetic tree of Evolution of Humans (Hominids):
Why is the Chimpanzee still with us?
Why have so many of our early ancestors gone extinct?
Notice that bipedalism was an adaption that occurred long before large brains?
What possible selective pressures made bipedalism an advantage OR do you think that bipedalism was just a non adaptive form of evolution?
A very interesting article on this last question:
End of Thursday.
10/26- Friday- period 7/8
1. Review Evolution and Speciation Forms (Wed night homework – 2 subs)
2. Review Plankton Form (Last Nights Homework – 1 sub)
Notes from connections above will Allele a.
3: Genetic Drift/Natural Selection/Gene Flow —-> Speciation ——> Extinction ——> Adaptive radiation
Lab:
1. Started Brine Shrimp Class Data compilation with Excel.
AlleleA1.app.zip
Download
Download
4. Brine Shrimp Data collection /graph and data table design
Tutorial video on creating Graphs (from your data table) in Excel:
I am making a line graph in this tutorial but you can just select a bar graph instead in the initial stage of the video and all of the other things I demonstrate would be the same in the video below.
10/26- Friday- Weekend HW:
1. Work on the Brine Shrimp Lab formal Lab Write-up –
You are to include the Data Tables and Graph in your data section.
You will need the class data which had your lab groups data as well.
I know that we somehow did get a chance to do them in class but what I am looking to do is make 2 different data tables and graphs. You will need a data table on YOUR Groups Data and a data table from the whole class.You will also need a graph from your Group’s Data and a graph from The Entire Classes data.
Both graphs will illustrate the changes in Hatching Viability (in 72 hours) in different saline salt solutions (0%, 0.5%, 1.0%, 1.5%, 2.0%). These graphs must have error bars (+/- 2 SEM).
We have done this once in class but I am making a tutorial that you will follow to make YOUR OWN individual graphs for this Lab. YOU ARE TO ADD THESE DATA TABLES and GRAPHS MADE IN EXCEL INTO YOUR google doc that I linked to you previously.
Video on how to make the Brine Shrimp data tables and graphs:
You are to add calculations of how you determined the % hatching viability from 72 hours.
You are to write a results section – Summary of the most important data based on your hypothesis.
You are to write a conclusion.
See the Lab format below for more details:
I will read every lab and give you feedback and give you an opportunity to rewrite
your lab before I grade.
2: All students will complete this form this weekend.
Please view the evolution Presentation and the Origin of Life Presentation for the Form Below:
LAB FORMAT:
1: Write up of Brine Shrimp.
HERE IS AN EXAMPLE (link to a AP BIO student’s lab last year)
Using the general rubric below and the one explained in the Lab Report Rubric link I gave out I would like to see the following sections in your Lab write up.
There is another example posted in the Lab Report Rubric. I am requiring these sections below to be titled and inclusded in your lab report but you are making this lab your own. Although we did the same data collection and experiment, you are to make your lab unique in the lab write-up. You will spin this lab to your interests by writing a unique background that will cover a least a page single spaced or 2 pages double spaced. Use this opportunity to research something about Brine Shrimp that may relate to your experiment. This is something that you will bring back into your discussion in your conclusion. This could really be anything related to your experiment or the Brine Shrimp BUT you must direct your discussion to your Question and then Hypothesis.
1: Title Page – Your name, Date, Title of experiment
2: Background – Your background is like a literary review of the topic in a published study. I am not asking you to write a term paper on the Brine Shrimp but I am asking you to write an essay on the ANYTHING that is remotely related to this investigation. Develop your Background so that your discussion eventually LEADS to a Questionthat you will test with your Hypothesis. I know this is open ended but this is how you make this lab your own. Do make this a cohesive piece of writing and you may probably need to investigate this information. At the end of the lab I will ask for your resources, so make note of where you are gathering information. DO NOT MAKE THIS a bunch of unrelated ideas or facts. I gave you some example below from past students of mine so take a look to get a feel of what I am asking. This part of your lab should be 1 page single spaced or 2 pages double spaced.
3: Question – testable question that relates to your hypothesis
4: Hypothesis: Use the correct format: If the Independent variable is modified…
5. Materials:
6: Procedure: Step by step instructions on how you would complete this experiment.
7: Data: Graphs, Data Tables, etc.
8: Results: Summarize your data, but do not make conclusion statements. “the trend of the data is that as the salinity increases the … Do not state that Brine Shrimp prefer this or that (those inferences are conclusion statements). THis will be a short section. A couple sentences will usually suffice.
9: Conclusion: This section will be heavily scrutinized. What does the data tell us about the Brine Shrimp? Here is where you get dirty with the data. What is the data inferring about the Brine Shrimp? Was your hypothesis supported or not and Why? What are the implications or possibilities because of your outcomes. What could be further investigated?
If you get vague you will lose points. You must fully develop your points and support them with logic! Remember that many experiments are built from the conclusions of other labs. This means your points in your discussion will not be facts but just very good possible explanations. Another experiment would be needed to test the validity of these statements. However, if you support your statements with solid logic from evidence collected in the lab then you are addressing all the possible implications from YOUR WORK or experiment. In this point of your conclusion you will be MAKING A LEAP from your work based on data analysis to a POSSIBLE implication BIOLOGICALLY for the Brine Shrimp. If you do this by tying the Background discussion with your discussion here it will result in very will impressive lab write – up!
The second part of your conclusion must discuss the limitation of the lab. What are the errors in the lab that may affected your outcomes. You need to be specific and heavily detailed here.
10. Sources – Just give me web address of the sites that you got information from.
END OF WEEK 8