Allelic Frequencies

Ok, Question of the Day:
1. (5 pts.) Population Genetics Based Upon Phenotypes. Cyanogenesis in white clover, Trifolium repens, is controlled by two unlinked loci. One locus controls synthesis of a cyanogenic substrate while a second locus codes for synthesis of the enzyme that releases the cyanide radical from the substrate. Cyanogenic plants rapidly release cyanide when they are crushed. Cyanogenic plants can be identified by crushing their leafs in the presence of dinitrotoluene (I nitro away from TNT!) which turns red in the presence of free cyanide. The cyanogenesis phenotype is polymorphic in white clover populations throughout the world. Alleles at the first gene that encodes the cyanogenic substrate are usually fixed. Cyanogenic alleles are incompletely dominant to acyanogenic alleles at the second gene. Acyanogenic plants are assumed to be homozygous recessive. Numerous studies have shown that cyanogenic plants are eaten (by a variety of things) less often than acyanogenic plants. On the other hand, cyanogenic plants don't recover well from being trampled or crushed and generally show less vegetative growth and lower fecundity. The fitness of the genotype is thus dependent on the environment. You observe the following frequency of cyanogenic phenotypes in three populations. Assume the existence of two alleles at the second gene that encodes the enzyme that releases the cyanide radical.

Population 1 Population 2 Population 3
Cyanogenic

+ 0.2 0.5 0.95

- 0.8 0.5 0.05

a) Calculate the frequency of the cyanogenic allele in each population.

b) In two or three sentences provide a hypothesis to explain the maintenance of alleles at these frequencies in these populations. How would you test this hypothesis? (Hint: What selective forces might be operating in each of these populations?)


If anyone can tell me whether or not the part about incomplete dominance of the cyanogenic allele to the acyanogenic allele makes any difference at all, I will buy you a candy bar!!!! If you could also give me a better nudge in the right direction for question "b" that would be much appreciated and warrant an even better ICE CREAM CONE!!!

Ok, now that you all are on that...

It's Monday again, and I'm struggling with my homework. Also, unless my friend Emily comes to pick me up, I'm stranded on campus until 7:15, at which point we go over to the student center for an officer meeting, and then a team meeting at 8pm, meaning I will not get home until around 9pm. At which point I will have been on campus for a solid 12 hrs. Whoa.
Today was payday!!! I wasn't able to save anything this month, and probably won't be able to for the next two months, mostly because I have to make payments to CSU for my fees. I won't complain b/c certain people like to point out how cheap in-state tuition is vs out of state....but it's still a lot of money for me :)
Better get back to it, I have a bunch of homework still, and a tiny bit more lab stuff to finish up today if I can just buckle down.
Thanks for reading! Hope you all had a great Monday!

-Megan

ps. I forgot to mention trail work weekend #2! It went well, no one broke any bones...

FRIDAY!!!!

I'm so glad it's Friday!!!!!!!! This week has been possibly the longest of my life, and I can't imagine how Caley feels. Poor guy has been at my beck and call all week, and he's been amazing about it, but I still feel bad.
This weekend should be full of fun! Tonight is Tirrels "going away" party :( I'm super sad!! I'll miss her calming influence and general Tirrely awesomeness. We have, however, inherited her lovely sister Marlena, so perhaps she will be a good replacement:)
Saturday morning we are volunteering for the Rist Canyon Road race, starting at 6:45am!!! We get free lunch though, so it should be worth it. Saturday evening it's back up to Beaver Meadows for some more "trail work" aka sitting around relaxing for me:) I have a feeling though, that the weekend is going to fly by, and before we know it, it'll be back to the grind. Man I can't wait to be done with school!
Short post today, lot's to do!
-Megan

Broken Ankle

So, I broke my ankle. Not doing anything spectacular, it was a very slow motion fall on the mtn bike. My foot didn't clip out, and my body acted as a nice lever to snap the tip off of my fibula. A picture for your enjoyment:



Other than that, school has started, my Population Genetics class is going to be super tough, a lot of statistics and convoluted math. Hopefully I can stay on top of it seeing as my adviser is my teacher...I'm also taking Spanish again which should be fun! The teacher is really enthusiastic and seems nice. I'm taking the first year review class, it's definitely the right level for me to be in. Hopefully they won't get me into trouble for not taking the placement test and just signing up for it :)
Research is going well, I'm about ready to take the next step in both of the projects I'm working on. I think I'm going to hatch some eggs tomorrow to start my first cross between my mosquitoes and the Mexican mosquitoes. Cross your fingers that they all hatch well!!! I collected the eggs from my mosquitoes about 2-3 months ago which is the very end of their viability. Hopefully I won't lose any...another thing to keep me up at night.
I tried Vicodin (sp?) for the first time last night. It was awesome! It put me right to sleep, I didn't have any nausea and my foot felt great! I told Caley, under no circumstances is he allowed to let me get addicted to it:)
Well, off to class, hope you all are having a nice week!
-Megan

Summer is Gone :(

Wow, I just realized it's been over a month since I last posted anything! How could I let that happen? :)

I am a mixed bag of feelings about the coming school year. While I'm pretty excited about getting back into the routine of school and going on a lot of fun biking trips this fall, I'm also reminded of how much I have to accomplish between now and the end of the school year! So much remains to be done on my research project, and of course I find every little thing to stress about...every nit-picky little detail that could go wrong, and probably will...At least I have a pretty clear idea about what has to be done to finish the project. Then comes the thesis writing and defending! I take comfort that many people have gone before me and survived:)

The past month has been full of fun adventures! A crazy trip to see the sister and friends and family in Durango:


Fun riding bikes, Emily made it to the top of Rist Canyon for the first time!!



Also, we went to Nantucket! How could I almost forget??! Favorite pic of the week:



Quite a bit of work, although I don't have any fun pictures for that....

Caley and I marked our 2nd year of togetherness with some epic trail work on the reservoir loop and then some fun downtown at New West Fest. We can't decide whether the past two years have gone really fast or really slow...still not sure:)

I should head to bed, we're getting up early to ride some mtn bikes! I'm trying to get some good riding in the next few weeks before racing starts. Somehow the summer went without me riding nearly as much as I would have liked. I guess I'll be forced to this fall with races every weekend, racing into shape is my favorite thing to do anyway...:)

I'll make a more concerted effort to keep you updated this fall!

-Megan