Struggling with my genetics experiments. Breeding fruit flies and looking at their eye colors.
Out of 229 flies, I got 173 wild type, and 56 sepia. That's 75.55% and 24.45%. A textbook clear example of 3:1 inheritance of a recessive allele.
But the chi square analysis says that I have to accept the null hypothesis, that it's just coincidence. Something about that seems wrong when the data fits so perfectly.
I am going to start studying genétics next year, mind giving moar details Senpai?
:^3
This is a very simple experiment on inheritance tracking eye color. Wild type is a brick red (as shown in the op picture) and sepia is a yellow-brown color.
We did two crosses. 4 female sepia x 4 male wild type. And 4 female wild type x 4 male sepia.
Allowed them to breed, and isolated the F1 generation. All of the F1 generation have wild type eye coloration. From the F1 generations we crossed 4 females and 4 males.
The F2 generation yielded 229 flies total, which we counted as 173 wild type and 56 sepia eyed.
Because the trait is not sex linked (or it would have appeared in one of our F1 generations) I lumped them all together.
the most important thing you can do at this point is learn how to make a standard deviation
I guess. It's just frustrating. Talked to my professor when I first added them up and her words were that it was "Textbook for an autosomal recessive allele." That was before I had done the chi-square analysis mind.
Just ugh.
vp here
does your fly have the ha? it doesn't come from nowhere
This is sick. Absolutely fucking sick.
You're telling me you're forcing fruit flies to have sex and then you're LOOKING AT THE COLORS OF THEY'RE EYES?! Inhumane. How is this shit allowed?
Pretty segoi desu senpai
Do you develop zoofilia after watching animals fucking each other like stated?
Only the ones with pretty eyes are attractive. But my feelings (or lack thereof) aren't going to give me a bigger sample size.
Not significant.
FML
You would expect to accept the null hypothesis.
Also, nice blog you got here.
but user, you should accept the null hypothesis because it IS pure coincidence
genetics is the devil's science and is one small step from "evolution"
God made the eye color of the fruit flies the way they are to test your faith
I know I have to accept the null, but it still irks me when the data is so on point.
....no.... accepting the null hypothesis is what you wanted from the beginning, you are misunderstanding the purpose of the chi square test
The chi square test is really confusing. So my P value was between 0.09 and 0.05. Doesn't that mean that it's statistical noise?
No, it's chi square test, not t-test.
Haven't taken statistics yet, so I don't even know what a t-test is.
>biology majors on Veeky Forums
wew lad
Biotechnology major here. We're not all like OP, I swear
Oh hush. Everyone has to start somewhere, and the null hypothesis isn't terribly intuitive.
the null hypothesis IS intuitive as a concept but the statistical tests you have to do aren't.
Have fun learning ANOVA when you finally get around to stat.
>Something about that seems wrong
No shit. Are you following the rules for chi square analysis?
To be fair, his knowledge on the matter is highly dependent on the college he goes to. If they just dont teach this stuff, then this is his first brush off with the null hypothesis which is why he is asking for help and trying to understand it on his own with no prior academic guidance.
He wasn't even asking for help if you read the thread. He just came to the wrong conclusion then assumed he did it correctly without even understanding the tools he was using.
He misunderstood a concept and came to realise it in this thread. Most people would just not give a damn tb h. Everyone has to start somewhere, no matter how intentionally ignorant of a person they have been until now.
>He just came to the wrong conclusion then assumed he did it correctly
Obviously not otherwise he wouldn't have made this thread
wild type best type
You can sit here and try to defend science babies making freshmen tier threads and I am going to continue to point out their mistakes like an asshole
Probably error caused by small sample sizeXbig mean distro
Increase your sample size
Your null hypothesis is actually that your distribution is no different from the 3:1 distribution.
i.e 75.55/24.45 is not significantly different from 75/25.
Your analysis says that you accept the null, which means you're accepting that your results are >A textbook clear example of 3:1 inheritance of a recessive allele.
You've simply misunderstood what the null hypothesis is.
suck me off at the next train station please
...
Shut the FUCK up you piece of shit. Fuck outta here with those disgusting eyes that aren't cinnabar.
don't talk shit about my wildfu
just fuck off dude, you're not impressing anybody with your shit taste in drosophila
I think I am, but it's giving me trouble.
My two lines seperated out: Tube 5A F2 yields 141 flies: 105 wt and 36 sepia.
((105-106)^2/106) + ((36-35)^2/35) = 0.038
Tube 5B F2 yields 88 flies:68 wt and 20 sepia.
((68-66)^2/66) + ((20-22)^2/22) = 0.0242
P value for 0.05 and one degree of freedom = 3.84. I'm off in the 0.8 range, so accept the null.
>science babies making freshmen tier threads
You better criticise every math and physics thread on Veeky Forums as well, then.
Thanks. Guess I'm just having a hard time determining how I should have set up the null.