Spider question

[RandyRemington]

I recently went to the funeral of a 100 year old female relative on my dad's side. My dad and pretty much all of his male cousins and uncles where bald. Figured that was a classic case of getting it from the females. Maybe in your case it was from an X passed down through female lines for several generations with no males getting it until you got "lucky". Since women have two X maybe the other males on your mom’s side got the non balding one and in my dad’s relatives case they all hit their odds and got the balding X.

Very interesting on the spiders! We think we know how things work but good to crunch the numbers to see if we need a new theory. I was reading something a while back about the classic model of crossovers perhaps only applying to males. But then snakes are like birds and the females are the ones with the mismatched gender chromosomes (w and z) and so they determine the gender of the offspring. So maybe in other things you would need to swap the gender genetics when comparing to mammals.

I tried to get some data on gender distribution once and was just told that it's 50/50 in the long run. Even if that is the case as expected it would be interesting to plot the distribution and see if it's the expected normal curve or concentrated at the ends.

Maybe the females don't produce each egg randomly as expected but do something like copy a smaller number of eggs. In the spider case maybe spider sperm are bad swimmers but spider eggs cells are favored somehow.

[wolfy-hound]

You could go a bit further, and do spider x other morph, and see if fewer or more spiders were produced in combonation with other morphs. That way things like bumblebees would be counted as a spider, since they carry the spider in combo with pastel.

Always neat to see the tweaking of real life vs the math numbers. Once in a while you can get a little surprise! If you gather the numbers for 10,000 spider clutches each of male spider to female normal, and female spider to male normal... would the odds be 45%/65%.... or would it swing to the 50/50?

Interesting things to ponder.

[OhhWatALoser]

I recently went to the funeral of a 100 year old female relative on my dad's side. My dad and pretty much all of his male cousins and uncles where bald. Figured that was a classic case of getting it from the females. Maybe in your case it was from an X passed down through female lines for several generations with no males getting it until you got "lucky". Since women have two X maybe the other males on your mom’s side got the non balding one and in my dad’s relatives case they all hit their odds and got the balding X.

Very interesting on the spiders! We think we know how things work but good to crunch the numbers to see if we need a new theory. I was reading something a while back about the classic model of crossovers perhaps only applying to males. But then snakes are like birds and the females are the ones with the mismatched gender chromosomes (w and z) and so they determine the gender of the offspring. So maybe in other things you would need to swap the gender genetics when comparing to mammals.

I tried to get some data on gender distribution once and was just told that it's 50/50 in the long run. Even if that is the case as expected it would be interesting to plot the distribution and see if it's the expected normal curve or concentrated at the ends.

Maybe the females don't produce each egg randomly as expected but do something like copy a smaller number of eggs. In the spider case maybe spider sperm are bad swimmers but spider eggs cells are favored somehow.

but my grandpa had hair, and i would have to get his "x" since he only had one to give and my greatgrandpa from my grandma had hair, and my great great grandpa had hair (no picture but my grandma says he did), so unless it came from a great great great relative, which i guess is possible, but i don't think it a simple gene as they say it is, mayb im a genetic mutation and im starting a new line of male pattern baldness yay!

[Egapal]

well im 21 years old and already balding, im sure it will be gone when im 30. every man on my moms side had hair til the day they died, however just about every man on my dads side has lost it. i think im walking proof that the whole balding thing being on your moms side is eigher not that simple or just bullcrap completly.

Wow wow wow. Ok first of all, if you assume that its a mystery then your deviation from the norm reinforces that assumption. If you assume its a well understood science then your situation is pretty easily understood. Every man on your mothers side should not be taken into account, only your mothers brothers and your mothers father. If your mother's father had hair then he had a good X chromosome. Your mothers mother's had at least one Good X chromosome. Now your Uncles all got your mother's fathers Y chromosome. And your mother's mother's good X. So they all are not Bald. Your mother could have gotten her Mothers bald X and her fathers Good X.

Your mother then gave you the bald X and you got a Y from your Dad who coincidently had a bad X. So the Baldness could have come from your Mothers Father, or her Mothers Father, or her Mothers Father. It gets based down the mothers side. Your father's side's baldness is a coincidence. Its not like being bald is rare.

but i think it was said before, the spider gene is not the same as balding, its a simple dominate trait (well mayb not simple, we still don't seem to have a solid answer on whole "why are their no super spiders")

There is a good solid answer to the no homozygous spider question. It could be fatal in the egg. If we see more bad eggs, or smaller clutch sizes in spiders than thats a perfectly good answer to that question. There are many examples of homozygous genetics being fatal both before and after birth in other species.

[Egapal]

but my grandpa had hair, and i would have to get his "x" since he only had one to give and my greatgrandpa from my grandma had hair, and my great great grandpa had hair (no picture but my grandma says he did), so unless it came from a great great great relative, which i guess is possible, but i don't think it a simple gene as they say it is, mayb im a genetic mutation and im starting a new line of male pattern baldness yay!

You didn't have to get your grandpa's "x" at all. You got one of your mother's "x's" She either gave you your grandpa's or your grandma's. Since you are balding it stands to reason that she gave you your grandma's. It would also stand to reason that your grandma gave your mother your greatgrandmother's "x" and not your greatgrandfather's "x". Its really not that hard. Its like flipping a coin and getting heads twice in a row. Its not even a little bit weird.

[Egapal]

Ok results are in and I had 1326 clutches that were from female spiders and the total eggs from female spiders were.................................. 7956 that is an average of 6 eggs to a clutch...

I had a lot more males so to make it more fair I took a chart and wrote down all th females and how many eggs laid..... then took and matched things up... So say this chutch had 5 eggs in it froma female spider i found a clutch that had 5 eggs from a male spider.... I did not look at the outcome of each clutch until I had the exact numbers of eggs and clutches done and then I took and added up spiders produced the males and spiders produced by the females....

So who is ready for the results?????????


From male spiders bred to normal females the total number of spiders produced in 1326 clutches of eggs with a total count of 7956 eggs was 3291 spiders................41.36%

From a male normal bred to a female spider the total number of spiders produced in 1326 clutches of eggs with a total count of 7956 eggs was 5264 spiders....................66.16%

So I have concluded that from these results and the data I recieved the spider gene is more dominant in females and is more likely to be passed to offspring than it is from a male...

Thank you all for your help. Now to find out if this is actually true or just the clutches I had for reference so I am going to start a massive spider project.

There is a lot wrong with this. First. Its not about being fair. You have two separate experiments running. If it was one experiment then your percentages would equal 100%. So lets look at them as two separate things.

Male spider bred to Female normal. You said that the actual numbers were 45%, not sure why you felt the need to leave out data, but lets look at that. So what you are saying is that when you add that missing data in you go from 41.36% to about 45% So thats a 3% gain. So assuming the amount of eggs you left out was smaller than what you kept in the data you kept out must have been much closer to 50/50.

Female spiders bred to male normals. 66.61%, there are two possible explanations. One is a statistical bias that would even out if you increased your sample size. The other is a genetic explanation. So whats your hypothesis for a genetic explanation.

Rule number one of a good experiment is never throw out data. You show all your data and then create hypothesis for why there are variations from what was expected. Your focusing on the results you are trying to prove which in my opinion are just wrong, and because of that focus you are missing out on possible discoveries. Look at the data you collected as a whole and see what its telling you then look closer and try and see what its hiding.

[nixer]

Rule number one of a good experiment is never throw out data. You show all your data and then create hypothesis for why there are variations from what was expected. Your focusing on the results you are trying to prove which in my opinion are just wrong, and because of that focus you are missing out on possible discoveries. Look at the data you collected as a whole and see what its telling you then look closer and try and see what its hiding.

rule number 2 is statistics can be bent and twisted either way. every person on this board should of seen that by now

[DM1975]

The OP seems to have posted limited data on what he collected due to everyone asking him to do so, not to just simply make things even. I bet for his paper (what this was done for, not our entertainment) he posted all data.

It amazes me that as many people on here did not get what he was talking about at first and resisted as much as they did. It was almost like people were either offended or scared of the question.

[Egapal]

The OP seems to have posted limited data on what he collected due to everyone asking him to do so, not to just simply make things even. I bet for his paper (what this was done for, not our entertainment) he posted all data.

It amazes me that as many people on here did not get what he was talking about at first and resisted as much as they did. It was almost like people were either offended or scared of the question.

I think it has a lot more to do with the fact that the question was asked as if it were an unanswered question and that he was attempting to show that the spider trait was sex linked. Many people, myself included, believe its an asked and answered question, spider is not sex linked and that attempting to prove otherwise is a waste of time. Personally I reacted so negatively because there are questions being debated regarding spiders. Such as whether Spider is a dominant trait or a co-dominant. Is the super form lethal. I further think that his research shows that its a straight 50/50 and that the variation he is seeing can be explained by a small sample set and unreliable data. And yes data that you get from other people is unreliable. The collector has to assume things that should not be assumed in order to rely on it. Given that the OP posted his results even to us with omitted data shows just how unreliable people can be when giving numbers. Further it sounded to me like the OP was very delibrate in his omission of data. I don't recall anyone asking him to make things even so it seams like he did so "to make it more fair"

[J.Vandegrift]

You should not have left out any results from the males bred to normal females. You are looking for a percentage, not the total number of spiders produced so the larger the sample size is the more accurate your results will be.

Also a question about your "normal" males being used. Are you counting the female spiders bred to other morph males like pastels pins, albinos...If not I would question your data because there is no chance that so many people used a truly normal male to breed a female spider. Sorry, I am just not buying it. I would bet that pairing was done less than a dozen times worldwide last year (if that).

Good luck with your paper, but I think you are putting a lot of work in on trying to disprove something that is not just a theory but is a fact.