rthmjohn Posted September 17, 2005 Share Posted September 17, 2005 Have geneticists identified the alleles for the height phenotype? I've always tried to explain to my mom why I'm so short (despite my dad's relatively tall height) in terms of Mendelian genetics, but I'm sure that the height genes are much more complex. Could anybody give me an insight? Link to comment Share on other sites More sharing options...
Martin Posted September 17, 2005 Share Posted September 17, 2005 Have geneticists identified the alleles for the height phenotype? If I was just starting college I would be tempted to major in something related to human genetics. it is really interesting and I know almost nothing----all my life I've focused on other stuff. I wish i could answer, maybe some knowledgeable person will. I guess you know about the dominant recessive business. there might be four important genes involved with height and your dad in each case might have a mix of "tall" allele paired with "short" but in him the tall ones are dominant and get expressed, and the short ones don't get expressed and go along for the ride. but when sperm cells are made they DIVVY UP, they divide each pair and flip a coin, and that particular sperm could have gotten all his four recessive alleles that say "short" It is like tossing a coin and getting tails four times in a row. the probability is 1/16 which is small, but it can happen. and then that sperm goes and gets your mom pregnant and the EGG has half a set of genes made the same way by splitting each pair and tossing a coin so the EGG might also have the alleles that say "short" the combined fertilized egg has a full complement of genes and all four height genes say "short-short". I can see how that can easily happen all right. You say you have been explaining this to your Mom, this is basic Mendelian genetics I guess. I actually dont know how many genes are important in determining height----maybe it is four and maybe some other number----and maybe there are other factors besides genes. do they ever do genetics experiments (like mendel) in highschool? I somehow missed out on this. Or are there computer programs that let you SIMULATE genetics experiments? Produce mice with really big ears, and so on. Has your Mom had anything to say about it, after you explained Mendelian genetics to her? Link to comment Share on other sites More sharing options...
rakuenso Posted September 17, 2005 Share Posted September 17, 2005 genetics may play a part of the role, but the nuture part also has alot to do with a person's height. Calcium deficiency may greatly limit someone's height as its an integral part to bone development Link to comment Share on other sites More sharing options...
ecoli Posted September 17, 2005 Share Posted September 17, 2005 Calcium is just one thing. Things like coffee and cigarettes may also stunt your growth. (not supported, just something I heard). Genetics have a lot to do with it, maybe also the hormones they're injecting into catlle these days. Link to comment Share on other sites More sharing options...
Mokele Posted September 17, 2005 Share Posted September 17, 2005 Because humans have such a great variety of heights (even in countries like the US where we can assume there to be negligible malnutrition), I'd be pretty confident in it being a polygenic trait. Basically, you'd have, say, 6 loci (genes), and if you have 3 short and 3 tall, you're average. Of course, there could be many more than 6, and many more alleles than "tall and short" at each gene, but that's just an example to explain the concept. Mokele Link to comment Share on other sites More sharing options...
bengkulu Posted September 18, 2005 Share Posted September 18, 2005 Height is determinded by Multifactorial Polygenic Traits. Polygenic traits are determined by more than one gene, with each gene providing a small, but additive effect. Multifactorial traits are determined by interactions between a gene or genes and the environment, and do not exhibit Mendelian ratios. Polygenic Traits Are Continuously Varying. Polygenic traits usually produce a continuum of phenotypes. Individual genes of a polygenic trait follow Mendel's laws, but together do not produce Mendelian ratios. Understood? Link to comment Share on other sites More sharing options...
rthmjohn Posted September 19, 2005 Author Share Posted September 19, 2005 got ya, bengkulu. It's just as I figured, human height isn't a Mendelian trait, but oh well, I just hope that I'll reach at least 5'8" because I'm 16 years old and only 5'4" Just for the record, I didn't have a calcium deficiency last i checked... Link to comment Share on other sites More sharing options...
bengkulu Posted September 19, 2005 Share Posted September 19, 2005 John I just wanted to add that you should not be concerned with your height. You are luckier than you realize. There is a LOT of evidence that short men live healthier, happier lives than there taller counterparts. Besides, chicks dig short guys (honest!) Females feel much less intimidated by males of shorter stature and therefore are much more likely to approach them and get to better know them. This may be a evolutionary process(?) Anyway, shorter men will generally have more female friends than there taller counterparts and therefore have a wider selection of possible mates. You should look at being short as a good thing Isn't the understanding of genetics and evolution awesome? Link to comment Share on other sites More sharing options...
rthmjohn Posted September 22, 2005 Author Share Posted September 22, 2005 Thanks for the consolation Link to comment Share on other sites More sharing options...
ashennell Posted September 26, 2005 Share Posted September 26, 2005 The average height has increased considerably over the last couple of hundred years. I am always amazed when I visit castles or other old estates at the size of the medieval beds. They're tiny. This change is not genetic but to do with improved diet though. I'm sure a read that shorter people are less likely to be promoted to a position of management/leadership than their taller coworkers. Link to comment Share on other sites More sharing options...
druv Posted October 7, 2005 Share Posted October 7, 2005 hi everybody,, im new here. please welcome me.. this was some great information on calcium deficiency. One of the major symptoms of a deficiency of this important mineral are skeletal abnormalities. Osteopenia, osteomalacia, osteoporosis and rickets may all be caused by calcium deficiency. The bones act as a reservoir for calcium. When the amount of calcium in the blood supply dips too low, calcium is borrowed from the bones. It is returned to the bones from calcium supplied through the diet. When diets are low in the mineral, there may not be sufficient amounts available to be returned to the bones. Over time, this net loss can lead to osteopenia or osteoporosis. Other symptoms of calcium deficiency include :insomnia ,tetany ,premenstrual cramps and hypertension (high blood pressure) . Low calcium intakes have also been linked to premature births and some forms of cancer, including colon and breast cancer. how is this supplemented .. are these deformities reversible.. Link to comment Share on other sites More sharing options...
Royston Posted October 7, 2005 Share Posted October 7, 2005 Well the obvious supplement would be milk, however it's not a great idea to drink lots of milk if you're an *adult. I usually have a couple of glasses of skimmed milk a week. *I remember a case of a man dying due to drinking full fat milk everyday, he was only in his thirties and needless to say it was his arteries that simply couldn't take any more. Ashennell it's interesting you made the comment about managers and height, I was thinking just the other day how tall all the 'heads of' are at my place of work. Link to comment Share on other sites More sharing options...
rakuenso Posted October 9, 2005 Share Posted October 9, 2005 hmm I used to drink 4 cups of whole milk every day for about 7 years... yet my cholestrol levels are under normal levels... Link to comment Share on other sites More sharing options...
muhali3 Posted October 9, 2005 Share Posted October 9, 2005 John, what are your parents heights? I am having the same problem as you right now. I am 16 and i am only 5' 6" even though my genetic potential is 5' 9.5", my height has remained constant for the past eight months; my 14.0 year old bro is even taller than me. Height is predominantly determined by genes but nutrition, exercise, and amount of sleep affect it greatly too. Maybe these will answer your question. http://www.scienceforums.net/forums/showthread.php?t=9169 http://en.wikipedia.org/wiki/Growth_hormone http://www.scienceforums.net/forums/showthread.php?t=9425 http://www.unu.edu/unupress/food2/UID06E/uid06e18.htm Link to comment Share on other sites More sharing options...
The Spith Posted October 10, 2005 Share Posted October 10, 2005 I've drunk at least a pint of full fat milk each morning of my life and I'm 6"6. Although literally just this week I've switched to semi-skimmed as it contains nearly exactly the same amount of 'good stuff' with much less saturated fat. Link to comment Share on other sites More sharing options...
3eyeshedevil Posted October 10, 2005 Share Posted October 10, 2005 John I just wanted to add that you should not be concerned with your height. You are luckier than you realize. There is a LOT of evidence that short men live healthier, happier lives than there taller counterparts. Besides, chicks dig short guys (honest!) Females feel much less intimidated by males of shorter stature and therefore are much more likely to approach them. lol you right in some aspects, i have always gone out with short guys, my current boyfrnd is short, Link to comment Share on other sites More sharing options...
Royston Posted October 11, 2005 Share Posted October 11, 2005 hmm I used to drink 4 cups of whole milk every day for about 7 years... yet my cholestrol levels are under normal levels... Well that's good news, and I was referring to an extreme case...although the guidelines are no more than 2 cups a day. I think the guy was consuming 4 - 5 pints a day. You also said you used to drink this amount, cholestrol levels can be improved as I'm sure you're aware by swapping the types of fats you consume. Another reason is that breaking down lactose is harder as you grow up, so the consumption of milk should really go down as you get older. As mammals, milk is really only necessary in early development...although it's very rich in nutrients a balanced diet should be enough for an adults needs. Sorry that this is totally off topic. Milky facts...http://www.bbc.co.uk/dna/ww2/A817517 Link to comment Share on other sites More sharing options...
papia Posted October 15, 2005 Share Posted October 15, 2005 hi druv, That was some interesting info.. I really dont know and I think that deformities cannot be reversed but can be corrected , if possible, through surgical procedures. Well, I did hear my doctor mention about calcium gluconate injections for the treatment and prevention of calcium deficiences though they are aslo available in tablet both chewable and swallowing forms. One should keep a note of calcium gluconate side effects , though there are few but still the more common ones for injection form only are dizziness, heatflushes , irregular heartbeats, nausea or vomiting, skin redness, rash, pain, or burning at injection site, sweating and tingling sensation Link to comment Share on other sites More sharing options...
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