Genomics, for the dorks

Off Topic
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Ok, I don’t want to take over thalove4u’s thread, and some people asked about genomics. Here’s some stuff. This isn’t nearly everything there is on genomics and the differences between anyone and everyone. Feel free to ask questions, and I’ll answer them as best as I can, and hopefully some others will too.

Here’s a link to just one article. I don’t want to link tons of things.

Ferrell et. al., Frequent Sequence Variation in the Human Myostatin (GDF8) Gene as a Marker for Analysis of Muscle-Related Phenotypes. Genomics, Vol 62, Issue 2, Dec. 99, p 203-7.

You can look it up on Pubmed and search for “Myostatin and race”. It was the 3rd article to come up for me. You may only get the abstract, but that should be enough to understand and extrapolate what I said in his thread.

So basically, in terms of the human genome, it has yet to be MAPPED. It has been SEQUENCED. There is a hyoooooge difference, like natural competing vs a 'roid freak. Sequenced is just getting all the ATCG’s in their respective orders. After doing this for the # of base pairs that humans have (I can’t remember off the top of my head), you have to look for Open Reading Frames, or ORFs. ORFS may encode for a specific protein or numerous proteins via different post-translational (post-protein making) methods. If we weren’t all genetically different, we’d all look alike and have the same underlying traits, seriously. It would be like a world of incest. Mix-breeding between non-related people is a good thing due to everyone having different genetics (same reason why buying a mix-breed dog is good). Having different alleles (different genes encoding for the same type of thing, such as eye color, skin color, etc.) and having different non-specific mutations is what makes us different and unique. Of course there are only so many alleles for a specific parental phenotype, and cross-breeding increases the chance of survival of that specific phenotype, granted that is advantageous to the individual and their offspring.

Here’s an evolutionary explanation:

Europeans (caucasians) have historically been docile and settled. They have traditionally have had no need to be nomadic, due to the crop-loving land they live on. Caucasians have also historically lived in colder climates, which is why they are shorter and in most cases fatter. This is to keep heat in their bodies better. This is also beneficial in crop gathering, due to the fact of constantly bending over and picking things up. Think about when you are trying to sleep and you are cold. You tend to curl up in a fetal position to increase overall body warmth due to the nature of heat + heat = more heat. Trying to stay tall and straight while cold will only allow more latent transfer of heat to the surrounding air, and if you know about air and thermodynamics, it takes a lot of energy to heat it up, hence the use of double pane glass windows which keep housing units more energy efficient.

Africans (people of “black” descent) are historically taller, leaner and more muscular. They are taller for all the reasons caucasians aren’t - Africa is naturally hotter than Europe. In order to cool off more, they are taller, which means more surface area, which means cooling off faster, just like the cold while sleeping analogy, except it’s the hot while sleeping analogy. Africans are more muscular for exactly the opposite reasons caucasians aren’t. The area they are descended from has been hot, decrepit, and dry, which means horrendous farming practices. For this reason, they had to hunt more for food sources, hence the nomadic nature. In doing so, they required more muscle and less fat (leanness) to move swiftly and silently as they approach their prey. Of course, there were always nuts and berries to eat during certain times of the year, but those aren’t nearly as filling as a nice lion or gazelle.

So there’s the nutshell of genomics.

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JW: you’re a nerd. jk.

I agree with everything you just said about population genetics. I took an anthropology course in undergrad and this reflects the current thinking. Fitness of an organism and survival of alleles that give a phenotypic advantage are well established explanations for the variances we see in humans. The greater the surface area a person’s body has, the more efficient it is at dissipating heat. Longer limbs = more skin. Eskimos are short and squat to conserve body heat. Word.

I’ve always been amazed by the fact that skin color is nothing more than a geographical adaptation. We know that melanin is the pigment that protects us from the sun, and the closer to the equator, the darker the skin. But now that we as humans have the ability to travel and live where we want, who knows what will happen with the genotypic shuffling that results when people are no longer limited to one area of the world. Sure, any noticeable changes would take hundreds, if not thousands of years, but I always wondered how different life would be if there were only one race. It’s bound to happen once the entire world becomes industrialized and everyone has the ability to travel, but we’ll probably blow up the planet before that happens anyway.

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Excellent post. Makes sense. Call me a genre selector, but there must be no statistics for endomorph, mesomorph and ectomorph population composition (percentages) for the populations mentionned, eh?

Based on that theory, you would have a population more concentrated toward the endomorph frame to the north and the more and more ectomorh as you go south.

A similar gradient must also exist for eye/hair color. I mention eye because at start I thought hair color was the major determinant in link with sunlight tolerance (sunburn) but somebody pointed to me that I needed to look at eye color. Brown eyes generally have a better predisposition towards sun than blue eyes. And that also could explain the case when I saw a copper (read: penny) skinned natural redhair.

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Dan-

The gradient for hair and eye color does exist. It goes along with skin color. I just got done working in an ophthalmologists lab and he worked on uveal melanoma, which is just melanoma of the inside of the eye. It’s fairly rare, so you don’t see it that much, but we got to talking about the racial implications of it. He said that usually, caucasians will get it a lot more than africans get it. This is due to the pigmental differences in our eyes (caucasians are blue, green, grey, etc and africans are usually brown, hazel and near-black) Obviously, if the skin is darker, it protects a person from skin melanomas. The same goes for an eye, darker is better protected from melanoma. He also said that africans tend to have shallower eye sockets and they can pop their eyes out more than caucasians can. That was just a weird tidbit.

There was a great post about steroid testing in the steroids forum by lats2dope. I can’t give him credit for it because he took it from another site, and he said he would. Anyways, in that post, it related hair drug testing of caucasians to africans, and since africans naturally have more melanin in their hair, 2nd hand and 1st hand drugs tend to “stick” to their hair a lot better than caucasians. Never knew that.

Honestly, I don’t know that much about gradient differences in terms of Asia, as in why Asians tend to have flatter faces and skinnier eye openings (don’t mean to offend any Asians). I do know why Asians tend to be shorter though. This is due partly to their historical diet of rice. Eating tons and tons of rice is good, but it lacks sooooo many key nutrients that they just don’t make up for. Being nutrient deficient will cause a person to have stunted growth because they have nothing to use to grow. Nowadays you see a lot more asians that are a lot taller, and this is due to the fact of better nutrition and just genetic luck sometimes.

I want more questions please. Seriously. If you have a question about this, I’ll try my best to answer it. We’ve all questioned african vs. caucasian stereotypes before. I will try to explain them if you please.

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SNiPs

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JWright-
This may be slightly off but it came up this weekend and wanted to get your insight. Someone was telling me that we are all evolutionarily disposed to binge on carbs because in cave man times we were mainly hunters and when we did stumble across certain carbs we would chow on them until we exhausted the source. Any validity to this?

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SNP’s - Single Nucleotide Polymorphisms. This is used in discovery of important regions of DNA in terms of start, stop, promoter, enhancer etc. Say you have a 100 base pair (bp) sequence and you want to know what nucleotides are crucial for getting that 100 bp fragment to be translated. Well, you go down the line with all 100 bp and change every single bp, one at a time, and determine if your sequence still works. You will get something like a bar graph detailing all 100 bp and how much transcription was up or down regulated after mutation. You have to start out with a baseline of the original 100 bp first, then determine regulational regions relative to that baseline.

Cavemen - first, you have to think about different times of the year and different plants of the year. Each plant will have a different blooming time relative to other plants. So all plants will bloom at some time or another during the year. Some years see better yields than others, in terms of just natural production. So for instance, during the spring, lets say 75 out of 100 plants will bloom. You’re going to have tons of food to eat. If you eat all of an apple, it’s not all carbs. There will be protein and maybe fat in it. But of course, you only eat the sugar part of it because the core contains cyanide, hence the horrible taste. So if you eat tons of apples, you will gain weight, obviously. So basically, at that time, you don’t want to stop hunting though, albeit you briefly cease doing so because you have an abundance of fruit/nuts for certain periods. Basically, they shouldn’t gain a ton of weight because their metabolism is out of the world, due to the incessant hunting/running/dragging prey, etc.

This is why they were called hunter/gatherers and not just hunters or just gatherers. You ate what is available at the time. If it is carbs, you eat carbs. If it is protein/fat, you eat that. You also have to remember that a fat person was a sign of a well-fed person, which meant good hunter/gatherer, which meant more offspring because of the “attraction” of survival of the fittest. Nowadays, we know this to not be true due to disease, genetic defects, etc. So in essence, you could eat what you could get your hands on.

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While the rest of y’all are having this genomic love fest, I’ll raise a dissenting voice.

This is some of the stupidest stuff I’ve every heard put forth in the name of science. European farming requires stooping while African farming doesn’t? On the average Africans are taller than Europeans? I don’t know where you live, but I’m Alabama where there are plenty of “African Americans”, and I’m in a “New South” kind of town so I’ve got plenty of African friends and lots of friends from the Carribbean Islands. There are no appreciable differences.

You know one of the theories I heard put forth under of the name of genomics, and it’s consistent with the same logic you’ve presented here, is that Africans have bigger dicks because they’re in a warmer climate and they don’t shrink up like the Europeans in a colder climate. Yeah, right. I’ve been in enough lockerrooms to know that one ain’t true either.

And Africans are more muscular because they’re in the sun more? Ever heard of the Highland games? Seen pictures of the original Greek Olympians? Watched the burly powerlifters from Slavic countries? There are plenty of examples of muscular Europeans.

I think you’re confused. It was SuperMan who benefitted from being exposed to the warm sun of Planet Earth. That’s how he got his powers. Oh, wait. That was fiction. . . . And so is all this genomic crap.

PEACE!

G

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And how do you explain the existence of pygmy tribes in Africa?

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“Caucasians have also historically lived in colder climates, which is why they are shorter and in most cases fatter. This is to keep heat in their bodies better. This is also beneficial in crop gathering, due to the fact of constantly bending over and picking things up. Think about when you are trying to sleep and you are cold. You tend to curl up in a fetal position to increase overall body warmth due to the nature of heat + heat = more heat. Trying to stay tall and straight while cold will only allow more latent transfer of heat to the surrounding air, and if you know about air and thermodynamics, it takes a lot of energy to heat it up, hence the use of double pane glass windows which keep housing units more energy efficient.”

If you live in a cold climate i.e. russia, nothern europe, ect. you dont not need to pick crops and all that fun stuff because they do not grow. This could be the reason why many-a-tall men come from these areas? Also tall men w/o the use of weight (pre weight lifitng)tend to be stronger and faster than shorter people. These people (taller) might have been better hunters and did not need to crawl up into the fetal position becaue they had some extra skin from that buffalo they just ate laying around. Just some food for thought.

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If I remember correctly, pygmy tribes have some mutations that make them short. The same reasoning applies to the myostatin gene. There are appreciable differences in all of us.

I went to a 60% black high school and yes, there are appreciable differences. Compare an african person and a caucasian. There are differences, such as skin color, hair color, hair type, eye color and genotypic differences that can only be read using sequencing. Besides, I was comparing average people. If you don’t understand that, then that’s your fault. Yes, there are less muscular africans and more muscular caucasians. I was also comparing most of africa, which is not the greatest of farmland, to Europe, which has excellent farmland. It’s AVERAGES.

If you don’t understand it, read some journal articles on the differences between us all, such as the one I posted in the first post. There are appreciable differences in all of us. Without acknowledging these differences, we will never make progress.

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Oh, and penis size doesn’t really relate to warmth. Sure, it shrivels when it gets cold, but what really matters is the temperature of your scrotum. If I remember correctly, it should be 5 degrees cooler. Is this right, Scrub? Anything shrivels when it gets cold, so penis size has nothing to do with relative warmth.

There has been another theory on why africans have bigger penises than their caucasian counterparts. It has to do with the size of the vagina of the african women. African women tend to have larger (read: deeper) vaginas, so in order to impregnate a woman with better chances of having offspring, the male would need a larger penis. Personally, I’ve never measured a woman’s vagina, so I wouldn’t know about that stuff.

About the pygmy tribes, here are some journal articles to look up.

Coia, et. al. Variation at 10 protein coding loci in the Mbenzele Pygmies from the Central African Republic and a comparison with microsatellite data. Am J Human Biol. 2002 Jan-Feb;14(1):9-14.

Destro-Bisol, et. al. Microsatellite variation in Central Africa: an analysis of intrapopulational and interpopulational genetic diversity.
Am J Phys Anthropol. 2000 Jul;112(3):319-37.

Bruges Armas, et. al. HLA class I variation in the West African Pygmies and their genetic relationship with other African populations. Tissue Antigens. 2003 Sep;62(3):233-42.

G-dawg, hope that satisfies your curiosity. Next time, don’t just provide circumstantial evidence with no scientific basis. What I provided has been studied numerous times and is still being studied.

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Africans have bigger penises because they wear boxers and Caucasians are smaller because they where tighty whiteys.

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G Dawg: you might want to compare your sample size (a region in Alabama) to the sample size used to PROVE all of this genetics crap (the entire planet). Sorry bud, it’s all true and backed by science. I’ve never heard the part about bending over to pick crops, but statistical observations of body compositions across geographic regions are not someone’s opinion. Just because you know a tall person form Antarctica doesn’t mean that what JWright is saying isn’t true. It’s simple really. The skin is an organ that forms a barrier, protecting us from UV radiation, and also involved in regulating body temperature. It’s all about survival of the fittest in certain environments. If the environment is hot, those individuals with more body surface area can blow off excessive heat. Those with less surface area conserve body heat.

As far as the scrotum question, sperm cells thrive in an environment that is slightly cooler than the body’s 98.6.

I don’t really spend time studying penises, so I don’t have much to contribute on that one. I do have an Asian friend who tells me that Asian men are generally lacking in that department. I hope to show her mine sometime soon, so maybe I’ll have more feedback at that time.

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Not to skew the debate too much, but for the guy who uses African-Americans as a sample for blacks, may I remind you that this sample is not representative.

Without pulling out too much history, everybody know only the strongest of them survived the trip to the USA.

Always take the strongest and/or more apt to survive, and youve got time-compressed survival of the fittest (read: natural selection) at work. Since that selection was mostly based on physical attributes, I would not be surprised that out of 100 people in black and white skin tones in America, the African-American will automatically have better average results in everything physical (like we didnt already know that, duh, I know).

Just my 2 cents. In no way does this invalidate what was said for bigger population.

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I think the sperm likes 78.9 degress or something. or 86.

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Actually, Dan, that would be considered a “bottle-neck” effect. It’s like taking tons of people, and the weak die, leaving on the strong to survive in a short period of time, allowing for the strong to reproduce more offspring, hence a better “crop” of offspring.

Some people just don’t understand science because they can’t see it firsthand. I don’t understand other cultures because I can’t be around them, but I don’t bash it or say it’s dumb. For instance, a girl in my lab is from Cyprus, which is half Turkish and half Greek. Well, she’s on the Turkish side, and I’ve never met anyone from Cyprus or Turkey, so I want to know all about it. Just makes me a better person.

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What DAN C said. Thank you.

Also, if you guys think that genetic and/or evolutionary changes need to take millenia to be accomplished, you need to read a book called The Beak of the Finch. It explains very clearly why evolutionary change can - and does - take place across just a few generations.

If you want a better-known example, just look at the moths in London during the 1800s. First they were white, then - as the city became more polluted - they became darker and darker, finally becoming totally black. This took place over a couple of decades, not centuries. And then, as pollution ordinances got stricter, they changed back to white. Again, within a few dozen years, not hundreds.

So comparing a Southern American black person to someone who’s actually from Africa isn’t really valid.

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Char-dawg,

The problem with looking to animals for lifespans and comparing them to humans is a big one. You made a good comparison on moths, but how long do they live? Months, maybe at most. You have to look at generations instead. Let’s say that they reproduce 4 times a year. Take that over 30 years, and that’s 120 generations. Assuming that a human will generate new offspring at 25 years old, 120 generations would be 3000 years. Comparing us to animals does prove many valid points, but we also have to consider generational lifespans.

I haven’t read Darwin’s books, as they were extremely boring to read (I tried to, I swear), but I have read a lot of other evolution stuff. I didn’t really care to do so as I wanted more molecular biology, but it stuck with me. Nowadays, we are using Ribosomal RNA for evolutionary tracking, and that’s some cool shit, because it is so extremely conserved over thousands and thousands of generations. Any little change will signify a big event.

Char, you were exactly correct in comparing a African-American with an African. I have friends from Ghana, Cameroon and Kenya, and they are totally different than my African-American friends. Just their overall looks, skin tone, etc. Completely different.

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Hypothesis: A tentative explanation for an observation, phenomenon, or scientific problem that can be tested by further investigation.

Theory: A set of statements or principles devised to explain a group of facts or phenomena, especially one that has been repeatedly tested or is widely accepted and can be used to make predictions about natural phenomena.

Speculation: A conclusion, opinion, or theory reached by conjecture.