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MonkeyDLuffy
07-07-2020, 10:40 AM
Came across this neat video today, as I have always been curious why I am so tall, the tallest in my family so far. Grandfather was 6'2", Dad 6, myself 6'5.5" and brother 6'3".


https://youtu.be/0cuO5OSDMbw

drobbah
07-07-2020, 11:17 AM
It definitely is genetic but it isn't easily predictable by looking at the height of the parents.My parents for example are 5'9 & 5'6 but my brothers are all above 6ft & above except for me (5'10).My grandfathers were 6'0 (father side) and 5'11 (maternal grandpa).My female cousins are all my height lol with the men generally being above 6ft.This height in my ethnicity probably came from our Dinka ancestry and thousands of years of natural selection.

RP48
07-07-2020, 02:14 PM
Everything is genes plus environment.

Riverman
07-07-2020, 02:26 PM
Everything is genes plus environment.

That's so true. For traits which can vary depending on the situation and whether an optimal environemnt is given, what's inherited is a potential. This potential won't ever be realised 100 percent, but it can be completely ruined or it can get closer to 100 percent, the maximum achievement. This is true for traits like health, attractiveness, intelligence, height, strength, speed etc. A very bad environmental influence, like a disease, serious malnutrition or accident, can completely ruin any of this, and usually nobody will realise 100 percent of his/her potential. But depending on the environment you might get closer to 70, 80 or 90 percent usually and of course, the upper limit and what kind of environment you need to achieve a higher level is genetic.
So for some people even a simple factor like nutrition might work - genetically determined - in a different way. Like its possible that some people realise less of their growth potential if their diet is not high in proteins and energy, while the same environmental factor might cause less of a reduction in others. Its also known that hard physical stress and work can reduce height, not just the diet. So if someone has a bad diet, a hard, physically demanding life and an additional disease, he would be usually significantly shorter than a twin brother in which all this would be not as bad. Yet how they both react to the stress factors or optimimised living conditions is strictly genetic.

jstephan
07-07-2020, 02:41 PM
DNA Switches (https://www.ncbi.nlm.nih.gov/books/NBK26872/), basically, your body decides what you need or not to survive in your current environment !

Other article : https://news.harvard.edu/gazette/story/2017/12/harvard-study-identifies-genetic-switches-that-affect-height/

jstephan
07-07-2020, 02:48 PM
Another interesting question is how humans are going to evolve in the future, do we still need to get taller and taller, or did we already reach the limit, or are we going to decrease in size over the next generations ? Difficult to predict because humans are now over control of their own evolution.

Adam A
07-07-2020, 03:09 PM
It definitely is genetic but it isn't easily predictable by looking at the height of the parents.My parents for example are 5'9 & 5'6 but my brothers are all above 6ft & above except for me (5'10).My grandfathers were 6'0 (father side) and 5'11 (maternal grandpa).My female cousins are all my height lol with the men generally being above 6ft.This height in my ethnicity probably came from our Dinka ancestry and thousands of years of natural selection.

Similar here. My dad was 6'1 at his tallest, maternal grandfather was 6', brother is 6' pushing 6'1, i'm only 5'11. My maternal grandma is tiny, only about 4'9 right now so there's a chance that's got something to do with it

Kulin
07-07-2020, 03:14 PM
It is genetic but also related to environmental factors, the most important of which is diet. Lot of populations have had growth spurts over the past century, while others still face significant amount of malnutrition (esp in S/SE Asia & Africa) which have stunted their growth.

Riverman
07-07-2020, 03:32 PM
It is genetic but also related to environmental factors, the most important of which is diet. Lot of populations have had growth spurts over the past century, while others still face significant amount of malnutrition (esp in S/SE Asia & Africa) which have stunted their growth.

I think that the places and social groups were this is as significant as it was even 2 generations ago is drastically shrinking. Yet I saw, to illustrate the pattern, two brothers from India of which one was adopted as a kid by a Western family, the other living in a very destitute, extremely hard environment of malnutrition and hard physical work in the tropical part of the country. Remind you, both even shared the same prenatal influences, yet they looked almost like two different races and the Western grown brother really towered the other and he was much more European looking as well. But the difference is really shrinking with a growing majority of Indians getting closer to the Western living standards for the factors that really matter.

MethCat
07-07-2020, 04:51 PM
Imagine having to ask that question when the answer's that obvious.

Of course its partly genetic, to what extent is maybe not entirely known though. Pygmies are shorter than non-Pygmy Africans for a reason, its not because they're just terribly fed.

gudar
07-07-2020, 04:58 PM
bro i think apart from genetics, fertile plains people are well fed and have more variety of food available due to being agriculture society and i often see correlation among this , people of central punjabi pak are more robust and taller then other areas even if they are from same biradri or gotra

same i read punjab is tallest state of india but i also read some south indians can be very tall as well

https://i.imgur.com/LbBQnJV.png

Riverman
07-07-2020, 05:18 PM
Imagine having to ask that question when the answer's that obvious.

Of course its partly genetic, to what extent is maybe not entirely known though. Pygmies are shorter than non-Pygmy Africans for a reason, its not because they're just terribly fed.

The funny thing is this might be, ultimately, the reason for them being so short. The short term effect of malnutrition is phenotypical, the long term effect genetic, because selection will usually work in the direction of the environmental pressures on individuals. Like if people constantly drink large amounts of raw milk, they don't necessarily get lactase persistent at all, but the pressure will be build up to favour individuals which can. The same game can be played with every outstanding trait, like breathing in high altitude or diving deep in the sea, running fast or long and so on. First there is a way of life, then there is the selection which changes the genotype.
In the same way bad nutrition will favour people which can survive, fairly healthy, just like that, with a bad diet. If the living conditions improve again, and there is competition which favours large males, they will get larger (again), if having the chance to and not being replaced before.

Magnetic
07-07-2020, 06:10 PM
yes and nutrition + some other factors like if you slept enough or if you played basketball etc. while in puberty xD

Caius Agrippa
07-07-2020, 06:55 PM
I think so, based on what I read I think individual height is 70-80% genetics and 20-30% environment. That can change on a populational level though because many other factors are involved.