Is Height Genetics Only, or Nature Also Plays a Role?

I come from a family where we have both Giants, Average height, and Short people. This is a combination of extended family including cousins, nephews, nieces, uncles, aunts, and grandparents. With this mixed range in height, I begin to ask myself if height or genetic or there is more to it?

In our world today, the average female is 5 feet 4 inches (5’4”), and the average male is 5 feet 9 inches (5’9”) but this hasn’t been how it had always been. About 3 million years ago, our ancestors Australopithecus was only about 4 feet tall and we have since increased in height. About 1.5 million years ago our more recent ancestors Homo Erectus reached up to 5 feet 6 inches (5’6”) and about 30 thousand years ago, men of the Gravettian Hunter-gatherers were about 6 feet (6’). Historically height records were majorly males because of reasons like inequality, sexism, patriarchy, and chauvinism.

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At the beginning of agriculture, when men in europe swithced to high grain lower protein diet, men lost 8 inches of their height on average and so in the 18th century, the average european man was 5 feet 5 inches (5’5”) tall but this height changed a little to 5 feet 8 inches tall when they migrated to America. It wasn’t like it was all rosy for height in the US as there was a crash in height during in industrial boom as a result of diseases and overcrowding but this changed soon after followed by a spike in the height.

With everything I have mentioned, does it not look pike our environment has a big role to play with how tall we are but then when you look at different families in different parts of the world, it shows that genes also have a big role to play. In the early 19th century, height was associated with wealth, where it was seen that rich people were taller than short people.

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In identical twins, they are genetically identical while fraternal twins can be very different genetically just like any other siblings even when they are the same age. When genetically identical twins are separated, growing up in very different environments they can tend to grow in height, but their height isn't the same thing showing that genes only have a part in height but it doesn't make up the entire things but this doesn't mean that gene plays a small role, A study in 2007 examined twins height in DNA for over 11,000 twin pair, and found that 86% of height variation can be explained by genetics.

Scientists have found over 12000 genetic variants influencing height. Genes such as HGMA2 only make small contribution in height for tallness, and it can be about 1/8th of an inch and this is similar to almost all 800 known genes for height. In fact, the 800 known genes can only account for 27% of height variation so this means that there are a lot of genetic influences that we do not know.

Asides from genetics, our environment, certain diets, help in shaping our height, and ones diet in childhood is important in shaping our height as we become adults. Some scientist agree that both nurture and nature affect our height and some propose that height is an omnigenic trait influenced by all our genes.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4961475/
https://ourworldindata.org/human-height
https://www.cdc.gov/nchs/data/series/sr_03/sr03_039.pdf
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10368389/
https://pubmed.ncbi.nlm.nih.gov/17924350/
https://www.cell.com/ajhg/pdf/S0002-9297(07)63884-1.pdf
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https://answers.childrenshospital.org/genetics-height/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5116096/