Humans are actually growing taller at record speed if you like, so they have increased quite a lot in the last two centuries and that’s a matter of fact across the globe, actually. So for males between around 160 centimetres to 170 and for females from 150 to around 160. In total, we can say that the average adult today is around five percent taller than their ancestors used to be 100 years ago. – Dr. Eirini Marouli (Lecturer in Computational Biology Queen Mary University of London)
The incredibly steep rise in height is generally thought to be driven by better health and diet standards. But in Holland, where a 20 centimetre increase has been recorded in the last 200 years, something a little extra may be going on.
The Dutch growth is a very good example of human evolution in action. Average height women had higher fertility compared to both shorter and taller women, and that taller man had higher fertility compared to the shorter men. – Dr. Eirini Marouli (Lecturer in Computational Biology Queen Mary University of London)
Does that mean we’ll keep getting taller forever?
At the moment, Latvian women and Dutch men are supposed to be the tallest individuals on the planet that they could be actually representing the limit that we could reach. The differences in average height are due to genes and these are also different depending on the population that we are talking about. But also different environments, lifestyle improvements in height and social economic status. Actually, it’s a combination of both. So height could have actually reached its limit, but only time can tell. And I would say it’s a kind of a wait and see game.
This all begs the question, why are scientists so interested in studying height in the first place?
Height is a model trait for all the rest of the complex genetic traits, because it’s very easy to measure. So if you could master genetics of a complex trait like height, that might give us actually the blueprint of start the other multifactorial disorders such as diabetes, heart disease, and so on.
In most recent obvious study from the Giant(Genetic Investigation ANthropometric Traits) Consortium, we have identified a bit more than 3,000 genetic variations, genetic modifications, DNA changes that affect human height. And if you had this genetic change, it could actually increase your height by up to two centimetres. Many of these DNA changes are also located in or close to genes that are involved in bone biology and skeletal growth.
And some also said biological processes that modulate actually height, because it’s quite interesting how we go from a small baby to an adult with an increased height. That’s one of the very interesting and complex questions that we haven’t completely answered up to now. And identifying a gene that is located in the pathway, for example, of growth factors in the blood, that can give quite a lot of new insights into therapeutic strategies to treat growth failure. It affects, let’s say, three to five percent of the population, and that could also inform treatments for other common diseases. So that’s quite important.