What are some of the ways in which the human species biologically evolved in the last millennia?
Great question. I think 1,000 years is an extremely short timeframe for genetic change caused by external factors such as disease, climate, population movement etc.
Overbiting – a large proportion of people have top teeth overlapping the bottom teeth. Even the wisdom tooth is considered to be an issue. The tendency now is to get rid of the wisdom tooth because fewer people have the jaw structure to allow for them to grow. People are born nowadays and they either never develop a wisdom tooth or develop them only as small buds that don’t affect the other teeths.
A few other ways in which human species changed include increase of many medical conditions that used to make reproduction extremely difficult (i.e diabetes); isolated people living in high altituted environments quickly develop changes in their blood allowing them to carry more oxygen.
In my opinion, some significant changes that happened in the last 1,000 years that are not necessarily on the positive side include the invention of insulin which allowed those with diabetes to live long enough to give birth to children. If the invention of insulin meant that there will be less people with diabetes, them having children would tend to cause a linear increase in diabetes in all developed nations from the mid 50s.
Another significant change has occured because the use of eyeglasses has spread more widely around the world. This was a more accurate method of correcting severe astigmatisms and deformities of the eye. In the past, people with poor eyesight were labeled as ‚blind’ and their chances of reproducing were close to none.
The three I have heard about are:
Ginger hair: a mutation in the MC1R gene causes red hair, freckles and an increased incidence of melanoma.
Bone density: One of the genes that governs bone density in human beings is called low-density lipoprotein receptor-related protein 5, or LRP5. Mutations which impair the function of LRP5 are known to cause osteoporosis. However, different kinds of mutations can amplify its function, causing one stronger and denser than average bones.
Malaria resistence: Italian researchers who studied the population in Burkina Faso found a protective effect associated with a different variant of henoglobin, named HbC. People with just one copy of this gene are 29% less likely to get malaria, while people with two copies present a 93% reduction in risk.