I understand that evolution occurred to form the current hominids from a common ancestor millions of years ago. As evolutionary processes take a long time, is there proof of evolution occurring with humans today?
Answer
Yes, there are examples. First: If you want to say, that humans and monkeys evolved, than it is better to say that they evolved from a common ancestor. This makes quite a difference.
If you are looking for examples of human evolution then one of the most obvious traits under evolutionary selection is pigmentation. There is a clear correlation with lattitude (and this UV-index):
The changes in pigmentation occured - seen from a evolutionary perspective - pretty recent when humans moved out of africa and to other regions (see here). See these papers for more details:
Other examples would be the tolerance for lactose (the sugar contained in the milk) in adults which arose during the last 5-10.000 years. Normally only babies can process these sugar which is contained in large amounts in the mothers milk. When they are weaned, usually the enzyme is not expressed anymore. However with the settling of the humans and the domestication of cattle this changed, so we can still drink milk and eat milk products without producing intestinal problems. See here for more details:
A third example would be the sickle-cell anemia, which happens due to a point mutation in the human hemoglobin protein. This causes an aggregation of the hemoglobin molecules in the red blood cells which then leads to a reduced elasticity (see here for more details). It also leads to a protection against malaria (most likely by the reduction of the life span of the erythrocytes). The areas with high prevalence of the sickel cell anemia in africa correlate pretty nicely with the distribution of malaria.
If you look further, you will find a number of different examples, where evolution is present after humans went through a genetic bottleneck (meaning the number of humans was drastically reduced).
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