Are humans subject to evolution

Answer 1

Yes. Although perhaps not to the same extent that other species are subject to evolution. Today, mankind has an unprecedented control over its environment, and an unprecendented ability to travel, to make genes spread over the whole world. But this is a recent development, and there have been millennia in which humans were far less able to adjust their environment to suit their needs.

As an example of human evolution, one could point to the spread of lactose tolerance in adults. Historically, mammals suckle when they're young, but no longer tolerate lactose in their adult forms, as their production of lactase, the enzyme used to break down lactose, declines. However, since humans developed agriculture and were able to keep and exploit cattle - some ten to fifteen thousand years ago, lactase persistence has spread from various populations in the world. When one projects the incidence of lactose tolerance in adults against the permeation of agriculture, one can easily see how this trait propagated as a result of natural selection.