I'm a little confused with your post.
I can relate to what I think you're talking about in regards to "changes".
We're full of upgrades that might be necessy, but at the same time an inconvenience, or irritant.
An example might be places where there was free access for everyone, but because of public misuse, we now have to go through security. It's great that the problem of public abuse might be curtailed, but at the same time it might be a hassle.
The internet is another example. Right off the bat there seemed to be more unrestricted access to forums and social media websites. But again, because of user abuse, we find we have to register, or have to provide an email or cell phone# just to register. On the one it's an improvement. On the other, a hassle.
The evolution of the body, if there is such a thing may be similar. Afflictions may occur which are bad, but may also be a blessing in disguise if it stops us from abusing our bodies with unhealthy substances.
I'm not sure if you're talking about the physiology of humans as a whole, or simply changes of the body through aging.
Do you consider aging of the body as evolution of the body?