So this doesn't turn into a semantics argument we might want to address the specific operating mechanisms. If we disagree there, then we disagree. If we agree there then we may just be arguing semantics of the terms, "controlling, vs only operating", and "natural" which always bothered me as a term since I consider a human-made structure as natural as an animal's den.
First, a short sidetrack on the term, natural. I don't view humans as 'special' when it comes to the natural order of the Universe. On the other hand, there is nothing akin to our leap in technology in the rest of the animal world. The term, natural, is often used to mean, not human-made. And technology is usually considered all human-made.
So, getting back to natural selection pressures, until we start manipulating the human genome, which we are actually close to doing and have done so with plants, animals and microorganisms, Cuddles is more correct that we are affecting selection pressures, not controlling evolution.
The argument that affecting selection pressures is somehow unique in evolutionary terms is questionable. Animal migration affected past selection pressures. If you consider one mechanism of affecting selection pressures, you'll have to come up with a definition that distinguishes one means of affecting selection pressures from another than simply saying human-affected.
And, the statement, "mankind's ability to reproduce is no longer controlled by natural selection", while it supports the claim that humans have an affect on evolution, the statement is a long stretch from saying, "natural selection was [no longer] 'controlling'" evolution. A few in-vitro fertilizations and medical interventions which allow reproduction in a group of people who without technology would not have lived to reproduce hardly changes the balance of power in what/who is controlling humankind's evolutionary path.
What leads to the misconception we are currently having some huge impact on human evolution with our modern medical abilities is the false assumptions made on how fast evolution actually occurs. In microorganisms, evolution is very fast. In the collective human genome, it is incredibly slow.
Take for example the thousands of years it took for humans who migrated to higher latitudes to develop lighter skin. People of all skin types have now spread out around the world. Do you see light skinned Europeans in Australia giving birth to darker skinned children yet? No, you see an epidemic of malignant melanoma in light skinned Australians. It will be many many generations before natural selection pressures affect the evolution of skin in newcomers to Australia.
Are we affecting the selection pressures? Yes. People can wear hats, use sunscreen and get early treatment thus surviving melanoma.
I understand how one can make the semantics argument that is controlling evolution. But my view is that statement is far to big a stretch to describe the current impact humans are actually having on our evolutionary pathway. Affecting it, yes, controlling it, no way.
My poor kids all got my bad eyesight, and my allergies would have killed me long ago if it weren't for interventions. Ah well. Makes me appreciate my good fortune all the more to be living nowadays.