The ubiquity of search engines has affected our ability to memorize. If people can easily look up information on their computer or phone, they are a lot less likely to learn to memorize things. Technology has led people to become lazy in the modern world. People should rely less on computers.
Search engines are affecting our ability to memorize much in the same way that calculators affected the way we did math. It's not that we become dumber thanks to the technology, it's simply a logical shift in priority regarding what is worth remembering. Why burden your brain with details when the computer has them in a permanent file?
Memory can be improved with practice but not necessarily - people have innate memories, and having ready access to information does not change this. People are most definitely memorizing things less, and people are less inclined to write things down to remember things, but this doesn't relate to the ability to do so.
No, using search engines does not affect our ability to memorize, because people generally don't search for things that they already know. People still memorize websites. They go to them directly when they know they want to go to the page. You use a search engine when you don't know what page you want to go to, or you just want general information.
Using search engines does not affect our ability to memorize. This is because of the fact that the human brain is amazing and capable of memorizing many things regardless of using a search engine. A search engine is not a drug or something that will affect our ability to memorize.