The JW Org stance has always been that Adam and Eve were crated a little over 6,000 years ago. As they try to make every story in the Bible literal, they believe Adam and Eve were real people and the first humans.
In which case they are in deep do-do, because there are buildings , which appear to be Temples, but certainly built by human hands , that are at least three thousand years OLDER than when A&E were supposedly created.
Scientists in any field do not merely " believe" what has been established , use of the word "believe" is deliberate by the Org and other Bible believers who are anti-Science to make it appear there is room for doubt.
There is no doubt at all that life on Earth got to be as it is today by Natural Selection, or if you prefer Evolution. No room for doubt.
What is not 100% proven , and probably will not be, is when the first true "man" Homo Sapiens actually appeared. We know it was hundreds of thousands of years ago possibly, or maybe a bit closer to our time, but as it probably was with most changes, it happened slowly, and with a few cases at first, there was no single point in time we can identify. But we DO know, and no room for doubt, that it happened at least 100,000 years ago, and probably much earlier.
Men and women like us have been around a lot longer than Bible Myths and Fables would have you believe.
With the original question there was the element of "should I tell the truth", I always think you should, if you are sure that the person will not react angrily, in a devastating way. But you cannot sacrifice truth to spare mere feelings.
Perhaps the best thing is to say " Why don't we have a look at what Wiki says together ?" JW Org does not disapprove of Wiki. Then when you get something like " Pfffttt, so that is what they believe is it ?" you can explain as I did above, that the Scientific Method results in Facts and Evidence that are Truth, no belief needed.