Hopefully these are in English. But I want to warn you this might take about 3-4 weeks. Much of modern biogeography would be absolutely rubbish under such an assumption. This is false on the face of it. Of course not.
Corn is a new species but teosinte is still in existence.
By your reasoning, today's existence of teosinte is proof positive that corn did not come from that grass. If you want another example, the grain triticale is a polyploid cross between wheat and rye. Of course not. That logic is flawed. Geology tells us that the odds of an individual being preserved are quite slim.