Ben Stein says …

… nobody’s ever seen an individual species evolve! – interview on Fox & Friends, no date

Darwin was never able to point to any clear evidence of any species that had originated by evolution. And there hasn’t been much progress in Darwinism since then. – interview on the Glenn Beck show, November 13, 2007

Despite the fact that no one has ever been able to prove the creation of a single distinct species by Darwinist means, Darwinism dominates the academy and the media. – blog entry “Darwinism: The Imperialism of Biology?”, October 31, 2007

Nicholas Covington answers

Scientists have now directly observed new species evolving (http://www.talkorigins.org/faqs/faq-speciation.html). Recently a scientist performed experiments which show that new species of stick insect originate from small adaptations to their environment via natural selection (http://www.sciencedaily.com/releases/2008/04/080402071538.htm). Scientists have also studied a new species of mosquito which evolved in the underground tunnels of London (http://www.nature.com/hdy/journal/v82/n1/full/6884120a.html). Obviously there has been a lot of progress made in the field of evolutionary biology.

and Christopher Petroni adds

There are two major problems with this statement.

First, the reason that speciation is rarely observed is that it takes time. A lot of time. For example, the closest living relatives of humans are the chimpanzees and the bonobos. We share 96-98% of our genome with chimpanzees, yet our most recent shared ancestor lived 5-7 million years ago. If it takes as much as 5 million years for that much change to accumulate, how can Ben expect to observe speciation in his lifetime?

This leads to the second problem with Ben’s statement. Despite the limitation imposed by the immense time scales involved, speciation has been observed many times. For example, Dobzhansky and Pavlovsky (1971) noticed that a strain of fruit flies they had been breeding became unable to produce fertile offspring with other strains of the same species. In effect, this strain had become a new species of fruit fly, right under the researchers’ noses. There are many other observed instances of speciation.

So yes, Ben Stein, many people have “seen an individual species evolve.”