Nova (PBS, 8-9 p.m.): Wooly mammoths - hairy cousins of today's elephants - have been updated.
Until recently, scientists thought the fascinating paleolithic creatures had died out in the last ice age, about 10,000 years ago. But recent discoveries suggest they were still around as recently as 4,000 years ago. Paleontologically speaking, that's breaking news - the Pyramids, for instance, were already hundreds of years old.
``Mammoths of the Ice Age'' - the latest edition of the noted science series - explains how mammoth teeth found on Wrangel Island off northeastern Russia turned out to be much younger than they should have been - if the animals had really become extinct in the last ice age. The program says these mammoths - a dwarf population about one-third the size of their forebears - nearly avoided extinction.
Why they didn't survive, despite superb adaptation to their arctic environment, is one of the questions probed by the show. It may have a been a warming trend they couldn't handle. It may even have been human hunters migrating through the area into the Americas, although many scientists dispute this reason for the mammoths' disappearance. In any case, the mystery has meaning for some of today's species, including the elephant. * WEDNESDAY
Fangs! (The Discovery Channel, 8-9 p.m.): If the title with its exclamation point doesn't deliver the message, let me explain that the focus of this new anthology is sharp-toothed creatures - leopards, hyenas, sharks, and more.
Each episode describes how a species - facing extinction in some cases - deals with the unique challenges of its environment. The show goes all over the world to view these animals as they hunt, raise their young, and otherwise cope.
The opener, ``Secret World of Bats,'' with Stacy Keach as host, was shot on five continents to reflect the amazing diversity of these often-misrepresented creatures.
Please check local listings for these programs.