Charlene McKenna (A.D.: The Bible Continues) has joined the cast of Lifetime's drama pilot The Clan Of The Cave Bear, from Imagine TV, Allison Shearmur Prods., Fox 21 TV Studios and Lionsgate TV. Written by Maleficent scribe Linda Woolverton based on Jean M. Auel's series of best-selling novels, Clan Of The Cave Bear draws from the first book. It takes place at a time in prehistory more than 25,000 years ago when Neanderthals shared the planet with the first early modern…