Why have creatures evolved as they are? Which species have been the most successful? How do life forms adapt to a world dominated by nearly seven billion humans? Christopher Lloyd leads us on an exhilarating journey from the birth of life to the present day, as he attempts to answer these fundamental questions. Along the way, he reveals the stories of the 100 most influential species that have ever lived, from slime, dragonflies, and dung beetles to dogs, yeast, and bananas. These 100 species are scored and ranked in order of their impact on the planet, life and people. "What on Earth Evolved ...in Brief?" is a lively and eye-opening insight into mankind's place in nature, and our pivotal relationship with the Earth itself: past, present and future.