on animal species can survive indefinitely on earth. Centuries ago species went extince from natural causes for example they were unable to adapt to bad weather and other diffcult condition.Howrver animals are now dying out faster than ever because of hunman activity.it is estimated that until the 18th century one species disappeared from the earth every four years.By the 19th century this had increased to one species per year By 1975 it was 1,000 species per year, and today animals are disappearing at the alaming rate of more than 40,000 species per year.