Although more than a million animal species have been described, the actual number may be closer to 10 million (according to http://texasnature.blogspot.com/2003/10/how-many-animal-species-exist.html) Institution entomologist Terry Erwin estimates there may be 30 million species of tropical insects alone. 10 million species of animals. First of all, how did Noah find and collect every species of animal? He would have had to literally travel all over the world. Secondly, if he even found all these species of animals, how did he fit a male and female of each animal into the ark? If there are 10 million species of animals, he would have had to fit 20 million animals in the ark. Think about that: 20,000,000 animals. However, "Vertebrates, the mammals, birds, reptiles, amphibians, and fish, those species with a backbone, number only about 44,000 species in total." Even so, that's still 88,000 big vertebrates on one boat. 88 thousand. The ark would have to have been at least the size of Texas, right?