The abiogenesis occurred about how many billion years ago?

According to one of the accepted theories, primitive earth's atmosphere consisted of water, ammonia, hydrogen and

The theory of catastrophism was given by

The theory of pangenesis was introduced by

The book Philosophic zoologique was written by

According to Oparin, which one of the following was not present in the primitive atmosphere of the earth?

The famous book "origin of species" was written by

The presence of gill slits, in the embryos of all vertebrates, supports the theory of

Naturalistic theory was given by