About how many species ever lived on earth?

Question

Like ever since the beginning of time till now

Thanks (:

Answer 1

There are about 1.5 million now.  About 99.99% of all species that ever lived are extinct.  So, that 1.5 million represents about 0.01%.  So, 1.5 million x 99.9 = just under 150 billion species.

Answer 2

it is impossible to know because we do not have a complete fossil record of every species that existed.

some say 99% or 99.9% or 99.99% or 99.999% of all species are extinct.  these are just estimations and have little evidence to support why it is that number.