How do you know that 90% of species are undiscovered if they are undiscovered? how do you know they are there if you haven’t discovered them yet?

Question

Everyone keeps saying its like a list, how does that work?? Do you have like a pokedex where the undiscovered species appear in grey or something like that???

In: Biology

Answer 1

A part of it is that nowadays we are able to determine the existence of some species using what we call shotgun DNA sequencing.   We basically take a bunch of seawater and just look to see what dna is in it.  Almost always we find a bunch of dna that we cannot identify, except to say that it belongs to something we have not found yet.

But in other cases it is just making rough educated guesses based on how likely it is that there are more species out there.