The fact that the writer avoided laying out the ten-percent is obvious. It would have been nice to know. There are presently around 8-million animal species on the Earth.
There are presently around 8-million animal species on the Earth.
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They only collected samples from 100,000 species. So the conclusions are based, apparently, on the assumptions that the other 7,900,000 species will follow the same pattern; their methodology reminds me of political polls before an election.