Diversity is one of the most shocking aspects when it comes to life on Earth, and knowing how many species walk this planet alongside us is perhaps one of the most important questions in science. However, despite major advancements being made in the field, an answer to that question is still miles away, as efforts to thoroughly sample and describe biological life on Earth are extremely limited, and assertions often prove to be questionable.

The research in case, published in PLoS Biology the higher taxonomic classification of species (assignment to a class, order, genus, etc) follows a consistent and estimable pattern, especially when applied to large groups. This approach was validated by numerous discoveries, and it predicts ~8.7 million (±1.3 million SE) eukaryotic species globally, of which ~2.2 million (±0.18 million SE) are marine.

In spite of 250 years of taxonomic classification, results show that 86% of existing species on Earth and 91% of species in the ocean still await description