How many different kinds of life forms are believed to exist on Earth?

The belief that there are over 10 million different kinds of life forms on Earth is based on a combination of scientific estimations, ongoing discoveries, and the complexity of biodiversity. Current estimates suggest that millions of species, particularly microorganisms and undiscovered species in rainforest and ocean ecosystems, have yet to be formally identified. While some studies indicate that the number could be between 10 million to possibly 30 million or more, the most widely accepted figure tends to hover around 10 million, particularly when factoring in known species and a broad array of potential undiscovered varieties. This estimation reflects a general consensus within the scientific community, making it a reasonable choice for the answer.