As a biologist with a focus on biodiversity, I am often asked about the number of species that have been discovered on Earth. The question is not just about counting what we already know, but also about understanding the vastness and complexity of our planet's ecosystems.

Species discovery is a continuous process that involves the work of countless scientists, researchers, and explorers. It's a field that is as much about the past as it is about the future, with new species being discovered and described every year. However, quantifying the exact number of species that have been discovered is a challenging task due to several factors.

Firstly, the classification of species is a dynamic and evolving science. As our understanding of biology and genetics advances, so too does our ability to classify and reclassify organisms. This means that the number of known species can change as species are split or merged based on new evidence.

Secondly, the vast majority of species on Earth are believed to be terrestrial, with a significant portion living in the deep sea or in remote, hard-to-reach areas. These environments are difficult to study, and as a result, many species remain undiscovered.

According to a study published in 2011, it is estimated that there are approximately 8.7 million species on Earth. However, it's important to note that this figure includes all forms of life, from microorganisms to large mammals. Of these, only about 1.2 million species have been described and given scientific names. This leaves a staggering 86 percent of Earth's species that are yet to be fully described.

The study's findings are based on a combination of empirical data and mathematical models. Researchers used a method known as "taxonomic diversity estimation," which involves extrapolating from the known to estimate the unknown. They considered factors such as the rate at which new species are being discovered and the diversity of life in different habitats.

One of the key challenges in species discovery is the rate of biodiversity loss. Many species are going extinct before we even have a chance to discover and study them. This is a significant concern for conservation efforts and underscores the importance of continued species discovery and research.

In conclusion, while it is difficult to provide a precise number of species that have been discovered on Earth, current estimates suggest that we have described and named approximately 1.2 million species. However, this represents only a small fraction of the total estimated biodiversity on our planet. The ongoing process of species discovery is crucial for our understanding of Earth's ecosystems and for the conservation of our natural world.

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Various species of sea life found along the California coast (pictured). Even after centuries of effort, some 86 percent of Earth's species have yet to be fully described, according to new study that predicts our planet is home to 8.7 million species.Aug 25, 2011read more >>