FACTS ABOUT LIFE

1. Scientists believe that Earth will exist for another 7.5 billion years before the sun becomes a red giant star and, in all probability, destroys the planet. Earth may cease to support life forms far before that date, however, due to increased energy output from the sun over time.
2. Living organisms are divided into two basic domains: prokaryotes and eukaryotes. Eukaryotes, to which humans belong, have a cellular structure with a nucleus and membrane-bound genetic information, while the cells of prokaryotes do not contain a nucleus.
3. Today, all identified living organisms are scientifically named and categorized according to Swedish scientist Carl Linnaeus’s taxonomy. In his 1758 publication, Systema Naturae, Linnaeus divided and classified different living organisms with a ranking scale: kingdom, phylum, class, order, family, genus, and species.
4. Scientists estimate that anywhere from five million to 100 million unique species of plants and animals currently live on Earth. However, only about two million of these species have been identified.
5. Insect species account for 950,000 of the two million identified species on Earth.
6. There are nearly 300,000 different species of plants currently living on Earth.
7. Mammals make up just 5,416 of the two million identified species on Earth.
8. The theory of evolution, which explains how living things change over time through natural selection, was first publicized by Charles Darwin in 1859. Many scientists now point to this natural phenomenon as the reason behind Earth’s great biodiversity.
9. Worldwide, there are currently just over 6.7 billion people living in the world. The population of males is slightly higher than females (3.41 billion compared to 3.37 billion).