Most of the earth's surface is covered by oceans, and life is born in the oceans  However, it is estimated that 80% of Earth's species live on land, compared to only 15% in the oceans and the remaining 5% in freshwater
The researchers believe that the physical layout of terrestrial habitats may be more fragmented than the ocean, which is one of the main reasons for the greater diversity of terrestrial species
The earth's surface can be divided into five temperature zones: tropical zone, south temperate zone, north temperate zone, southern frigid zone, and northern frigid zone. Each temperature zone has great differences in species and rich species.