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.
Over time, natural selection can even turn different groups of the same species on two islands into distinct species, according to records from one archipelago would most strengthen the researcher's argument.