上游充通大￥ Shanghai Jiao Tong University Distribution of species on Earth The land has more species Land species 1,750,000 World species because it has greater (86%) environmental variability than Marine species (14%) the ocean Most ocean species are Benthic (98%) benthic because of greater Pelagic environmental variability 250,000 (2%) Marine species compared to pelagic environments Figure 12-6Shanghai Jiao Tong UniversityDistribution of species on Earth The land has more species because it has greater environmental variability than the ocean Most ocean species are benthic because of greater environmental variability compared to pelagic environments Figure 12-6