Answer: Earth's equator is about 40,075 kilometers (24,901 mi) long; 78.7% is across the water and 21.3% is over land. Near the Equator, there is little distinction between summer, winter, autumn, or spring. The temperatures are usually high year-round—with the exception of high mountains in South America and in Africa. (See Andes Mountains and Mount Kilimanjaro.) The temperature at the Equator can plummet during rainstorms. In many tropical regions, people identify two seasons: the wet season and the dry season, but many places close to the Equator are on the oceans or rainy throughout the year. The seasons can vary depending on elevation and proximity to an ocean. So our early civilizations started moving away from the equator towards some coolers places and started civilizations but this climate was best for rainforests and due to the absence of any civilization rainforests took over complete areas near the equator. So civilizations lost contact with the original habitat of the equator. In mid 19th century, we resume contact with people living near equators and then some development work started that why till now they are less developed than most of the countries.