The avocado, alligator pear or avocado pear is a medium-sized, evergreen tree in the laurel family (Lauraceae). It is native to the Americas and was first domesticated in Mesoamerica more than 5,000 years ago. Then as now it was prized for its large and unusually oily fruit. The tree likely originated in the highlands bridging south-central Mexico and Guatemala. Its fruit, sometimes also referred to as an alligator pear or avocado pear, is botanically a large berry containing a single large seed. Sequencing of its genome showed that the evolution of avocados was shaped by polyploidy events and that commercial varieties have an hybrid origin. Avocado trees are partly self-pollinating, and are often propagated through grafting to maintain consistent fruit output. Avocados are presently cultivated in the tropical and Mediterranean climates of many countries. Mexico is the world's leading producer of avocados as of 2020, supplying nearly 30% of the global harvest in that year.