The avocado is a fruit of a different time. The plant hit its evolutionary prime during the beginning of the Cenozoic era when megafauna, including mammoths, horses, gomphotheres and giant ground sloths (some of them weighing more than a UPS truck) roamed across North America, from Oregon to the panhandle of Florida. The fruit attracted these very large animals (megafauna by definition weigh at least 100 pounds) that would then eat it whole, travel far distances and defecate, leaving the seed to grow in a new place. That’s the goal of all botanical fruits, really. Survival and growth via seed dispersal.
But the great mammals disappeared forever about 13,000 years ago in the Western Hemisphere. Around that time, North America lost 68 percent of its diverse Pleistocene megafauna, and South America lost 80 percent, Connie Barlow, author of The Ghosts of Evolution: Nonsensical Fruit, Missing Partners, And Other Ecological Anachronisms says. But even after this major shift in the land mammal population, the wild avocado still requires the same method of seed dispersal, which makes it somewhat of an evolutionary anachronism.
“After 13,000 years, the avocado is clueless that the great mammals are gone,” Barlow explains. “Without larger mammals like the ground sloth to carry the seed far distances, the avocado seeds would rot where they’ve fallen and must compete with the parent tree for light and growth.”
A fruit with smaller seeds, like a berry, for example, can be consumed whole and dispersed by small mammals, making the chances of fruiting in a new place higher.
Written By: K. Annabelle Smith
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