Pre-Columbian people spread fruit species across Latin America

https://arstechnica.com/science/2018/03/pre-columbian-people-spread-fruit-species-across-latin-america/

Pre-Columbian people spread fruit species across Latin America

Humans played an important role in spreading fruit species around Latin America.

Prehistoric humans helped spread edible fruit species across Central and South America, even as they wiped out the megafauna that had done so previously. In the process, we maintained and even expanded the plants’ habitats, increased biodiversity, and engineered ecosystems on two continents. Today, these fruit species could be important in 21st-century efforts to diversify human diets, address food scarcity, and improve agricultural sustainability.

Fruiting plants have evolved a very solid strategy for getting their offspring out into the world. Animals eat the fruit, they drop the seeds, and the next generation of plants takes root, often quite a distance away from their parents. Before about 12,000 years ago, animals like the giant sloth, elephant-like mammals called gomphotheres, and native horses did most of the work of seed dispersal in Latin America.

When those animals died out around the end of the Pleistocene, many of the fruit species they’d helped spread found their ranges contracting. But as the early Holocene climate shifted toward warmer, wetter conditions, humans picked up the slack in a big way for some fruit species.

to paraphrase Sepp

"if you don't have animals, then you have to do the work of animals"

How picky eaters promote genetic diversity

All that human meddling generally increases the genetic diversity of the plants involved. Humans are picky eaters, so we tend to eat fruit that’s appealing in some way, whether because of taste, texture, appearance, amount of actual fruit compared to rind and seeds, or willingness to grow in the right places. Because we typically only drop seeds from fruits we eat, that choosiness gradually selects for different combinations of traits people want. The effect is even more noticeable in domesticated species, where pre-Columbian farmers deliberately bred plants for certain traits.

The result is a lot more diversity in human-modified species than in wild ones.