[elzbardico]

Natural boundary crossing isn't rare; it's the mechanism that built much of the biosphere. Every fucking oceanic island on Earth, Hawaii, the Galápagos, New Zealand, the Mascarenes, was stocked entirely by organisms that crossed open ocean or sky without any help from us.

The entire South American primate and caviomorph rodent lineages (everything from capuchins to capybaras) descend from African ancestors that rafted across the Atlantic on vegetation mats roughly 40 million years ago.

When the Isthmus of Panama closed (~3 million years ago), North American placental mammals poured south and drove a large fraction of South America's endemic fauna—native ungulates, many marsupial lineages—to extinction.

Yeah. Some species get crowded out, maybe we should avoid that in a lot of cases, but is not the capital sin western people have been brainwashed to believe it when they replaced their christianism with new age Gaia worship. Species get extinct, eco-systems change, sometimes it is worth preventing that, in other, who fucking cares?