Oceanic dispersal is a wild idea. Some animals can swim from where they are to an entirely different place. Even among those that can't, some have been relocated via vegetation rafts.
Rafting doesn't guarantee safe arrival, of course. In some cases creatures may simply find themselves floating out into the ocean with no way to survive. This is sad, although the sadness is somewhat abstract, there not actually being anyone to mourn.
But then there are successes. New World monkeys, for one. Simians that made the long journey from Africa to South America. They actually got a chance to start a new life, and it was a gain for all.
2 comments:
That was a most informative article about species traveling from one continent to another on rafts made up, often enough, of floating storm debris. There are definitely more than I would have guessed including the New World monkeys.
The next wave of animal migration came from people deliberately carrying creatures on boats either as pets or foodstuffs. Rabbits didn't get to Australia on their own and neither did cane toads.
https://www.bbc.com/news/world-australia-39348313
Nowadays modern transport has taken a turn in helping creatures travel to new shores - usually by accident and consequently destructive.
But the part I really want to draw your attention to is the theory that people thousands of years ago made their own rafts so they could move from one place to another. Thor Heyerdahl was a major proponent of human migration by raft and he built and sailed the Kon Tiki to prove his belief. The following article and video show his results:
https://runawayjuno.com/runaway-tales/thor-heyerdahls-kon-tiki-expedition-across-the-pacific-by-raft/
Kon Tiki - Thor Heyerdahl - the Academy Award winning documentary from 1950
https://youtu.be/gvBYfba8nv8?si=EdeuRCiT3IaUKC95
Yeah, it's kind of wild the way some species have wound up getting transported to a very different place. New World monkeys are a prime example. Most of them, as I found out very recently, don't have opposable thumbs. Was that an adaptation that arose after their ancestors left Africa/Asia? Perhaps.
English colonists brought rabbits to Australia as a food crop. Within a few generations they found out what a mistake that was. The article on cane toads was pretty hair-raising. I hope they can get a handle on that problem.
If a species can't adapt to a new place where they've been introduced, that's bad for them. If they adapt a little too well that might be bad for everyone else. Sometimes this is by accident, and sometimes it's more lack of foresight.
Thor Heyerdahl's theory that South American natives settled Polynesia was always controversial, and largely rejected. There now seems to be some supporting evidence. As the Smithsonian article says, it wasn't a linear process, so much of the region probably was settled by people from Asia, but there definitely could have been neighboring groups. In any case, Heyerdahl's work on the rafts was pretty brilliant.
Post a Comment