How did Monkeys get to South America?

Hi, Engineer. South American rodents are thought to have come across this way, because they arrived in South America before the Americas were connected.I'm not sure, but I think procyonids (raccoons and their relatives) might have also come to South America from Africa.As Mr Jack said, marsupials predate the break-up of Gondwana, and, today, are present on both Australia and South America (former Gondwana). There is a fossil platypus found in South America, and a single species of marsupial in South America (the "monito del monte") is more closely related to Australian marsupials than South American marsupials.The ratites (large, flightless birds) are also distributed across the southern hemisphere (former Gondwana), but there is still debate as whether they constitute a single lineage.Finally, though there isn't a great deal of literature on it, insects show the Gondwana/Laurasia split very well. The families of stoneflies in the southern hemisphere (former Gondwana), for example, are quite different from the families found in the northern hemisphere (former Laurasia).

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-Bluejay/Mantis/ThylacosmilusDarwin loves you.

Hi, Engineer. I'm not sure I understand what your problem with the idea is.Science has dates, science has fossil records, and science has no evidence of a way between Africa and South America by conventional means.

1. Do you think this is a reason to doubt the veracity of our current picture of Earth's natural history?
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2. Or do you simply think we need to come up with a better way to explain monkeys in South America?

The trouble is that we've tried all the "better" ways, and the "freedom flotilla" hypothesis is the only idea left that's consistent with the evidence.The Ark hypothesis suffers from chronology issues and the complete lack of evidence for a global Flood, so it seems (at least at the moment) a highly untenable alternative. Continental drift explanations also suffer from chronology issues, and land-bridge explanations suffer from their own non-existence in the region in question.Meanwhile, the rafting hypothesis suffers only from your doubts that there would be enough food and water to survive a trip of uncertain duration.Clearly, one of these hypotheses has the least against it, and we are obliged to tentatively accept that explanation until it is no longer the least contested (Occam's razor).Scientists would love to believe that there is a convenient land-bridge theory to explain the controversy away, but intellectual honesty forbids us from asserting that without evidence of a land bridge. Thus, we are forced to conclude that something unusual happened. I'm sorry that this disturbs you so much, but, unless you have a better explanation, you'll just have to accept that nature is under no obligation to minimize our psychological distress.

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-Bluejay/Mantis/ThylacosmilusDarwin loves you.

Hi, Engineer. No doubt this is meant to prove a point about the limitations of science.I think Dr Adequate and Theodoric and every other scientist you'll ever speak with will agree with you that there are innumerable scores of things that scientists currently do not know or cannot do, and, indeed, may never be able to know or do.But, this doesn't in anyway vindicate a position of cynicism towards science. There is a lot of merit in the work we do, and I humbly submit that it deserves a great deal of respect. The continued existence of questions and mysteries is not evidence of the shortcomings of science, but rather an indicator of a vibrant future. But, the future has to be built on the present, and, presently, there's only so much we can tell you.The current "flotilla" hypothesis was arrived at by process of elimination, not by process of overwhelming positive evidence. As unsatisfying as that sounds, it really is the best we can offer at this current time. But then, that's all science ever is: the best we can come up with so far. Part of the trick of becoming a great scientist is learning to live with tentativity.As Theodoric has incessantly repeated, your best recourse is to come up with something better than the flotilla model, because it's going to be difficult to find direct evidence for or against the flotilla model (maybe monkey fossils at the bottom of the sea in the central Atlantic would do it, though).

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-Bluejay/Mantis/ThylacosmilusDarwin loves you.

Hi, Engineer. I think it's worth noting that many plants disperse their seeds by ocean currents. The coconut and the mangroves are good examples of plants that disperse on the ocean.Granted, this is different from vegetation rafts, but it's still something.

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-Bluejay/Mantis/ThylacosmilusDarwin loves you.

Hi, Bluegenes. A pregnant female with a long enough gestation period might suffice.If the mating season is timed with the monsoon, pregnancy and flooding may coincide regularly, presenting many opportunities for pregnant females to raft out to sea.

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-Bluejay/Mantis/ThylacosmilusDarwin loves you.

Hi, Engineer. It's really quite simple.Ever since the break-up of Gondwana, South America was not connected to any other continent (not even North America) until about 3 million years ago. When the two Americas finally connected, it resulted in what is known as the Great American Interchange (Wiki link).By the time of the Great American Interchange, all of North America's primates had apparently gone extinct, so that none were left to colonize South America 3 million years ago. Furthermore, when there were primates in North America (millions of years earlier), they were an outgroup to all modern primates. This means that lemurs are more closely related to South American monkeys than these extinct North American primates were, so proposing these North American primates as the ancestors of South America's primates is like proposing that tigers evolved from hyenas while the rest of the cats evolved from bears.Fossil monkeys have been found in South America dating to much earlier than the Great American Interchange, which means that, either two very different groups of animals evolved to become more similar to one another genetically than either was to their respective closest relatives, or some monkeys crossed the ocean.Basically, the options are like this:

1. A Ukrainian couple gave birth to an Aztec baby.
2. Some Aztecs migrated to Ukraine.

Both sound very bizarre, but one of them is actually marginally possible, while the other is not.

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-Bluejay/Mantis/ThylacosmilusDarwin loves you.