… based on the molecular clock (how fast evolution supposedly occurred), in accounting for odd dispersals of life forms:
A recent study of the evolutionary relationships of fossil primates highlights the profound influence of chance dispersal in a particularly obvious way. The phylogenetic placement of various groups in this study can be debated, but, if true, the results imply that, some 40 million years ago or earlier, an ancient primate species made an unlikely, accidental journey from Asia across the Tethys Sea to Africa, which was then an island (PNAS, 109:10293-97, 2012). Over many millions of years, those seafaring ancestors’ descendants evolved into diverse lineages, including baboons, guenons, mangabeys, and the monkeys that would go on to raft from Africa to the New World. Those ancestors would also give rise to gorillas, chimpanzees, Australopithecus, Homo erectus, and us. Given the massive impact of our species on the planet, this case, if it holds up, will rank as an extreme illustration of the profound influence of improbable, unpredictable ocean crossings on the history of life. [Colour emphasis added.]
Apparently molecular clock claims have won out over continental drift claims, but see this from a Pearson text:
Some biologists are skeptical about the accuracy of molecular clocks because the rate of molecular change may vary at different times, in different genes, and in different groups. The judicial use of molecular clocks, however, may provide approximate markers of elapsed time. An abundant fossil record extends back only about 550 million years, and molecular clocks have been used to date evolutionary divergences that occurred a billion or more years ago. But the estimates assume that the clocks have been constant for all that time. Thus, such estimates are highly uncertain. [Colour emphasis added.] Excerpt.
So, “improbable, unpredictable,” meet “highly uncertain.” (There is no reason to trust any such estimates for any time period in the fossil record in the absence of constancy.)
Oh, and by the way, Darwinian evolution is supported by “mountains of evidence,” or “mountains and mountains of evidence.” Or is even“fact! fact! FACT!” Most of the facts are just like these ones. Fun with ancient geography.
 Michael Ruse, Darwinism Defended: A Guide to the Evolution Controversies, (Addison-Wesley, 1982) 1983, Third Printing, p.58. Emphasis Ruse’s.