During most of the Cenozoic era, from the Cretaceous–Tertiary boundary 65 million years ago [sic] until roughly 24 million years ago [sic], Afro-Arabia was [sic] an island continent drifting steadily [sic] northwards towards Eurasia. Fossil mammals documenting this period are scarce and belong almost exclusively to endemic forms restricted to Afro-Arabia, such as proboscideans, hyraxes and elephant-shrews. But by around 24 million years ago [sic], a permanent land bridge had formed between the two landmasses. A burst of faunal interchange followed: many Eurasian mammals, such as rhinos and ruminants, dispersed into Africa, and some Afro-Arabian mammals, such as elephants, migrated in the opposite direction. (Emphasis added in all quotations.)That forms the plot line, but there are problems. The Chilga specimens he describes seem to fit the story, but there are puzzles among the bones:
Among the proboscideans recorded are primitive [sic] forms such as Palaeomastodon and Phiomia (also known from older deposits in Egypt). But there are also representatives of modern families, for example taxa such as Gomphotherium, the earliest proboscidean on the branch leading to extant elephants. Another surprise is the oldest occurrence of deinotheres, peculiar proboscideans with downward-curved lower tusks, which were previously recorded only from rocks younger than 24 million years old [sic]. The new species of deinothere displays molars that are more ‘bunodont’ in form (that is, made of several distinct cusplets arranged in transverse crests) than its descendant, whose molars display plain transverse crests. This discovery seems to rule out the possibility that deinotheres are derived from an ancestor bearing plain, transverse-crested molars, as was formerly supposed, and provides new evidence about proboscidean evolution [sic].Jaeger bemoans the scarcity of the fossil record for this period, but claims, “Nonetheless, considerable information has been inferred from the evidence we do have.” He talks about how systematists have grouped the African fauna into a superorder Afrotheria based on fossil and molecular evidence. Though “African mammalian faunas are dominated by these endemic forms,” a few other groups did get over to the big island somehow, including our alleged remote ancestors, the catarrhine primates, fathers of hominoids. These “newcomers” went through “rapid evolution” on the landmass, he claims.
Finally, the discoveries of Kappelman et al. highlight two other palaeobiological issues. First, on northern continents glaciation caused a significant cooling around 33 million years ago [sic], which resulted in numerous extinctions [sic] among mammalian communities. From these new data, however, it seems that large Afro-Arabian herbivores were not affected, either at that time or later, implying that the climatic changes were less severe on southern continents. Second, the fossil record of the Afro-Arabian continent is not only scanty but also largely concentrated on the northern edge. This has led to the proposal that other groups of mammals existed in Afro-Arabia during its period of isolation, but that they were restricted to more southern latitudes. However, the Chilga mammal community is rather like that found at Fayum in Egypt, which is some five million years older [sic], providing hints that there was little provinciality among Afro-Arabian mammals at that time. As yet, though, we have unveiled [sic] only a few of the secrets of mammal evolution on the Afro-Arabian continent. Many more surprising discoveries are to be expected.Got that?
We’re going to give our readers an opportunity to go baloney detecting on this story before we have at it. Hint: separate data from storytelling, and look for the damaging admissions.Link
Their entire position consists of whining that their simplistic, and dated, view of a very complex process, evolution, doesn't make sense.
I will not play games arguing over your youthful concepts of evolution, possibly learned from a 'Classic Comics' than I would arguing the accuracy of Newtonian Gravitation.
The problem, dear Fundy, lies not in our Theories, but in your lack of education.
So9
Fast skim. Same crap. You've really lost my attention with that one sad-sack guy's empty bag of tricks.
Very interesting post, bondserv!
In your commentary you [sic]-ed a whole lot of time references. On my present understanding, there is no reason to argue about the "time problem" here. Plus the time scales described do not appear to be out of line with state-of-the-art natural science theories that have actually been put to objective test, and continue to be profitably tested.
If there is a problem with the present author's (seemingly disgruntled) thesis, you would have to go to motive to find it. IMHO.
When Jaeger says the fossil record is scant, does this mean that he doesn't feel he has an adequate inventory of fossils to test? Or could it mean that he has a sufficient number of fossils to test; but that the test results do not support his theory?
We non-specialist consumers of scientific information seem often quite left in the dark, when it comes to questions of epistemology, the "science" of what we know; how we know it; and how we know we know it.
Jaeger does not immediately appear to be terribly helpful on those questions....