Despite New Fossil, Origin of Marsupials Still Puzzles Evolutionists
Although the earliest known marsupial has just been found in China1, Richard L. Cifelli and Brian M. Davis, writing in the Dec. 12 issue of Science2 consider the phylogenetic trees of marsupial and placental mammals conflicting and puzzling. Problems include (emphasis added):
- Switcheroo: Fossil marsupials are predominately found in North America, but living ones are primarily found in Australia and South America. “This geographical switch remains unexplained. The timing of the split between eutherians [placental mammals] and metatherians [marsupials] is also controversial.”
- Known Bones: “To date, the geological record has yielded few fossils that bear directly on the origin of marsupials.”
- Good News, Bad News: This new, exciting, earliest fossil marsupial was found in China, but “The balance of paleontological and morphological data suggests that the last common ancestor of metatherians and eutherians was Laurasian” (i.e., European-North American].
- Divergence and Convergence: “Clearly, the relative successes of the two groups differed widely on the two continents. Yet, the early representatives of both groups seem to have been highly similar ecologically–most were small, insectivorous, and probably nocturnal. This puzzle remains to be resolved.” It is also commonly known that many marsupials, such as the marsupial wolf, have placental look-alikes, yet very different reproductive systems.
- DNA Doubts: “Molecular data have yielded conflicting results for the timing of the metatherian-eutherian split.” Molecular estimates are usually much older than fossil estimates.
- The Gap Theory: “These divergence estimates have implications for the relative timing of most other divergences on the mammalian family tree. However, they are difficult to reconcile with the (admittedly imperfect) mammalian fossil record. When the entire tree is considered (top panel), it becomes clear that large gaps in the fossil record (most with durations of more than 30 million years) must be inferred to explain the distribution of each group represented.”
- Tooth Truth: Paleontologists attempt to classify the groups based on teeth, but its a difficult job: “But such criteria are not applicable to dentally more primitive fossils. Furthermore, they are of limited utility when it comes to assessing which biological niches they might have occupied, beyond the suggestion that most early metatherians fed on animal tissues ranging from insects to meat, depending on body size.”
- Why We Gotta Figure This Out: “The paleontological evidence is important because it provides an independent test for dates based on molecular data. It also provides some basis for calculating the rates of change of skeletal (and dental) morphology and molecular structure. Given the far-reaching implications for evolutionary studies, it is crucial that the widely differing estimates of divergence time are reconciled and that the place of origin of both metatherians and eutherians is further elucidated with fossil discoveries. The many open questions provide fertile ground for future and paleontological studies.”
1Luo et al., “An Early Cretaceous Tribosphenic Mammal and Metatherian Evolution,” Science Dec. 12, 2003, 10.1126/science.1090718.
2Richard L. Cifelli and Brian M. Davis, “Enhanced: Marsupial Origins,” Science Dec. 12, 2003, 10.1126/science.1092272. This article contains a list of links for further study and an annotated bibliography on mammal origins.
This would be funny if they spent their own money. For more on evolutionary confusion about mammal origins, see the Dec. 2 headline and the big National Geographic story festival in the March 18 headline. MSNBC News, as usual, is all agog at this wonderful new discovery and what it tells us about evolution.
Meanwhile, the Europeans are all flustered trying to drum up interest to join the “Assembling the Tree of Life” bandwagon (see 10/30/2002 headline). A letter to the editor in the same issue of Science by two UK scientists moans that Europe doesn’t seem to see the connection between evolutionary studies and practical benefits:
Perhaps the best explanation is that AToL is still seen to be about taxonomy, a domain that urgently needs rebranding if it wants to attract funds for big programs such as the Genome Project. Only when the linkage of the tree of life to conservation, genomics, and DNA-based identification for medicine and ecology is made obvious will the project be put in its proper perspective. Taxonomic study is fundamental to all areas of science, but as demonstrated by the projects funded by the NSF program, it is only a starting point. A great deal more needs to be done to move modern evolutionary science to the heart of society’s efforts to understand the living world and make its utilization sustainable and effective.” (Emphasis added.)
Notice how they conflate evolutionary study with taxonomy. Taxonomy is good. Linnaeus, the father of taxonomy, was a creationist. Evolutionists keep trying to sneak Darwinist religion into “all areas of science” and “utilization” when, in fact, it is useless.