Science Literature

Entomologists interested in the Coleoptera (beetles) may find themselves struggling with an information overload because there are said to be about 350,000 species alive today. A previous blog drew attention to Darwinian approaches to explaining these large numbers, and to an evidence-based explanation that is not Darwinian. The presumption seems to have been that speciation has occurred so readily that the life-time of an individual species is short. This has affected studies of Pleistocene sub-fossil specimens, in that the finds were assumed to represent extinct species:

"Originally, the remains from the Pleistocene peat-bog or asphalt deposits were assigned to extinct species by historical authors, supporting the idea of a high evolutionary rate induced by the climate changes during the Pleistocene."

General view of the modern Helophorus sibiricus and its newly discovered Early Miocene fossil counterpart. The close-ups show the species-specific granulation of the pronotum in both the recent specimen (top) and the fossil (bottom), one of the characteristics that allowed a reliable identification of the fossil. (Source here. Credit: Martin Fikacek)

With further research, similarities with modern species were recognised and the previous "finding" was completely overturned!

"Later, more detailed studies of sub-fossil specimens sometimes based even on the study of their well-preserved genitalia revealed that the majority of Pleistocene sub-fossil beetles belong to recent species and resulted in the Pleistocene evolutionary stasis paradigm."

The stasis paradigm has not been applied to pre-Pleistocene specimens. This is largely because the information needed to assign a fossil to a modern species is largely lacking in these fossils - so it is assumed (again) that the finds represent extinct species.

"A large missing piece for the acceptance of long-living insects as a general phenomenon and for understanding the reasons for survival of the particular species is the scarcity of the fossils of such species. The reasons seem to be rather straightforward - the majority of the fossils bear too few details to allow a detailed comparison with living species, whose taxonomy is often based on the shape of male genitalia and other details."

Consequently, the recent find of an early Miocene beetle that can be assigned to an extant species was unexpected. The ScienceDaily report notes: "A study of an Early Miocene fossil from southern Siberia [. . .] led to the surprising find that the fossil belongs to a species of aquatic beetles which is still alive today and widely distributed in Eurasia." We should note that the age assigned to this fossil is 16-23 million years, but the average duration of an insect species (let alone a beetle species) is considered to be much shorter.

"The Siberian fossil provides new data for the long-lasting debate among scientists about the average duration of an insect species. It was originally estimated to be ca. 2-3 million years based on the available fossil record, but slowly accumulating data begin to show that such an estimate is an oversimplification of the problem."

Oversimplification is a problem, but it is not solved by the token concession that acknowledges there are a few long-lived species. The root problems are the assumptions that scholars bring to the study of fossil beetles. Just as reconsideration of the Pleistocene beetles led to the recognition of stasis, coleopterists need to be open to stasis being a pervasive feature of the fossil record. Although diversification has occurred readily in the past, in general speciation is followed by stasis. This is not the Darwinian paradigm! Sad to say, this is point in the argument where we struggle to get a meaningful response from Darwinists. There is plenty of scope for discussion of these issues - for more on this and the relevance to intelligent design, go here.

A long-living species of the hydrophiloid beetles: Helophorus sibiricus from the early Miocene deposits of Kartashevo (Siberia, Russia)
Martin Fikacek, Alexander Prokin, Robert Angus.
ZooKeys, 2011; 130 (0): 239 | DOI: 10.3897/zookeys.130.1378

Abstract: The recent hydrophiloid species Helophorus (Gephelophorus) sibiricus (Motschulsky, 1860) is recorded from the early Miocene deposits of Kartashevo assigned to the Ombinsk Formation. A detailed comparison with recent specimens allowed a confident identification of the fossil specimen, which is therefore the oldest record of a recent species for the Hydrophiloidea. The paleodistribution as well as recent distribution of the species is summarized, and the relevance of the fossil is discussed. In addition, the complex geological settings of the Kartashevo area are briefly summarized.

See also:

Living Species of Aquatic Beetle Found in 20-Million-Year-Old Sediments, ScienceDaily (Oct. 6, 2011)