Fossils, Taxonomy and Debate: Is fossil classification fundamentally flawed?
- Guest post by Winston Zack, Department of Geography (University of North Texas)
Linnaeus improved the organization of taxa into related groups, but this is still fundamentally a flawed system of organizing biology given that the foundations of evolutionary principles are a continuum of constant genetic changes and mutations. Therefore, there is no such thing as a ‘static’ taxon or species; rather these animals are always evolving and always show anatomical variations. Therefore, when it comes to classifying fossils, especially those of early hominids (e.g., early genus Homo), I find these debates to be unnecessarily complicated. Archaeology should consider that we have only just scratched the surface when understanding our early human past and not try to hurry and classify fossils or get bogged down about classifying an unusual hominin fossil as a ‘new species’. We still have much to learn about how early human fossils relate to each other. Our sample sizes of early hominin fossils are extremely small as well and come from millions of years of history and across thousands of miles of earth. Different populations, especially if ‘isolated’ for long-periods of time, should show increased biological/anatomical variations from contemporaneous species found elsewhere. A case in point is the Dmanisi fossils, which after 20+ years since they have been discovered, a consensus as to where they fall into the hominin family tree (i.e., their species) has not been formally classified and the debate continues. I personally feel the Dmanisi team is taking very good and cautionary measures before settling upon which ‘species’ is at Dmanisi; although in journals and other published works the Dmanisi team has labeled these hominin fossils to many different species over the years, including but not limited to: Homo habilis, Homo erectus, Homo ergaster, Homo georgicus; the first three species listed all lived at the same time while the last species, Homo georgicus, is a potentially new species classification.
So, is the Linnaean taxonomic system flawed?
Personally, such a characterization of biology distinct from the Linnaean system would call every individual a unique taxon because we all have slightly different physical characteristics which make us all unique. The Linnaean system will not go away and may very likely stay here forever. But for fossil classification, when we lack populations of individuals that were recovered from the same area from about the same time, it is difficult to understand how a few fossils may relate to the greater scheme of evolution. All archaeologists and paleoanthropologists, and anyone else trying to interpret the past from fossil evidence should use as much caution as possible prior to classifying fossils…and many of these professionals do this.
Winston Zack is a geoarchaeologist and graduate student at University of North Texas. His work has thus far primarily been conducted on Plio-Pleistocene and Pleistocene sites such as Dmanisi, Republic of Georgia and several hominid fossil-bearing sites in Spain. He begins work in Germany on several Pleistocene sites this summer. Much of his research has focused on archaeological sediments and stratigraphy, artefact densities and what these analyses can tell us about hominid procurement, transport and provisioning behaviours. He is currently in the process of coauthoring an article for Quaternary Science Reviews, which will be published in the near future.