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- Order: Primates (collar bone, eyes face forward, grasping hands with fingers, and two types of teeth: incisors and molars);
- Family: Hominidae (upright posture, large brain, stereoscopic vision, flat face, hands and feet have different specializations);
- Genus: Homo (s-curved spine, "man"); and
- Species: Homo sapiens (high forehead, well developed chin, skull bones thin).
All species are classified in a ranked hierarchy. The Linnaean system has proven robust, and yet expansion of knowledge has let to an expansion of
the number of hierarchical levels within the system. Today there is a related science called systematics, which studies the relationships between taxa, and is
influenced by data from DNA, from nuclei, from mitochondria and chloroplasts, and is influencing traditional classification hierarchies.
As the 300th birthday of Carolus Linnaeus
passed on the 23rd of May 2007, there are profound changes in his classification schema with the introduction of on-line databases based on "DNA barcodes."3.238 As a specific example, researchers scanned the DNA of 643 bird species in North America, which is 93%
of all bird species in the region, and 87 bat species in Guyana, as a trial run
of the ambitious plan to “barcode“ all life on earth. They discovered six new bat species and 15 new bird species.3.239 All of the new species had previously been misclassified because they looked and sounded the same as other species, and the DNA screening showed they belonged to a distinct species. These technologies have the potential to create a
complete listing of life on earth. The identification of these new species does not mean they just came into existence. Rather, it means the new species were
just identified.
Despite controversy regarding the definition of what
a species is, most textbooks define a species as all of the individual organisms of a natural population that generally interbreeds at maturity in the wild, and who's interbreeding produces fertile offspring.3.240 The next section will go into more detail regarding species, and specifically will explore whether species are the framework of the biological matrix, the content of the biological matrix, or an interaction between the framework and the content.
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paradoxes