Tuesday, August 24, 2010

Trajectories

Here is what Senter says about "trajectories of dots" (morphological evolution within a lineage):
"It is noteworthy that bifurcating trajectories are visible in the 2009 scatter plot in a number of places. Within Dromaeosauridae, the sequence Velociraptor [dot 28]→Deinonychus [dot 29] and the sequence Sinornithosaurus [dot 26]→Microraptor [dot 27] extend in different directions from Bambiraptor, which is at the apex of the 'V'. Another bifurcation is present within the Tyrannosaur Cluster, with Guanlong + Ornitholestes at its apex and with Gorgosaurus→Tyrannosaurus leading in one direction and Huaxiagnathus→ (Sinosauropteryx + Compsognathus) leading in another direction. Baraminologists recognize that a trajectory of dots within a CMDS or ANOPA scatter plot represents morphological evolution within a lineage (Wood & Cavanaugh, 2003; Wood, 2005a,b), in which case bifurcating trajectories must represent speciation. It is also noteworthy that these bifurcating patterns correspond reasonably well to the bifurcations on the cladogram in Fig. 1, with the more basal members of each group closer to the origin of each scatter plot bifurcation."

As an example, let's focus on:
"Within Dromaeosauridae, the sequence Velociraptor→Deinonychus and the sequence Sinornithosaurus→Microraptor extend in different directions from Bambiraptor"

On the cluster diagram, he is referring to Velociraptor (dot 28) being close to Deinonychus (dot 29). And he is referring to Sinornithosaurus (dot 26) being close to Microraptor (dot 27). This all makes sense. As Senter says this "represents morphological evolution within a lineage".
BUT here is the big point. We do not see anything like this between the "Tyrannosaur cluster" and the "Birdlike cluster". These clusters are separate, with no trajectory of dots between them.
So by Senter's own logic, the "Birdlike cluster" is not related to the "Tyrannosaur cluster".
And even though Senter himself does not draw the obvious conclusion, the obvious conclusion is that birds did not develop from dinosaurs.

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