Earlier we discussed in parts 1, 2, 3, 4, 5 and 6 the criticisms leveled at ReptileEvolution.com by Darren Naish, author of the Tetrapod Zoology blog titled “Why the world has to ignore ReptileEvolution.com. Here is part 7.
Darren grants credit for my attempt to use species-level taxa and for my criticisms of previous analyses for not including enough of these. He disagrees with my novel nestings because “(1) he finds the ‘conventional’ positions to be far more convincingly supported by character data, and (2) because Dave’s alternative positions are based on erroneous or incomplete analysis of the data available.” Unfortunately, once again, no details are given.
Darren suggests my character list needs to be longer than 228. By comparison, he is working on a project in which 800 characters are employed. I don’t have the references, but I remember the thesis on a paper on cladistic analysis. The more characters the better, of course, but after 150, the logarithmic curve starts to flatten and you don’t get greatly different results thereafter. You’re already in the high 90th percentile of reliability between 175 and 200.
Darren was deeply perplexed by my statement that I didn’t intend to add more characters to my matrix. Of course that would involved reexamining every one of my over 300 taxa for each new trait and I’m going to leave that for the next guy. I have a job, a life, a blog… I can only give paleontology so much and no more. I hope you all understand. Adding taxa is relatively easy by comparison and with a single tree result, so far so good.
Darren asked, “What the hell happened to Test. Test. and Test again?” Well, Darren, I have tested again and again over the past two decades. I am adding taxa and none have shaken the tree. I do make corrections. When I say, “Test,” that’s for those guys and gals who refuse to test lizards and archosaurs and pterosaurs and thalattosaurs together. Get it?
Darren considers my character list to be cherry-picked. Well the list was put in place long ago when their were just 150 to 200 taxa. Since the list has grown to twice that size, I don’t think I a priori picked any cherries. I don’t include the number of characters for ANY particular clade needed for a more focused study. My aim was to include characters that could be applied to as many reptiles as possible. That’s why there is no “plastron” associated with my turtles and no “wing” associated with my pterosaurs.
Darren notes that I really don’t know how to read a cladogram. He says it’s not such a good thing to recover only a few trees in a cladogram (complete resolution). First time I’ve heard that. There are no “findings” without resolution. I also misunderstand the concept of sister taxa, according to Darren. Lucky for me, PAUP understands. Darren then explained that pterosaurs and phytosaurs nested together because they diverged from a common ancestor. That common ancestor was derived from a sister to Erythrosuchus, according to the tree. I don’t know about you, but I’d like to see much less of a mental leap between related taxa, as I found closer sisters among the little fenestrasaurs. And it scares me when professionals stand by such hypotheses.
Concluding, Darren, provides personal praise, but notes that my work will never be accepted (so be it), that (quoting Bennett 2005), I have made no attempt to convince academic palaeontologists of my findings (btw, Chris is the one who said he refuses to read my emails that attempt to convince him of my findings), and I have taken my ideas directly to the general public and presented them as true and correct, (doesn’t everybody??).
All I can say is what I’ve said before: 1) Don’t be afraid to test lizards and fenestrasaurs with pterosaur and archosaurs. 2) Don’t be afraid to trace fossils, even if they seem daunting and difficult. 3) Don’t be afraid to let your results give you your hypothesis, even if it differs from the status quo. 4) Don’t be afraid to make changes when necessary and 5) When others shun you, hang in there if you’ve done good work.
Tomorrow, we’ll ‘cleanse the palate’ with a “nude” Archaeopteryx.
See you then.