Consider this a PSA about the “nested hierarchy.” This post is an unattended roadside display: I won’t be back to respond to replies, because I am a bad person who, according to John Harshman, “flounces” off like an irresponsible pixie. (Seriously: I shouldn’t even be posting this, if you could see the barely-polite emails from my Discovery Institute co-workers about my unfinished projects…but I can’t help myself, at least not this afternoon.)
First, some leftover business from the Gould: Evolution as Fact and Theory thread. T. aqua wrote:
Why would an information retrieval system need to be a nested hierarchy? This makes no sense.
Look at the file structures of your computer, or whatever device you are using to read this. Nested hierarchies. The Library of Congress classification system? Nested hierarchy. Almost any data storage system one can conceive? Nested hierarchy. The groups-within-groups logic, arranged in most-to-least inclusive sets, is superbly suited – maybe even optimally suited – for information storage and retrieval.
John Harshman didn’t complain about that, but he did say that, in my own “vague way,” I denied the reality of the nested hierarchy, seeing it as “merely a matter of convenience.”
Actually, this is what I said, about which John failed to comment:
My nominalist interpretation [of the hierarchy] is supported by many thousands of anomalous character distributions, typically dumped into a bin labeled “not phylogenetically informative.”
Time to set up my little display; there is lemonade in the cooler, as long as it lasts.
Below is the standard three-domain hierarchy of life on Earth. The node on the right, marked by an arrow, represents the Last Eukaryotic Common Ancestor (LECA).
Ask yourself this question: given that LECA is inferred to have possessed chromosomal segregation machinery (for mitotic and meiotic cell division), what would the nested hierarchy predict about the character distribution of such essential cellular machinery throughout the domain Eukarya? Homologous or not homologous?
Write down your answer, then go here: