(October 18, 2013 at 9:30 am)John V Wrote: The article points out that paleontology is largely guesswork, without even operational definitions for a species.We don't have practical operational definitions for species, and this is because evolution is a process. It's very hard to draw lines between transitional forms. The standard high school science textbook definition- organisms who can produce fertile offspring- gets less and less useful as it becomes more and more evident that among closely related species, more interbreeding happens than was previously supposed, and the majority of life on Earth isn't sexually reproducing, anyway, and (among most animals, anyway) there usually isn't a clear moment when one species transitions into another (anymore than there's a clear moment where a middle-aged person suddenly becomes an old person).
Most people who yap on about this don't understand that the very reason determining species is a headache is because, in the real world, species largely doesn't exist- it's a human-invented term to try to categorize organisms that often fall along subtle lines of genetic relationships.
