>>My response is to recommend the book Wonderful Life by Stephen J Gould. It is the scholarly story of three individuals that studied the fossils in the Burgess Shale. That is a geologic formation high in the Canadian Rockies.
Any one who reads that book and attempts to understand that all those fossils result in all that is alive today.
Thanks. That is a wonderful book. It has been in my library for years. This is one of my favorite passages:
“Several of my colleagues (Jaanusson, 1981; Runnegar, 1987) have suggested that we eliminate the confusion about diversity by restricting this vernacular term to the first sense-number of species. The second sense-difference in body plans-should then be called disparity. Using this terminology, we may acknowledge a central and surprising fact of life’s history-marked decrease in disparity followed by an outstanding increase in diversity within the few surviving designs. . . Measured as number of species, Burgess [Shale] diversity is not high. This fact embodies a central paradox of early life: How could so much disparity in body plans evolve in the apparent absence of substantial diversity in number of species? of vertebrates? or of life on land? or simply of multicellular persistence for 600 million difficult years? “ [The Meanings of Diversity and Disparity, in Stephen Jay Gould, “Wonderful Life: The Burgess Shale and the Nature of History.” W. W. Norton & Company, 1989, Chap. I, pp.48-49]
For all practical purposes, Gould said that Darwinian evolution, which predicted diversity before disparity, is falsified.
Mr. Kalamata
Total nonsense.
Darwin said nothing about "disparity", that's a word Gould invented because he thought the 600 genera discovered in the Cambrian Explosion (~540 million years ago) was just too, too different to be described by mere "diversity".
Those are nothing but words, the reality is later mass extinctions eliminated up to ~90% of species but there's still no reason to think that 600 Cambrian genera 540 million years ago were somehow more "disparate" than 200,000 animal genera today.
Here's the problem: those 600 Cambrian genera are thought to represent up to 100 different phyla -- think of it, on average a phylum with only six genera.
Today the average animal phylum has nearly 6,000 genera.
But there's more: 8 of our current 36 animal phyla have been traced to the Cambrian Explosion.
Why only 8? Well, because 24 of our current 36 animal phyla have never been found as fossils!
So we don't know how many phyla were in the Cambrian and we don't know how many arose since.
Point is, anybody can form hypotheses and invent terms like "disparity" vs. "diversity", but regardless of the names, the processes appear to be the same then as now.