A common popular idea in evolution is that diversity is
continually increasing. The text discusses a “Paleozoic
plateau”, however more recent studies (e.g., Alroy et al. 2008)
suggest no clear plateau. According to Alroy et al. (2008),
there has been little increase in diversity since the midCretaceous (about 100Mya) and, more importantly, the global
evenness (a measure of the distribution of the diversity) does
not track the estimates of diversity. Based on what you
learned in this class, how do you explain (a) the difference in
perception of the “Paleozoic plateau”, and (b) the importance
of the lack of correlation between evenness and diversity?