ABSTRACT
Origins of higher taxonomic groups entail dramatic and nearly simultaneous changes in morphology and ecological function, limiting our ability to disentangle the drivers of evolutionary diversification. Here we phylogenetically compare the anatomy and life habits of Cambrian-Ordovician echinoderms to test which facet better facilitates future success. Rates of morphological evolution are faster and involve more volatile trait changes, allowing morphological disparity to accrue faster and earlier in the Cambrian. However, persistent life-habit evolution throughout the early Palaeozoic, combined with iterative functional convergence within adaptive strategies, results in major expansion of ecospace and functional diversity. The interactions between tempo, divergence and convergence demonstrate not only that anatomical novelty precedes ecological success, but also that ecological innovation is constrained, even during a phylum's origin.
Subject(s)
Biological Evolution , Fossils , Animals , Biodiversity , EchinodermataABSTRACT
The Special Interest Groups of the American Burn Association provide a forum for interested members of the multidisciplinary burn team to congregate and discuss matters of mutual interest. At the 47th Annual Meeting of the American Burn Association in Chicago, IL, the Fluid Resuscitation Special Interest Group sponsored a special symposium on burn resuscitation. The purpose of the symposium was to review the history, current status, and future direction of fluid resuscitation of patients with burn shock. The reader will note several themes running through the following presentations. One is the perennial question of the proper role for albumin or other fluid-sparing strategies. Another is the unique characteristics of the pediatric burn patient. A third is the need for multicenter trials of burn resuscitation, while recognizing the obstacles to conducting randomized controlled trials in this setting.
