Lineage diversification

Thus, together these studies suggest that the oxidative burst machinery has evolved before the crown diversification of eukaryotes (Baldauf 2003) to provide marine algal lineages with natural and induced innate immunity mechanisms. These play a role similar to the HR in terrestrial plants infected by incompatible pathogens and they share important common traits with the innate immunity response of mammalian phagocytes. 

Dong C Diversification of T-helper-cell lineages finding the family root of IL-17-producing cells. Nat Rev Immunol 2006 6 329-333. 

I will extend this argument to encompass the diversification of such systems in lineages of plants in an effort to correlate enzyme-mediated glycoside toxicity with the evolution of host plant specificity and the coevolution of plants and insects. 

Orkin SH (2000), Diversification of haematopoietic stem cells to specific lineages, Nat. Rev. Genet. 1 57-64. 

Hashiguchi Y, Nishida M (2007) Evolution of trace amine associated receptor (TAAR) gene family in vertebrates lineage-specific expansions and degradations of a second class of vertebrate chemosensory receptors expressed in the olfactory epithelium. Mol Biol Evol 24 2099-2107 Hashiguchi Y, Furuta Y, Kawahara R, Nishida M (2007) Diversification and adaptive evolution of putative sweet taste receptors in threespine stickleback. Gene 396 170-179 Hemess MS, Gilbertson TA (1999) Cellular mechanisms of taste transduction. Annu Rev Physiol 61 873-900... 

P.D.N Hebert, D.B. McWalter (1983), Cuticular pigmentation in Arctic Daphnia adaptive diversification of asexual lineages. Am. Nat., 122, 286-291. 

The Neoproterozoic interval witnessed supercontinent formation and breakup and profound global-scale glaciations that persisted for perhaps millions of years (Knoll 1991). It therefore is not surprising that this interval experienced substantial isotopic excursions reminiscent of those during the Paleoproterozoic (Fig. 10). Eukaryotic lineages that would lead directly to plants and animals had developed by this time. It is generally believed that the events associated with tectonics, climate and the biogeochemical cycles played important roles in the enormous diversification of plant and animal life at the dawn of the Phanerozoic Eon. 

Tray tor-Knowles N, Hansen U, Dubuc TQ, Martindale MQ, Kaufman L, Finnerty JAR. The evolutionary diversification of LSF and Grainyhead transcription factors preceded the radiation of basal animal lineages. BMC Evol Biol. 2010 10 101. 

The appearance of pleurocarpy was dated at 194-161 mya, significantly earlier than the radiation of the majority of pleurocarp lineages about 165-131 mya. This radiation coincides with the diversification of the angiosperms in the Early Cretaceous, but predates appearance of complex angiosperm forests in the early Cenozoic. The hypothesis that pleurocarpous mosses evolved to exploit the angiosperm forests is modified — pleurocarpous mosses diversified in the same time frame as the early angiosperms and the recovered pattern suggests a putative correlation of these diversification events. 

The most recent classification of mosses (Goffinet and Buck, 2004) and data from the Checklist of Mosses (http //www.mobot.org/mobot/tropicos/most/checklist.shtml [Crosby et al., 1999, update February 2000]), were used to estimate species-, genus- and family-level diversity in different lineages. To evaluate temporal variation in rates of diversification, an LTT plot was calculated based on the 100 calibrated phytogenies resulting from our age estimation analyses. 

Estimates of species-, genus- and family-level diversity in different lineages are summarized in Table 17.3, with classification based in part on that of Gofflnet and Buck (2004), and in part on Crosby et al. (1999). Temporal variation in rates of diversification was evaluated in a LTT plot and reported in Figure 17.2. The plot is calculated across all age estimates obtained for the 100 trees randomly drawn from the posterior distribution. For comparison, corresponding curves calculated for angiosperms and polypod ferns by Schneider et al. (2004) are included in Figure 17.2. 

Fossils of organisms that are clearly mosses exist from the Palaeozoic, from the Carboniferous and Permian periods onwards (see Krassilov and Schuster, 1984 and Ooslendorp, 1987 for comprehensive discussion of these), but it is evident from our results that the majority of lineages of extant mosses originated in the Mesozoic, with considerable diversification occurring in the Cretaceous and in the Cenozoic (Figure 17.1). 

Despite this conclusion, it is evident that additional diversification undoubtedly occurred during later periods. Of the three most diverse lineages of hypnalean mosses (Hypnaceae, Sematophyl-laceae and Brachytheciaceae), our sampling did not allow us to date nodes within the first two... 

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