Higher taxa as paleoecological and paleoclimatic indicators: A search for the modern analog of the Florissant fossil flora

2008 ◽  
Author(s):  
Brad Boyle ◽  
Herbert W. Meyer ◽  
Brian Enquist ◽  
Silvia Salas
Keyword(s):  
Fossil Flora ◽  
Higher Taxa

Unfinished Synthesis

1986 ◽  
Author(s):  
Niles Eldredge
Keyword(s):  
Modern Synthesis ◽  
Ernst Mayr ◽  
Conventional Theory ◽  
Higher Taxa ◽  
Evolutionary Thought ◽  
Wide Range ◽  
Theodosius Dobzhansky ◽  
George Gaylord Simpson

This study provides a stimulating critique of contemporary evolutionary thought, analyzing the Modern Synthesis first developed by Theodosius Dobzhansky, Ernst Mayr, and George Gaylord Simpson. The author argues that although only genes and organisms are taken as historic "individuals" in conventional theory, species, higher taxa, and ecological entities such as populations and communities should also be construed as individuals--an approach that yields the ecological and genealogical hierarchies that interact to produce evolution. This clearly stated, controversial work will provoke much debate among evolutionary biologists, systematists, paleontologists, and ecologists, as well as a wide range of educated lay readers.

scholarly journals Historical evolutionary information in the traditional Linnean hierarchy

1992 ◽  
Vol 6 ◽  
pp. 16-16 ◽  
Author(s):  
Richard K. Bambach ◽  
J. John Sepkoski
Keyword(s):  
Fossil Record ◽  
Latitudinal Gradients ◽  
Evolutionary Information ◽  
Simulation Studies ◽  
Biological Organization ◽  
Diversity Patterns ◽  
Higher Taxa ◽  
History Of ◽  
The Stability ◽  
And Function

The first two ranks above the species level in the traditional Linnean hierarchy — the genus and family — are species based: genera have been erected to unify groups of morphologically similar, closely related species and families have been erected to group genera recognized as closely related because of the shared morphologic characteristics of their species. Diversity patterns of traditional genera and families thus appear congruent with those of species in (a) the Recent (e. g., latitudinal gradients in many groups), (b) compilations of all marine taxa for the entire Phanerozoic (including the stage level), (c) comparisons through time within individual taxa (e. g., Foraminifera, Rugosa, Conodonta), and (d) simulation studies. Genera and families often have a more robust fossil record of diversity than species, especially for poorly sampled groups (e. g., echinoids), because of the range-through record of these polytypic taxa. Simulation studies indicate that paraphyly among traditionally defined taxa is not a fatal problem for diversity studies; in fact, when degradation of the quality of the fossil record is modelled, both diversity and rates of origination and extinction are better represented by including paraphyletic taxa than by restricting data to monophyletic clades. This result underscores the utility of traditional rank-based analyses of the history of diversity.In contrast, the three higher ranks of the Linnean hierarchy — orders, classes and phyla — are defined and recognized by key character complexes assumed to be rooted deep in the developmental program and, therefore, considered to be of special significance. These taxa are unified on the basis of body plan and function, not species morphology. Even if paraphyletic, recognition of such taxa is useful because they represent different functional complexes that reflect biological organization and major evolutionary innovations, often with different ecological capacities. Phanerozoic diversity patterns of orders, classes and phyla are not congruent with those of lower taxa; the higher groups each increased rapidly in the early Paleozoic, during the explosive diversification of body plans in the Cambrian, and then remained stable or declined slightly after the Ordovician. The diversity history of orders superficially resembles that of lower taxa, but this is a result only of ordinal turnover among the Echinodermata coupled with ordinal radiation in the Chordata; it is not a highly damped signal derived from the diversity of species, genera, or families. Despite the stability of numbers among post-Ordovician Linnean higher taxa, the diversity of lower taxa within many of these Bauplan groups fluctuated widely, and these diversity patterns signal embedded ecologic information, such as differences in flexibility in filling or utilizing ecospace.Phylogenetic analysis is vital for understanding the origins and genealogical structure of higher taxa. Only in such fashion can convergence and its implications for ecological constraints and/or opportunities be understood. But blind insistence on the use of monophyletic classifications in all studies would obscure some of the important information contained in traditional taxonomic groupings. The developmental modifications that characterize Linnean higher taxa (and traditionally separate them from their paraphyletic ancestral taxa) provide keys to understanding the role of shifting ecology in macroevolutionary success.

scholarly journals Proposals Concerning the Higher Taxa of Bacteria

1978 ◽  
Vol 28 (1) ◽  
pp. 1-6 ◽  
Author(s):  
N. E. GIBBONS ◽  
R. G. E. MURRAY
Keyword(s):  
Higher Taxa

Using higher taxa to estimate species richness: birds on New Zealand islands

Ibis ◽  
2001 ◽  
Vol 143 (1) ◽  
pp. 146-148 ◽  
Author(s):  
SIMON HODGE ◽  
CHRIS FRAMPTON
Keyword(s):  
Species Richness ◽  
New Zealand ◽  
Higher Taxa

Higher Taxa as Surrogates of Plant Biodiversity in a Megadiverse Country

2005 ◽  
Vol 19 (1) ◽  
pp. 232-238 ◽  
Author(s):  
JOSE L. VILLASEÑOR ◽  
GUILLERMO IBARRA-MANRÍQUEZ ◽  
JORGE A. MEAVE ◽  
ENRIQUE ORTÍZ
Keyword(s):  
Plant Biodiversity ◽  
Higher Taxa

scholarly journals Mechanical constraint from growing jaw facilitates mammalian dental diversity

2017 ◽  
Vol 114 (35) ◽  
pp. 9403-9408 ◽  
Author(s):  
Elodie Renvoisé ◽  
Kathryn D. Kavanagh ◽  
Vincent Lazzari ◽  
Teemu J. Häkkinen ◽  
Ritva Rice ◽  
...  
Keyword(s):  
Gene Regulatory Networks ◽  
Regulatory Networks ◽  
Self Regulation ◽  
Specific Aspect ◽  
Body Parts ◽  
Mammalian Evolution ◽  
Lateral Expansion ◽  
Model Species ◽  
Higher Taxa ◽  
Gene Regulatory

Much of the basic information about individual organ development comes from studies using model species. Whereas conservation of gene regulatory networks across higher taxa supports generalizations made from a limited number of species, generality of mechanistic inferences remains to be tested in tissue culture systems. Here, using mammalian tooth explants cultured in isolation, we investigate self-regulation of patterning by comparing developing molars of the mouse, the model species of mammalian research, and the bank vole. A distinct patterning difference between the vole and the mouse molars is the alternate cusp offset present in the vole. Analyses of both species using 3D reconstructions of developing molars and jaws, computational modeling of cusp patterning, and tooth explants cultured with small braces show that correct cusp offset requires constraints on the lateral expansion of the developing tooth. Vole molars cultured without the braces lose their cusp offset, and mouse molars cultured with the braces develop a cusp offset. Our results suggest that cusp offset, which changes frequently in mammalian evolution, is more dependent on the 3D support of the developing jaw than other aspects of tooth shape. This jaw–tooth integration of a specific aspect of the tooth phenotype indicates that organs may outsource specific aspects of their morphology to be regulated by adjacent body parts or organs. Comparative studies of morphologically different species are needed to infer the principles of organogenesis.

scholarly journals IV.—Heer's Flora Fossilis Arctica

1872 ◽  
Vol 9 (92) ◽  
pp. 69-72 ◽  
Author(s):  
Robert H. Scott
Keyword(s):  
Fossil Flora ◽  
Fossil Plants ◽  
Black Forest ◽  
Lower Carboniferous ◽  
West Greenland

In vol. ii. of his Flora Fossilis Arctica, Professor Oswald Heer has treated of the Fossil Flora of Bear Island, and shown that it belongs to the Lower Carboniferous Formation, of which it forms the lowest beds (named by him the “Ursa” beds), close to the junction with the Devonian. The Yellow Sandstone of Kiltorcan in Ireland, the Grauwacke of the Vosges, and the southern part of the Black Forest, and of St. John in Canada, belong to the same group. In the summer of 1870 two young Swedish naturalists (Wilander and Nathorst) discovered this same formation in the Klaas Billen Bay of the Eisfiord in Spitzbergen, and brought home fine specimens of Lepidodendron Veltheimianum, and Stigmaria ficoides. It has also been found in West Greenland, for Prof. Nordenskiold tells us that the Swedish expedition, which went to Disco in the course of last summer, to fetch the meteorite, weighing 25 tons, which he discovered at Ovifak in that island, has brought home fossil plants of true Carboniferous age.

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