Phanerozoic Diversity Research Articles

Phanerozoic Diversity Patterns: Profiles in Macroevolution. Proceedings of a Symposium Held June 21, 1982. at the University of California, Santa Barbara. James W. Valentine

Previous articleNext article No AccessNew Biological BooksPhanerozoic Diversity Patterns: Profiles in Macroevolution. Proceedings of a Symposium Held June 21, 1982. at the University of California, Santa Barbara. James W. Valentine Jerzy TrammerJerzy Trammer Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by The Quarterly Review of Biology Volume 61, Number 4Dec., 1986 Published in association with Stony Brook University Article DOIhttps://doi.org/10.1086/415156 Copyright 1986 Stony Brook Foundation, Inc.PDF download Crossref reports no articles citing this article.

Paleobiology: Phanerozoic Diversity Patterns . Profiles in Macroevolution. James W. Valentine, Ed. Princeton University Press, Princeton, NJ, and Pacific Division, American Association for the Advancement of Science, San Francisco, 1985 (distributor, Princeton University Press). x, 442 pp., illus. $50; paper, $15. Princeton Series in Geology and Paleontology. From a symposium, Santa Barbara, CA, June 1982.

Paleobiology: <i>Phanerozoic Diversity Patterns</i> . Profiles in Macroevolution. James W. Valentine, Ed. Princeton University Press, Princeton, NJ, and Pacific Division, American Association for the Advancement of Science, San Francisco, 1985 (distributor, Princeton University Press). x, 442 pp., illus. $50; paper, $15. Princeton Series in Geology and Paleontology. From a symposium, Santa Barbara, CA, June 1982.

Diversity and the Fossil Record - Phanerozoic Diversity Patterns: Profiles in Macroevolution. Edited by James W. Valentine Princeton University Press and Pacific Division, American Association for the Advancement of Science; Princeton and San Francisco. 1985. $50.00 (cloth); $15.00 (paper).

Diversity and the Fossil Record - Phanerozoic Diversity Patterns: Profiles in Macroevolution. Edited by James W. Valentine Princeton University Press and Pacific Division, American Association for the Advancement of Science; Princeton and San Francisco. 1985. $50.00 (cloth); $15.00 (paper).

Biological Diversification and Its Causes

Three major patterns of diversity are defined and a general hypothesis proposed to explain them. These patterns include (a) macroevolutionary diversity, encompassing temporal changes in species richness within and among clades, (b) global diversity, in which gradients of diversity among communities or biotas vary spatially and temporally, and (c) Phanerozoic diversity, which describes largescale temporal variation in species richness within the entire biosphere. Current explanatory hypotheses for these patterns are generally formulated for systems that are assumed to be in a state of ecological equilibrium, with speciation and extinction rates being diversity-dependent. This paper describes an alternative model of diversification in which speciation and extinction rates are independent of standing diversity. It is postulated that speciation rate is controlled primarily by large-scale changes in lithospheric (geomorphological) complexity. This hypothesis is a deductive consequence of biological data showing that allopatric speciation is the general mode of differentiation, and of geological data showing that tectonic changes within the lithosphere are responsible for the formation of geographic and ecological barriers. This hypothesis makes a number of predictions about patterns of endemism, historical biogeography, and spatial gradients of diversity, and data consistent with these predictions are presented. Other potential regulators of speciation rate (degree of morphogenetic variability within species, behavioral-ecological variability within species, intensity of sexual selection) are discussed and their potential roles in shaping diversity patterns are evaluated. Although they may occasionally be important for explaining some intracladal patterns of diversification, they are insufficient by themselves to account for spatial patterns or long-term changes of diversity within biotas. Extinction rate is postulated to be controlled primarily by spatial and temporal changes in environmental harshness, particularly as the latter is manifested by gradients of temperature and moisture. Considerable neontological and paleontological data suggest that change in harshness is a major factor shaping temporal and spatial patterns of diversity through its effects on extinction rate. Other causal mechanisms of extinction, particularly the tectonic elimination of habitats, may be of importance for specific groups of organisms (e.g., marine shelf communities following continent-continent collisions) at specific localities and times (e.g., near a volcanic eruption) but are not likely to play as important a role as does change in harshness. Together, the two main controls on speciation and extinction define a diversity-independent process of diversification. The biosphere can be viewed as an open thermodynamic system that can be expected to grow in complexity (including diversity) through time as a result of the inflow of matter and energy. This increase in complexity is constrained by external factors (physical changes in the biosphere or

PATTERNS OF EVOLUTION AMONG THE ARTIODACTYLA AND PERISSODACTYLA (MAMMALIA).

Diversity changes through time of the mammalian ungulate orders Artiodactyla and Perissodactyla have been touted long and widely as exemplifying ordinal level taxonomic (and presumably ecologic) displacement (Simpson, 1953; Stanley, 1974) since, as Van Valen (1971) has pointed out, they have a nearly identical way of life (=adaptive zone, Simpson, 1953; plus competitive interactions, Van Valen, 1971). The controversial assumption that herbivores are food limited (cf. Hairston et al., 1960; Murdoch, 1966; Ehrlich and Birch, 1967; Slobodkin et al., 1967) is implicit to this generalization. Both orders presumably appeared in the late Paleocene, as they are well differentiated by the early Eocene (Figs. 1 and 2). While perissodactyls seem to have undergone taxonomic diversification at both generic and familial levels somewhat earlier than artiodactyls, the difference is much less than most authors suggest. Perissodactyls declined in importance after the middle Eocene, while the artiodactyls maintained a stable dominance from the early Oligocene until their apparently enormous Plio-Pleistocene radiation. Various deterministic hypotheses have been forwarded in explanation of this pattern. Such hypotheses usually invoke the acquisition of one or more characters (double trochleated astragalus, selenodont molars, ruminant digestion) by the artiodactyls as giving that group a relative adaptive advantage. Here I review the evolutionary histories of these two orders in search of evidence supporting these hypotheses. Further, I analyze overall patterns to detect possible correspondence to or support for the various empirical (Valentine, 1973) and equilibrium (Mark and Flessa, 1977) models of Phanerozoic diversity. All data have been compiled from Romer (1966). Current revisions might alter the data somewhat, but it is doubtful that the differences would be systematic or great. Question-marked taxa or those not designated chronostratigraphically to subepoch were ignored. The time scale used is from Harland et al. (1964).

Relationship between biological extinctions and geomagnetic reversals

Research Article| December 01, 1980 Relationship between biological extinctions and geomagnetic reversals Roy E. Plotnick Roy E. Plotnick 1Department of the Geophysical Sciences, University of Chicago, 5734 South Ellis Avenue, Chicago, Illinois 60637 Search for other works by this author on: GSW Google Scholar Author and Article Information Roy E. Plotnick 1Department of the Geophysical Sciences, University of Chicago, 5734 South Ellis Avenue, Chicago, Illinois 60637 Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1980) 8 (12): 578–581. https://doi.org/10.1130/0091-7613(1980)8<578:RBBEAG>2.0.CO;2 Article history First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Roy E. Plotnick; Relationship between biological extinctions and geomagnetic reversals. Geology 1980;; 8 (12): 578–581. doi: https://doi.org/10.1130/0091-7613(1980)8<578:RBBEAG>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract It has been repeatedly suggested that reversals of Earth's magnetic field play a controlling role in evolution. Empirical evidence put forward to support this hypothesis has come from comparisons of the stratigraphic positions of microfossil extinctions with individual reversals and from comparisons of various estimates of changes in Phanerozoic diversity or turnover rates to some measurement of polarity change. Published associations between microfossil extinctions and magnetic reversals are reanalyzed using probabilistic techniques. The interrelationships of Phanerozoic diversity and turnover rates to measurements of the magnetic field are examined through correlation analysis. Results indicate that no currently demonstrable relationship exists between faunal extinctions and geomagnetic reversals. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

On the relationship between Phanerozoic diversity and changes in habitable area

Applications of the species-area equation to studies of fluctuations in Phanerozoic diversity have great promise but can involve questionable assumptions. Sepkoski's (1976) analysis of marine diversity throughout the Phanerozoic record assumes that total rock volume is a sufficient measure of sampling efficiency and that an isomorphous equation is appropriate for all of Phanerozoic time. The area of marine sedimentary rock and the area of continental seas are not independent variables. Residual variation in diversity (that which remains after subtracting the effects of rock volume) might be explained by either the species-area relationship or by another component of sampling efficiency. A species-area equation in which the slope (z) and intercept (k) are assumed constant receives mixed support from arguments based on Recent terrestrial and aquatic organisms. Observed z-values cluster near a value of 0.30 despite a wide taxonomic range, but are generally below those found for the Phanerozoic record. Temporal fluctuations in k values, in response to changes in the area of continental seas, may produce elevated estimates of z.

Phanerozoic Diversity Patterns: Tests for Randomness

Patterns of origination within taxa, and patterns of dominance diversity among taxa are examined to distinguish nonrandom from random components. Numbers of first appearances per stage are sporadic and tend to be distributed nonrandomly through time. However, many taxa show a randomly distributed order of stages containing first appearances. A stochastic model of origination only partially reflects the patterns seen in the fossil record. Levels of dominance diversity among many taxa vary synchronously and at the same rates. The Phanerozoic is characterized by a succession of groups of taxa. Such associations are not predicted by a random model of diversity change. The fossil record is examined for evidence of an evolutionary equilibrium with constant taxonomic turnover. Fossil extinction and origination rates do not support the assumption of a static evolutionary equilibrium. Taxonomic and morphological evidence is consistent with a model of progressive specialization through the Phanerozoic.