Theoretical Evolutionary Rates in Plant Groups and the Fossil Record

Brittonia ◽  
1977 ◽  
Vol 29 (3) ◽  
pp. 241 ◽  
Author(s):  
Karl J. Niklas
Keyword(s):  
Fossil Record ◽  
Evolutionary Rates ◽  
Plant Groups

Fossil preservation and the stratigraphic ranges of taxa

Paleobiology ◽  
1996 ◽  
Vol 22 (2) ◽  
pp. 121-140 ◽  
Author(s):  
Mike Foote ◽  
David M. Raup
Keyword(s):  
Fossil Record ◽  
Mammalian Species ◽  
Evolutionary Rates ◽  
Extinction Rate ◽  
Mammal Species ◽  
Original Distribution ◽  
Lower Ordovician ◽  
Stratigraphic Ranges ◽  
Fossil Preservation ◽  
Rule Out

The incompleteness of the fossil record hinders the inference of evolutionary rates and patterns. Here, we derive relationships among true taxonomic durations, preservation probability, and observed taxonomic ranges. We use these relationships to estimate original distributions of taxonomic durations, preservation probability, and completeness (proportion of taxa preserved), given only the observed ranges. No data on occurrences within the ranges of taxa are required. When preservation is random and the original distribution of durations is exponential, the inference of durations, preservability, and completeness is exact. However, reasonable approximations are possible given non-exponential duration distributions and temporal and taxonomic variation in preservability. Thus, the approaches we describe have great potential in studies of taphonomy, evolutionary rates and patterns, and genealogy.Analyses of Upper Cambrian-Lower Ordovician trilobite species, Paleozoic crinoid genera, Jurassic bivalve species, and Cenozoic mammal species yield the following results: (1) The preservation probability inferred from stratigraphic ranges alone agrees with that inferred from the analysis of stratigraphic gaps when data on the latter are available. (2) Whereas median durations based on simple tabulations of observed ranges are biased by stratigraphic resolution, our estimates of median duration, extinction rate, and completeness are not biased. (3) The shorter geologic ranges of mammalian species relative to those of bivalves cannot be attributed to a difference in preservation potential. However, we cannot rule out the contribution of taxonomic practice to this difference. (4) In the groups studied, completeness (proportion of species [trilobites, bivalves, mammals] or genera [crinoids] preserved) ranges from 60% to 90%. The higher estimates of completeness at smaller geographic scales support previous suggestions that the incompleteness of the fossil record reflects loss of fossiliferous rock more than failure of species to enter the fossil record in the first place.

Evolution and the fossil record: patterns, rates, and processes

1987 ◽  
Vol 65 (5) ◽  
pp. 1053-1060 ◽  
Author(s):  
Philip D. Gingerich
Keyword(s):  
Fossil Record ◽  
Evolutionary Rates ◽  
Short Intervals ◽  
Evolutionary Diversification ◽  
Extinction Rates ◽  
Local Areas ◽  
Climatic Cooling ◽  
Intensive Sampling ◽  
Underlying Processes ◽  
Morphological Innovation

Mammals have an unusually good Cenozoic fossil record providing evidence of their evolutionary diversification. We view this record in hindsight, which biases our perception in many ways. Overall worldwide diversity appears to increase exponentially through time, while intensive sampling in local areas indicates that modern levels of diversity were achieved early in the Cenozoic. The evident significance of Pleistocene extinctions depends critically on how extinction rates are quantified. Our taxonomic hierarchy probably reflects the number of major faunal turnovers a group has survived rather than declining intensity of successive turnovers. Morphological innovation and taxonomic diversification appear following intervals of climatic cooling, suggesting that major features of evolution are extrinsically controlled. Favorable stratigraphic settings yield detailed records of gradual anagenesis and cladogenesis in mammals, with intermediates present as evidence of transition. The apparent dichotomy between high evolutionary rates measured by neontologists over short intervals of time and low evolutionary rates measured by paleontologists over long intervals of time disappears when rates are measured on intermediate scales of time. Microevolution and macroevolution are manifestations of common underlying processes expressed on different time scales.

scholarly journals Ecological opportunity and the rise and fall of crocodylomorph evolutionary innovation

2021 ◽  
Vol 288 (1947) ◽  
Author(s):  
Thomas L. Stubbs ◽  
Stephanie E. Pierce ◽  
Armin Elsler ◽  
Philip S. L. Anderson ◽  
Emily J. Rayfield ◽  
...  
Keyword(s):  
Fossil Record ◽  
Evolutionary Biology ◽  
Evolutionary Dynamics ◽  
Evolutionary Rates ◽  
Apex Predators ◽  
Ecological Opportunity ◽  
Evolutionary Innovation ◽  
Great Heterogeneity ◽  
Living Species

Understanding the origin, expansion and loss of biodiversity is fundamental to evolutionary biology. The approximately 26 living species of crocodylomorphs (crocodiles, caimans, alligators and gharials) represent just a snapshot of the group's rich 230-million-year history, whereas the fossil record reveals a hidden past of great diversity and innovation, including ocean and land-dwelling forms, herbivores, omnivores and apex predators. In this macroevolutionary study of skull and jaw shape disparity, we show that crocodylomorph ecomorphological variation peaked in the Cretaceous, before declining in the Cenozoic, and the rise and fall of disparity was associated with great heterogeneity in evolutionary rates. Taxonomically diverse and ecologically divergent Mesozoic crocodylomorphs, like marine thalattosuchians and terrestrial notosuchians, rapidly evolved novel skull and jaw morphologies to fill specialized adaptive zones. Disparity in semi-aquatic predatory crocodylians, the only living crocodylomorph representatives, accumulated steadily, and they evolved more slowly for most of the last 80 million years, but despite their conservatism there is no evidence for long-term evolutionary stagnation. These complex evolutionary dynamics reflect ecological opportunities, that were readily exploited by some Mesozoic crocodylomorphs but more limited in Cenozoic crocodylians.

scholarly journals Trilobite evolutionary rates constrain the duration of the Cambrian explosion

2019 ◽  
Vol 116 (10) ◽  
pp. 4394-4399 ◽  
Author(s):  
John R. Paterson ◽  
Gregory D. Edgecombe ◽  
Michael S. Y. Lee
Keyword(s):  
Fossil Record ◽  
Evolutionary Rates ◽  
Cambrian Explosion ◽  
Molecular Clocks ◽  
Genomic Evolution ◽  
Quantitative Evidence ◽  
Dating Methods ◽  
Marine Biosphere ◽  
Evolutionary Stasis ◽  
Broad Scale

Trilobites are often considered exemplary for understanding the Cambrian explosion of animal life, due to their unsurpassed diversity and abundance. These biomineralized arthropods appear abruptly in the fossil record with an established diversity, phylogenetic disparity, and provincialism at the beginning of Cambrian Series 2 (∼521 Ma), suggesting a protracted but cryptic earlier history that possibly extends into the Precambrian. However, recent analyses indicate elevated rates of phenotypic and genomic evolution for arthropods during the early Cambrian, thereby shortening the phylogenetic fuse. Furthermore, comparatively little research has been devoted to understanding the duration of the Cambrian explosion, after which normal Phanerozoic evolutionary rates were established. We test these hypotheses by applying Bayesian tip-dating methods to a comprehensive dataset of Cambrian trilobites. We show that trilobites have a Cambrian origin, as supported by the trace fossil record and molecular clocks. Surprisingly, they exhibit constant evolutionary rates across the entire Cambrian, for all aspects of the preserved phenotype: discrete, meristic, and continuous morphological traits. Our data therefore provide robust, quantitative evidence that by the time the typical Cambrian fossil record begins (∼521 Ma), the Cambrian explosion had already largely concluded. This suggests that a modern-style marine biosphere had rapidly emerged during the latest Ediacaran and earliest Cambrian (∼20 million years), followed by broad-scale evolutionary stasis throughout the remainder of the Cambrian.

A reappraisal of the systematics, biogeography, and evolution of fossil horses

Paleobiology ◽  
1982 ◽  
Vol 8 (4) ◽  
pp. 315-327 ◽  
Author(s):  
M. O. Woodburne ◽  
Bruce J. MacFadden
Keyword(s):  
United States ◽  
Fossil Record ◽  
Evolutionary Rates ◽  
Western United States ◽  
Vertebrate Paleontology ◽  
Evolutionary Trends ◽  
Evolutionary Pattern ◽  
Major Mode ◽  
The Rich

The founders of North American vertebrate paleontology, F. V. Hayden, Joseph Leidy, E. D. Cope, O. C. Marsh, and their colleagues, collected and described the first suites of fossil mammals obtained from the rich Tertiary successions of the western United States. Among them were remains of fossil horses, and subsequent study of these resulted in an interpretation that supported the concept of Darwinian gradualism as the major mode of evolution. The fossil record of horses also contributed importantly to the demise of orthogenesis as an evolutionary pattern, and to the evaluation of evolutionary rates and long-term evolutionary trends in a major phyletic group of organisms.

Stasis in Homo erectus defended

Paleobiology ◽  
1986 ◽  
Vol 12 (3) ◽  
pp. 324-325 ◽  
Author(s):  
G. Philip Rightmire
Keyword(s):  
Fossil Record ◽  
Homo Erectus ◽  
Evolutionary Rates ◽  
Careful Study ◽  
Continuous Change ◽  
Recent Discussion ◽  
Morphological Stasis ◽  
Geological Age ◽  
Definition Of ◽  
Key Characters

Wolpoff's (1984) recent discussion of evolutionary rates in Homo erectus deserves careful study. Whether Homo erectus or other hominid species exhibit gradual, continuous change in key characters or whether instead there is evidence for morphological stasis in the fossil record is an important question. By allocating all Homo erectus specimens to three groups of early, intermediate, and later geological age and by comparing group means for 13 measurements, Wolpoff attempts to show that gradualism is the rule for this mid-Pleistocene taxon. This method is straightforward, but it is crucial that the samples be composed in a manner which is biologically reasonable. I argue here that Wolpoff has not done this. While there may be legitimate doubt concerning sorting of the fossils, especially where specimens are incomplete, several of the individuals said to be representative of Homo erectus are simply inappropriate for use in this analysis. Wolpoff insists that he has employed a “conservative” definition of the species, but instead he has measured everything in sight. This approach to the record does influence his results.

scholarly journals Testing reduced evolutionary rates during the Late Palaeozoic Ice Age using the crinoid fossil record

Lethaia ◽  
2017 ◽  
Vol 51 (3) ◽  
pp. 330-343 ◽  
Author(s):  
Daniel C. Segessenman ◽  
Thomas W. Kammer
Keyword(s):  
Fossil Record ◽  
Evolutionary Rates ◽  
Ice Age ◽  
Late Palaeozoic

Random walk and the existence of evolutionary rates

Paleobiology ◽  
1987 ◽  
Vol 13 (4) ◽  
pp. 446-464 ◽  
Author(s):  
Fred L. Bookstein
Keyword(s):  
Random Walk ◽  
Random Walks ◽  
Empirical Data ◽  
Fossil Record ◽  
Null Model ◽  
Evolutionary Rates ◽  
Square Root ◽  
Symmetric Random Walk ◽  
Elapsed Time ◽  
Mathematical Literature

Before one can study evolutionary rates one must reject the null model of symmetric random walk. for which the requisite quantity does not exist. As random walks reliably simulate all the features we find so compelling in the fossil record—jumps, trends, and irregular cycles—rejection of this irritating hypothesis is much more difficult than one might hope. This paper reviews principal theorems from the mathematical literature of random walk and shows how they may be applied to empirical data by scaling net changes according to the square root of elapsed time. The notorious pair of “opposite” findings, equilibrium and anagenesis, may be construed as deviations from random walk in opposite directions. Malmgren's data on Globorotalia tumida, previously interpreted as an example of punctuated anagenesis, are consistent with a random walk showing neither punctuation nor anagenesis, but instead varying in speed over four subsequences.

Diversity and evolutionary rates of Cambro-Ordovician nautiloids

Paleobiology ◽  
1981 ◽  
Vol 7 (2) ◽  
pp. 216-229 ◽  
Author(s):  
Rex E. Crick
Keyword(s):  
North American ◽  
Fossil Record ◽  
Evolutionary Rates ◽  
Time Interval ◽  
Time Intervals ◽  
Frequency Distributions ◽  
Extinction Rates ◽  
History Of ◽  
Biological Aspects ◽  
Stratigraphic Ranges

The history of diversity, origination and extinction of Cambro-Ordovician nautiloid cephalopods is explored to determine if differences in evolutionary rates between nautiloid orders are sufficient to document significantly high or low rates of evolutionary turnover (taxotely of Raup and Marshall 1980). The stratigraphic ranges of 425 nautiloid genera are analyzed for this purpose.Evolutionary rates for five of the seven time intervals analyzed fall within frequency distributions of rates which are thought to be characteristic for a given time interval (horotelic distribution of Simpson 1944). Sufficient heterogeneity is present among extinction rates of Arenigian orders and origination rates of Caradocian orders to reject the null hypotheses of horotely in favor of taxotely. The orders Ellesmerocerida and Tarphycerida, each with a significantly high rate of extinction (P ≥ 0.99), and the Actinocerida, with a significantly low rate of extinction (P ≥ 0.99), were responsible for taxotely during the Arenigian. The Oncocerida and Discosorida, each with a significantly high rate of origination (P ≥ 0.99), were responsible for taxotely during the Caradocian. In each case, taxotely is attributable to the influence of North American endemics. This effect is believed to be more the result of real biological aspects of nautiloid evolution than an artifact of the fossil record.

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