Authors Schad W. Institution Institut fur Evolutionsbiologie und Morphologie, Universitat
Authors
Schad W.
Institution
Institut fur Evolutionsbiologie und Morphologie, Universitat
Witten/Herdecke, Germany.
Title
Heterochronical patterns of evolution in the transitional stages of
vertebrate classes.
Source
Acta Biotheoretica. 41(4):383-9, 1993 Dec.
Abstract
Transitional forms of the recent classes of vertebrates are only known in
paleontology. The well described examples are: Eusthenopteron foordi
(Crossopterygii), Ichthyostega and Acanthostega (Labyrinthodontia) between
Osteichthyes and Amphibia, Seymouria baylorensis (Amphibiosaria) between
Amphibia and Reptilia, Archaeopteryx lithographica (Archaeornithes)
between Reptilia and Aves, and the mammal-like reptiles Pelycosauria,
Therapsida and Cynodontia between Reptilia and Aves, and the description
of their phylogenetical heterochronies in terms of peramorphosis and
paedomorphosis shows the progressive role of the motorial, especially the
locomotorial organ systems and their functions in comparison with the
retarded evolution of the axial system, especially the skull and central
nervous system. The evolution of the Hominidae shows the same rule. The
evaluation of these transitional forms in their fossil context reveals
them as inhabitants of biotopes situated in the border areas of coastal
and shore landscapes of marine, brackish or fresh water. These biotopes
have obviously favoured the innovations on the high taxonimic level of
macro-evolutionary characteristics.
Authors
Trinkaus E.
Institution
Department of Anthropology, University of New Mexico, Albuquerque 87131.
Title
Cladistics and the hominid fossil record [see comments]. [Review]
Source
American Journal of Physical Anthropology. 83(1):1-11, 1990 Sep.
Abstract
Cladistic methodology has become common in phylogenetic analyses of the
hominid fossil record. Even though it has correctly placed emphasis on
morphology for the primary determination of affinities between groups and
on explicit statements regarding traits and methods employed in making
phylogenetic assessments, cladistics nonetheless has limitations when
applied to the hominid fossil record. These include 1) the uncritical
assumption of parsimony, 2) uncertainties in the identification of
homoplasies, 3) difficulties in the appropriate delimitation of samples
for analysis, 4) failure to account for normal patterns of variation, 5)
methodological problems with the appropriate identification of
morphological traits involving issues of biological relevance,
intercorrelation, primary versus secondary characters, and the use of
continuous variables, 6) issues of polarity identification, and 7)
problems in hypothesis testing. While cladistics has focused attention on
alternative phylogenetic reconstructions in hominid paleontology and on
explicit statements regarding their morphological and methodological
underpinnings, its biological limitations are too abundant for it to be
more than a heuristic device for the preliminary ordering of complex human
paleontological and neonatological data. [References: 69]
Authors
Diamond MK.
Institution
Department of Organismal Biology and Anatomy, University of Chicago,
Illinois 60637.
Title
Homologies of the stapedial artery in humans, with a reconstruction of the
primitive stapedial artery configuration of Euprimates.
Source
American Journal of Physical Anthropology. 84(4):433-62, 1991 Apr.
Local Messages
Data drawn from the perspectives of paleontology, comparative anatomy,
embryology, teratology, and normal adult variation were analyzed with nine
homology criteria in order to determine the homologues of the stapedial
artery in adult humans. It was determined that 1) the stem of the
stapedial artery does not persist within the cranial cavity; 2) the stem
of the ramus inferior is retained in its entirety and forms the upper
portion of the stem of the middle meningeal artery; 3) the proximal part
of the ramus infraorbitalis is normally absent and is replaced by a
collateral shunt arising from the ramus mandibularis; 4) the ramus
mandibularis is retained and forms the lower portion of the middle
meningeal stem and the inferior alveolar artery; 5) the most proximal
portion of the maxillary artery is formed by an anastomotic shunt
connecting the external carotid artery to the ramus mandibularis; 6) the
anterior division of the ramus superior is normally present and well
developed; 7) the posterior division of the ramus superior is present in
many individuals; and 8) the junction of the two divisions of the ramus
superior with the ramus inferior usually migrates to the floor of the
middle cranial fossa. The range of human arterial patterns, and those of
all other euprimates, can be derived from a hypothetical primitive pattern
that is very similar to that of primitive rodents. In this pattern, the
stapedial artery stem enters the middle cranial fossa and trifurcates into
the anterior and posterior divisions of the ramus superior and the ramus
inferior. In their evolution, strepsirhines initially lose the ramus
inferior and haplorhines initially reduce the stapedial artery stem.
Authors
Fox RC. Youzwyshyn GP. Krause DW.
Institution
Laboratory for Vertebrate Paleontology, Department of Geology, University
of Alberta, Edmonton, Canada.
Title
Post-Jurassic mammal-like reptile from the Palaeocene.
Abstract
Mammal-like reptiles of the order Therapsida document the emergence of
mammals from more primitive synapsids and are of unique zoological and
palaeontological interest on that account. Therapsids, first appearing in
the Early Permian, were thought to become extinct in the Middle Jurassic,
soon after the Late Triassic origin of mammals. Here, however, we report
the discovery of a therapsid from the late Palaeocene, 100 million years
younger than the youngest previous occurrence of the order. This discovery
nearly doubles the stratigraphic range of therapsids and furnishes their
first record from the Cenozoic. The documenting fossils, an incomplete
dentary containing three teeth, and four isolated teeth from other,
conspecific individuals (Fig. 1), are from the Paskapoo Formation, at
Cochrane, Alberta, Canada, from beds yielding a diverse mammalian fauna of
early Tiffanian age. These specimens are catalogued in the collections of
the University of Alberta Laboratory for Vertebrate Paleontology (UALVP)
and provide the basis for a new taxon, as named and described below: (see
text)
Authors
Ciochon RL. Piperno DR. Thompson RG.
Institution
Department of Anthropology, University of Iowa, Iowa City 52242.
Title
Opal phytoliths found on the teeth of the extinct ape Gigantopithecus
blacki: implications for paleodietary studies.
Source
Proceedings of the National Academy of Sciences of the United States of
America. 87(20):8120-4, 1990 Oct.
Abstract
Identification of opal phytoliths bonded to the enamel surface of the
teeth of Gigantopithecus blacki indicates that this extinct ape had a
varied diet of grasses and fruits. By using the scanning electron
microscope at magnifications of 2000-6000x specific opal phytoliths were
observed and photographed on the fossilized teeth of an extinct species.
Since opal phytoliths represent the inorganic remains of once-living plant
cells, their documentation on the teeth of Gigantopithecus introduces a
promising technique for the determination of diet in extinct mammalian
species which should find numerous applications in the field of
paleoanthropology as well as vertebrate paleontology.
Authors
Nee S. Mooers AO. Harvey PH.
Institution
Department of Zoology, University of Oxford, United Kingdom.
Title
Tempo and mode of evolution revealed from molecular phylogenies.
Source
Proceedings of the National Academy of Sciences of the United States of
America. 89(17):8322-6, 1992 Sep 1.
Abstract
The analysis of the tempo and mode of evolution has a strong tradition in
paleontology. Recent advances in molecular phylogenetic reconstruction
make it possible to complement this work by using data from extant
species.
Authors
Nee S. Mooers AO. Harvey PH.
Institution
Department of Zoology, University of Oxford, United Kingdom.
Title
Tempo and mode of evolution revealed from molecular phylogenies.
Source
Proceedings of the National Academy of Sciences of the United States of
America. 89(17):8322-6, 1992 Sep 1.
Abstract
The analysis of the tempo and mode of evolution has a strong tradition in
paleontology. Recent advances in molecular phylogenetic reconstruction
make it possible to complement this work by using data from extant
species.
Authors
Gould SJ.
Institution
Museum of Comparative Zoology, Harvard University, Cambridge, MA 02138.
Title
Tempo and mode in the macroevolutionary reconstruction of Darwinism.
[Review]
Source
Proceedings of the National Academy of Sciences of the United States of
America. 91(15):6764-71, 1994 Jul 19.
Abstract
Among the several central meanings of Darwinism, his version of Lyellian
uniformitarianism--the extrapolationist commitment to viewing causes of
small-scale, observable change in modern populations as the complete
source, by smooth extension through geological time, of all magnitudes and
sequences in evolution--has most contributed to the causal hegemony of
microevolution and the assumption that paleontology can document the
contingent history of life but cannot act as a domain of novel
evolutionary theory. G. G. Simpson tried to combat this view of
paleontology as theoretically inert in his classic work, Tempo and Mode in
Evolution (1944), with a brilliant argument that the two subjects of his
title fall into a unique paleontological domain and that modes (processes
and causes) can be inferred from the quantitative study of tempos
(pattern). Nonetheless, Simpson did not cash out his insight to
paleontology's theoretical benefit because he followed the strict doctrine
of the Modern Synthesis. He studied his domain of potential theory and
concluded that no actual theory could be found--and that a full account of
causes could therefore be located in the microevolutionary realm after
all. I argue that Simpson was unduly pessimistic and that modernism's
belief in reductionistic unification (the conventional view of Western
intellectuals from the 1920s to the 1950s) needs to be supplanted by a
postmodernist commitment to pluralism and multiple levels of causation.
Macro- and microevolution should not be viewed as opposed, but as truly
complementary. I describe the two major domains where a helpful
macroevolutionary theory may be sought--unsmooth causal boundaries between
levels (as illustrated by punctuated equilibrium and mass extinction) and
hierarchical expansion of the theory of natural selection to levels both
below (gene and cell-line) and above organisms (demes, species, and
clades). Problems remain in operationally defining selection at
non-organismic levels (emergent traits vs. emergent fitness approaches,
for example) and in specifying the nature and basis of levels, but this
subject should be the central focus in formulating a more ample and
satisfactory general theory of evolution on extended Darwinian principles.
[References: 43]
Authors
Savic IR. Nevo E.
Institution
Institute of Zoology, Faculty of Science, University of Belgrade,
Yugoslavia.
Title
The Spalacidae: evolutionary history, speciation and population biology.
[Review]
Source
Progress in Clinical & Biological Research. 335:129-53, 1990.
Abstract
The evolutionary history of Spalacidae is reviewed taxonomically,
paleontologically and neontologically. We focused selectively on taxonomy,
biogeography, paleontology and evolutionary origins, chromosomal
evolution, population biology and the species concept in Spalacidae. We
concluded that the taxonomy of Spalacidae needs a modern revision based on
chromosome and molecular-genetic data, beside that of morphology,
physiology and behavior. The subterranean Spalacidae originated probably
from a muroid-cricetoid stock in Asia Minor or vicinity, in Upper
Oligocene times and adaptively radiated underground in the Balkans,
steppic Russia and Middle East, extending into North Africa. The major
important evolutionary feature in peripatric or allopatric speciation and
adaptive radiation was karyotypic evolution, primarily through
Robertsonian changes. More than 30 karyotypes (2n = 38-62; NF = 72-124)
earlier represented by 8 classical species, occur primarily allopatrically
or parapatrically, with only marginal sympatry, across the Eastern
Mediterranean range of the family. Most karyotypes represent biospecies
adapted at multiple organizational levels to their different ecologies. A
short overview is presented on population biology and life history
parameters of the Spalacidae which result in K-selected, "equilibrium
species". Speciation in action and adaptive radiation embracing molecular
and organismal adptations to the subterranean unique ecotope and to four
different climatic regimes, have been multidisciplinarily studied in the
Israeli Spalax ehrenbergi superspecies. [References: 75]
In truth, I have read some of the above material. When Dr. Gould tells me
that there is a serious flaw in evolutionary theory, I will believe it.
For every one of the haphazard ICR tractw you post, I have THOUSANDS of
articles that show that evolution occured.
E-Mail Fredric L. Rice / The Skeptic Tank
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