Report on the archetype and homologies of the vertebrate skeleton,

Owen, Richard

doi:10.5962/bhl.title.61890

Cited by 86 publications

(66 citation statements)

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“…Patterson (1982) focused on operational criteria for recognition ofhomologies (and other relations among characters), and suggests a set of three tests for homology: similarity, conjunction, and congruence. Similarity and congruence with other homologies have long been used to recognize homologies (e.g., Owen, 1848, andHennig, 1950, respectively;see Wiley, 1981). The conjunction test is new and posits that homologous characters cannot cooccur in the same organisms.…”

Section: Hybrids and Character Analysismentioning

confidence: 99%

Hybrids and Phylogenetic Systematics I. Patterns of Character Expression in Hybrids and Their Implications for Cladistic Analysis

McDade

1990

Evolution

118

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Abstract. -Interspecific hybridization is considered common among plants, but the methods of cladistic systematics produce only divergently branching phylogenetic hypotheses and thus cannot give the correct phylogeny ifan analysis includes hybrids. Empirical studies ofthe impact ofknown hybrids on phylogenetic analysis are lacking, and are necessary to begin to understand the problems that we face if hybrids are often included in cladistic analysis. Examination of the implications of hybrids for cladistics must begin with patterns of character expression in hybrids. This study includes 17 hybrids and their nine parental taxa that are Central American species ofAphelandra (Acanthaceae), analyzed using a set of50 morphological characters. The hybrids are overwhelmingly intermediate as quantitatively scored for phylogenetic analysis. They express maternal and paternal, and primitive and derived characters in equal frequencies, showing no evidence of predominant inheritance of derived character states as has been assumed by most cladists who have considered hybrids theoretically. Because oftheir known genetic constitution, hybrids were useful in homology assessment and ordering character states. The parental character set was generally robust, but some changes were made to reflect the special evidence offered by the hybrids. These hybrids suggest that the inclusion of hybrids in phylogenetic analysis will not lead to unresolved cladograms with rampant homoplasy, as has been predicted by other authors. Instead, the patterns of character inheritance in these hybrids lead to the prediction that a hybrid will be placed by phylogenetic analysis as a basal lineage to the clade that includes its most derived parent, with relatively little effect on homoplasy. These predictions will be evaluated by incorporation of the hybrids in phylogenetic analyses, to be reported in a subsequent paper.

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Section: Hybrids and Character Analysismentioning

confidence: 99%

Hybrids and Phylogenetic Systematics I. Patterns of Character Expression in Hybrids and Their Implications for Cladistic Analysis

McDade

1990

Evolution

118

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“…(7) Finally, the term Pegasoferae has recently been proposed (38) for a position of bats closer to Ferae than artiodactyls, i.e., a perissodactyl-carnivoranpangolin-chiropteran clade. Placentalia plus mammals (e.g., asioryctitheres, zalambdalestids) closer to placentals than to marsupials 2 Placentalia (106) All descendants of the last common ancestor of sloth, tenrec, human, horse 3 Atlantogenata (20) Xenarthra, Afrotheria Xenafrotheria (107) Notoplacentalia (18) 4 Afrotheria (108) Paenungulata, Afroinsectiphilia Afroplacentalia (18) 5 Afroinsectiphilia (109) Tubulidentata, Afroinsectivora Fossoromorpha (110) 6 Afroinsectivora (109) Tenrecoidea, Macroscelididae Haemochoralia (110) 7 Tenrecoidea (111) Tenrecidae, Chrysochloridae Afrosoricida (108) Tenrecomorpha (34) 8 Paenungulata (25) Hyracoidea, Tethytheria Uranotheria (112) 9 Tethytheria (26) Proboscidea, Sirenia 10 Boreoeutheria (22) Laurasiatheria, Euarchontoglires Boreotheria (109) Boreoplacentalia (18) 11 Laurasiatheria (20) Lipotyphla, Scrotifera Laurasiaplacentalia (18) 12 Scrotifera (20) Ferae, Chiroptera, Euungulata Variamana (110) 13 Euungulata (109) Artiodactyla, Perissodactyla 14 Artiodactyla (113) Whippomorpha, Ruminantia, Tylopoda, Suiformes Cetartiodactyla (114) Eparctocyona (112) 15 Ferae (112) Carnivora, Pholidota Ostentoria (37) 16 Whippomorpha (20) Cetacea, Hippopotamidae Cetancodonta (34) 17 Lipotyphla (115) Erinaceidae, Talpidae, Soricidae, Solenodon Eulipotyphla (20) 18 Euarchontoglires …”

Section: Laurasiatheriamentioning

confidence: 99%

The new framework for understanding placental mammal evolution

2009

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An unprecedented level of confidence has recently crystallized around a new hypothesis of how living placental mammals share a pattern of common descent. The major groups are afrotheres (e.g., aardvarks, elephants), xenarthrans (e.g., anteaters, sloths), laurasiatheres (e.g., horses, shrews), and euarchontoglires (e.g., humans, rodents). Compared with previous hypotheses this tree is remarkably stable; however, some uncertainty persists about the location of the placental root, and (for example) the position of bats within laurasiatheres, of sea cows and aardvarks within afrotheres, and of dermopterans within euarchontoglires. A variety of names for sub‐clades within the new placental mammal tree have been proposed, not all of which follow conventions regarding priority and stability. More importantly, the new phylogenetic framework enables the formulation of new hypotheses and testing thereof, for example regarding the possible developmental dichotomy that seems to distinguish members of the newly identified southern and northern radiations of living placental mammals.

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“…Traditionally, homology was never considered in terms of landmarks or points, but rather solely in terms of whole structures. Owen first formalized it in 1843 as the same organ in different animals (Owen, 1846). In contrast, the raw data for geometrical homology are landmarks, which are presumed, (if not always satisfying the criterion) to be in some sense 'homologous'.…”

Section: The Problem Of Homologymentioning

confidence: 99%

A Fourier-wavelet representation of 2-D shapes: sexual dimorphism in the Japanese cranial base

Lestrel

César

Takahashi

et al. 2004

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We present a new approach called computational shape analysis, which utilizes a Fourierwavelet representation for characterizing shape features of 2-D forms commonly encountered in a wide set of sub-disciplines within the biological sciences. The morphology of interest consists of the human cranial base (CB) as depicted on lateral cephalometric radiographs. Given a complex irregularly bounded form in Cartesian coordinate space, we first compute elliptical Fourier functions (EFFs) using a set of closely-spaced pseudo-homologous (x, y) points, starting at basion, to create a precise analog of the closed contour. This computed contour is then scaled (size-standardization) and rotated (positional-orientation) to provide for a common normalization. This insures that the representation is invariant with respect to starting point, size and orientation. Utilizing the EFFs, global aspects of the CB can then be extracted. The coordinates derived from the EFF were subsequently submitted to a continuous wavelet transform (CWT). Wavelet coefficients were then computed to identify localized features. The significant advantage of wavelets is that they are able to objectively identify changes in boundary curvature, thereby depicting localized aspects not easily attainable with other methods. Utilizing a sample of 297 Japanese cranial base outlines, statistically-significant differences in sex and archeological age were found. Although archeological age differences were present, they were small and largely random in character, suggesting stability in the CB structures. The presence of sexually dimorphic differences is consistent with earlier data derived from studies of Macaca nemestrina. In the current study, these differences in sexual dimorphism were present for every group starting with the Yayoi period and continuing up to the Modern period. Consequently, one may infer that the pattern of sexual dimorphism documented in the Japanese CB, is a primate pattern with an ancient evolutionary history. Wavelets were particularly useful in objectively identifying this sexual dimorphism. The results demonstrate that the Fourier-wavelet representation is a practical approach for numerically describing and visually depicting both global and localized features.

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Report on the archetype and homologies of the vertebrate skeleton,

Cited by 86 publications

References 0 publications

Hybrids and Phylogenetic Systematics I. Patterns of Character Expression in Hybrids and Their Implications for Cladistic Analysis

Hybrids and Phylogenetic Systematics I. Patterns of Character Expression in Hybrids and Their Implications for Cladistic Analysis

The new framework for understanding placental mammal evolution

A Fourier-wavelet representation of 2-D shapes: sexual dimorphism in the Japanese cranial base

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