The functional significance of facultative hyperthermia varies with body size and phylogeny in birds

Abstract It has previously been stated that geckos are characterized by smooth cranial bones bearing no sculpturing; however, there are many exceptions. Here we systematically characterize variation in sculpturing in cranial bones across all seven gekkotan families and examine patterns of evolutionary transitions in these traits on a multigene molecular gekkotan phylogeny to elucidate trends in phenotypic diversification in bone sculpturing. Over 195 species were reviewed using specimens where smooth, grooved, pitted and rugose sculpturing patterns were found. Of the 26 cranial bones, only seven (premaxilla, maxilla, nasal, prefrontal, frontal, parietal and postorbitofrontal) were found to bear sculpturing across more than three species. Sculpturing was found to extend beyond these seven bones onto either the dentary, surangular and/or quadrate within five species. Phylogenetic analysis showed that sculpturing evolved recently and repeatedly in several distinct lineages. The remaining 19 skull bones were smooth, except in the five species above, supporting the suggestion that smooth skull bones were ancestral in gekkotans. There is no apparent relationship between body size and the presence of bone sculpturing. The functional significance, if any, of sculpturing requires further investigation.

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Allometry of secondary, primary, and nonsexual traits in the beautiful demoiselle (Calopteryx virgo meridionalis)

Canadian Journal of Zoology ◽

10.1139/z2012-076 ◽

2012 ◽

Vol 90 (9) ◽

pp. 1094-1101 ◽

Cited By ~ 8

Author(s):

D. Outomuro ◽

A. Cordero-Rivera

Keyword(s):

Body Size ◽

Functional Significance ◽

Spot Size ◽

The Body ◽

Shaft Length ◽

Positive Allometry ◽

Selective Pressures ◽

Functional Knowledge ◽

Significant Regression ◽

Static Allometry

The static allometry between the size of a trait and the body size results from the net selection forces acting on the evolution of both the trait and the body size. An increased knowledge of the functional significance of traits is necessary to understand observed allometric patterns. We studied several traits of males of the beautiful demoiselle ( Calopteryx virgo meridionalis Sélys, 1873), for which there is a good functional knowledge of the genitalic traits and ornaments. We found positive allometry for the wing spot size (considered a secondary sexual trait) and for the distal width (but not length) of the anal appendages, which are used for grasping the female prior to copulation. Regarding the male secondary genitalia, the length but not the width of the big horns of the aedeagus showed an isometric pattern. The aedeagus shaft length showed a negative allometric pattern, while its distal width did not show a significant regression. The slopes of the regressions were higher when using wing length than when using body length as estimators of body size, with the exception of wing spot length. Results are discussed based on the functional significance of the study traits, as well as the pre- and post-copulatory selective pressures acting on them.

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Differential development of the rostrum and mandible of the swordfish (Xiphias gladius) during ontogeny and its possible functional significance

Canadian Journal of Zoology ◽

10.1139/z88-070 ◽

1988 ◽

Vol 66 (2) ◽

pp. 496-503 ◽

Cited By ~ 9

Author(s):

C. McGowan

Keyword(s):

Body Size ◽

Functional Significance ◽

Radical Change ◽

Cutting Efficiency ◽

Mandibular Growth ◽

Differential Development ◽

Retarded Growth ◽

Accelerated Growth ◽

Xiphias Gladius

The swordfish, with its much shortened mandible and long thin snout, commences life with mandibles that extend to the tip of the snout. The radical change in jaw proportions occurring during ontogeny has been known since Cuvier's time, and although many descriptive accounts have been given, there have been few attempts to quantify the changes taking place. Bivariate analyses of snout, head, and mandibular growth were conducted upon published larval data, and upon unpublished adult data for 336 individuals. Mandibular growth conforms to simple negative allometry in larvae, and the same appears to be true for adults, but the growth of the snout and head is complex, with significant departures from linearity when logarithmically transformed data are plotted against body size. The disproportionate development of the upper and lower jaws results primarily from the retarded growth of the mandible, rather than from the accelerated growth of the snout. The possible functional significance of the abbreviated mandible is briefly discussed in terms of the cutting efficiency of the sword and the potential for seizing freshly injured prey..

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Functional significance of preserved color patterns of mollusks from the Gosport Sand (Eocene) of Alabama

Journal of Paleontology ◽

10.1017/s0022336000058911 ◽

1988 ◽

Vol 62 (01) ◽

pp. 83-87 ◽

Cited By ~ 4

Author(s):

Patricia H. Kelley ◽

Charles T. Swann

Keyword(s):

Functional Morphology ◽

Functional Significance ◽

Intraspecific Variability ◽

Color Pattern ◽

Color Patterns ◽

Historical Factors ◽

Life Mode ◽

Molluscan Fauna ◽

Excellent Preservation ◽

Architectural Constraints

The excellent preservation of the molluscan fauna from the Gosport Sand (Eocene) at Little Stave Creek, Alabama, has made it possible to describe the preserved color patterns of 15 species. In this study the functional significance of these color patterns is tested in the context of the current adaptationist controversy. The pigment of the color pattern is thought to be a result of metabolic waste disposal. Therefore, the presence of the pigment is functional, although the patterns formed by the pigment may or may not have been adaptive. In this investigation the criteria proposed by Seilacher (1972) for testing the functionality of color patterns were applied to the Gosport fauna and the results compared with life mode as interpreted from knowledge of extant relatives and functional morphology. Using Seilacher's criteria of little ontogenetic and intraspecific variability, the color patterns appear to have been functional. However, the functional morphology studies indicate an infaunal life mode which would preclude functional color patterns. Particular color patterns are instead interpreted to be the result of historical factors, such as multiple adaptive peaks or random fixation of alleles, or of architectural constraints including possibly pleiotropy or allometry. The low variability of color patterns, which was noted within species and genera, suggests that color patterns may also serve a useful taxonomic purpose.

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Complex Vesicles, Microtubules, and Cytoplasmic Filaments in the Endothelial Cells of Normal Dog Aorta

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100100603 ◽

1968 ◽

Vol 26 ◽

pp. 172-173

Author(s):

C. N. Sun ◽

J. J. Ghidoni

Keyword(s):

Electron Microscopy ◽

Endothelial Cells ◽

Cross Sections ◽

Functional Significance ◽

Tubular Structures ◽

Aldehyde Fixation ◽

Cytoplasmic Filaments

Endothelial cells in longitudinal and cross sections of aortas from 3 randomly selected “normal” mongrel dogs were studied by electron microscopy. Segments of aorta were distended with cold cacodylate buffered 5% glutaraldehyde for 10 minutes prior to being cut into small, well oriented tissue blocks. After an additional 1-1/2 hour period in glutaraldehyde, the tissue blocks were well rinsed in buffer and post-fixed in OsO4. After dehydration they were embedded in a mixture of Maraglas, D.E.R. 732, and DDSA.Aldehyde fixation preserves the filamentous and tubular structures (300 Å and less) for adequate demonstration and study. The functional significance of filaments and microtubules has been recently discussed by Buckley and Porter; the precise roles of these cytoplasmic components remains problematic. Endothelial cells in canine aortas contained an abundance of both types of structures.

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