Functional Morphology of the Paratympanic Organ in the Middle Ear of Birds

1994 ◽  
Vol 44 (2) ◽  
pp. 61-73 ◽  
Author(s):  
Christopher S. von Bartheld
Keyword(s):  
Functional Morphology ◽  
Middle Ear ◽  
Paratympanic Organ

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

1988 ◽  
Vol 62 (01) ◽  
pp. 83-87 ◽  
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.

The Effect of Stapedectomy on the Loudness of One’s Own Voice

1965 ◽  
Vol 8 (3) ◽  
pp. 223-234 ◽  
Author(s):  
William Melnick
Keyword(s):  
Middle Ear ◽  
Normal Subjects ◽  
Sound Energy ◽  
Loudness Function ◽  
Before And After ◽  
Increased Sensitivity

Five subjects with normal middle ear mechanisms, and otosclerotic patients, before and after stapedectomy, matched the loudness of their voices to the loudness of a 125-cps-sawtooth noise. The results showed loudness matching functions with gradual slopes, less than 1.00, for the normal subjects and the patients prior to stapedectomy. Post-surgically, the loudness function for the patients increased in steepness to considerably more than 1.00. These results are explained, most logically, in terms of increased sensitivity of the altered middle ear to sound energy generated by the listener’s own voice.

Sign in / Sign up

Export Citation Format

Share Document