quora
Nobody downloaded yet

A comparison/analysis of the evolution, function, and structure of the hearing appartii of reptilians versus mammalians - Essay Example

Comments (0) Cite this document
Summary
One of the greatest stepping stones in the evolutionary scene was the development of mammals from the ancestral reptile.While this involved a number of changes,a major breakthrough in this respect was the development of acute hearing and language in mammals…
Download full paperFile format: .doc, available for editing
GRAB THE BEST PAPER98.8% of users find it useful
A comparison/analysis of the evolution, function, and structure of the hearing appartii of reptilians versus mammalians
Read TextPreview

Extract of sample
"A comparison/analysis of the evolution, function, and structure of the hearing appartii of reptilians versus mammalians"

Download file to see previous pages One of the greatest stepping stones in the evolutionary scene was the development of mammals from the ancestral reptile.While this involved a number of changes,a major breakthrough in this respect was the development of acute hearing and language in mammals In the context of the hearing apparti in particular there are an increasing number of studies which indicate that the modification of the jaw bones (in reptiles) led to the formation of the middle ear bones in mammals as we shall see later in this essay. However the quote from BBC is indeed an accurate summation of the evolutionary scene.Any comparison of the evolutionary course of the hearing apparti in reptiles and mammals would be incomplete without an overall understanding of what the auditory(hearing) apparatus comprises and its role in perception of sound. Broadly speaking hearing is a result of two linked process; the physical apparatus (ear) which gathers and modulates sound waves and the neurological transmission and processing of the sound waves to a form recognizable to the species.In mammals, the best documented and most extensively studied auditory pathway is seen in man. The human ear consists of three parts - the outer, middle, and inner ear. The outer ear consists of the pinna and the external auditory canal which primarily serve to gather sound waves. These waves enter the middle ear comprising the tympanic membrane and the three auditory bones. The vibrations are transferred down the ossicles after amplification by the ossicles to the oval window membrane which divides the middle ear and the inner ear. It is the inner ear which houses the main organ responsible for hearing, i.e the cochlea. The cochlea is a fluid-filled organ comprising the basilar membrane and the organ of Corti. Sound waves, once in the cochlea, travel across the length of the basilar membrane which lodges the organ of Corti containing sensory cells, that transform these vibrations into the neural code for sound processing by the brain. (Yost 1994)This is a brief overview of the physical auditory apparatus in the modern mammal. While most terrestrial mammals exhibit similar acoustic structure, there are slight modification in aquatic mammals (cetaceans) and bats.
The main difference lies in the absence of the external ear or pinna in cetaceans. In cetaceans, sound waves from the environment are transmitted to the middle ear through the lower jaw. Along with fats that align the lower jaw a thin bony area called the pan bone is instrumental in conducting sound to the tympanic membrane of the middle ear.
The inner ear of cetaceans however is functionally similar to terrestrial mammals with differences primarily in the number of nerve cells, the size of the basilar membrane, and the support of the basilar membrane (Wartzok,1999 pg 117)

This difference between aquatic and non aquatic mammals becomes more interesting in the context of the evolutionary process. It has been established that the equilibrial organ of the primitive bony fish, was passed to subsequent classes which evolved their own auditory systems based on the balance organ inherited from fish. While amphibians independently evolved an an apparatus combining the eardrum and ossicle, reptiles evolution comprised a flexible basilar membrane for the receptor cells. (Peck 1994, pg 291)The external ears were a mammalian addition which as mentioned previously is lacking in aquatic mammals. The aquatic mammals hence demonstrate a link between modern mammals like man and reptiles in their auditory apparatus and hearing mechanisms.

1.2 Evolution of the hearing region

The course of evolution is best studied by means of fossil remains of organisms. Structures which ...Download file to see next pagesRead More
Cite this document
  • APA
  • MLA
  • CHICAGO
(“A comparison/analysis of the evolution, function, and structure of the Essay”, n.d.)
Retrieved from https://studentshare.org/biology/1509583-a-comparisonanalysis-of-the-evolution-function-and-structure-of-the-hearing-appartii-of-reptilians-versus-mammalians
(A comparison/Analysis of the Evolution, Function, and Structure of the Essay)
https://studentshare.org/biology/1509583-a-comparisonanalysis-of-the-evolution-function-and-structure-of-the-hearing-appartii-of-reptilians-versus-mammalians.
“A comparison/Analysis of the Evolution, Function, and Structure of the Essay”, n.d. https://studentshare.org/biology/1509583-a-comparisonanalysis-of-the-evolution-function-and-structure-of-the-hearing-appartii-of-reptilians-versus-mammalians.
  • Cited: 0 times
Comments (0)
Click to create a comment or rate a document
CHECK THESE SAMPLES - THEY ALSO FIT YOUR TOPIC
The effect of protein structure and function on protein evolution
11 7. - Tools of the Trade; X-ray Crystallography and NMR. p.13 - Summary p. 16 References. p. 17 Abstract: A meta-analysis covering sixty years of biochemical research into the history and evolution of both the study and reality of proteins was conducted.
18 Pages(4500 words)Essay
Chloroplast: Structure to Function Relation
This is the principal and the universal mode of energy conversion to make it useful for the living organisms (Nelson and Yocum 521-565), and without this method of conversion, life on this planet would cease to exist (Nelson and Yocum 521-565). Therefore, it is only fair that the mechanism of the conversion as relates to the structure of the chloroplast be studied in order to determine the functional correlation with the structure.
3 Pages(750 words)Essay
Ecosystem Structure, Function, and Change Paper
stem can be looked from a more vivid angle as we get to its structure, functional dynamics, human interaction, chemical interference and species implication. This lake does have abundant terrestrial plants which are unique to the geographical location. The littoral zone gets
3 Pages(750 words)Essay
Evolution Versus Religion
They used lawsuits to try to prevent evolution from being taught. Not much has changed in the last 84 years. While most of the rest of the developed world would blanch at the notion of teaching Creationism—the idea that God created the world and everything in it—in the United States there are institutes and public figures who promote the idea.
10 Pages(2500 words)Essay
Comparison Between Structure and Function of Human and Animal Eyes
This study analyzes the similarities and differences between the structures and functions of eyes of humans and dogs, eagles, fish, chameleons, and snakes. The aspects of visual function that include visual acuity, color discrimination, motion and the depth perception, contrast sensitivity and brightness perception will also be described.
9 Pages(2250 words)Assignment
Real estate and capital structure decisions- Lease versus Buy Analysis
One significant factor is the stability and probability of company expansion. To achieve a clearer view on this, research and study to determine feasibility is suggested. It will not
8 Pages(2000 words)Essay
Structure and Function of the Lower Limb
The muscles acting about the hip and knee may be categorized according to their function, that is, the relative limb displacements they produce when stimulated. Relative limb displacements are usually described anatomically, in terms of three independent rotations, e.g. at the hip we have flexion/extension, abduction/adduction and internal/external rotation.
12 Pages(3000 words)Essay
Protein structure and function
2002). The primary structure of DNA polymerase depends on the organism from which the enzyme has been isolated. The number and sequences of amino acids vary in the different subunits in different species. The amino acid
1 Pages(250 words)Essay
Hearing
In old people between 61 to 80 years, the prevalence of sensorineural and conductive hearing loss of forty five decibels for the better ear is 14.3% and 3.1% respectively. Hearing impairment is common and frequently disabling. It is therefore, important for
1 Pages(250 words)Essay
Gas Exchange: Structure and Function of Alveoli
Alveoli make up the pulmonary parenchyma. When air enters the lung through the bronchus, it continues to pass through dividing smaller and smaller airways called bronchioles. The smallest bronchiole at the end of the airway, the terminal bronchiole, leads into the alveolar duct, that opens into several alveoli.
4 Pages(1000 words)Essay
sponsored ads
We use cookies to create the best experience for you. Keep on browsing if you are OK with that, or find out how to manage cookies.
Let us find you another Essay on topic A comparison/analysis of the evolution, function, and structure of the hearing appartii of reptilians versus mammalians for FREE!
logo footer
Contact us:
+16312120006
Contact Us Now
FREE Mobile Apps:
  • StudentShare App Store
  • StudentShare Google play
  • About StudentShare
  • Testimonials
  • FAQ
  • Blog
  • Free Essays
  • New Essays
  • Essays
  • Miscellaneous
  • The Newest Essay Topics
  • Index samples by all dates
Join us:
Contact Us