HOME >> BIOLOGY >> NEWS
Evolution of whale hearing unfolds in fossil record

Arlington, Va.--An international team of scientists has traced the evolution of hearing in modern cetaceans (whales, dolphins and porpoises). "This study of the early evolution of whales demonstrates the changes that took place in whales' outer and middle ears, required for the transition from a land-based to a marine-based existence," said Rich Lane, director of the National Science Foundation (NSF)'s geology and paleontology program, which funded the research.

The findings are published in the Aug. 12 issue of the journal Nature.

The ear is the most important sense organ for modern toothed whales, say scientists, because these whales locate their prey using echolocation. Directional hearing is critical: A blind such whale could find food without much trouble; a deaf one would starve.

The study documents how hearing in these whales evolved. The research is based on cetacean fossils representing four groups of early whales. The earliest cetaceans, pakicetids (those that swam in ancient seas 50 million years ago), used the same sound transmission system as did land mammals, and so had poor underwater hearing. More recent cetaceans, remingtonocetids and protocetids (those that lived 43-46 million years ago), retained the land-mammal system, but also developed a new sound transmission system.

"The fossils document the ways in which cetacean hearing has changed, starting with ear fossils of whales' land ancestors and ending with the ear of near-modern looking whales," said Hans Thewissen, an anatomist at the Northeastern Ohio Universities College of Medicine (NEOUCOM). Thewissen and NEOUCOM researcher Sirpa Nummela led the study.

The newer system was similar to that of modern whales. The later whales could hear better in water than pakicetids could, and could also hear in air, but hearing in both media was compromised by the existence of two systems. With the advent of basilosauroids (approximately 40 million
'"/>

Contact: Cheryl Dybas
cdybas@nsf.gov
703-292-7734
National Science Foundation
11-Aug-2004


Page: 1 2

Related biology news :

1. Evolutions mirror in a fishs spines
2. Evolutions twist
3. New Understanding Evolution Web site provides one-stop-shop for nations science teachers
4. Evolution caught in the act
5. Evolutionary Genomics meeting in Tucson
6. Evolution boosted anti-cancer prowess of a primordial gene
7. Evolution upset: Oxygen-making microbes came last, not first
8. Evolution: Driving Change
9. Evolution of language: FOXP2 and human uniqueness in religious perspective
10. Rutgers to host 14th annual Human Behavior and Evolution Society meeting
11. Evolutionary speed limit governs how quickly life bounces back after extinction

Post Your Comments:
*Name:
*Comment:
*Email:


(Date:7/18/2020)... ... July 16, 2020 , ... A ... of the Invictus Medical Neoasis™ active noise control device to attenuate typical noises ... the Neoasis™ device attenuated the alarm sounds from patient monitors, ventilators and other ...
(Date:7/4/2020)... ... July 03, 2020 , ... Aesthetics Biomedical (ABM), a ... awards for not only the products and treatments developed, but also the dedicated ... RF. All the brands built by ABM have received several honors already for ...
(Date:7/1/2020)... ... July 01, 2020 , ... Cure Glioblastoma, a ... most common and aggressive adult brain cancer—announced today the appointments of its first ... charged with supporting the organization’s initiatives and overall vision. , "Senior Fellows are ...
Breaking Biology News(10 mins):
(Date:7/31/2020)... ... July 29, 2020 , ... G-CON Manufacturing, ... its new tagline, “BUILDING FOR LIFE.” The adoption of this taglines comes at ... requiring fast track capacity to provide patients with urgently needed vaccines and other ...
(Date:7/31/2020)... ... 2020 , ... The SDX® Respiratory Gating System , ... reached its 20th anniversary of worldwide use. Introduced in the US over the ... University of Pennsylvania, University of Michigan, University of Maryland, University of California San ...
(Date:7/18/2020)... , ... July 16, 2020 , ... ... to aid in the early detection and prevention of high-burden diseases, and Centric ... US-based hospitals and healthcare organizations to utilize existing data in order to identify ...
(Date:7/10/2020)... ... July 09, 2020 , ... Sentien ... announced the hiring of Allen R. Nissenson, M.D., F.A.C.P., as its Chief Medical ... development of Sentien’s lead product, SBI-101. Dr. Nissenson serves as an Emeritus ...
Breaking Biology Technology:
Cached News: