The origin of whales (order Cetacea) is one of the best-documented examples of macroevolutionary change in vertebrates. As the earliest whales became obligately marine, all of their organ systems adapted to the new environment. The fossil record indicates that this evolutionary transition took less than 15 million years, and that different organ systems followed different evolutionary trajectories. Here we document the evolutionary changes that took place in the sound transmission mechanism of the outer and middle ear in early whales. Sound transmission mechanisms change early on in whale evolution and pass through a stage (in pakicetids) in which hearing in both air and water is unsophisticated. This intermediate stage is soon abandoned and is replaced (in remingtonocetids and protocetids) by a sound transmission mechanism similar to that in modern toothed whales. The mechanism of these fossil whales lacks sophistication, and still retains some of the key elements that land mammals use to hear airborne sound.
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http://dx.doi.org/10.1038/nature02720 | DOI Listing |
Eur J Ophthalmol
January 2025
University of Lille, Inserm, CHU Lille, UMR-S 1172 - Lille Neurosciences and Cognition, CNRS, 59000 Lille, France.
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Department of General Nursing Science, Faculty of Health Sciences, University of Eswatini, Mbabane, Eswatini.
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December 2024
Experimental Otology Group, InnerEarLab, Department of Otolaryngology, University Medical Center Göttingen, Göttingen, Germany.
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Key Laboratory of Urban and Architectural Heritage Conservation, Ministry of Education, School of Architecture, Southeast University, 2# Sipailou, Nanjing, 210096, China.
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December 2024
Department of Allergy, ShengJing Hospital of China Medical Universty, Shenyang110000, China.
Ragweed, as an exotic invasive species, which is one of the most important allergens for hay fever, has been invading China for more than 80 years. The increasing number of people with hay fever makes effective treatment, as well as the prevention and control of pollen transmission critical. This article delves into a comprehensive research summary focusing on the allergenic properties of ragweed pollen, its pathogenic characteristics, epidemiological patterns, monitoring and control measures, as well as concentrated management approaches.
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