نتایج جستجو برای: cranial morphological change

تعداد نتایج: 736233  

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2014
Xiu-Jie Wu Isabelle Crevecoeur Wu Liu Song Xing Erik Trinkaus

One of the morphological features that has been identified as uniquely derived for the western Eurasian Neandertals concerns the relative sizes and positions of their semicircular canals. In particular, they exhibit a relatively small anterior canal, a relatively larger lateral one, and a more inferior position of the posterior one relative to the lateral one. These discussions have not include...

Journal: :The Onderstepoort journal of veterinary research 2013
Esmey B E Moema Pieter H King Johnny N Rakgole Chantélle Baker

The metacercarial (larval) stages of diplostomid digeneans are known to inhabit freshwater fish, causing tissue damage in the process. Due to their widespread diversity, little is known about their life cycle. The classification of these parasitic stages to the species level using only the morphology is very challenging due to the lack of genitalia; they are regarded to be the most important st...

Journal: :The Journal of experimental zoology 1988
J Hanken C H Summers

Metamorphosis of cranial cartilages in anuran amphibians constitutes one of the most dramatic and extensive ontogenetic transformations in vertebrates. We quantitatively examined the role of thyroid hormone (3,3',5-triiodo-L-thyronine; T3) in mediating gross aspects of this morphological repatterning in the skull of the Oriental fire-bellied toad, Bombina orientalis. T3 was administered via pla...

Journal: :Evolution; international journal of organic evolution 2007
Sarah A Smith Saad Arif Adrian Nieto Montes de Oca John J Wiens

Among the various types of evolutionary changes in morphology, the origin of novel structures may be the most rare and intriguing. Here we show statistically that the origins of different novel structures may be correlated and phylogenetically clustered into "hot spots" of evolutionary novelty, in a case study involving skull elements in treefrogs. We reconstruct phylogenetic relationships with...

2015
Emma Shubin

Montane and Long-tailed voles (Microtus montanus and Microtus longicaudus) are notoriously difficult to distinguish through external characteristics and measurements in the field, particularly among juveniles. Being able to accurate identify these species is important, due to their central role in ecosystems (as keystone species) and as indicator species of climate change (due to their high sen...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - دانشکده علوم 1390

in current study, 63 samples of bat populations collected from differ regions were used for evaluating the geographic variations. twenty cranial and dental characters for traditional morphometric and landmarks method on the ventral, dorsal skull and mandible for geometry morphometric studies were used. statistical analyses of traditional morphometric and geometry morphometric data indicated low...

Journal: :Evolution; international journal of organic evolution 2009
Rose L Carlson Peter C Wainwright Thomas J Near

When the morphological diversity of a clade of species is quantified as the among-species variance in morphology, that diversity is a joint consequence of the phylogenetic structure of the clade (i.e., temporal pattern of speciation events) and the rates of change in the morphological traits of interest. Extrinsic factors have previously been linked to variation in the rate of morphological cha...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید