Open Access. Powered by Scholars. Published by Universities.®

Other Ecology and Evolutionary Biology Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 8 of 8

Full-Text Articles in Other Ecology and Evolutionary Biology

The Evolution Of Lateralized Foot Use In Parrots: A Phylogenetic Approach, Culum Brown, Maria Magat Nov 2011

The Evolution Of Lateralized Foot Use In Parrots: A Phylogenetic Approach, Culum Brown, Maria Magat

Sentience Collection

Cerebral lateralization refers to the division of cognitive function in either brain hemisphere and may be overtly expressed as behavioral asymmetries, such as handedness. The evolutionary history of laterality is of considerable interest due to its close link with the development of human language. Although considerable research effort has aimed at the proximate explanations of cerebral lateralization, considerably less attention has been paid to ultimate explanations. The extent to which laterality is constrained by phylogeny or shaped by ecological forces through natural selection has received little attention. Here, the foot preference of 23 species of Australian parrots was examined to …


Lack Of Assortative Mating Between Incipient Species Of Stickleback From A Hybrid Zone, F. C. Jones, C. Brown, V. A. Braithwaite Jan 2008

Lack Of Assortative Mating Between Incipient Species Of Stickleback From A Hybrid Zone, F. C. Jones, C. Brown, V. A. Braithwaite

Evolutionary Biology Collection

Both premating and postmating barriers to gene flow can contribute to reproductive isolation but the relative role of these factors, particularly in the early stages of speciation, is not well understood. Evidence suggests that factors contributing to assortative mating and, thus, the development and maintenance of divergent species, can be ecology-dependent. Here, we present results from a study of assortative mating between recently diverged anadromous and freshwater sticklebacks conducted in semi-natural conditions. Sympatric anadromous and freshwater sticklebacks were sampled from a contact zone and multiple male and female morphs were allowed to breed in replicate ponds. Mate choice was determined …


Stable Isotopic Niche Predicts Fitness Of Prey In A Wolf–Deer System, C. T. Darimont, P. C. Paquet, T. E. Reimchen Jan 2007

Stable Isotopic Niche Predicts Fitness Of Prey In A Wolf–Deer System, C. T. Darimont, P. C. Paquet, T. E. Reimchen

Evolutionary Biology Collection

Interindividual variation in niche presents a potentially central object on which natural selection can act. This may have important evolutionary implications because habitat use governs a suite of selective forces encountered by foragers. In a free‐living native black‐tailed deer, Odocoileus hemionus, population from coastal British Columbia, we used stable isotope analysis to identify individual variation in foraging niche and investigated its relationship to fitness. Using an intragenerational comparison of surviving and nonsurviving O. hemionus over 2 years of predation by wolves, Canis lupus, we detected resource‐specific fitness. Individuals with isotopic signatures that suggested they foraged primarily in cedar ( …


Cortical Complexity In Cetacean Brains, Patrick R. Hof, Rebecca Chanis, Lori Marino Nov 2005

Cortical Complexity In Cetacean Brains, Patrick R. Hof, Rebecca Chanis, Lori Marino

Veterinary Science and Medicine Collection

Cetaceans (dolphins, whales, and porpoises) have a long, dramatically divergent evolutionary history compared with terrestrial mammals. Throughout their 55–60 million years of evolution, cetaceans acquired a compelling set of characteristics that include echolocation ability (in odontocetes), complex auditory and communicative capacities, and complex social organization. Moreover, although cetaceans have not shared a common ancestor with primates for over 90 million years, they possess a set of cognitive attributes that are strikingly convergent with those of many primates, including great apes and humans. In contrast, cetaceans have evolved a highly unusual combination of neurobiological features different from that of primates. As …


Big Brains Do Matter In New Environments, Lori Marino Apr 2005

Big Brains Do Matter In New Environments, Lori Marino

Evolutionary Biology Collection

No abstract provided.


Origin And Evolution Of Large Brains In Toothed Whales, Lori Marino, Daniel W. Mcshea, Mark D. Uhen Dec 2004

Origin And Evolution Of Large Brains In Toothed Whales, Lori Marino, Daniel W. Mcshea, Mark D. Uhen

Veterinary Science and Medicine Collection

Toothed whales (order Cetacea: suborder Odontoceti) are highly encephalized, possessing brains that are significantly larger than expected for their body sizes. In particular, the odontocete superfamily Delphinoidea (dolphins, porpoises, belugas, and narwhals) comprises numerous species with encephalization levels second only to modern humans and greater than all other mammals. Odontocetes have also demonstrated behavioral faculties previously only ascribed to humans and, to some extent, other great apes. How did the large brains of odontocetes evolve? To begin to investigate this question, we quantified and averaged estimates of brain and body size for 36 fossil cetacean species using computed tomography and …


Reconstructing Cetacean Brain Evolution Using Computed Tomography, Lori Marino, Mark D. Uhen, Nicholas D. Pyenson, Bruno Frohlich May 2003

Reconstructing Cetacean Brain Evolution Using Computed Tomography, Lori Marino, Mark D. Uhen, Nicholas D. Pyenson, Bruno Frohlich

Veterinary Science and Medicine Collection

Until recently, there have been relatively few studies of brain mass and morphology in fossil cetaceans (dolphins, whales, and porpoises) because of difficulty accessing the matrix that fills the endocranial cavity of fossil cetacean skulls. As a result, our knowledge about cetacean brain evolution has been quite limited. By applying the noninvasive technique of computed tomography (CT) to visualize, measure, and reconstruct the endocranial morphology of fossil cetacean skulls, we can gain vastly more information at an unprecedented rate about cetacean brain evolution. Here, we discuss our method and demonstrate it with several examples from our fossil cetacean database. This …


A Comparison Of Encephalization Between Odontocete Cetaceans And Anthropoid Primates, L. Marino Apr 1998

A Comparison Of Encephalization Between Odontocete Cetaceans And Anthropoid Primates, L. Marino

Veterinary Science and Medicine Collection

There have been very few studies of brain size and encephalization in cetaceans and essentially none that have made direct quantitative comparisons of cetaceans and another mammalian group using large normative samples. In the present study two different measures of encephalization were calculated and used to rank and compare 21 odontocete species and 60 anthropoid primate species. Comparisons were made both within and between the two groups. Results show that the encephalization level of Homo sapiens is still extraordinary relative to that of nonhuman species. Nevertheless, a subset of delphinid odontocetes are significantly more highly encephalized than the most highly …