![]() Patterns and habitats where each species lives. These rodents are mostly related to concealment, with associations between colouration/ Testing a number of hypotheses connecting coat colouration or patterns with ecobehavioural With and without taking into account the phylogeny of Sciuromorpha, by building upĪ comprehensive phylogenetic tree based on the published literature, as well as by ![]() Sciuromorpha, a successful group within rodents, was carried out. The subterranean niche is not homogeneous across space, and morphological adaptation of subterranean species occurs following this spatial gradient.Īn analysis on the adaptive meaning of coat colouration and colour patterns in We found high morphological variation within each of the eight clades and a geographical structuring. The mandible is less variable in shape than the cranium. Such structural differences may be following an environmental gradient. We observed that many species from the extreme north of the distribution had a robust skull shape, whereas the southern ones had a gracile skull shape. We found geographical structuring in skull shape among the eight clades of Ctenomys structured along east-west and north-south morphological gradients. We used geometric morphometric approaches to quantify this morphological diversity across its range. We analyzed 1359 craniums and 830 mandibles of 49 species of Ctenomys. We investigated different aspects of morphological evolution in the genus Ctenomys, with special attention to the skull. It is the largest collection of fossorial mammals that occupy underground habitats, mainly in the grasslands of South America. The genus Ctenomys is comprised of more than 70 valid living species. Despite many previous studies of tuco-tucos having estimated ecological data using various approaches, it remains difficult to corroborate those data with ecological parameters at broad scales. In this chapter, we discuss spatial habitat use patterns, general ecological characteristics, species interactions, and social structure in tuco-tucos, as well as their impacts on the local environment and implications for conservation. However, obtaining sufficient ecological information about tuco-tucos is challenging due to the majority of life activities taking place underground. Regional distributions of Ctenomys species vary substantially with soil and vegetation characteristics and resource availability, and it is apparent that tuco-tucos can also increase local environmental heterogeneity at the landscape level. The habitat requirements and ecological characteristics of animals that live underground influence numerous aspects of their biology, including where they live and how they behave. Subterranean rodents are widely recognized as ecological engineers. We review our recent studies on this topic with emphasis on the following key results: the identification of a single gene (the melanocortin-1-receptor, Mc1r) in one population that appears to be largely responsible for color differences, the balance between selection and migration among neighboring melanic and light races, and the finding that melanism has evolved independently on different lava flows through changes at different genes. Motivated by the wealth of data on the genetics, biochemistry, and molecular biology of the pigmentation process, we have used a candidate-gene approach to identify the genetic basis of adaptive coat color variation in C. Dice and Blossom (1937) suggested that this crypsis is an adaptation to avoid predation. intermedius coat color typically matches the color of the rocks on which the mice live the dorsal pelage varies from a light, sandy color for populations found on some granites to a dark, nearly black color for populations found on basalt lava flows. Throughout the activity, students learn concepts such as fitness, natural selection, mutation, and phenotype.In a series of classic studies in mammalian evolutionary biology, Sumner (1921), Benson (1933), and Dice and Blossom (1937) described striking coat color variation in the rock pocket mouse, Chaetodipus intermedius, in the deserts of Arizona and New Mexico. Students then watch the HHMI Video on pocket mice and answer discussion questions. Students also graph the color differences at each location to show how the dark variation increased over time in response to an environmental change. (Cards can be printed and laminated for multiple uses.) Students collect data on the number of mice phenotypes in each location and develop a hypothesis about the order of the cards. Students look at cards showing light and dark mice on different substrates. It has been simplified from the original activity so that it is suitable for beginner biology students. This worksheet was modified from the HHMI Activity on color variation in the rock pocket mouse.
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