نتایج جستجو برای: parrot cichlid
تعداد نتایج: 2978 فیلتر نتایج به سال:
Complete vertebrate genome sequencing has revealed a remarkable stability and uniformity in the protein-coding gene set, which at first glance might suggest that gene duplication events are relatively rare. This may be a red herring, or at least a red cichlid, as the Lake Malawi cichlid fishes show rapid and extensive duplication and diversification of their retinal cone photoreceptor opsin genes.
Evidence exists for a form of imitation, vocal segmentation, by a Grey parrot. Data show that the bird understands that his labels are comprised of individual units that can be recombined in novel ways to create a novel referential vocalization; that is, a novel act. Previous data suggested, but could not substantiate, this behaviour. Such evidence implies that a parrot not only has phonologica...
The question of how genetic variation translates into organismal diversity has puzzled biologists for decades. Despite recent advances in evolutionary and developmental genetics, the mechanisms that underlie adaptation, diversification and evolutionary innovation remain largely unknown. The exceptionally diverse species flocks of cichlid fishes are textbook examples of adaptive radiation and ex...
Cichlid fishes are an ideal model system for studying biological diversification because they provide textbook examples of rapid speciation. To date, there has been little focus on the role of gene regulation during cichlid speciation. However, in recent years, gene regulation has been recognized as a powerful force linking diversification in gene function to speciation. Here, we investigated t...
Cichlid fishes are an excellent model system for studying speciation and the formation of adaptive radiations because of their tremendous species richness and astonishing phenotypic diversity. Most research has focused on African rift lake fishes, although Neotropical cichlid species display much variability as well. Almost one dozen species of the Midas cichlid species complex (Amphilophus spp...
Four choice experiments were conducted with both sexes of the cichlid Pelvicachromis taeniatus using computer-manipulated stimuli of digital images differing in movement, body shape or colouration. The results show that computer animations can be useful and flexible tools in studying preferences of a cichlid with complex and variable preferences for different visual cues.
23 The African Great Lakes are characterized by an extraordinary diversity of endemic cichlid 24 fish species. The cause of this diversity is still largely unknown. Most studies have tried to 25 solve this question by focusing on macro-evolutionary processes, such as speciation. 26 However, the ecological processes determining local cichlid diversity have so far been 27 understudied, even thoug...
Indonesia is one of mega biodiversity countries and inhabited by 300.000 animal species including 1,531 bird species which constitutes 15 % of all bird in the world (Mittermeier et al. 1997, Andrew 1992). IUCN recorded 104 bird species to be endangered. In the world, about 350 parrot species are distributed primarily in hotspots of biodiversity such as Brazil, tropical Africa and Indonesia. Thi...
In the current study, we examined for the first time, the potential for adult neurogenesis throughout the brain of the Congo African grey parrot (Psittacus erithacus) and Timneh grey parrot (Psittacus timneh) using immunohistochemistry for the endogenous markers proliferating cell nuclear antigen (PCNA), which labels proliferating cells, and doublecortin (DCX), which stains immature and migrati...
background: aquatic ecosystems are frequently subjected to contamination by toxic heavy metals and pesticides, yet very little is known about the influence of pesticides on bioaccumulation of heavy metals in aquatic organisms. mercury is a toxic metal with no known biological benefit to organisms. bioavailability of mercury in aquatic environments depends on biological and non-biological parame...
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