نتایج جستجو برای: speciation
تعداد نتایج: 14852 فیلتر نتایج به سال:
Speciation rates among extant lineages of organisms vary extensively, but our understanding of the causes of this variation and, therefore, the processes of speciation is still remarkably incomplete. Both theoretical and empirical studies have indicated that sexual selection is important in speciation, but earlier discussions have focused almost exclusively on the potential role of female mate ...
Diversity of the primary groups of contemporary Indo-West Pacific coral reef organisms, including mantis shrimps (stomatopod crustaceans), peaks in the Indo-Australian Archipelago (IAA), reaches a lower peak in East Africa and Madagascar [Indian Ocean continental (IOC)], and declines in the central Indian Ocean (IO) and Central Pacific (CP). Percent endemism in stomatopods (highest in the IAA, ...
This contribution studies speciation from the standpoint of evolutionary robotics (ER). A common approach to ER is to design a robot’s control system using neuro-evolution during training. An extension to this methodology is presented here, where speciation is incorporated to the evolution process in order to obtain a varied set of solutions for a robotics problem using a single algorithmic run...
Sympatric speciation is the splitting of one evolutionary lineage into two without the occurrence of geographic isolation. The concept has been intimately tied to entomology since the 1860s, when Benjamin Walsh proposed that many host-specific phytophagous insects originate by shifting and adapting to new host plant species. If true, sympatric speciation would have tremendous implications for o...
Polymorphic species, in which multiple variants coexist within a population, are often used as model systems in evolutionary biology. Recent research has been dominated by the hypothesis that polymorphism can be a precursor to speciation. To date, the majority of research regarding polymorphism and speciation has focused on whether polymorphism is maintained within a population or whether morph...
Speciation is a fundamental process responsible for the diversity of life. Progress has been made in detecting individual 'speciation genes' that cause reproductive isolation. In contrast, until recently, less attention has been given to genome-wide patterns of divergence during speciation. Thus, major questions remain concerning how individual speciation genes are arrayed within the genome, an...
Species are one of the few fundamental units in biology. Yet, study of how they form has had an erratic history. Despite the title of his book, Darwin gave the process of speciation little attention in the 'Origin of Species' — even though his earlier notebooks show that he thought deeply about many issues that are still current. (Darwin's apparent neglect of speciation may have been due to his...
Abrupt speciation through interspecific hybridisation is an important mechanism in angiosperm evolution. Flowering plants therefore offer excellent opportunities for studying genetic processes associated with hybrid speciation. Novel molecular approaches are now available to examine these processes at the level of both genome organization and gene expression - transcriptomics. Here, we present ...
Arsenic Speciation Analysis by Ion Chromatography - A Critical Review of Principles and Applications
Multiple acute and chronic toxicity of arsenic species and its mobilisation from geological deposits into ground and drinking water resources are one of the greatest threats to human health. Arsenic speciation analysis, mostly done by liquid chromatography, is a challenging task which requires an intense high quality work with respect to extraction, preservation, separation, detection and valid...
Evolution appears to be especially rapid during speciation, and the genes involved in speciation should be evident in species such as humans that have recently speciated or are presently in the process of speciation. Haldane's rule is that when one sex is sterile or inviable in interspecific F(1) hybrids, it is usually the heterogametic sex. For mammals, this implicates genes on the X chromosom...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید