منابع مشابه
Cambrian Lattices
For an arbitrary finite Coxeter group W , we define the family of Cambrian lattices for W as quotients of the weak order on W with respect to certain lattice congruences. We associate to each Cambrian lattice a complete fan, which we conjecture is the normal fan of a polytope combinatorially isomorphic to the generalized associahedron for W . In types A and B, we obtain, by means of a fiber-pol...
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The sudden appearance of fossils that marks the so-called 'Cambrian explosion' has intrigued and exercised biologists since Darwin's time. In On the Origin of Species, Darwin made it clear that he believed that ancestral forms 'lived long before' their first fossil representatives. While he considered such an invisible record necessary to explain the level of complexity already seen in the foss...
متن کاملCambrian Hopf Algebras
Cambrian trees are oriented and labeled trees which fulfill local conditions around each node generalizing the conditions for classical binary search trees. Based on the bijective correspondence between signed permutations and leveled Cambrian trees, we define the Cambrian Hopf algebra generalizing J.-L. Loday and M. Ronco’s algebra on binary trees. We describe combinatorially the products and ...
متن کاملThe Cambrian Explosion
The Precambrian genesis plus Cambrian explosion scenario also implies a perplexing view of a major evolutionary radiation: a long period of cryptic speciation with increasing developmental complexity and anatomical sophistication, yet without substantial behavioural or ecological modification or diversification, followed by a sudden increase in morphological and ecological innovation. Page 1046...
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The meiotic chromosomes of 10 species (Pohlia elongata, Anomobryum cymbifolium, Brachymenium acuminatum, B. ochianum, B. sikkimense, Bryum cellulare, B. pseudotriquetrum, B. apiculatum, B. capillare and B. atrovirense), in four genera of the family Bryaceae of acrocarpous mosses are studied with special emphasis on their evolution, polyploidy and cytological features with reference to interrela...
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ژورنال
عنوان ژورنال: Papers in Palaeontology
سال: 2016
ISSN: 2056-2799,2056-2802
DOI: 10.1002/spp2.1043