English   español  
Please use this identifier to cite or link to this item: http://hdl.handle.net/10261/59797
Share/Impact:
Statistics
logo share SHARE logo core CORE   Add this article to your Mendeley library MendeleyBASE

Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL
Exportar a otros formatos:

Title

Tempo, mode and phylogenetic associations of relative embryo size evolution in angiosperms

AuthorsVerdú, Miguel
KeywordsAnagenesis
Cladogenesis
Comparative method
Evolutionary trends
Gradualism
Issue DateMar-2006
CitationJournal of Evolutionary Biology 19(2): 625-634 (2006)
AbstractRelative embryo size (E : S, the ratio of embryo to seed) is a key trait related to germination ecology and seed plant evolution. A small, underdeveloped embryo is a primitive feature of angiosperms, which has led to the hypothesis that an evolutionary trend towards increasing E : S has occurred. Here, I examine first the tempo and mode of E : S evolution in angiosperms; then I test for phylogenetic associations of E : S with traits hypothetically related to anagenetic (germination time) and cladogenetic (number of species per family and differential speciation) change, and finally I test the existence of a directional increasing trend in E : S. The analysis of the evolutionary tempo suggests that E : S changed very fast early in evolutionary time and remained stable later, which is consistent with early radiations and fits well with the history of angiosperms consisting of rapid spread associated with great diversification rates soon after their origin. E : S evolution in angiosperms has not followed a punctuational mode of evolution but a scaled-gradualism evolution in which stasis has occurred in longer branches of the phylogeny. An evolutionary trend towards increasing E : S has not been actively driven by anagenesis nor cladogenesis, although large E : S is associated with high levels of diversification (i.e. number of species per family). This rapid ecological diversification occurring in the early radiation probably produced an increasing phenotypic variance in the E : S. Because the ancestral embryo was so small, an increase in variance might have produced a passive trend towards the only direction allowed for the ancestral embryo to evolve. Thus, a passive diffusion away from a lower bound may explain the average increase in E : S.
Description10 páginas, 3 figuras.
Publisher version (URL)http://dx.doi.org/10.1111/j.1420-9101.2005.00998.x
URIhttp://hdl.handle.net/10261/59797
DOI10.1111/j.1420-9101.2005.00998.x
ISSN1010-061X
E-ISSN1420-9101
Appears in Collections:(CIDE) Artículos
Files in This Item:
There are no files associated with this item.
Show full item record
Review this work
 

Related articles:


WARNING: Items in Digital.CSIC are protected by copyright, with all rights reserved, unless otherwise indicated.