The diversity of organismic form has evolved nonuniformly during the history of life. Quantitative morphological studies reveal profound changes in evolutionary rates corresponding with the generation of morphological disparity at low taxonomic diversity during the early radiation of many clades. These studies have also given insight into the relative importance of genomic and ecological factor...

This study develops the random phylogenies rate test (RAPRATE), a likelihood method that simulates morphological evolution along randomly generated phylogenies, and uses it to determine whether a considerable difference in morphological diversity between two sister clades of South American fishes should be taken as evidence of differing rates of morphological change or lineage turnover. Despite...

exiting diversity is the basis of selection in plant breeding programs. diversity in morphological traits is studied by different methods of multivariate analysis. this study was conducted to estimate the genetical diversity of new corn hybrids based on the morphological traits. in this study, 40 new grain and forage corn hybrids with five commercial varieties as control treatments were planted...

sperms are highly specialized cells for delivering dna from male to the ovum. incredibly, wide degree of diversity in sperm morphology in their basic structures i.e. head, middle piece and tail is found across species. differences in terms of overall size of the sperm, shape and number of sperm produced are also incredible. one of the key for this variations or diversity in sperm may be associa...

genetic diversity is one of principle factors to succeed in breeding programs, so its determination is vital in the using of plant genetic resources. with the aim of evaluation of genetic diversity among safflower landraces, 20 lines (14 iranian and 6 foreign lines) were studied for phenotypic and genotypic variations using agro-morphological traits and rapd markers. field study was conducted i...

Recent South Americans have been described as presenting high regional cranial morphological diversity when compared to other regions of the world. This high diversity is in accordance with linguistic and some of the molecular data currently available for the continent, but the origin of this diversity has not been satisfactorily explained yet. Here we explore if this high morphological variati...

The Madagascar-endemic microhylid genus Rhombophryne consists of a range of partly or completely fossorial frog species. They lead a poorly known, secretive lifestyle, and may be more diverse than previously thought. We describe a new species from the high altitude forests of the Sorata massif in north Madagascar with unusual characteristics for this genus; R. longicrus sp. n. has long, slender...