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Species-level Differences (species-level + difference)
Selected AbstractsTranslocation of 14C-sucrose within the Ear in Durum and Aestivum Wheat VarietiesJOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 1 2001I. Ravi Excised ears of Triticum durum (HD 4502 and B 449) and T. aestivum (Kalyansona and Kundan) varieties were cultured in 14C-sucrose, and the uptake and distribution of 14C within the ear was examined. Species-level differences in the distribution of 14C to spikelets at basal, middle and apical positions in the wheat ear (vertical distribution) were observed. T. aestivum var. Kalyansona and Kundan showed no limitation in vertical translocation of 14C-sucrose, whereas in T. durum there was a decrease in the distribution of 14C to apical spikelets. Within a spikelet, the distribution of 14C-sucrose to distal grains was significantly less than that to proximal grains in all the genotypes. Translokation von 14C-Sukrose innerhalb der Ähre von Durum-und Aestivumweizen-varietäten Abgetrennte Ähren von T. durum (HD 4502 und B 449) und T. aestivum (Sorten: Kalyansona und Kundan) wurden in14C-Sukrose kultiviert und Aufnahme und Verteilung von14C innerhalb der Ähren untersucht. Die artspezifischen Differenzen in der Verteilung von14C im Hinblick auf die Ährchen im basalen, mittleren und apikalen Teil der Weizenähre (vertikale Verteilung) wurden beobachtet. Triticum aestivum var. Kalyansona und Kundan zeigten keine Limitierung in der vertikalen Translokation von14C-Sukrose, während bei Triticum durum eine Abnahme in der Verteilung von14C zum apikalen Ährchen vorlag. Innerhalb der Ährchen war die Verteilung von14C-Sukrose zu den distalen Körnern bei allen Genotypen signifikant geringer als zu den proximalen Körnern. [source] Divergence between the Courtship Songs of the Field Crickets Gryllus texensis and Gryllus rubens (Orthoptera, Gryllidae)ETHOLOGY, Issue 12 2001Mark J. Fitzpatrick Acoustic mating signals are often important as both interspecific prezygotic isolating mechanisms and as sexually selected traits in intraspecific mate choice. Here, we investigate the potential for cricket courtship song to act as an isolating mechanism by assessing divergence between the courtship songs of Gryllus texensis and Gryllus rubens, two broadly sympatric cryptic sister species of field crickets with strong prezygotic isolation via the calling song and little or no postzygotic isolation. We found significant species-level differences in the courtship song, but the song has not diverged to the same extent as the calling song, and considerable overlap remains between these two species. Only two related courtship song characters are sufficiently distinct to play a possible role in prezygotic species isolation. [source] GENETIC VARIATION OF KOGIA SPP.MARINE MAMMAL SCIENCE, Issue 4 2005WITH PRELIMINARY EVIDENCE FOR TWO SPECIES OF KOGIA SIMA Abstract Concordance between mitochondrial DNA (mtDNA) markers and morphologically based species identifications was examined for the two currently recognized Kogia species. We sequenced 406 base pairs of the control region and 398 base pairs of the cytochrome b gene from 108 Kogia breviceps and 47 K. sima samples. As expecred, the two sister species were reciprocally monophyletic to each other in phylogenetic reconstructions, but within K. sima, we unexpectedly observed another reciprocally monophyletic relationship. The two K. sima clades resolved were phylogeographically concordant with all of the haplotypes in one clade observed solely among specimens sampled from the Atlantic Ocean and with those in the other clade observed solely among specimens sampled from the Indo-Pacific Ocean. These apparently allopatric clades were observed in all phylogenetic reconstructions using the maximum parsimony, maximum likelihood, and neighborjoining algorithms, with the mtDNA gene sequences analyzed separately and combined. The nucleotide diversity for the combined gene sequence haplotypes of the two K. sima clades resolved in our analyses was 0.58% and 1.03% for the Atlantic and Indo-Pacific, respectively, whereas for the two recognized sister species, nucleotide diversity was 1.65% and 4.02% for K. breviceps and K. sima, respectively. The combined gene sequence haplotypes have accumulated 44 fixed base pair differences between the two K. sima clades compared to 20 fixed base pair differences between the two recognized sister species. Although our results are consistent with species-level differences between the two K. sima clades, recognition of a third Kogia species awaits supporting evidence that these two apparently allopatric clades represent reproductively isolated groups of animals. [source] Ontogeny and phyletic size change in living and fossil lemursAMERICAN JOURNAL OF PRIMATOLOGY, Issue 2 2010Matthew J. Ravosa Abstract Lemurs are notable for encompassing the range of body-size variation for all primates past and present,close to four orders of magnitude. Benefiting from the phylogenetic proximity of subfossil lemurs to smaller-bodied living forms, we employ allometric data from the skull to probe the ontogenetic bases of size differentiation and morphological diversity across these clades. Building upon prior pairwise comparisons between sister taxa, we performed the first clade-wide analyses of craniomandibular growth allometries in 359 specimens from 10 lemuroids and 176 specimens from 8 indrioids. Ontogenetic trajectories for extant forms were used as a criterion of subtraction to evaluate morphological variation, and putative adaptations among sister taxa. In other words, do species-level differences in skull form result from the differential extension of common patterns of relative growth? In lemuroids, a pervasive pattern of ontogenetic scaling is observed for facial dimensions in all genera, with three genera also sharing relative growth trajectories for jaw proportions (Lemur, Eulemur, Varecia). Differences in masticatory growth and form characterizing Hapalemur and fossil Pachylemur likely reflect dietary factors. Pervasive ontogenetic scaling characterizes the facial skull in extant Indri, Avahi, and Propithecus, as well as their larger, extinct sister taxa Mesopropithecus and Babakotia. Significant interspecific differences are observed in the allometry of indrioid masticatory proportions, with variation in the mechanical advantage of the jaw adductors and stress-resisting elements correlated with diet. As the growth series and adult data are largely coincidental in each clade, interspecific variation in facial form may result from selection for body-size differentiation among sister taxa. Those cases where trajectories are discordant identify potential dietary adaptations linked to variation in masticatory forces during chewing and biting. Although such dissociations highlight selection to uncouple shared ancestral growth patterns, they occur largely via transpositions and retention of primitive size-shape covariation patterns or relative growth coefficients. Am. J. Primatol. 72:161,172, 2010. © 2009 Wiley-Liss, Inc. [source] | ||||||||||