Underlying Synapomorphies and Anagenetic Analysis

Evaluations of holomorphological similarities are based on synapomorphies, symplesiomorphies, convergence, and parallelisms as results of parallel selection and of underlying synapomorphies respectively. Only synapomorphies and underlying synapomorphies can show genealogical relationships. Distinctions between parallel selections and underlying synapomorphies are of major phylogenetic importance, while distinctions between different evolutionary histories (eu-parallelisms and pseudo-parallelisms) are not. The circumstance when underlying synapomorphies are of special phylogenetic importance has been termed unique inside-parallelism. Three such unique inside-parallelisms are found in the female genitalia of the Chironomidae, where they are shown necessary for the understanding of subfamily relationships. — The first minimum criterion for recognizing synapomorphy (Schlee 1971) is corrected to: It should be present within the whole group or clearly secondarily reduced an apomorphic taxa. It should not be present in the same formation in any taxon outside the group which can be regarded as a possible sister group. — The anagenetic component of the evolutionary processes can, following a cladistic analysis, be calculated by means of the adjusted evolution index assigning the different recognizable steps of trends or morphocline number from 1 to 2 and calculating the arithmetic mean of all numbers. Examples from Chaoboridae and Chironomidae support the cladistic diagrams and point out that different stages belong to differing "grades". Methods of numerical taxonomy may give a finer gradation of anagenetic levels.     

Potyviral resistance derived from cultivars of Phaseolus vulgaris carrying bc-3 is associated with the homozygotic presence of a mutated eIF4E allele

Eukaryotic translation initiation factors (eIFs) play a central role in potyviral infection. Accordingly, mutations in the gene encoding eIF4E have been identified as a source of recessive resistance in several plant species. In common bean, Phaseolus vulgaris , four recessive genes, bc-1 , bc-2 , bc-3 and bc-u , have been proposed to control resistance to the potyviruses Bean common mosaic virus (BCMV) and Bean common mosaic necrosis virus . In order to identify molecular entities for these genes, we cloned and sequenced P. vulgaris homologues of genes encoding the eIF proteins eIF4E, eIF(iso)4E and nCBP. Bean genotypes reported to carry bc-3 resistance were found specifically to carry non-silent mutations at codons 53, 65, 76 and 111 in eIF4E . This set of mutations closely resembled a pattern of eIF4E mutations determining potyvirus resistance in other plant species. The segregation of BCMV resistance and eIF4E genotype was subsequently analysed in an F₂ population derived from the P. vulgaris all-susceptible genotype and a genotype carrying bc-3 . F₂ plants homozygous for the eIF4E mutant allele were found to display at least the same level of resistance to BCMV as the parental resistant genotype. At 6 weeks after inoculation, all F₂ plants found to be BCMV negative by enzyme-linked immunosorbent assay were found to be homozygous for the mutant eIF4E allele. In F₃ plants homozygous for the mutated allele, virus resistance was subsequently found to be stably maintained. In conclusion, allelic eIF4E appears to be associated with a major component of potyvirus resistance present in bc-3 genotypes of bean.     

THE MYTH OF OBJECTIVITY—POST-HENNIGIAN DEVIATIONS

Abstract— The punctuated equilibrium speciation mode is an implied consequence of the deviation rule and the differences between cladograms and phylogenetic trees implicitly were recognized by Hennig. Neocladism and transformed cladism, however, both are contradictory to the view of Hennig. Neither of them will be consistent when parallel changes exceed informative unparallel changes, which in the real world there are many indications to believe they do. In three tables cladogenetic trends used in erecting three schemes of argumentation, on the specific, generic, and subfamily levels respectively, are analyzed and divided into: " objective" synapomorphies not allowing for outside parallelism or secondary change, subjective synapomorphies , and underlying synapomorphies . Evaluations based on the strictest criteria for asserting synapomorphy are possible only when comparing higher taxa of subfamily level and up. On the generic level trends showing outside parallelism can be rejected if all other possibly synapomorphic trends are included. On the specific level it is necessary to take all kinds of synapomorphies into consideration, including those showing outside parallelism. There may often be a preponderance of trends caused by parallel selection in taxa with specialized sexual and/or feeding behaviors, as exemplified by some chironomid male imagines and larvae. It is necessary to have knowledge of the nature of the different possible natural processes and try to explain these before undertaking estimations of patterns of kinship. The persistent intuitive and subjective element in phylogenetics was stressed by Hennig. Objectivity is a myth.     

Respiration of midges (Diptera; Chironomidae) in British Columbian lakes: oxy-regulation, temperature and their role as palaeo-indicators

1. The specific respiration rate of 13 chironomid taxa and Chaoborus were measured to test the hypothesis of the relation between a species' ability to regulate their oxygen uptake and their distributional patterns among nine study lakes in British Columbia, Canada.
2. Respiration patterns of individual taxa were modelled using piecewise linear regression with break point and simple hyperbolic functions. Three types of respiration curves were identified: (i) classical oxy-conformers (e.g. littoral Cricotopus ) which cannot sustain a sufficient oxygen uptake with decreasing oxygen availability; (ii) oxy-regulators (e.g. profundal Chironomus ) which can regulate and maintain a constant respiration until a certain critical point and (iii) oxy-stressors ( Micropsectra ) which increase their respiration rate with decreasing oxygen availability until a critical point.
3. Respiration was measured at two different temperatures (10 and 20 °C), and over the range of oxygen saturation conditions studied here (0–90%) mean Q ₁₀ values varied from 1.3 to 2.5.
4. The results show that different chironomid taxa have varying sensitivity to low oxygen concentrations and different respiratory responses to increased temperature. The critical point increased to higher oxygen saturation for six taxa, decreased for one taxon and was unchanged for two taxa.
5. The results illustrate one of the possible biological mechanisms behind the use of chironomids as temperature and climate indicators in palaeoecological studies by exploring the link between temperature and respiration physiology.     

The phylogenetic relationships of Berthelot's Pipit Anthus berthelotii illustrated by DNA sequence data, with remarks on the genetic distance between Rock and Water Pipits Anthus spinoletta

The phylogenetic relationships of Berthelot's Pipit Anthus berthelotii , which is endemic to three groups of North Atlantic islands, have puzzled ornithologists for more than a century. A total of 1041 base pair cytochrome b mitochondrial DNA sequences from Berthelot's Pipit are compared with homologous sequences from the Tawny Pipit Anthus campestris , Richard's Pipit Anthus novaeseelandiae , the Meadow Pipit Anthus pratensis , the Red-breasted Pipit Anthus cervinus , the Tree Pipit Anthus trivialis , Rock and Water Pipits Anthus spinoletta and the White Wagtail Motacilla alba. In the resulting phytogeny, the sister taxon of Berthelot's Pipit is unambiguously the Tawny Pipit, with Richard's Pipit forming a deeper branch on the same clade. Sequences of a Danish Rock Pipit and a Swiss Water Pipit support a close relationship between these two species, but more comprehensive studies of intra- and interpopulation variation are required before considering their taxonomic ranking. Some preliminary inferences are made regarding phylogenetic tendencies in the genus Anthus.     

HOMING AND OLFACTION IN SALMONIDS: A CRITICAL REVIEW WITH SPECIAL REFERENCE TO THE ATLANTIC SALMON

(1) Based on data from the literature, the phenomenon of homing in salmonids is examined with special reference to the Atlantic salmon. Wild, native fish demonstrate an excellent homing ability, judged from percent return to the home river (1–3 %) and straying to non-native watersheds (less than 3 % of returning fish). (2) The homing ability in wild fish is shown to be closely related to the existence of reproductively isolated populations between and within watersheds, as demonstrated by data from salmonid ecology and biochemical genetics. (3) Two main hypotheses have dominated the literature on salmonid homing during recent years: (a) An ‘imprinting’ hypothesis based on a process of learning of stream odours during seaward migration, coupled with sun-orientation for open sea navigation, (b) A ‘pheromone’ hypothesis related to odours from fish and based on inheritance and the seasonal migrating schedules of discrete populations. (4) The olfactory sense has been demonstrated as mandatory for salmonids, both in near range and open sea navigation. According to genetic, sensory and ecological aspects of homing, the pheromone hypothesis is therefore concluded to be the most appropriate. (5) Fish produced from artificially fertilized eggs, released within native systems or transplanted, demonstrate a reduced homing ability. Since hatchery-raised fish demonstrate a survival in sea equivalent to that of wild fish, a genetic disturbance of navigational ability has been suggested, resulting from the production of population hybrids by man. (6) Studies made in the fields of behaviour, electrophysiology and chemistry strongly suggest that population-specific fish odours are involved in home-stream recognition by salmonids. (7) An evaluation of ‘imprinting’ experiments related to artificial organic compounds reveals that: (a) the odorant properties of the applied chemicals must be questioned, (b) imprinting related to olfaction may be based on a weak theoretical foundation, (c) returns obtained in census experiments may be adequately explained through ecological interpretations, and (d) behavioural preferences obtained from exposure to non-natural compounds may be founded on mechanisms not associated with homing. (8) A logical link between the use of olfaction and the role of genetics in salmonid homing is emphasized, together with its practical implications for salmonid management.     

Habitat partitioning among sympatric wintering Common Eiders Somateria mollissima and King Eiders Somateria spectabilis

We studied the distribution of sympatric wintering Common Elders Somateria mollissima and King Eiders Somateria spectabilis in northern Norway in relation to the water depth and substrate type. The Common Eider selected water shallower than 10 m, mainly over kelp beds and sand/rock habitats. At the darkest time of the year, Common Elders also fed much more than expected over urchin barrens. In contrast, the King Eider usually dived deeper than 20 m, and when they arrived in December, King Eiders fed especially in areas which were dominated by cobbles. Later in the season, they dispersed into areas with other substrates but still preferred deep water. The segregation between the two species was significant both for depth and substrate type, but depth was the most important factor. The change in the use of various substrate types throughout the winter was also significantly different between the two species, thus very little interspecific competition seemed to occur.     

A model for predicting the emergence of dragonflies in a changing climate

1. Precise models for the phenology of different species are essential for predicting the potential effects of any temporal mismatch of life cycles with environmental parameters under different climate change scenarios. Here we investigated the effects of ambient water temperature on the onset and synchrony of emergence for a widespread European riverine dragonfly, Gomphus vulgatissimus .
2. Long-term field data on the annual emergence from two rivers in northern Germany, and additional data from a laboratory experiment with different temperature regimes, were used to develop a model that predicted the onset of emergence by using mainly the temperature sum (degree days) as a parameter.
3. Model predictions of the onset of emergence fitted the observations well and could be transferred between localities. This was particularly so when weighting early winter temperature data by using a day length and a temperature-response function, implying potential additional control mechanisms for the onset of emergence.
4. We simulated effects of different winter temperature regimes on the emergence curves in order to predict the effects of climate change. These indicated an acceleration of emergence by 6–7 days per 1 °C temperature increase, which is corroborated by the laboratory data and is in the upper range of data published for other dragonflies.     

Levels of Growth Regulating Substances during Vernalization of Winter Wheat

Seeds of winter wheat (Triticum vulgare L.) cultivars Fema and Ferto, were vernalized at 3°C in the dark. Samples were taken 9, 18, 27, 36 and 45 days after the start of vernalization, and extracts were analysed for auxins, gibberellins and growth inhibiting substances. As vernalization progressed the levels of auxins and gibberellins increased whereas the levels of growth inhibitors decreased. The pattern of growth regulator changes was almost similar in both the cultivars. Vernalization seemingly controls the balance between growth promoting and growth inhibiting substances in winter wheat.