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.     

Vibration and sound communication in solitary bees and wasps

ABSTRACT. Females of solitary bees ( Colletes cunicularius L.) and of digger wasps ( Bembix rostrata L.) produce buzzing sounds and are known to secrete volatile odours when digging their way from the subterranean nests to the soil surface. The odours allow patrolling males to determine the approximate position of the digging virgin female. The buzzes are measured as substrate-borne sound (soil buzz vibrations) and as air-borne sound (soil buzz sounds). Play-back experiments suggest that the soil buzzes are used by the males as additional cues for localization. Faint buzz sounds are emitted regularly by the male during genital contact in copulation. They may serve to change the receptivity of the female. Intense and broadband buzz sounds are produced by bees of either sex, if restrained from moving, perhaps serving to deter predators.     

CHANGES IN CLICK SOURCE LEVELS WITH DISTANCE TO TARGETS: STUDIES OF FREE-RANGING WHITE-BEAKED DOLPHINS LAGENORHYNCHUS ALBIROSTRIS AND CAPTIVE HARBOUR PORPOISES PHOCOENA PHOCOENA

ABSTRACT

Probably all odontocetes use echolocation for spatial orientation and detection of prey. We used a four hydrophone “Y” array to record the high frequency clicks from free-ranging White-beaked Dolphins Lagenorhynchus albirostris and captive Harbour Porpoises Phocoena phocoena. From the recordings we calculated distances to the animals and source levels of the clicks. The recordings from White-beaked Dolphins were made in Iceland and those from Harbour Porpoises at Fjord & Baelt, Kerteminde, Denmark during prey capture. We used stringent criteria to determine which clicks could be defined as being on the acoustic axis. Two dolphin and nine porpoise click series could be used to track individual animals, which presumably focused on the array hydrophones or a fish right in front of the array. The apparent source levels of clicks in the individual tracks increased with range. One individual White-beaked Dolphin and three Harbour Porpoises regulate their output signal level to nearly compensate for one-way transmission loss while approaching a target. The other dolphin regulated the output differently. For most of the recordings the sound level at the target remains nearly constant and the echo level at the animal increases as it closes on the target.     

A photographic census of flamingos in the Rift Valley lakes of Tanzania

An aerial photographic census of flamingos ( Phoenicopterus minor and P. ruber) was conducted on 20 July 1994 on nine lakes in Tanzania: Lakes Natron, Manyara, Magadi (Ngorongoro), Burungi, Embagai, Eyasi, Lagarja, Masek, and Ambussel. This census, conducted concurrently with a survey in Kenya, documented the numbers and distribution of flamingos in the Rift Valley Lakes of East Africa. The total population size of flamingos in the Tanzanian lakes surveyed was |mF907,000. The largest concentrations in Tanzania were found in Lake Natron and Embagai Crater Lake. Although flamingos are known to breed in Lake Natron, no evidence of breeding was observed during the survey. The total estimate for the southern Kenya and northern Tanzania Rift Valley was |mF2·8 million. Trends in flamingo populations, survey methodology, and future monitoring needs are discussed.     

Macromolecular Physiology of Plastids

The composition and amount of carotenoid pigments were determined in etiolated seedling leaves of 6 barley (Hordeum vulgare L.) mutants, comprising 1 xantha and 5 tigrina mutants. All mutants had on a mole basis approximately the same content of carotenoids as the wild type. The mutants xan-u²¹, tig-n³², and tig-³³ contained significantly higher amounts of carotenes than the wild type, ranging from 32 to 68% of the total carotenoid content as compared to the 4–8% found in the wild type. In the mutants tig-b²³ and tig-o³⁴, only a slight increase in the amount of carotenes was notable. The carotene content and composition in tig-d¹² was indistinguishable from that of the wild type. The carotenes extracted from xan-u²¹, tig-b²³, tig-n³², tig-³³, and tig-o³⁴ were characterized by adsorption chromatography and spectrophotometry. Mutant xan-u²¹ is in the dark blocked in β-carotene synthesis, and accumulates the aliphatic polyenes: phytofluene, proneurosporene, poly-cis-lycopenes, neo-lycopene and lycopene. The other four mutants synthesize β-carotene, but accumulate in addition various higher saturated carotenes, the main components being ζ-carotene in tig-b²³, a lycopenic pigment in tig-n³² and tig-³³, and lycopene in tig-o³⁴. Accumulation of higher saturated carotenes appears correlated with specific aberrations of the membrane structure in plastids. The regulation of carotene and protochlorophyllide syntheses in etioplasts are closely linked as shown by the single gene mutants which affect both pathways. However, several mutants have been identified which cause defects in protochlorophyllide synthesis only.     

The Ultrastructure of the Glandular Trichomes of Solanum tuberosum

The potato plant has two types of glandular trichomes whichwere investigated by electron microscopy. One type has a eight celled globular head on a neck cell anda stalk cell Each glandular cell has many rather large vacuoles,a large nucleus, many ribosomes and mitochondria, a few Golgibodies, and darkly coloured, often irregular plastids (chloroplasts).The plastids are mostly located near the axial cell wall borderinga large central intercellular space filled with secretion materialThe plastids are assumed to participate in the formation ofthe secretion material, which reacts positively to esterasetests. The outer wall is covered by a thin cuticle. The other type has a club-shaped multicellular head on a singlestalk cell. The cytoplasmic features in the cells are similarto those of the globular-headed trichome, except that they possesslarge central vacuoles and randomly distributed plastids. Centricendoplasmic reticulum has been observed in young cells. Intercellularspaces develop between the cells and into the outer wall, whichis thus split into two. Whereas the older glandular cells reactpositively to tests for esterase, the secretion material itselfis pectinaceous and reacts negatively. The outer wall is cutinizedand covered by a cuticle. Solanum tuberosum L., potato, glandular trichomes, ultrastructure