Genetic and evolutionary relationships among Asian Macaques

Published gene frequency data, checked for consistency of allele definitions across laboratories and for comparability of geographically identical samples, were pooled into a data set containing frequencies at nine loci for each of 20 populations that encompassed 10 macaque species. Genetic distances were calculated by the methods of Kidd and Cavalli-Sforza (1974). These distances were used to construct phylogenetic trees and to evaluate the relationships between divergence times and effective population sizes. Inter-and intraspecific genetic distances and the groupings defined by phenetic tree analyses support Fooden’s (1976) classification of the genus Macacainto four species groups. A paleozoogeographical model of Asia including the known times of major sea-level changes allows us to explain Macacainto four species groups. A paleozoogeographical model of Asia including the known times of major sea-level changes allows us to explain qualitatively the inferred evolutionary relationships among macaque species. Many assumptions are required in order to estimate the variables necessary in the quantitative prediction of genetic differences for a comparison between any two populations. Examination of those assumptions demonstrates the need for more accurate genetic as well as paleozoogeographic information. An erratum to this article is available at .     

Glycosylation of high-affinity thrombin receptors appears necessary for thrombin binding.

Monosaccharide binding competition, lectin affinity chromatography, and glycosylation inhibitors have been used to determine if glycosylation plays a role in thrombin-receptor interactions. Mannose appeared to specifically inhibit thrombin binding to mouse embryo (ME) and hamster fibroblasts. Concanavalin A bound to antibody-purified receptor fractions, and was used as an affinity ligand to purify receptor fractions that retained thrombin binding activity. Cells treated with tunicamycin (6.25 ng/ml) for 24 h lost approximately 35% of their high-affinity thrombin binding sites, yet binding of receptor monoclonal antibody TR-9 was not affected, indicating that the receptor was present in the membrane, but unable to bind thrombin. Thus thrombin receptor glycosylation may be directly involved in thrombin binding.     

Biochemical Conservation and Evolution of Germacrene A Oxidase in Asteraceae

Sesquiterpene lactones are characteristic natural products in Asteraceae, which constitutes ∼8% of all plant species. Despite their physiological and pharmaceutical importance, the biochemistry and evolution of sesquiterpene lactones remain unexplored. Here we show that germacrene A oxidase (GAO), evolutionarily conserved in all major subfamilies of Asteraceae, catalyzes three consecutive oxidations of germacrene A to yield germacrene A acid. Furthermore, it is also capable of oxidizing non-natural substrate amorphadiene. Co-expression of lettuce GAO with germacrene synthase in engineered yeast synthesized aberrant products, costic acids and ilicic acid, in an acidic condition. However, cultivation in a neutral condition allowed the de novo synthesis of a single novel compound that was identified as germacrene A acid by gas and liquid chromatography and NMR analyses. To trace the evolutionary lineage of GAO in Asteraceae, homologous genes were further isolated from the representative species of three major subfamilies of Asteraceae (sunflower, chicory, and costus from Asteroideae, Cichorioideae, and Carduoideae, respectively) and also from the phylogenetically basal species, Barnadesia spinosa, from Barnadesioideae. The recombinant GAOs from these genes clearly showed germacrene A oxidase activities, suggesting that GAO activity is widely conserved in Asteraceae including the basal lineage. All GAOs could catalyze the three-step oxidation of non-natural substrate amorphadiene to artemisinic acid, whereas amorphadiene oxidase diverged from GAO displayed negligible activity for germacrene A oxidation. The observed amorphadiene oxidase activity in GAOs suggests that the catalytic plasticity is embedded in ancestral GAO enzymes that may contribute to the chemical and catalytic diversity in nature.     

What can economics contribute to the study of human evolution?

The revised edition of Paul Seabright’s The Company of Strangers is critically reviewed. Seabright aims to help non-economists participating in the cross-disciplinary study of the evolution of human sociality appreciate the potential value that can be added by economists. Though the book includes nicely constructed and vivid essays on a range of economic topics, in its main ambition it largely falls short. The most serious problem is endorsement of the so-called strong reciprocity hypothesis that has been promoted by several prominent economists, but does not pass muster with biologists.     

The role of humans in the diversification of a threatened island raptor

Background  

Anthropogenic habitat modifications have led to the extinction of many species and have favoured the expansion of others. Nonetheless, the possible role of humans as a diversifying force in vertebrate evolution has rarely been considered, especially for species with long generation times. We examine the influence that humans have had on the colonization and phenotypic and genetic differentiation of an insular population of a long-lived raptor species, the Egyptian vulture (Neophron percnopterus).     

Spinal Loads during Cycling on an Ergometer

Cycling on an ergometer is an effective exercise for improving fitness. However, people with back problems or previous spinal surgery are often not aware of whether cycling could be harmful for them. To date, little information exists about spinal loads during cycling. A telemeterized vertebral body replacement allows in vivo measurement of implant loads during the activities of daily living. Five patients with a severe compression fracture of a lumbar vertebral body received these implants. During one measurement session, four of the participants exercised on a bicycle ergometer at various power levels. As the power level increased, the maximum resultant force and the difference between the maximum and minimum force (force range) during each pedal revolution increased. The average maximum-force increases between the two power levels 25 and 85 W were 73, 84, 225 and 75 N for the four patients. The corresponding increases in the force range during a pedal revolution were 84, 98, 166 and 101 N. There were large variations in the measured forces between the patients and also within the same patient, especially for high power levels. In two patients, the maximum forces during high-power cycling were higher than the forces during walking measured on the same day. Therefore, the authors conclude that patients with back problems should not cycle at high power levels shortly after surgery as a precaution.     

Zeitaufwand für das Ernten und Verstecken von Kiefernsamen bei Dünnschn?bligen Tannenh?hern (Nucifraga caryocatactes macrorhynchos) im Fernen Osten Russlands

Zusammenfassung In einem Vorkommen des Dünnschnäbligen Tannenhähers an der Küste des Ochotskischen Meeres im Fernen Osten Sibiriens wurde das Ernten und Verstecken von Samen aus den Zapfen der Zwergzirbelkiefer (Pinus pumila) untersucht. Der Inhalt von durchschnittlich 2,8 Zapfen, das sind etwa 80 Samen, wurde in der gefüllten Kehltasche transportiert und auf eine Anzahl unter niedriger Zwergstrauchvegetation gelegener Bodenverstecke verteilt. Die Verstecke wurden in annähernd linearer Anordnung ohne Bevorzugung einer bestimmten Himmelsrichtung angelegt. Die Versteckserien enthielten im Median 79, maximal mehr als 120 Samen, das Einzelversteck durchschnittlich 19,6 Samen. Das Ernten und Leeren eines Zapfens geschah im Schnitt innerhalb von 47 s. Für das Verstecken einer Füllung des Kehlsacks benötigten die Vögel ca. 170 s. Für das gesamte Beschaffen und Verstecken eines einzelnen Kiefernsamens errechnet sich ein durchschnittlicher Zeitbedarf von 3,26 s. Nach 20 Tagen war der Zapfenvorrat in der lokalen Kiefernpopulation erschöpft. Jeder Häher hat nach den Hochrechnungen bis zu 100.000 Samen vergraben.

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Harvesting and caching capacities of Thin-billed Nutcrackers in the Russian Far East

Summary At the Ochotskian sea coast Thin-billed Eurasian Nutcrackers (Nucifraga caryocatactes macrorhynchos) harvested seeds of ripe cones of the brush pinePinus pumila in late summer. The mean number of seeds carried in their sublingual pouch was 80, which respresents the harvestable contents of 2.8 cones. These were distributed in an average of 5 caches, exclusively in the soil under low tundra vegetation. Caches were organized in nearly straight lines. Series contained a mean of 82.7 seeds, single caches a mean of 19.6 seeds. Plucking one cone and harvesting its seeds took 47 seconds on average. The caching of a complete pouchful took on average 123.4 seconds. The time invested for harvesting and caching one single seed was calculated at 3.26 seconds. Within three weeks in July, an average individual bird was calculated to have cached a total of up to 100,000 seeds.

     

Die Entwicklung der Laut?u?erungen bei der Graugans (Anser anser)

Zusammenfassung Das Lautrepertoire von sechs handaufgezogenen Graugänsen wurde in individuellen Längsschnitten vom Schlüpfen bis zum Alter von 100 Tagen mit sonagraphischer Methode analysiert. Die Einteilung des Repertoires erfolgte nach drei verschiedenen Kriterien: Klang, Sonagramm und Kontext. Im jugendlichen Repertoire ließen sich 4 Rufklassen voneinander trennen. Im Laufe der Jugendentwicklung veränderten sich vor allem die phonetischen Parameter der Rufe, während die syntaktischen weitgehend konstant blieben. Nach einem Anstieg in der ersten Woche fiel die Tonhöhe der Rufe bei allen untersuchten Individuen und Rufklassen gleichmäßig ab. Der Stimmbruch, meßbar an der Zunahme geräuschhafter Komponenten, war ein kontinuierlicher, langfristiger Prozeß. Die Individualität war nicht in einem einzelnen, wohl aber in der Kombination mehrerer Merkmale faßbar. Die Geschlechter waren schon früh an Unterschieden in der Tonhöhe erkennbar. An sonstigen ontogenetischen Veränderungen innerhalb des Untersuchungszeitraumes konnten die Erweiterung des Repertories durch Aufspaltung und Reifung sowie ein möglicher Verlust von Rufklassen beobachtet werden.

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Juvenile development of vocalizations in Greylag Geese (Anser anser)

Summary The juvenile vocal development of six Greylag Geese from hatching up to the age of 100 days was analysed by using sonagraphic methods. The calls were classified by means of the acoustic phenomenon, sonagrams, and context criteria. The juvenile repertoire included four main call types. During ontogeny, changes of call parameters mainly referred to phonetic characteristics, whereas syntactic parameters remained more or less constant. The frequency pitch of calls changed to higher levels during the first week of development while in older goslings this parameter decreased constantly. This held true for each individual and call type. Breaking of the voice, defined as an increment of noisy parts in the vocalizations, is described as a continuous long term process. Structural individuality of calls apparently was not based on one single parameter, but on the combination of several ones. Sex differences were found in the pitch of vocalizations, correlating with different body weights of male and female geese. Additional developmental processes of the vocal repertoire included differentiation, maturation of new call types, and apparent suppression of juvenile ones. The functional organization of the juvenile call system in Greylags is discussed.

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Herrn Dr. Hans Löhrl zum 75. Geburtstag gewidmet