PHYLOGENY OF THE RUBIACEAE AND THE LOGANIACEAE: CONGRUENCE OR CONFLICT BETWEEN MORPHOLOGICAL AND MOLECULAR DATA?

Phylogenetic analyses of 33 genera of Rubiaceae were performed using morphological and a few chemical characters. Parsimony analysis based on 29 characters resulted in eight equally parsimonious trees, with a consistency index of 0.40 and a retention index of 0.69. These results were compared to a phylogenetic analysis of the same genera based on chloroplast DNA restriction site data. There are discrepancies between the two analyses, but if we consider groupings reflected in the present classification there is much congruency. With the exception of four genera, all the genera are positioned in the same group of taxa in the two analyses. Clades of taxa representing three of the four subfamilies (~the Antirheoideae, ~the Rubioideae, and the ~Ixoroideae) are monophyletic, while the fourth subfamily Cinchonoideae is shown to be paraphyletic. Both analyses support a widened tribe Chiococceae, including the former subtribe Portlandiinae (Condamineeae). Furthermore, in both analyses the tribe Hamelieae is placed outside the subfamily Rubioideae where it is now housed. In search for the most plausible sister group to the Rubiaceae, the genus Cinchona (Rubiaceae) was analyzed together with 13 genera of the Loganiaceae, Nerium (Apocynaceae), and Exacum (Gentianaceae). Cornus (Comaceae), Olea (Oleaceae), and these two genera together were used as outgroups. The analysis, including 25 characters, 16 taxa, and with Cornus and Olea together as an outgroup, resulted in four equally parsimonious trees, with a consistency index of 0.53 and a retention index of 0.62. The non-Loganiaceae taxa Cinchona (Rubiaceae), Nerium (Apocynaceae), and Exacum (Gentianaceae) were all found to have their closest relatives within the Loganiaceae indicating that the Loganiaceae are paraphyletic and ought to be reclassified. As a result of the morphological data the most plausible sister group to the Rubiaceae is the tribe Gelsemieae of the Loganiaceae.     

THE QUICK AND THE DEAD? SPERM COMPETITION AND SEXUAL CONFLICT IN SEA

Our view of sperm competition is largely shaped by game-theoretic models based on external fertilizers. External fertilization is of particular interest as it is the ancestral mode of reproduction and as such, relevant to the evolution and maintenance of anisogamy (i.e., large eggs and tiny, numerous sperm). Current game-theoretic models have been invaluable in generating predictions of male responses to sperm competition in a range of internal fertilizers but these models are less relevant to marine broadcast spawners, the most common and archetypal external fertilizers. Broadcast spawners typically have incomplete fertilization due to sperm limitation and/or polyspermy (too many sperm), but the effects of incomplete (<100% fertilization rates) fertilization on game-theoretic predictions are unclear particular with regards to polyspermy. We show that incorporating the effects of sperm concentration on fertilization success changes the predictions of a classic game-theoretic model, dramatically reversing the relationship between sperm competition and the evolutionarily stable sperm release strategy. Furthermore, our results suggest that male and female broadcast spawners are likely to be in conflict at both ends of the sperm environment continuum rather than only in conditions of excess sperm as previously thought. Across the majority of the parameter space we explored, males release either too little to too much sperm for females to achieve complete fertilization. This conflict could result in a coevolutionary race that may have led to the evolution of internal fertilization in marine organisms.     

DO TRADE‐OFFS HAVE EXPLANATORY POWER FOR THE EVOLUTION OF ORGANISMAL INTERACTIONS?

The concept of a trade-off has long played a prominent role in understanding the evolution of organismal interactions such as mutualism, parasitism, and competition. Given the complexity inherent to interactions between different evolutionary entities, ecological factors may especially limit the power of trade-off models to predict evolutionary change. Here, we use four case studies to examine the importance of ecological context for the study of trade-offs in organismal interactions: (1) resource-based mutualisms, (2) parasite transmission and virulence, (3) plant biological invasions, and (4) host range evolution in parasites and parasitoids. In the first two case studies, mechanistic trade-off models have long provided a strong theoretical framework but face the challenge of testing assumptions under ecologically realistic conditions. Work under the second two case studies often has a strong ecological grounding, but faces challenges in identifying or quantifying the underlying genetic mechanism of the trade-off. Attention is given to recent studies that have bridged the gap between evolutionary mechanism and ecological realism. Finally, we explore the distinction between ecological factors that mask the underlying evolutionary trade-offs, and factors that actually change the trade-off relationship between fitness-related traits important to organismal interactions.     

POPULATION ON THE VERGE OF A MUTATIONAL MELTDOWN? FITNESS COSTS OF GENETIC LOAD FOR AN AMPHIBIAN IN THE WILD

Abstract.— The fitness costs of high genetic load in wild populations have rarely been assessed under natural conditions. Such costs are expected to be greatest in small, bottlenecked populations, including those occurring near range edges. Britain is at the northwesterly range limit of the natterjack toad Bufo calamita . We compared fitness attributes in two populations of this amphibian with very different recent histories. Key larval fitness attributes in B. calamita , notably growth rate and metamorph production, were substantially higher in the large outbreeding population (Ainsdale) than in the small and isolated one (Saltfleetby). These differences were manifest under seminatural conditions, when larvae were reared in mesh cages within breeding ponds at the site of the small population, and were exacerbated by high stress treatments. The results indicate that genetic load effects can be sufficiently severe enough to predispose extinction over relatively short time frames, as predicted by extinction vortex models.     

DO PHOTOPERIOD AND TEMPERATURE INFLUENCE THE MOLT CYCLE OF PHOCA VITULINA IN CAPTIVITY?

Photoperiod variations are the principal environmental signals entraining circannual activity in mammals, which is also believed to be influenced by changes in temperature and nutrition. Control of the molt in phocids has not been extensively studied with experimental manipulations of environmental factors, but substantial work indicates that photoperiod has a primary influence on mammalian breeding and furring mechanisms. Studies were under taken to reestablish the molt cycle in five harbor seals ( Phoca vitulina ) previously kept in an enclosed facility with a limited air/water temperature gradient and artificial photoperiod. The seals were exposed to an extended temperature gradient during the first period of study, and no molting was observed. The second period of study was characterized by a natural occurring photoperiod of 8 h 53 min light (L)/15 h 07 min dark (D) and a maximal 15 h 31 min L/8h 29 min D duration, and molting occurred in all individuals. These results suggest a prevalent influence of photoperiod variation on the harbor seal molt.     

IS MOM IN CHARGE? IMPLICATIONS OF RESOURCE PROVISIONING ON THE EVOLUTION OF THE PLACENTA

The Trexler–DeAngelis model shows that placentas are most likely to evolve in environments with consistent, high levels of resource availability. An assumption imperative to the model is that placental species abort embryos in low food conditions. However, a previous experimental test of this assumption using the northern clade of Poeciliopsis showed no evidence for abortion. To distinguish between the alternatives that placental species either sacrifice body condition to maintain reproduction when resources are restricted, or that the previously documented pattern of resource allocation is a function of other life‐history correlates of placentation rather than placentation alone, we perform a similar experiment on the southern clade of Poeciliopsis. The southern clade has the opposite relationship between life‐history traits and placentation as seen in the northern clade. Our results mirror those from the northern clade, indicating that reproductive mode, rather than life history, dictates the pattern of resource allocation. These results add to the difficulties of explaining placental evolution within the constraints of the Trexler–DeAngelis model by restricting the range of resource conditions in which placental species can outcompete nonplacental species. They also lend support to hypotheses that suggest parent–offspring conflict in utero drives the evolution of the placenta.     

DO EMBRYOS INFLUENCE MATERNAL INVESTMENT? EVALUATING MATERNAL‐FETAL COADAPTATION AND THE POTENTIAL FOR PARENT‐OFFSPRING CONFLICT IN A PLACENTAL FISH

The evolution of matrotrophy introduces the potential for genomic conflicts between mothers and embryos. These conflicts are hypothesized to accelerate the evolution of reproductive isolation and to influence the evolution of life-history traits, reproductive structures, and genomic imprinting. These hypotheses assume offspring can influence the amount of maternal investment they receive and that there is a trade-off between maternal investment into individual offspring and maternal survival or fecundity. We used field data and laboratory crosses to test whether these assumptions are met in the matrotrophic poeciliid fish Heterandria formosa . Comparisons of life histories between two natural populations demonstrated a trade-off between the level of maternal investment into individual embryos and maternal fecundity. Laboratory crosses between individuals from these populations revealed that offspring genotype exerts an influence on the level of maternal investment and affects maternal fecundity through higher rates of embryo abortion and lower numbers of full-term offspring. Our results show that the prerequisites for parent–offspring conflict to be a potent evolutionary force in poeciliid fish are present in H. formosa. However, determining whether this conflict has shaped maternal investment in nature will require disentangling any effects of conflict from those of several ecological factors that are themselves correlated with the expected intensity of conflict.     

BRAIN,MIND AND MACHINE: WHAT ARE THE IMPLICATIONS OF DEEP BRAIN STIMULATION FOR PERCEPTIONS OF PERSONAL IDENTITY,AGENCY AND FREE WILL?

Brain implants, such as Deep Brain Stimulation (DBS), which are designed to improve motor, mood and behavioural pathology, present unique challenges to our understanding of identity, agency and free will. This is because these devices can have visible effects on persons' physical and psychological properties yet are essentially undetectable when operating correctly. They can supplement and compensate for one's inherent abilities and faculties when they are compromised by neuropsychiatric disorders. Further, unlike talk therapy or pharmacological treatments, patients need not ‘do’ anything for the treatment to take effect. If one accepts, as we argue here, that brain implants are unique among implantable types of devices, then this can have significant implications for what it means to persist as the same person and be the source of one's thoughts and actions. By examining two of the most common indications for DBS in current use, namely in the motor (Parkinson's Disease) and psychiatric (Major Depression) domains, we further argue that although DBS, as it is currently applied, does not necessarily represent a unique threat to personal identity and agency per se, it introduces an unprecedented ‘third party’ into the debate on these concepts. In this way, DBS can be used as a tool to begin probing, both conceptually and empirically, some of philosophy's most perennial metaphysical questions.     

A 13-YEAR POPULATION STUDY OF THE BLACK EAGLES IN THEMATOPOS,RHODESIA, 1964–1976

Gargett, V. 1977. A 13-year population study of the Black Eagles in the Matopos, Rhodesia, 1964–1976. Ostrich 48:17-27.

The resident black Eagle Aquila verreauxi population in approximately 620 km² of the Matopos, Rhodesia, underwent changes from 1971 and appeared less stable than in the first five years. Six new territories were established in the National Park; two territories in Tribal Trust Land were abandoned; one territory in the National Park vacant for five years and one in Tribal Land vacant for at least 11 years were reoccupied. breeding data covering 13 years confirm the five-year findings. In 652 pair-years 442 breeding attempts were made with 339 young eagles f edging: a reproductive success rate of 0,52 young per pair per year. On average 68 % of the population bred every year, each pair attempted breeding in two years out of three, and one attempt in four was unsuccessful. Annual and individual variations in breeding performance were considerable, from 46% to 89% of the population breeding, and from two successes in six attempts for one pair to 12 successes in 12 attempts for two pairs. Over 13 years the percentage of the population breeding annually followed the form of a sine curve with a ten year period.

Fourteen factors that might affect annual and/or individual performance are considered. Below average rainfall years were followed by above average breeding; and generally fewer clutches were laid early after heavy rainfall in the three months preceding laying. Clutches laid late were less successful than those laid early. Breeding was affected by the proximity and intervisibility of nests, the previous year's performance and intraspecific disturbance. Appropriation of nests by other species prevented breeding and no new pair bred while establishing or re-establishing its territory. Building a new nest was followed by laying in the same season only if the nest was completed by mid-May, the peak laying period, building or partly building two nests in one season did not prevent breeding in the following year. At least 76% of clutches were c/2. The causes of two eaglets' deaths were ascertained and the remains of two adults were found. Pairs with territories in Tribal Trust Land had a significantly lower breeding performance than pairs in the protected National Park. Only traces of pesticide residues were found in four eggs. Observers' visits did not affect reproductive success.     

DO THE SIBERIAN TITS PARUS CINCTUS IN SCANDINAVIA AND SIBERIA SPEAK THE SAME LANGUAGE?

ABSTRACT

The vocabulary of Siberian tits Parus cinctus in South Norway and East Siberia is compared by means of tape recordings and spectrograms. The species has many different calls that are greatly confused in the literature. In this paper ten main call types are examined. On the whole, the equivalent utterings are geographically so similar that a distinction is usually impossible or questionable. This similarity also applies to the contextual use of the calls. Consistent structural differences in certain calls were nevertheless found. The sit foraging call embraced on average a broader frequency range and was of a slightly longer duration in Siberia than in Norway. The complex ‘gargle’ system could at both places be divided into three main groups equally represented in the populations: (1) trilled, (2) tonal and (3) simple gargles. The tonal gargles are characterized by a terminal tonal element (T) that varies in shape. In Norway, tonal gargles terminating with an even or upslurred T dominated, in Siberia those with a chevron-formed T. Historically, the west-east distribution throughout Eurasia was apparently continuous until quite recently, allowing an effective gene flow. Considering the huge distance from Norway to East Siberia and the markedly resident behaviour of the Siberian tit, it is nevertheless somewhat unexpected that so few vocal differences have evolved. Several of the calls of the Siberian tit are structurally very similar to equivalent (most likely homologous) calls in other species belonging to the subgenus Poecile, e.g. the willow tit Parus montanus and the black-capped chickadee P. atricapillus, suggesting that the multicall repertoire of their common ancestor remained largely intact despite Poecile's differentiation into different species.     

HOW AND WHEN DO LAMBS RECOGNIZE THE BLEATS OF THEIR MOTHERS?

ABSTRACT

In domestic sheep Ovis aries, the mother and the young display a preferential bond for each other that relies on multimodal inter-individual recognition. Lambs show a preference for their own dam shortly after birth, and this is important for their survival. The role of acoustic cues in this early preference for the mother is not clear. The aim of the present work was to analyze the timing of acoustic recognition of the mother and to identify the physical parameters used in the recognition of maternal bleats by the lamb.

In a first study, we investigated the ability of lambs to discriminate between the bleats of their own mother and an alien equivalent mother in a two-choice test. Both ewes were hidden behind a canvas sheet and lambs were not allowed to approach the dams closer than 1 m, thus preventing visual as well as olfactory perception. Tests were conducted 12 hr, 24 hr or 48 hr after birth (n=19 or 20/group). An indication of vocal discrimination was already present at 24 hr and at 48 hr lambs spent significantly more time near their mother than near the alien dam.

In a second step, we investigated which physical parameters of the bleats were important for recognition. For this, we conducted playback experiments with modified bleats at two weeks postpartum. Ours results show that lambs pay attention to a combination of various time, energy and frequency parameters: timbre (distribution of energy within the spectrum), amplitude and frequency modulations appear to be the most important parameters encoding the individual signature.

We conclude that vocal recognition between the ewe and her lamb plays an important role in the display of preferential mother-young bond from very early on. Our studies also demonstrate that the encoding of the individual signature is not limited to the frequency domain but rather involves a multiparametric encoding process.     

NOTE ON THE EXCITATION AND INHIBITION OF LUMINESCENCE IN BER?

1. The ions of Ca and K condition general luminescence, and are therefore necessary to the conduction of the impulse. 2. In van''t Hoff''s solution from which Mg is omitted, Berœ shows hyperirritability with respect to luminescence. This is the result of the action of Ca and K ions unantagonized by Mg. 3. The luminescent material spread on filter paper does not show luminescence in sea water, NaCl, MgCl₂, or saccharose solutions isotonic with sea water. In solutions of CaCl₂, SrCl₂, BaCl₂, KCl, and K₂SO₄ the indicator paper glows with a bright luminescence. 4. In dark adapted Berœ, luminescence is inhibited by a certain quantity of light. This quantity has an average value of 57,285 meter-candle-minutes, which is twelve times the value given by Mnemiopsis.     

DO GEOLOGICAL OR CLIMATIC PROCESSES DRIVE SPECIATION IN DYNAMIC ARCHIPELAGOS? THE TEMPO AND MODE OF DIVERSIFICATION IN SOUTHEAST ASIAN SHREWS

Geological and climatic processes potentially alter speciation rates by generating and modifying barriers to dispersal. In Southeast Asia, two processes have substantially altered the distribution of land. Volcanic uplift produced many new islands during the Miocene–Pliocene and repeated sea level fluctuations during the Pleistocene resulted in intermittent land connections among islands. Each process represents a potential driver of diversification. We use a phylogenetic analysis of a group of Southeast Asian shrews ( Crocidura ) to examine geographic and temporal processes of diversification. In general, diversification has taken place in allopatry following the colonization of new areas. Sulawesi provides an exception, where we cannot reject within-island speciation for a clade of eight sympatric and syntopic species. We find only weak support for temporally declining diversification rates, implying that neither volcanic uplift nor sea level fluctuations had a strong effect on diversification rates. We suggest that dynamic archipelagos continually offer new opportunities for allopatric diversification, thereby sustaining high speciation rates over long periods of time, or Southeast Asian shrews represent an immature radiation on a density-dependent trajectory that has yet to fill geographic and ecological space.