Establishment of a coastal fish in the Azores: recent colonisation or sudden expansion of an ancient relict population?

The processes and timescales associated with ocean-wide changes in the distribution of marine species have intrigued biologists since Darwin''s earliest insights into biogeography. The Azores, a mid-Atlantic volcanic archipelago located >1000 km off the European continental shelf, offers ideal opportunities to investigate phylogeographic colonisation scenarios. The benthopelagic sparid fish known as the common two-banded seabream (Diplodus vulgaris) is now relatively common along the coastline of the Azores archipelago, but was virtually absent before the 1990s. We employed a multiple genetic marker approach to test whether the successful establishment of the Azorean population derives from a recent colonisation from western continental/island populations or from the demographic explosion of an ancient relict population. Results from nuclear and mtDNA sequences show that all Atlantic and Mediterranean populations belong to the same phylogroup, though microsatellite data indicate significant genetic divergence between the Azorean sample and all other locations, as well as among Macaronesian, western Iberian and Mediterranean regions. The results from Approximate Bayesian Computation indicate that D. vulgaris has likely inhabited the Azores for ∼40 (95% confidence interval (CI): 5.5–83.6) to 52 (95% CI: 6.32–89.0) generations, corresponding to roughly 80–150 years, suggesting near-contemporary colonisation, followed by a more recent demographic expansion that could have been facilitated by changing climate conditions. Moreover, the lack of previous records of this species over the past century, together with the absence of lineage separation and the presence of relatively few private alleles, do not exclude the possibility of an even more recent colonisation event.     

Continuity and/or Discontinuity in the Pleistocene peopling of Europe?

Today, a number of European fossils are known which can be dated between 500,000 and 900,000 years ago. These remains provide evidence of an early human settlement of Europe, which apparently predates the emergence of Neanderthals. However, the taxonomic attribution of these fossils and their phylogenetic relationship to each other and to Neanderthals remains unclear. Evidence for a direct phylogenetic relationship with Neanderthals or a discontinuity is not yet conclusive. The task is complicated by the fact that the emergence of the Neanderthal population was not abrupt, but progressive. It is probable that the peopling of Europe during the entire Pleistocene was unique and presented from its very origins an “endemic” (a cul-de-sac) character, which may explain that the first traces of fossils in Europe illustrate particularities in comparison those from Africa and from Asia. Further paleontological discoveries will be needed to redefine the status of these features and to improve our understanding of human evolution in Europe.     

Infectious disease in the Pleistocene: Old friends or old foes?

The impact of endemic and epidemic disease on humans has traditionally been seen as a comparatively recent historical phenomenon associated with the Neolithisation of human groups, an increase in population size led by sedentarism, and increasing contact with domesticated animals as well as species occupying opportunistic symbiotic and ectosymbiotic relationships with humans. The orthodox approach is that Neolithisation created the conditions for increasing population size able to support a reservoir of infectious disease sufficient to act as selective pressure. This orthodoxy is the result of an overly simplistic reliance on skeletal data assuming that no skeletal lesions equated to a healthy individual, underpinned by the assumption that hunter-gatherer groups were inherently healthy while agricultural groups acted as infectious disease reservoirs. The work of van Blerkom, Am. J. Phys. Anthropol., vol. suppl 37 (2003), Wolfe et al., Nature, vol. 447 (2007) and Houldcroft and Underdown, Am. J. Phys. Anthropol., vol. 160, (2016) has changed this landscape by arguing that humans and pathogens have long been fellow travelers. The package of infectious diseases experienced by our ancient ancestors may not be as dissimilar to modern infectious diseases as was once believed. The importance of DNA, from ancient and modern sources, to the study of the antiquity of infectious disease, and its role as a selective pressure cannot be overstated. Here we consider evidence of ancient epidemic and endemic infectious diseases with inferences from modern and ancient human and hominin DNA, and from circulating and extinct pathogen genomes. We argue that the pandemics of the past are a vital tool to unlock the weapons needed to fight pandemics of the future.     

Age-specific changes in different components of reproductive output in female reindeer: terminal allocation or senescence?

Two different processes can lead to a change in individual reproductive output with age in long-lived iteroparous vertebrates. The senescence hypothesis predicts a decline of performance in old age, whereas the terminal allocation hypothesis predicts an increase. Using long-term (>30 years) individually based data of female reindeer, we first assessed age-specific variation in body mass and different components of reproductive output. Then we investigated the contribution of senescence and terminal allocation (the increase in components of reproductive output) processes for shaping observed patterns. We found that female reindeer body mass increased up to about 11.5 years of age, and decreased afterwards, supporting the senescence hypothesis. Calf birth mass, both in absolute terms or for a given female mass, first increased and then declined with female age, also supporting the senescence hypothesis. The female mass gain (June–September) decreased with increasing age, and female change in mass between 2 consecutive years decreased with female age, all patterns again supporting the senescence hypothesis. However, the autumn calf mass did not change with age. Calf body mass in autumn tended to be positively related to female mass gain, supporting a quality effect. Raising a calf had a marked negative effect on female mass gain, indicating energetic reproductive costs of raising a calf. Calf body mass in autumn did not influence yearly female mass change. Overall, our results provided consistent evidence for general effects of senescence on most components of reproductive output and highlighted that both individual heterogeneity and reproductive costs shape female reindeer reproductive tactics.     

A carnivorous niche for Java Man? A preliminary consideration of the abundance of fossils in Middle Pleistocene Java

Considering anatomical and archaeological aspects of Homo erectus, it is likely that meat of vertebrates was an important part in its diet. Unfortunately, no or hardly any information is available for Java Man (Homo erectus). Therefore, in this paper, the Number of Identified Specimens (NISP) of five Middle Pleistocene Javanese sites are examined, and the Minimum Number of Individuals (MNI) from two of them are calculated, to acquire information about the possible ecological role of Javanese Homo erectus. Although one has to be extremely careful with the interpretation of fossil bone assemblages in order to try to gain some insight about the abundance of species in palaeocommunities, it is argued that both the NISP and the MNI indicate that the bone accumulations reflect at least two trophic levels in the ecological pyramid, that of primary and secondary consumers. The occurrences of the remains of Homo erectus are comparable with the quantity of secondary consumers, i.e., large carnivores. This could suggest that this species had, as an omnivore, a carnivorous niche, in Java.     

Study of EEG microstates in Parkinson’s disease: a potential biomarker?

The spontaneous activity of the brain is dynamic even at rest and the deviation from this normal pattern of dynamics can lead to different pathological states. EEG microstate analysis of resting-state neuronal activity in Parkinson’s disease (PD) could provide insight into altered brain dynamics of patients exhibiting dementia. Resting-state EEG microstate maps were derived from 128 channel EEG data in 20 PD without dementia (PDND), 18 PD with dementia (PDD) and 20 Healthy controls (CON) using Cartool and sLORETA softwares. Microstate map parameters including global explained variance, mean duration, frequency of occurrence (TF) and time coverage were compared statistically among the groups. Eight maps that explained 72% of the topographic variance were identified and only three maps differed significantly across the groups. TF of Map1 was lower in both PDND and PDD (p < 0.001) and that of Map3 (p = 0.02) in PDND compared to control. Cortical sources showed higher activation in precuneus, cuneus and superior parietal lobe (Threshold: Log-F = 1.74, p < 0.05) with maximum activity in the precuneus region (MNI co-ordinates: − 25, − 75, − 40; Log-F = 1.9) in PDND compared to control only for Map1. Lower TF of Map1 (prototypical microstate D) may potentially serve as a biomarker for PD with or without dementia whereas higher activation of precuneus, cuneus and superior parietal lobe at resting-state could favour signal processing, lack of which could be associated with dementia in Parkinson’s disorder.     

Livistona palms in Australia: Ancient relics or opportunistic immigrants?

Eighteen of the 34 species of the fan palm genus Livistona (Arecaceae) are restricted to Australia and southern New Guinea, east of Wallace’s Line, an ancient biogeographic boundary between the former supercontinents Laurasia and Gondwana. The remaining species extend from SE Asia to Africa, west of Wallace’s Line. Competing hypotheses contend that Livistona is (a) ancient, its current distribution a relict of the supercontinents, or (b) a Miocene immigrant from the north into Australia as it drifted towards Asia. We have tested these hypotheses using Bayesian and penalized likelihood molecular dating based on 4 Kb of nuclear and chloroplast DNA sequences with multiple fossil calibration points. Ancestral areas and biomes were reconstructed using parsimony and maximum likelihood. We found strong support for the second hypothesis, that a single Livistona ancestor colonized Australia from the north about 10–17 Ma. Spread and diversification of the genus within Australia was likely favoured by a transition from the aseasonal wet to monsoonal biome, to which it could have been preadapted by fire-tolerance.     

Dissemination of spores in a glasshouse: Pattern or chaos?

The dissemination of particles in a glasshouse with three united compartments was observed from experiments withLycopodium sp. The experiments were performed in a glasshouse with open and closed ventilation openings, spore sources on two heights above soil surface, and in two consecutive time intervals. The spores were caught with self constructed spore traps placed at regular distances from each other. Air circulation was observed using smoke-puffs. High ventilation caused a rapid cleaning of the air while in a closed glasshouse spores remained suspended for quite a long time. Though the three compartments of the glasshouse were not separated by walls, a so-called cell structure of the individual compartments could be indicated.     

Marine biogeographical disjunction in temperate Australia: historical landbridge,contemporary currents,or both?

Marine biogeographers have long recognized broad east–west differentiation of marine communities across southern Australia, but few studies have explicitly assessed the site of disjunction or the factors potentially underlying this biodiversity. A recent, detailed phylogeographical and distributional study of the dispersive gastropod genus Nerita revealed an abrupt shift in species abundance across mainland Australia, apparently correlated with the site of an historical vicariant barrier: the Bassian Isthmus. In the current study I provide an independent assessment of this vicariant hypothesis by morphologically analysing over 3000 intertidal Nerita specimens from eight coastal sites around Tasmania. Consistent with the Bassian Isthmus hypothesis, the study reveals a dramatic east–west disjunction across north-east Tasmania. A survey of marine biogeographical literature reveals several additional examples supporting the east–west species turnover detected in Nerita . I discuss the role of contemporary oceanographic factors in preserving the biogeographical signature of marine vicariance, even in highly dispersive taxa. Based on recent marine connectivity data, the east–west disjunction in Nerita taxa can be interpreted as an historic vicariant pattern perpetuated by contemporary oceanographic conditions. The results of this study emphasize the potential importance of considering relative abundance data – rather than just species range data – in marine biogeographical analyses. As the observed disjunction is likely to have broad implications for Australia's marine biodiversity, it is imperative that conservation biologists incorporate such data in the design of marine protected areas.     

Inflammation in atherosclerosis: a cause or a result of vascular disorders?

Sound data support the concept that in atherosclerosis, inflammation and dyslipidemia intersect each other and that irrespective of the initiator, both participate from the early stages to the ultimate fate of the atheromatous plaque. The two partakers manoeuvre a vicious circle in atheroma formation: dyslipidaemia triggers an inflammatory process and inflammation elicits dyslipidaemia. Independent of the initial cause, the atherosclerotic lesions occur focally, in particular arterial-susceptible sites, by a process that, although continuous, can be arbitrarily divided into a sequence of consecutive stages that lead from fatty streak to the fibro-lipid plaque and ultimately to plaque rupture and thrombosis. In the process, the initial event is a change in endothelial cells (EC) constitutive properties. Then, the molecular alarm signals send by dysfunctional EC are decoded by specific blood immune cells (monocytes, T lymphocytes, neutrophils, mast cells) and by the resident vascular cells, that respond by initiating a robust inflammatory process, in which the cells and the factors they secrete hasten the atheroma development. Direct and indirect crosstalk between the cells housed within the nascent plaque, complemented by the increase in risk factors of atherosclerosis lead to atheroma development and outcome. The initial inflammatory response can be regarded as a defense/protective reaction mechanism, but its further amplification, speeds up atherosclerosis. In this review, we provide an overview on the role of inflammation and dyslipidaemia and their intersection in atherogenesis. The data may add to the foundation of a novel attitude in the diagnosis and treatment of atherosclerosis.     

Nomenclature: or what's in a name?

Transgenic Research -     

p73: a Positive or Negative Regulator of Angiogenesis,or Both?

The role of p73, the homologue of the tumor suppressor p53, in regulating angiogenesis has recently been extensively investigated, resulting in the publication of five articles. Of these, two studies suggested a suppressive role, while the others implied a stimulatory role for the p73 isoforms in regulating angiogenesis. A negative role for TAp73, the full-length form that is often associated with tumor suppression, in blood vessel formation, is consistent with its general attributes and was proposed to be effected indirectly through the degradation of hypoxia-inducible factor 1α (HIF1-α), the master angiogenic regulator. In contrast, a positive role for TAp73 coincides with its recently understood role in supporting cellular survival and thus tumorigenesis, consistent with TAp73 being not-mutated but rather often overexpressed in clinical contexts. In the latter case, TAp73 expression was induced by hypoxia via HIF1-α, and it appears to directly promote angiogenic target gene activation and blood vessel formation independent of HIF1-α. This mini review will provide an overview of these seemingly opposite recent findings as well as earlier data, which collectively establish the definite possibility that TAp73 is indeed capable of both promoting and inhibiting angiogenesis, depending on the cellular context.