What was the evolutionary synthesis?

There has not been another scientific revolution that caused as much turmoil and dissension as the darwinian one. For almost 80 years it was again and again pronounced to be a failure and to be totally refuted, and at least three major alternatives were proposed to replace it. Yet, in the 1930s-1940s the opposing views were quickly and decisively refuted and a largely unified evolutionary theory emerged. Why and how this happened, however, is still rather controversial.     

Are subspecies useful in evolutionary and conservation biology?

The taxonomic rank of subspecies remains highly contentious, largely because traditional subspecies boundaries have sometimes been contradicted by molecular phylogenetic data. The most complete meta-analysis to date, for instance, found that only 3% of traditional avian subspecies represented distinct phylogenetic lineages. However, the global generality of this phenomenon remains unclear due to this previous study's narrow geographic focus on continental Nearctic and Palearctic subspecies. Here, we present a new global analysis of avian subspecies and show that 36% of avian subspecies are, in fact, phylogenetically distinct. Among biogeographic realms we find significant differences in the proportion of subspecies that are phylogenetically distinct, with Nearctic/Palearctic subspecies showing significantly reduced levels of differentiation. Additionally, there are differences between island and continental subspecies, with continental subspecies significantly less likely to be genetically distinct. These results indicate that the overall level of congruence between taxonomic subspecies and molecular phylogenetic data is greater than previously thought. We suggest that the widespread impression that avian subspecies are not real arises from a predominance of studies focusing on continental subspecies in North America and Eurasia, regions which show unusually low levels of genetic differentiation. The broader picture is that avian subspecies often provide an effective short-cut for estimating patterns of intraspecific genetic diversity, thereby providing a useful tool for the study of evolutionary divergence and conservation.     

Do the evolutionary interactions between moths and bats promote niche partitioning between bats and birds?

Ecological theory suggests that the coexistence of species is promoted by the partitioning of available resources, as in dietary niche partitioning where predators partition prey. Yet, the mechanisms underlying dietary niche partitioning are not always clear. We used fecal DNA metabarcoding to investigate the diets of seven nocturnal insectivorous bird and bat species. Low diet overlap (2%–22%) supported resource partitioning among all species. Differences in diet corresponded with species identity, prey detection method, and foraging behavior of predators. Insects with ultrasonic hearing capabilities were consumed significantly more often by birds than bats, consistent with an evolved avoidance of echolocating strategies. In turn, bats consumed a greater proportion of noneared insects such as spruce budworms. Overall, our results suggest that evolutionary interactions among bats and moths translate to dietary niche partitioning and coexistence among bats and nocturnal birds.     

What makes us human? Answers from evolutionary anthropology

Today, scholars from numerous and highly diverse fields are not only addressing the question of what makes us human, but also seeking input from other disciplines to inform their answers to this fundamental issue. However, for the most part, evolutionary anthropologists are not particularly prominent in this discussion, or at least not acknowledged to be. Why is this the case? One reason may be that although evolutionary anthropologists are uniquely positioned to provide valuable insight on this subject, the responses from any one of us are likely to be as different as the research specializations and intellectual experiences that we bring to the table. Indeed, one would anticipate that a paleoanthropologist would not only have different views than a primatologist, geneticist, or behavioral ecologist, but from other paleoanthropologists as well. Yet if asked by a theologian, psychologist, or political scientist, and perhaps most importantly, by any curious person outside the walls of academia, do we have a response that most evolutionary anthropologists could agree on as reflecting our contributions to the understanding of being and becoming human? Our introductory textbooks usually begin with this fundamental question, yet seldom produce a concise answer. © 2012 Wiley Periodicals, Inc.     

What limits the evolutionary emergence of pathogens?

The ability of a pathogen to cause an epidemic when introduced in a new host population often relies on its ability to adapt to this new environment. Here, we give a brief overview of recent theoretical and empirical studies of such evolutionary emergence of pathogens. We discuss the effects of several ecological and genetic factors that may affect the likelihood of emergence: migration, life history of the infectious agent, host heterogeneity, and the rate and effects of mutations. We contrast different modelling approaches and indicate how details in the way we model each step of a life cycle can have important consequences on the predicted probability of evolutionary emergence. These different theoretical perspectives yield important insights into optimal surveillance and intervention strategies, which should aim for a reduction in the emergence (and re-emergence) of infectious diseases.     

Is the functional interaction between adenosine A2A receptors and metabotropic glutamate 5 receptors a general mechanism in the brain? Differences and similarities between the striatum and the hippocampus

The aim of the present paper was to examine, in a comparative way, the occurrence and the mechanisms of the interactions between adenosine A_2A receptors (A_2ARs) and metabotropic glutamate 5 receptors (mGlu5Rs) in the hippocampus and the striatum. In rat hippocampal and corticostriatal slices, combined ineffective doses of the mGlu5R agonist 2-chloro-5-hydroxyphenylglycine (CHPG) and the A_2AR agonist CGS 21680 synergistically reduced the slope of excitatory postsynaptic field potentials (fEPSPs) recorded in CA1 and the amplitude of field potentials (FPs) recorded in the dorsomedial striatum. The cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) pathway appeared to be involved in the effects of CGS 21680 in corticostriatal but not in hippocampal slices. In both areas, a postsynaptic locus of interaction appeared more likely. N-methyl-D-aspartate (NMDA) reduced the fEPSP slope and FP amplitude in hippocampal and corticostriatal slices, respectively. Such an effect was significantly potentiated by CHPG in both areas. Interestingly, the A_2AR antagonist ZM 241385 significantly reduced the NMDA-potentiating effect of CHPG. In primary cultures of rat hippocampal and striatal neurons (ED 17, DIV 14), CHPG significantly potentiated NMDA-induced lactate dehydrogenase (LDH) release. Again, such an effect was prevented by ZM 241385. Our results show that A_2A and mGlu5 receptors functionally interact both in the hippocampus and in the striatum, even though different mechanisms seem to be involved in the two areas. The ability of A_2ARs to control mGlu5R-dependent effects may thus be a general feature of A_2ARs in different brain regions (irrespective of their density) and may represent an additional target for the development of therapeutic strategies against neurological disorders.     

Metabolic regulation of oxygen and redox homeostasis by p53: Lessons from evolutionary biology?

The genetic links between p53 and metabolic processes such as oxidative phosphorylation are being studied with increasing interest given that cellular metabolism seems to play an important role in tumorigenesis. This review focuses on how p53 regulation of various metabolic genes may influence redox homeostasis, as the genome is constantly susceptible to oxidative damage, a consequence of living in an aerobic environment. Because p53-like genetic sequences are also found in life forms that may not necessarily benefit from tumor suppression, an evolutionary introduction is given in an attempt to understand why p53 might regulate a basic cellular activity such as metabolism. The presented epidemiologic and experimental data suggest that one reason may be for the homeostatic regulation of oxygen, the essential substrate for reactive oxygen species generation.     

What lies at the interface of regenerative medicine and developmental biology?

At a recent Keystone Symposium on 'Developmental Biology and Tissue Engineering', new findings in areas ranging from stem cell differentiation, embryonic pattern formation and organ regeneration to engineered cell microenvironments, synthetic biomaterials and artificial tissue fabrication were described. Although these new advances were exciting, this symposium clarified that biologists and engineers often view the challenge of tissue formation from different, and sometimes conflicting, perspectives. These dichotomies raise questions regarding the definition of regenerative medicine, but offer the promise of exciting new interdisciplinary approaches to tissue and organ regeneration, if effective alliances can be established.     

What is driving the relationship between height and cognition? Evidence from the Twins Early Development Study

Taller children tend to have better cognitive ability, and the relationship between height and cognition has been proposed as an explanation for the height-wage labor market premium. Height-cognition associations may arise due to social factors that favor taller individuals or be driven by “common factors” that are correlated with height and cognition. Indeed, there is now evidence of a genetic correlation between height and cognition that provides specific evidence for this concern. We examine whether genetic factors explain the relationship by estimating associations between childhood height and cognition in the Twins Early Development Study. We find that height is associated with better cognition even after controlling for genetic and environmental factors shared by twins. The association between height and cognition within fraternal twin pairs is also robust to controlling for individual genetic predictors of height and cognition. These results suggest that genetic factors are not solely responsible for driving the relationship between height and cognition.     

Can medical genetics and evolutionary biology inspire drug target identification?

New strategies for target identification are urgently needed to tackle the current productivity challenges in drug discovery. By examining successful human drug targets, it can be seen that approximately 50% are associated with genetic disorders. Further analysis shows that these successfully targeted genes share some common evolutionary features, which strongly suggests that evolutionary information can help identify drug targets with the greatest potential for therapeutic development.     

Were the Spy fossils evolutionary intermediates between Classic Neandertal and Modern Man?

The author re-examined the Spy Mousterian skeletons. Spy I is a female with a cranial capacity of ± 1300 cm³ and Spy II a male with 1504 cm³ cranial capacity. Both postcranial skeletons, the neurocranium of Spy I and anatomical details of the Spy II skull are of preponderant Neandertal character.Hrdlička (1930) supposed that the Spy fossils were evolutionary intermediates between Classic Neandertal and Modern Man on the basis of the following arguments: (a) the presence of supraorbital arches in the Spy II Skull, (b) the modern profile of the Spy II front, (c) the absence of occipital “chignon” in Spy II, (d) the generally modern cranial shape of Spy II, (e) the smallness of teeth and (f) the modern characters of the Spy I mandible. Among these arguments (a) and (b) indicate borderline cases interpretable also in a different way; others are invalid.The Spy fossils are phylogenetically non-transitional Neandertals.     

Haloferax volcanii PitA: an example of functional interaction between the Pfam chlorite dismutase and antibiotic biosynthesis monooxygenase families?

A curious fusion between chlorite dismutase-like and antibiotic biosynthesis monooxygenase-like domains within a single open reading frame has been revealed by both sequence homology and structural modeling in Haloferax volcanii PitA and its homologues in other halophilic archaea. While this fusion may reflect an environmental adaptation to life in hypersaline environments and hence one specific to haloarchaea, PitA and its homologues may represent a paradigm of biologically-relevant interplay between these two distinct activities in accordance with the Rosetta Stone approach.