A protected and warningly coloured butterfly can become a muellerian mimic of another species in two steps: (i) a major mutation converts the pattern of the less protected species to an approximate resemblance of the better protected (one-way convergence); (ii) after the spread of this mutant, the species, which now resemble each other sufficiently to be mistaken one for the other by predators, undergo mutual convergence, using whatever major or minor genetic variation is available to them. Although sometimes one or other step might occur alone, in general early theorists were mistaken in attributing muellerian mimicry to only one of these processes. By hybridizing races of Heliconius melpomene and races of H. erato (a pair of parallel mimetic species from the neotropics, held in mutual muellerian mimicry across wide inter-racial variations in colour pattern) we have shown that, as expected from the two-step theory, the races differ at a number (two to nine) of genetic loci, usually unlinked or loosely linked, including at least one mutant of major effect in each case. We describe the genetic constitution of eight races of H. melpomene (for 11 loci affecting colour pattern) and of eight races of H. erato (for up to 15 loci), and have started to identify the linkage groups. Map distances for those loci that are linked range from around 0.3 to zero in males, with no recombination in females. Muellerian mimicry is expected to produce total uniformity of pattern: universal exceptions to this are the existence of distinct mimicry rings flying within the same habitat, geographical variation within nearly all the more widespread species (divergence in the face of normalizing selection), and, in a few species, polymorphism or sexual dimorphism. Sympatric mimicry rings will, according to the two-step model of evolution, persist indefinitely if their patterns are so distinct that under no circumstances do predators mistake one for the other. Gradual mutual convergence is then impossible, although members of a weakly protected mimicry ring that can produce a mutation giving sufficient initial resemblance to a better protected ring can still be captured by it. Batesian mimics promote this by lowering the protection of the ring that they belong to, but their models can escape only in this way as normalizing selection prevents their gradual evolution away from the batesian mimic. If the rings are too distinct in pattern even this capture of species becomes impossible as no single mutant is able to bridge the gap between the two patterns, and the necessary two mutations will be extremely unlikely to occur together. The five principal sympatric mimicry rings of the mature neotropical rain forests are very distinct in their appearance The capture of a species by another ring can produce geographical variation both in the species captured and in the capturing ring, whose pattern is somewhat altered by mutual convergence with the captured species in the second step of the evolution of the muellerian resemblance. We suggest that the striking differences between the races within H. melpomene, H. erato and other Heliconius species resulted from these effects of inter-ring capture. Distributional evidence suggests that this chiefly occurred in refuges formed by the contraction of the neotropical rain forests during the cool dry periods in the Quaternary; these, by differential extinction of elements of the flora and fauna of different refuges, could have produced long-term changes in the relative abundances of the mimicry rings, and hence (as the protection given to a ring is proportional to its abundance) somewhat different capture events in each refuge. Several existing species confirm that this mode of evolution occurs, by retaining a distinctive pattern in the absence of any other remotely similar species, but becoming mimetic in areas where they encounter a pattern somewhat like their own. The isolated populations of Heliconius hermathena show this particularly clearly; the effect can be discerned also in H. melpomene and H. erato . Although polymorphism in muellerian mimics is largely unexplained, in two species of Heliconius it may result from the existence of two or more similar but slightly differing ‘sub-rings’ among their comimics in the family Ithomiidae, which show both spatial and temporal heterogeneity in their local distribution, which apparently is able to maintain a polymorphic equilibrium in the more uniformly distributed Heliconius . We have tentatively reconstructed the ancestral patterns of H. melpomene and erato by two independent methods: first, as dominant genes are much more likely to be incorporated than recessive ones during changes of pattern, the phenotype produced by the recessive alleles at all the known loci will be close to the ancestral pattern; secondly, species that are becoming mimics evolve more than those that are not, so that non-mimetic relatives of melpomene and erato will have a pattern close to ancestral. Both methods suggest, for both species, that the ancestor was a black butterfly with yellow (or possibly white) bars, and it may be that melpomene and erato have been comimics for a very long time. Previous climatic cycles in the Quaternary have apparently caused full speciation within two mutually mimetic evolving lineages, producing pairs of parallel mimetic species within the genus, of which melpomene and erato constitute one pair.

This publication offers modern, state‐of‐the‐art International Neural Monitoring Study Group (INMSG) guidelines based on a detailed review of the recent monitoring literature. The guidelines outline evidence‐based definitions of adverse electrophysiologic events, especially loss of signal, and their incorporation in surgical strategy. These recommendations are designed to reduce technique variations, enhance the quality of neural monitoring, and assist surgeons in the clinical decision‐making process involved in surgical management of recurrent laryngeal nerve. The guidelines are published in conjunction with the INMSG Guidelines Part II, Optimal Recurrent Laryngeal Nerve Management for Invasive Thyroid Cancer–Incorporation of Surgical, Laryngeal, and Neural Electrophysiologic Data. Laryngoscope, 128:S1–S17, 2018

Climate change alters phenological relations between interacting species. We might expect the historical baseline, or starting-point, for such effects to be precise synchrony between the season at which a consumer most requires food and the time when its resources are most available. We synthesize evidence that synchrony was not the historical condition in two insect -plant interactions involving Edith's checkerspot butterfly (Euphydryas editha), the winter moth (Operophtera brumata) and their host plants. Initial observations of phenological mismatch in both systems were made prior to the onset of anthropogenically driven climate change. Neither species can detect the phenology of its host plants with precision. In both species, evolution of life history has involved compromise between maximizing fecundity and minimizing mortality, with the outcome being superficially maladaptive strategies in which many, or even most, individuals die of starvation through poor synchrony with their host plants. Where phenological asynchrony or mismatch with resources forms the starting point for effects of anthropogenic global warming, consumers are particularly vulnerable to impacts that exacerbate the mismatch. This vulnerability likely contributed to extinction of a well-studied metapopulation of Edith's checkerspot, and to the skewed geographical pattern of population extinctions underlying a northward and upward range shift in this species.

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RFT is a feasible remote access thyroidectomy approach. It appears from our initial experience that it may be performed in a safe and reproducible manner without a drain and on an outpatient basis. Additional clinical experience is warranted to further validate this technique.

This paper describes a novel method of measuring host specificity and determining host rank order. As applied to oviposition behavior of the butterfly Euphydryas editha, the rank order of preference is the order in which plants become acceptable as the insect searches, while specificity is quantified in terms of the rate at which searching insects become less discriminating. The information obtained is different from that gleaned from other preference testing techniques. It is useful in helping to assess the behavioral bases of interpopulation differences in the degree of host specialization, in understanding the ways in which multiple host use is generated within a population, and in testing hypotheses about the evolution of host specialization.The data presented here show interpopulation variation in both rank order of host species and in the degree of host specificity of E. editha.

There is increasing pressure from policymakers for ecologists to generate more detailed 'attribution' analyses aimed at quantitatively estimating relative contributions of different driving forces, including anthropogenic climate change (ACC), to observed biological changes. Here, we argue that this approach is not productive for ecological studies. Global meta-analyses of diverse species, regions and ecosystems have already given us 'very high confidence' [sensu Intergovernmental Panel on Climate Change (IPCC)] that ACC has impacted wild species in a general sense. Further, for well-studied species or systems, synthesis of experiments and models with long-term observations has given us similarly high confidence that they have been impacted by regional climate change (regardless of its cause). However, the role of greenhouse gases in driving these impacts has not been estimated quantitatively. Should this be an ecological research priority? We argue that development of quantitative ecological models for this purpose faces several impediments, particularly the existence of strong, non-additive interactions among different external factors. However, even with current understanding of impacts of global warming, there are myriad climate change adaptation options already developed in the literature that could be, and in fact are being, implemented now.