The Ever-Present Costs of Cosmetic Surgery Tourism: A 5-Year Observational Study.

BACKGROUND: Cosmetic surgery tourism is an ever-growing industry. Despite its associated risks, an increasing number of patients are presenting to NHS services with resulting complications. This study aims to evaluate the current presentation patterns for complications in cosmetic surgery tourism, and the financial burden to the NHS reported by a single UK level one trauma centre in Birmingham, UK. METHODS: From 2015 to 2020, all patients presenting to the department of plastic surgery with complications of cosmetic surgery performed outside of the UK were included. Data were collected for patients' characteristics including demographics, performed procedures, complications and treatment. A cost analysis was performed for each patient using published "National Schedule of NHS Costs." RESULTS: A total of 26 patients presented to our hospital within the study period. All patients were female, with the mean age being 35.1 years (range 22-55years). A total of 32 cosmetic procedures were undertaken, with the majority performed in Turkey (n = 14). Abdominoplasty was the most common procedure, followed by gluteal enhancement surgery. The total financial cost to the NHS from all cosmetic surgery-related complications was £152,946, with an average cost per patient of £5,882.54 (range £362-£26,585). CONCLUSION: Patients seek out medical tourism for multiple reasons including cost savings, shorter waiting times and surgical expertise. The costs displayed should predominantly be viewed as a reflection of the detrimental effect these complications can have on patients' lives. Global governing bodies should focus efforts on educating patients and raising awareness on this ever-prevalent issue. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Enhanced Recovery Pathways for Flap-Based Reconstruction: Systematic Review and Meta-Analysis.

BACKGROUND: Enhanced Recovery After Surgery (ERAS) pathways are known to improve patient outcomes after surgery. In recent years, there have been growing interest in ERAS for reconstructive surgery. OBJECTIVES: To systematically review and summarise literature on the key components and outcomes of ERAS pathways for autologous flap-based reconstruction. DATA SOURCES: Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, Current Controlled Trials, World Health Organization International Clinical Trials Registry Platform and reference lists of relevant studies. INCLUSION CRITERIA: All primary studies of ERAS pathways for free and pedicled flap-based reconstructions reported in the English language. OUTCOME MEASURES: The primary outcome measure was length of stay. Secondary outcomes were complication rates including total flap loss, partial flap loss, unplanned reoperation within 30 days, readmission to hospital within 30 days, surgical site infections and medical complications. RESULTS: Sixteen studies were included. Eleven studies describe ERAS pathways for autologous breast reconstructions and five for autologous head and neck reconstructions. Length of stay was lower in ERAS groups compared to control groups (mean reduction, 1.57 days; 95% CI, - 2.15 to - 0.99). Total flap loss, partial flap loss, unplanned reoperations, readmissions, surgical site infections and medical complication rates were similar between both groups. Compliance rates were poorly reported. CONCLUSION: ERAS pathways for flap-based reconstruction reduce length of stay without increasing complication rates. ERAS pathways should be adapted to each institution according to their needs, resources and caseload. There is potential for the development of ERAS pathways for chest wall, perineum and lower limb reconstruction. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Orthoplastic Management of Open Midfoot Injuries: Is Functional Limb Salvage Possible?

High energy open midfoot injuries are uncommon but devastating injuries. A combination of complex fracture dislocations and soft tissue injury patterns render reconstruction challenging. The aim of this study was to assess the surgical and patient reported outcomes following orthoplastic management of open midfoot injuries in a Major Trauma Center. A retrospective review of all open midfoot fractures admitted to our unit between January 2015 and December 2016 was undertaken. Demographics, operative details, complications, additional surgeries, and patient reported outcomes in the form of EQ-5D and Enneking scores were collected. Fifteen patients were identified (13 male, mean age 39.2 years). One patient underwent amputation at initial debridement and 8 required additional debridement. Of these 8 patients, 3 had an amputation during their index admission. In the limb salvage group (11 patients), definitive soft tissue cover involved free flaps in 6 patients, split skin graft in 3 patients, and delayed primary closure in 2 patients. Definitive orthopedic treatment was internal fixation in 8 and external fixation in 3 patients. Two patients required a Masquelet procedure for bone loss. One patient had a toe amputation and 1 had a below knee amputation for deep infection. The median EQ-5D score was 66 (interquartile range 43), and the median Enneking score was 20.5 (interquartile range 9). Limb salvage following open midfoot fractures is technically possible in most cases, however this often involves multiple procedures and the outcomes are variable and difficult to predict. Patients should be carefully counseled, and amputation considered in all such cases.

Metaplastic Breast Cancer Masquerading as Liposarcoma of the Breast: A Case Report following Oncoplastic Treatment.

Mammary liposarcoma is among the rarest of breast tumours. Here we report the presentation, macroscopic, microscopic, and immunohistochemical features of an extremely rare case of metaplastic carcinoma with extensive pleomorphic liposarcomatous differentiation. A 47-year-old woman presented with bilateral grade III breast ptosis and a 3 × 4 cm mass in the lower outer quadrant of the left breast. Mammography and ultrasound confirmed a well-defined mass. A core biopsy performed was diagnosed as pleomorphic liposarcoma. Microscopically, this was a well-defined, lobulated tumour comprising solid sheets of large pleomorphic and spindle cells with bizarre forms, vacuolated cytoplasm, and ample mitoses. Atypical lipoblasts were easily identifiable. Due to the strong, though patchy, cytokeratin expression, the diagnosis of metaplastic carcinoma with pleomorphic liposarcomatous differentiation was made. Extensive sampling, careful search for a biphasic pattern, ductal carcinoma in situ, and/or epithelial differentiation, and a panel of broad-spectrum cytokeratins are essential to establish the diagnosis.

Fake spawns and floating particles: a rebuttal of Karkarey et al. "Alternative reproductive tactics and inverse size-assortment in a high-density fish spawning aggregation".

Courtship and spawning behaviors of coral reef fishes are very complex, and sufficient sampling effort and proper methods are required to draw informed conclusions on their mating systems that are grounded in contemporary theories of mate choice and sexual selection. We reviewed the recent study by Karkarey et al. (BMC Ecol 17:10, 2017) on the spawning behavior of Squaretail coralgrouper (Plectropomus areolatus) from India and found no evidence to support their findings of alternative reproductive tactics, unique school-spawning involving a single male with multiple females, or inverse size-assortment. The study lacks scientific credibility due to a lack of rigor in the methodology used, misinterpretation of observed behaviors, misinterpretation of the literature, and insufficient data. Their approach led the authors to produce spurious results and profound, invalid conclusions that violate the most basic assumptions of mate choice and sexual selection theory as applied to mating systems in marine fishes.

Protection of large predators in a marine reserve alters size-dependent prey mortality.

Where predator-prey interactions are size-dependent, reductions in predator size owing to fishing has the potential to disrupt the ecological role of top predators in marine ecosystems. In southern California kelp forests, we investigated the size-dependence of the interaction between herbivorous sea urchins and one of their predators, California sheephead (Semicossyphus pulcher). Empirical tests examined how differences in predator size structure between reserve and fished areas affected size-specific urchin mortality. Sites inside marine reserves had greater sheephead size and biomass, while empirical feeding trials indicated that larger sheephead were required to successfully consume urchins of increasing test diameter. Evaluations of the selectivity of sheephead for two urchin species indicated that shorter-spined purple urchins were attacked more frequently and successfully than longer-spined red urchins of the same size class, particularly at the largest test diameters. As a result of these size-specific interactions and the higher biomass of large sheephead inside reserves, urchin mortality rates were three times higher inside the reserve for both species. In addition, urchin mortality rates decreased with urchin size, and very few large urchins were successfully consumed in fished areas. The truncation of sheephead size structure that commonly occurs owing to fishing will probably result in reductions in urchin mortality, which may reduce the resilience of kelp beds to urchin barren formation. By contrast, the recovery of predator size structure in marine reserves may restore this resilience, but may be delayed until fish grow to sizes capable of consuming larger urchins.

Human activities change marine ecosystems by altering predation risk.

In ocean ecosystems, many of the changes in predation risk - both increases and decreases - are human-induced. These changes are occurring at scales ranging from global to local and across variable temporal scales. Indirect, risk-based effects of human activity are known to be important in structuring some terrestrial ecosystems, but these impacts have largely been neglected in oceans. Here, we synthesize existing literature and data to explore multiple lines of evidence that collectively suggest diverse human activities are changing marine ecosystems, including carbon storage capacity, in myriad ways by altering predation risk. We provide novel, compelling evidence that at least one key human activity, overfishing, can lead to distinct, cascading risk effects in natural ecosystems whose magnitude exceeds that of presumed lethal effects and may account for previously unexplained findings. We further discuss the conservation implications of human-caused indirect risk effects. Finally, we provide a predictive framework for when human alterations of risk in oceans should lead to cascading effects and outline a prospectus for future research. Given the speed and extent with which human activities are altering marine risk landscapes, it is crucial that conservation and management policy considers the indirect effects of these activities in order to increase the likelihood of success and avoid unfortunate surprises.

An assessment of chemical contaminants in sediments from the St. Thomas East End Reserves, St. Thomas, USVI.

The St. Thomas East End Reserves or STEER is located on the southeastern end of the island of St. Thomas, USVI. The STEER contains extensive mangroves and seagrass beds, along with coral reefs, lagoons, and cays. Within the watershed, however, are a large active landfill, numerous marinas, resorts, various commercial activities, an EPA Superfund Site, and residential areas, all of which have the potential to contribute pollutants to the STEER. As part of a project to develop an integrated assessment for the STEER, 185 chemical contaminants were analyzed in sediments from 24 sites. Higher levels of chemical contaminants were found in Mangrove Lagoon and Benner Bay in the western portion of the study area. The concentrations of polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT), zinc, copper, lead, and mercury were above a NOAA Effects Range-Low (ERL) sediment quality guideline at one or more sites, indicating impacts may be present in more sensitive species or life stages. Copper at one site in Benner Bay was above a NOAA Effects Range-Median (ERM) guideline indicating effects on benthic organisms were likely. The antifoulant boat hull ingredient tributyltin (TBT) was found at the third highest concentration in the history of NOAA's National Status and Trends (NS&T) Program, which monitors the nation's coastal and estuarine waters for chemical contaminants and bioeffects. The results from this project will provide resource managers with key information needed to make effective decisions affecting coral reef ecosystem health and gauge the efficacy of restoration activities.

Angiosarcoma: a 10-year retrospective study from a high-volume UK regional referral centre.

PURPOSE: Angiosarcoma (AS) is a rare malignancy with considerable heterogeneity seen in its aetiology, anatomical location, and clinicopathological behaviour. Diagnosis is often delayed and prognosis poor. The purpose of this study was to perform a retrospective review of all cases of AS over 10 years at a high-volume regional UK referral centre. METHODS/PATIENTS: We reviewed all cases of AS discussed at the sarcoma multidisciplinary meetings of University Hospitals Birmingham NHS Foundation Trust from September 2013 to August 2023. Demographic and clinicopathologic features at diagnosis, approaches to treatment, and outcomes were compared between four AS subtypes. RESULTS: A total of 130 cases were identified. The median age at diagnosis was 71 years, with the majority being female (78%). The most common AS subtype was radiation-induced AS (RIAS) (n = 72; 55%), followed by primary cutaneous (n = 28; 22%), primary non-cutaneous (n = 25; 19%), and AS secondary to lymphoedema (n = 5; 4%). Metastases were present at diagnosis in 18% of patients. Treatment was with surgery in the majority of patients (71%). The median survival for the cohort was 30 months (95% CI 20-40), although this differed significantly by AS subtype (p < 0.001), ranging from 5 months in primary non-cutaneous AS to 76 months in RIAS. CONCLUSION: RIAS is the most common AS subtype, with surgery the only potentially curative treatment modality. Overall prognosis varies significantly by subtype. An international consensus on classification of AS subtypes is required to allow meaningful comparisons across studies and/or a prospective multi-centre registry.

Predicting evolutionary responses to climate change in the sea.

An increasing number of short-term experimental studies show significant effects of projected ocean warming and ocean acidification on the performance on marine organisms. Yet, it remains unclear if we can reliably predict the impact of climate change on marine populations and ecosystems, because we lack sufficient understanding of the capacity for marine organisms to adapt to rapid climate change. In this review, we emphasise why an evolutionary perspective is crucial to understanding climate change impacts in the sea and examine the approaches that may be useful for addressing this challenge. We first consider what the geological record and present-day analogues of future climate conditions can tell us about the potential for adaptation to climate change. We also examine evidence that phenotypic plasticity may assist marine species to persist in a rapidly changing climate. We then outline the various experimental approaches that can be used to estimate evolutionary potential, focusing on molecular tools, quantitative genetics, and experimental evolution, and we describe the benefits of combining different approaches to gain a deeper understanding of evolutionary potential. Our goal is to provide a platform for future research addressing the evolutionary potential for marine organisms to cope with climate change.

Does fish larval dispersal differ between high and low latitudes?

Several factors lead to expectations that the scale of larval dispersal and population connectivity of marine animals differs with latitude. We examine this expectation for demersal shorefishes, including relevant mechanisms, assumptions and evidence. We explore latitudinal differences in (i) biological (e.g. species composition, spawning mode, pelagic larval duration, PLD), (ii) physical (e.g. water movement, habitat fragmentation), and (iii) biophysical factors (primarily temperature, which could strongly affect development, swimming ability or feeding). Latitudinal differences exist in taxonomic composition, habitat fragmentation, temperature and larval swimming, and each difference could influence larval dispersal. Nevertheless, clear evidence for latitudinal differences in larval dispersal at the level of broad faunas is lacking. For example, PLD is strongly influenced by taxon, habitat and geographical region, but no independent latitudinal trend is present in published PLD values. Any trends in larval dispersal may be obscured by a lack of appropriate information, or use of 'off the shelf' information that is biased with regard to the species assemblages in areas of concern. Biases may also be introduced from latitudinal differences in taxa or spawning modes as well as limited latitudinal sampling. We suggest research to make progress on the question of latitudinal trends in larval dispersal.

Optimized electrocardiographic criteria for prior inferior and anterior myocardial infarction.

BACKGROUND AND PURPOSE: The first purpose of the study was to optimize empirically the detection of prior inferior myocardial infarction (IMI) and prior anterior myocardial infarction (AMI) by electrocardiogram (ECG). The second purpose was to compare the diagnostic performances of the new criteria with those of 3 widely used commercial diagnostic ECG algorithms. MATERIALS AND METHODS: We analyzed the digital ECG data from 1138 subjects with suspected coronary artery disease in whom the presence or absence of prior IMI or AMI was documented by coronary angiography and left ventriculography. We used receiver operating characteristic curves to develop the new criteria for prior IMI and AMI using a training set of 562 subjects and then tested their diagnostic performances using a separate test set of 576 subjects. In both the training and test sets, we used χ(2) test to compare the performances of the new criteria with those of 3 commercial computerized diagnostic algorithms. RESULTS: The best criterion for prior IMI was the algebraic sum of the Q and T amplitudes in leads III and aVF. Its sensitivities/specificities were 71%/98% and 74%/98% in the training and test sets, respectively. The best criterion for prior AMI was the algebraic sum of the Q, R, and T amplitudes minus the Q duration in leads V(2), V(3), and V(4). Its sensitivities/specificities were 68%/98% and 65%/98% in the training and test sets, respectively. In both the training and test sets, these diagnostic performances were generally superior to those of the 3 commercial algorithms. CONCLUSIONS: Using digital ECG data, we developed and tested new criteria for prior IMI and AMI whose diagnostic performances are generally superior to each of 3 widely used commercial ECG diagnostic algorithms.

Using standardized numerical scores for the display and interpretation of biomedical data.

The ability to review and analyze large amounts of data reliably and cost-effectively is important in both biomedical research and clinical care. We hypothesized that converting raw digital data to standard scores (Z scores) and gray-scale them based on their corresponding P values can be used to accomplish this. In Part 1 of the study, we recorded continuous digital electrocardiographic (ECG) and heart sound data from a subject undergoing acute anterior myocardial infarction (MI). We then computed Z scores of the digital data using the means and standard deviations of the data obtained during the pre-infarction period. In Part 2 of the study, we analyzed the digital ECG data from 576 subjects who had undergone coronary angiography and left ventriculography for the evaluation of possible coronary disease. We used the durations of Q waves in Lead aVF and of the initial R waves in Lead V2 as the ECG criteria of prior inferior and anterior MI, respectively. We calculated Z scores for these durations using the means and standard deviations of the subjects who had no angiographic evidence of coronary disease. Results show that in Part 1 of the study, the continuous recording of the gray-scale Z scores produced a highly intuitive display of the direction and statistical significance of simultaneous changes in five quantitative parameters known to be important for the detection and assessment of acute MI. In Part 2 of the study, the use of gray-scale Z scores revealed, in each of three subgroups, the distributions of subjects who met ECG criteria for inferior and anterior MI, respectively. Analyzing the Z scores to calculate diagnostic performances yielded results similar to those obtained using receiver-operating characteristic curves of the raw data. We conclude that the use of gray-scale Z scores is a highly efficient and statistically meaningful way to display diagnostic data produced by both continuous and individual recordings.

Postsettlement survival linked to larval life in a marine fish.

There is a growing realization that the scale and degree of population connectivity are crucial to the dynamics and persistence of spatially structured populations. For marine organisms with complex life cycles, experiences during larval life may influence phenotypic traits, performance, and the probability of postsettlement survival. For a Caribbean reef fish (Thalassoma bifasciatum) on an oceanic island, we used otolith (ear stone) elemental profiles of lead (Pb) to assign recent settlers to a group that developed in waters elevated in Pb concentrations throughout larval life (i.e., nearshore signature) and a group that developed in waters depleted in Pb (i.e., offshore signature), potentially dispersing from upstream sources across oceanic waters. Larval history influenced early life history traits: offshore developers initially grew slowly but compensated with fast growth upon entering nearshore waters and metamorphosed in better condition with higher energy reserves. As shown in previous studies, local production contributed heavily to settlement: at least 45% of settlers developed nearshore. However, only 23% of survivors after the first month displayed a nearshore otolith profile. Therefore, settlers with different larval histories suffered differential mortality. Importantly, selective mortality was mediated by larval history, in that the postsettlement intensity of selection was much greater for fish that developed nearshore, potentially because they had developed in a less selectively intense larval environment. Given the potential for asymmetrical postsettlement source-based survival, successful spatial management of marine populations may require knowledge of "realized connectivity" on ecological scales, which takes into account the postsettlement fitness of individuals from different sources.

Avoiding the night terrors: the effect of circadian rhythm on post-operative urine output and blood pressure in free flap patients.

Multiple studies demonstrate the importance of goal-directed fluid regimens in avoiding complications. These regimens do not take account of circadian fluctuations in urine output (UO), MAP (mean arterial pressure) and pulse rate (PR). This is the first study that aims to demonstrate the effect of circadian rhythm on these haemodynamic parameters in post-operative patients with free flaps, as well as analysing clinicians' response to these variations. Retrospective analysis of 116 patients with free flaps. Records were assessed for UO, MAP, IV fluid infusion rate, oral fluid intake. Parameters were measured from 8 am to 8 pm (diurnal) and from 8 pm to 8 am (nocturnal) in the first 48 h post operatively. Patients with diabetes or hypertension were excluded. Mean diurnal UO rate (1.7 ml/kg/hr) was higher than nocturnal UO rate (0.7 ml/kg/hr); and mean diurnal MAP (93) was higher than nocturnal MAP (73.8). Mean diurnal IV infusion rate was 1.25 ml/kg/hr (lower) and mean nocturnal infusion rate 1.81 ml/kg/hr (higher). These differences were all statistically significant by paired student t-test (p < 0.05). This study demonstrates that circadian rhythm has a statistically significant impact on UO, MAP and PR. UO, MAP and PR are expected to dip overnight. This dip is normal and does not necessarily need to be treated by increasing IV fluids to avoid over filling of free flap patients.

Comment on: "A structured pathway for accelerated postoperative recovery reduces hospital stay and cost of care following microvascular breast reconstruction without increased complications".

We read with great interest a recent article by O'Neill et al. on the implementation of an accelerated postoperative recovery protocol following DIEP flap breast reconstruction. Our department has formally introduced a DIEP Enhanced Recovery After Surgery (ERAS) Pathway in May 2019. Although in a much smaller sample size, our results were similar to this article and we would agree with the authors' conclusion that implementation of such protocol could effectively reduce the length of inpatient stay (LoS) and cost of care, without compromising patient care nor increasing complication rates. Prior to the introduction of ERAS Pathway, 28 of our patients who had DIEP between November 2018 and May 2019 had an mean LoS of 7.1 days (median 6 days, range 5-21 days); whereas 27 patients who experienced the ERAS Pathway between May and December 2019 had an mean LoS of 4.8 days (median 5 days, range 3-7 days). The cost of inpatient stay in a normal ward at our hospital is approximately £232 per patient per day. By reducing an extra 2.3 days of inpatient stay, our Trust could save at least an average of £32,016 per annum with the estimated 60 DIEP performed annually at our department. We would like to emphasise the benefits and effectiveness of this multimodal, patient-centre and evidence-based ERAS. This, perhaps, should be the standard of care for all patients who undergo microvascular breast reconstruction in the future.

Fishing indirectly structures macroalgal assemblages by altering herbivore behavior.

Fishing has clear direct effects on harvested species, but its cascading, indirect effects are less well understood. Fishing disproportionately removes larger, predatory fishes from marine food webs. Most studies of the consequent indirect effects focus on density-mediated interactions where predator removal alternately drives increases and decreases in abundances of successively lower trophic-level species. While prey may increase in number with fewer predators, they may also alter their behavior. When such behavioral responses impact the food resources of prey species, behaviorally mediated trophic cascades can dramatically shape landscapes. It remains unclear whether this pathway of change is typically triggered by ocean fishing. By coupling a simple foraging model with empirical observations from coral reefs, we provide a mechanistic basis for understanding and predicting how predator harvest can alter the landscape of risk for herbivores and consequently drive dramatic changes in primary producer distributions. These results broaden trophic cascade predictions for fisheries to include behavioral changes. They also provide a framework for detecting the presence and magnitude of behaviorally mediated cascades. This knowledge will help to reconcile the disparity between expected and observed patterns of fishing-induced cascades in the sea.

Field evidence for pervasive indirect effects of fishing on prey foraging behavior.

The indirect, ecosystem-level consequences of ocean fishing, and particularly the mechanisms driving them, are poorly understood. Most studies focus on density-mediated trophic cascades, where removal of predators alternately causes increases and decreases in abundances of lower trophic levels. However, cascades could also be driven by where and when prey forage rather than solely by prey abundance. Over a large gradient of fishing intensity in the central Pacific's remote northern Line Islands, including a nearly pristine, baseline coral reef system, we found that changes in predation risk elicit strong behavioral responses in foraging patterns across multiple prey fish species. These responses were observed as a function of both short-term ("acute") risk and longer-term ("chronic") risk, as well as when prey were exposed to model predators to isolate the effect of perceived predation risk from other potentially confounding factors. Compared to numerical prey responses, antipredator behavioral responses such as these can potentially have far greater net impacts (by occurring over entire assemblages) and operate over shorter temporal scales (with potentially instantaneous response times) in transmitting top-down effects. A rich body of literature exists on both the direct effects of human removal of predators from ecosystems and predators' effects on prey behavior. Our results draw together these lines of research and provide the first empirical evidence that large-scale human removal of predators from a natural ecosystem indirectly alters prey behavior. These behavioral changes may, in turn, drive previously unsuspected alterations in reef food webs.

The relationship between maternal phenotype and offspring quality: do older mothers really produce the best offspring?

Maternal effects are increasingly recognized as important drivers of population dynamics and determinants of evolutionary trajectories. Recently, there has been a proliferation of studies finding or citing a positive relationship between maternal size/age and offspring size or offspring quality. The relationship between maternal phenotype and offspring size is intriguing in that it is unclear why young mothers should produce offspring of inferior quality or fitness. Here we evaluate the underlying evolutionary pressures that may lead to a maternal size/age-offspring size correlation and consider the likelihood that such a correlation results in a positive relationship between the age or size of mothers and the fitness of their offspring. We find that, while there are a number of reasons why selection may favor the production of larger offspring by larger mothers, this change in size is more likely due to associated changes in the maternal phenotype that affect the offspring size-performance relationship. We did not find evidence that the offspring of older females should have intrinsically higher fitness. When we explored this issue theoretically, the only instance in which smaller mothers produce suboptimal offspring sizes is when a (largely unsupported) constraint on maximum offspring size is introduced into the model. It is clear that larger offspring fare better than smaller offspring when reared in the same environment, but this misses a critical point: different environments elicit selection for different optimal sizes of young. We suggest that caution should be exercised when interpreting the outcome of offspring-size experiments when offspring from different mothers are reared in a common environment, because this approach may remove the source of selection (e.g., reproducing in different context) that induced a shift in offspring size in the first place. It has been suggested that fish stocks should be managed to preserve these older age classes because larger mothers produce offspring with a greater chance of survival and subsequent recruitment. Overall, we suggest that, while there are clear and compelling reasons for preserving older females in exploited populations, there is little theoretical justification or evidence that older mothers produce offspring with higher per capita fitness than do younger mothers.

Evolutionary biology: sex change and relative body size in animals.

Organisms that change sex during their lifetime use a variety of strategies--they may be female first, male first or even repetitive sex changers. Natural selection should favour those individuals that change sex at a time when it increases their reproductive value. Allsop and West claim that the relative timing of sex change is invariant across all animals, with individuals changing sex at 72% of their maximum body size, and infer that natural selection for sex change must therefore be fundamentally similar across animals. Here we explain why we believe that Allsop and West's claims are not supported by their analysis or by their empirical data.