RESUMO
Emerging evidence suggests that gender is a defining feature of personhood. Studies show that gender is the primary social category individuals use to perceive humanness and the social category most strongly related to seeing someone-or something-as human. However, the universality of gender's primacy in social perception and its precedence over other social categories like race and age have been debated. We examined the primacy of gender perception in the Mayangna community of Nicaragua, a population with minimal exposure to Western influences, to test whether the primacy of gender categorization in humanization is more likely to be a culturally specific construct or a cross-cultural and potentially universal phenomenon. Consistent with findings from North American populations [A. E. Martin, M. F. Mason, J. Pers. Soc. Psychol. 123, 292-315 (2022)], the Mayangna ascribed gender to nonhuman objects more strongly than any other social category-including age, race, sexual orientation, disability, and religion-and gender was the only social category that uniquely predicted perceived humanness (i.e., the extent to which a nonhuman entity was seen as "human"). This pattern persisted even in the most isolated subgroup of the sample, who had no exposure to Western culture or media. The present results thus suggest that gender's primacy in social cognition is a widely generalizable, and potentially universal, phenomenon.
Assuntos
Identidade de Gênero , Humanos , Masculino , Feminino , Adulto , Nicarágua , Percepção Social , Pessoa de Meia-Idade , Adulto JovemRESUMO
Glioblastoma (GB) is the most aggressive and common primary malignant tumor of the brain and central nervous system. Without treatment, the average patient survival time is about six months, which can be extended to fifteen months with multimodal therapies. The chemoresistance observed in GB is, in part, attributed to the presence of a subpopulation of glioblastoma-like stem cells (GSCs) that are characterized by heightened tumorigenic capacity and chemoresistance. GSCs are situated in hypoxic tumor niches, where they sustain and promote the stem-like phenotype and have also been correlated with high chemoresistance. GSCs have the particularity of generating high levels of extracellular adenosine (ADO), which causes the activation of the A3 adenosine receptor (A3AR) with a consequent increase in the expression and activity of genes related to chemoresistance. Therefore, targeting its components is a promising alternative for treating GB. This analysis determined genes that were up- and downregulated due to A3AR blockades under both normoxic and hypoxic conditions. In addition, possible candidates associated with chemoresistance that were positively regulated by hypoxia and negatively regulated by A3AR blockades in the same condition were analyzed. We detected three potential candidate genes that were regulated by the A3AR antagonist MRS1220 under hypoxic conditions: LIMD1, TRIB2, and TGFB1. Finally, the selected markers were correlated with hypoxia-inducible genes and with the expression of adenosine-producing ectonucleotidases. In conclusion, we detected that hypoxic conditions generate extensive differential gene expression in GSCs, increasing the expression of genes associated with chemoresistance. Furthermore, we observed that MRS1220 could regulate the expression of LIMD1, TRIB2, and TGFB1, which are involved in chemoresistance and correlate with a poor prognosis, hypoxia, and purinergic signaling.
RESUMO
Previous research suggests that empathic concern selectively promotes motivation to help those with whom we typically have interdependent relationships, such as friends or siblings, rather than strangers or acquaintances. In a sample of U.S. participants (collected between 2018 and 2020), our studies not only confirmed the finding that empathic concern is directed somewhat more strongly toward interdependent relationship partners, but also showed cross-sectionally (Studies 1a-1b), and when manipulating target distress experimentally (Study 2), that empathic concern predicts higher willingness to help only when people perceive low interdependence in their relationship with the target. In Study 3, we manipulated perceived interdependence with an acquaintance via shared fate, and found that empathic concern only predicted helping motivation when we reduced shared fate, but not when we increased shared fate. These results suggest that when people perceive high interdependence in their relationships, shared fate is the driving force behind their desire to help, whereas when people perceive low interdependence with someone in need, empathic concern motivates them to help. A relationship-building perspective on empathic concern provides avenues for testing additional moderators, including those related to target-specific characteristics and culture and ecology. (PsycInfo Database Record (c) 2024 APA, all rights reserved).
Assuntos
Empatia , Amigos , Humanos , Motivação , Gerenciamento de DadosRESUMO
Human sociality is governed by two types of social norms: injunctive norms, which prescribe what people ought to do, and descriptive norms, which reflect what people actually do. The process by which these norms emerge and their causal influences on cooperative behavior over time are not well understood. Here, we study these questions through social norms influencing mask wearing during the COVID-19 pandemic. Leveraging 2 years of data from the United States (18 time points; n = 915), we tracked mask wearing and perceived injunctive and descriptive mask wearing norms as the pandemic unfolded. Longitudinal trends suggested that norms and behavior were tightly coupled, changing quickly in response to public health recommendations. In addition, longitudinal modeling revealed that descriptive norms caused future increases in mask wearing across multiple waves of data collection. These cross-lagged causal effects of descriptive norms were large, even after controlling for non-social beliefs and demographic variables. Injunctive norms, by contrast, had less frequent and generally weaker causal effects on future mask wearing. During uncertain times, cooperative behavior is more strongly driven by what others are actually doing, rather than what others think ought to be done.
Assuntos
COVID-19 , Humanos , COVID-19/epidemiologia , COVID-19/prevenção & controle , Pandemias , Comportamento Cooperativo , Coleta de Dados , Saúde PúblicaRESUMO
Given the importance of friendships during challenging times and the mixed associations between personality traits and disease-related behaviors, we investigated the correlations between personality traits and perceptions of friendships during the COVID-19 pandemic. Data were collected as part of a longitudinal investigation of the correlations between the pandemic and various cooperative relationships. In this investigation, we found that agreeableness and neuroticism predicted participants being more concerned about COVID-19 and bothered by friends' risky behavior, and extraversion predicted enjoying helping friends during the pandemic. Our results suggest that personality differences are associated with how individuals cope with friends' risky behaviors during the COVID-19 pandemic.
RESUMO
Glyphosate is a broad-spectrum and one of the most widely used herbicides in the world, which has led to its high environmental dissemination. In 2015, the International Agency for Research on Cancer stated that glyphosate was a probable human carcinogen. Since then, several studies have provided new data about the environmental exposure of glyphosate and its consequences on human health. Thus, the carcinogenic effects of glyphosate are still under debate. This work aimed to review glyphosate occurrence and exposure since 2015 up to date, considering studies associated with either environmental or occupational exposure and the epidemiological assessment of cancer risk in humans. These articles showed that herbicide residues were detectable in all spheres of the earth and studies on the population showed an increase in the concentration of glyphosate in biofluids, both in the general population and in the occupationally exposed population. However, the epidemiological studies under review provided limited evidence for the carcinogenicity of glyphosate, which was consistent with the International Agency for Research on Cancer classification as a probable carcinogen.
Assuntos
Herbicidas , Neoplasias , Exposição Ocupacional , Humanos , Exposição Ambiental , Carcinógenos/toxicidade , Herbicidas/toxicidade , Neoplasias/induzido quimicamente , Neoplasias/epidemiologia , GlifosatoRESUMO
Even though epidemiological studies suggest that tobacco smoking and high-risk human papillomavirus (HR-HPV) infection are mutually exclusive risk factors for developing head and neck cancer (HNC), a portion of subjects who develop this heterogeneous group of cancers are both HPV-positive and smokers. Both carcinogenic factors are associated with increased oxidative stress (OS) and DNA damage. It has been suggested that superoxide dismutase 2 (SOD2) can be independently regulated by cigarette smoke and HPV, increasing adaptation to OS and tumor progression. In this study, we analyzed SOD2 levels and DNA damage in oral cells ectopically expressing HPV16 E6/E7 oncoproteins and exposed to cigarette smoke condensate (CSC). Additionally, we analyzed SOD2 transcripts in The Cancer Genome Atlas (TCGA) Head and Neck Cancer Database. We found that oral cells expressing HPV16 E6/E7 oncoproteins exposed to CSC synergistically increased SOD2 levels and DNA damage. Additionally, the SOD2 regulation by E6, occurs in an Akt1 and ATM-independent manner. This study suggests that HPV and cigarette smoke interaction in HNC promotes SOD2 alterations, leading to increased DNA damage and, in turn, contributing to development of a different clinical entity.
Assuntos
Fumar Cigarros , Neoplasias de Cabeça e Pescoço , Proteínas Oncogênicas Virais , Infecções por Papillomavirus , Humanos , Papillomavirus Humano , Papillomavirus Humano 16/metabolismo , Infecções por Papillomavirus/complicações , Proteínas E7 de Papillomavirus/genética , Proteínas E7 de Papillomavirus/metabolismo , Proteínas Oncogênicas Virais/genética , Proteínas Oncogênicas Virais/metabolismo , Dano ao DNA , Neoplasias de Cabeça e Pescoço/complicaçõesRESUMO
Glioblastoma (GBM) is the most common and aggressive type of brain tumor due to its elevated recurrence following treatments. This is mainly mediated by a subpopulation of cells with stemness traits termed glioblastoma stem-like cells (GSCs), which are extremely resistant to anti-neoplastic drugs. Thus, an advancement in the understanding of the molecular processes underlying GSC occurrence should contribute significantly towards progress in reducing aggressiveness. High levels of endothelin-converting enzyme-1 (ECE1), key for endothelin-1 (ET-1) peptide activation, have been linked to the malignant progression of GBM. There are four known isoforms of ECE1 that activate ET-1, which only differ in their cytoplasmic N-terminal sequences. Isoform ECE1c is phosphorylated at Ser-18 and Ser-20 by protein kinase CK2, which increases its stability and hence promotes aggressiveness traits in colon cancer cells. In order to study whether ECE1c exerts a malignant effect in GBM, we designed an ECE1c mutant by switching a putative ubiquitination lysine proximal to the phospho-serines Lys-6-to-Arg (i.e., K6R). This ECE1cK6R mutant was stably expressed in U87MG, T98G, and U251 GBM cells, and their behavior was compared to either mock or wild-type ECE1c-expressing clone cells. ECE1cK6R behaved as a highly stable protein in all cell lines, and its expression promoted self-renewal and the enrichment of a stem-like population characterized by enhanced neurospheroid formation, as well as increased expression of stem-like surface markers. These ECE1cK6R-derived GSC-like cells also displayed enhanced resistance to the GBM-related chemotherapy drugs temozolomide and gemcitabine and increased expression of the ABCG2 efflux pump. In addition, ECE1cK6R cells displayed enhanced metastasis-associated traits, such as the modulation of adhesion and the enhancement of cell migration and invasion. In conclusion, the acquisition of a GSC-like phenotype, together with heightened chemoresistance and invasiveness traits, allows us to suggest phospho-ECE1c as a novel marker for poor prognosis as well as a potential therapeutic target for GBM.
Assuntos
Glioblastoma , Humanos , Glioblastoma/metabolismo , Enzimas Conversoras de Endotelina/genética , Enzimas Conversoras de Endotelina/metabolismo , Linhagem Celular Tumoral , Células-Tronco Neoplásicas/patologia , FenótipoRESUMO
Introducción: La atención primaria en salud y la distribución de médicos familiares son aspectos cruciales para garantizar el acceso equitativo a servicios médicos de calidad. Este estudio explora la distribución geográfica de los médicos familiares en Bogotá y su relación con diversos factores socioeconómicos y psicosociales. Materiales y Métodos: Se realizo un estudio observacional, analítico y transversal, utilizando datos recolectados para el año 2023. Se recopilaron datos de diversas fuentes sobre características geográficas, demográficas, socioeconómicas y de salud de las unidades de planeación zonal (UPZ) de Bogotá. Se utilizo análisis estadístico, incluyendo regresión lineal y logística, para explorar las asociaciones entre la distribución de médicos familiares y otros factores.
Introduction: Primary health care and the distribution of family physicians are crucial aspects to ensure equitable access to quality medical services. This study explores the geographic distribution of family physicians in Bogotá and its relationship with various socioeconomic and psychosocial factors. Materials and Methods: An observational, analytical and cross-sectional study was conducted using data collected for the year 2023. Data were collected from various sources on geographic, demographic, socioeconomic and health characteristics of the zonal planning units (UPZ) of Bogota. Statistical analysis, including linear and logistic regression, was used to explore associations between the distribution of family physicians and other factors.
Introdução: Os cuidados de saúde primários e a distribuição dos médicos de família são aspectos cruciais para garantir um acesso equitativo a serviços médicos de qualidade. Este estudo explora a distribuição geográfica dos médicos de família em Bogotá e a sua relação com vários factores socioeconómicos e psicossociais. Materiais e Métodos: Foi realizado um estudo observacional, analítico e transversal, utilizando dados recolhidos para o ano de 2023. Os dados foram recolhidos de várias fontes sobre as caraterísticas geográficas, demográficas, socioeconómicas e de saúde das unidades de planeamento zonal (UPZ) de Bogotá. A análise estatística, incluindo regressão linear e logística, foi utilizada para explorar associações entre a distribuição de médicos de família e outros factores.
Assuntos
HumanosRESUMO
Traits that exhibit differences between the sexes have been of special interest in the study of phenotypic evolution. Classic hypotheses explain sexually dimorphic traits via intra-sexual competition and mate selection, yet natural selection may also act differentially on the sexes to produce dimorphism. Natural selection can act either through physiological and ecological constraints on one of the sexes, or by modulating the strength of sexual/social selection. This predicts an association between the degree of dimorphism and variation in ecological environments. Here, we characterize the variation in hummingbird dimorphism across ecological gradients using rich databases of morphology, colouration and song. We show that morphological dimorphism decreases with elevation in the understorey and increases with elevation in mixed habitats, that dichromatism increases at high altitudes in open and mixed habitats, and that song is less complex in mixed habitats. Our results are consistent with flight constraints, lower predation pressure at high elevations and with habitat effects on song transmission. We also show that dichromatism and song complexity are positively associated, while tail dimorphism and song complexity are negatively associated. Our results suggest that key ecological factors shape sexually dimorphic traits, and that different communication modalities do not always evolve in tandem.
Assuntos
Evolução Biológica , Seleção Sexual , Animais , Seleção Genética , Ecossistema , Caracteres Sexuais , AvesRESUMO
Nectar-feeding birds provide an excellent system in which to examine form-function relationships over evolutionary time. There are many independent origins of nectarivory in birds, and nectar feeding is a lifestyle with many inherent biophysical constraints. We review the morphology and function of the feeding apparatus, the locomotor apparatus, and the digestive and renal systems across avian nectarivores with the goals of synthesizing available information and identifying the extent to which different aspects of anatomy have morphologically and functionally converged. In doing so, we have systematically tabulated the occurrence of putative adaptations to nectarivory across birds and created what is, to our knowledge, the first comprehensive summary of adaptations to nectarivory across body systems and taxa. We also provide the first phylogenetically informed estimate of the number of times nectarivory has evolved within Aves. Based on this synthesis of existing knowledge, we identify current knowledge gaps and provide suggestions for future research questions and methods of data collection that will increase our understanding of the distribution of adaptations across bodily systems and taxa, and the relationship between those adaptations and ecological and evolutionary factors. We hope that this synthesis will serve as a landmark for the current state of the field, prompting investigators to begin collecting new data and addressing questions that have heretofore been impossible to answer about the ecology, evolution, and functional morphology of avian nectarivory.
Assuntos
Aves , Néctar de Plantas , Animais , Aves/anatomia & histologia , FilogeniaRESUMO
High-risk human papillomaviruses (HR-HPV) are the causal agents of an important subset of oropharyngeal cancers that has increased considerably in incidence in recent years. In this study, we evaluated the presence of HPV in 49 oropharyngeal cancers from Chilean subjects. The presence of HPV DNA was analyzed by conventional PCR, the genotypes were identified through sequencing, and the expression of E6/E7 transcripts was evaluated by a reverse transcriptase polymerase chain reaction (RT-PCR). Additionally, to determine p16 expression-a surrogate marker for oncogenic HPV infection-a tissue array was constructed for immunohistochemistry (IHC). HPV was detected in 61.2% of oropharyngeal carcinomas, the most prevalent genotype being HPV16 (80%). E6 and E7 transcripts were detected in 91.6% and 79.1% of the HPV16-positive specimens, respectively, demonstrating functional HPV infections. Furthermore, p16 expression was positive in 58.3% of cases. These findings show a high prevalence of HR-HPV in oropharyngeal tumors from Chile, suggesting the necessity of additional studies to address this growing public health concern.
Assuntos
Alphapapillomavirus , Carcinoma de Células Escamosas , Neoplasias de Cabeça e Pescoço , Proteínas Oncogênicas Virais , Neoplasias Orofaríngeas , Infecções por Papillomavirus , Alphapapillomavirus/genética , Chile/epidemiologia , Inibidor p16 de Quinase Dependente de Ciclina/análise , Inibidor p16 de Quinase Dependente de Ciclina/genética , DNA Viral/análise , DNA Viral/genética , Humanos , Proteínas Oncogênicas Virais/genética , Neoplasias Orofaríngeas/metabolismo , Papillomaviridae/genética , Proteínas E7 de Papillomavirus/genética , Infecções por Papillomavirus/complicações , Infecções por Papillomavirus/epidemiologia , Infecções por Papillomavirus/metabolismo , RNA Viral/genéticaRESUMO
High-risk human papillomaviruses (HR-HPVs) are the etiological agents of cervical cancer. However, a low proportion of HR-HPV-infected women finally develop this cancer, which suggests the involvement of additional cofactors. Epstein−Barr virus (EBV) has been detected in cervical squamous cell carcinomas (SCCs) as well as in low- (LSIL) and high-grade (HSIL) squamous intraepithelial lesions, although its role is unknown. In this study, we characterized HR-HPV/EBV co-presence and viral gene expression in LSIL (n = 22), HSIL (n = 52), and SCC (n = 19) from Chilean women. Additionally, phenotypic changes were evaluated in cervical cancer cells ectopically expressing BamHI-A Rightward Frame 1 (BARF1). BARF1 is a lytic gene also expressed in EBV-positive epithelial tumors during the EBV latency program. HPV was detected in 6/22 (27.3%) LSIL, 38/52 (73.1%) HSIL, and 15/19 (78.9%) SCC cases (p < 0.001). On the other hand, EBV was detected in 16/22 (72.7%) LSIL, 27/52 (51.9%) HSIL, and 13/19 (68.4%) SCC cases (p = 0.177). HR-HPV/EBV co-presence was detected in 3/22 (13.6%) LSIL, 17/52 (32.7%) HSIL, and 11/19 (57.9%) SCC cases (p = 0.020). Additionally, BARF1 transcripts were detected in 37/55 (67.3%) of EBV positive cases and in 19/30 (63.3%) of HR-HPV/EBV positive cases. Increased proliferation, migration, and epithelial-mesenchymal transition (EMT) was observed in cervical cancer cells expressing BARF1. Thus, both EBV and BARF1 transcripts are detected in low- and high-grade cervical lesions as well as in cervical carcinomas. In addition, BARF1 can modulate the tumor behavior in cervical cancer cells, suggesting a role in increasing tumor aggressiveness.
RESUMO
Friendships provide social support and mental health benefits, yet the COVID-19 pandemic has limited interactions with friends. In August 2020, we asked participants (N = 634) about their friendships during the pandemic as part of a larger study. We found that younger people and people with higher subjective SES reported more negative effects on their friendships, including feeling more isolated and lonelier. We also found that stress, isolation, and guilt were associated with greater COVID-related social risk-taking, such as making and visiting new friends in person. Our results suggest the pandemic is affecting friendships differently across demographic groups and these negative effects might motivate social risk-taking.
RESUMO
High-risk human papillomaviruses (HR-HPVs) and Epstein-Barr virus (EBV) are recognized oncogenic viruses involved in the development of a subset of head and neck cancers (HNCs). HR-HPVs are etiologically associated with a subset of oropharyngeal carcinomas (OPCs), whereas EBV is a recognized etiological agent of undifferentiated nasopharyngeal carcinomas (NPCs). In this review, we address epidemiological and mechanistic evidence regarding a potential cooperation between HR-HPV and EBV for HNC development. Considering that: (1) both HR-HPV and EBV infections require cofactors for carcinogenesis; and (2) both oropharyngeal and oral epithelium can be directly exposed to carcinogens, such as alcohol or tobacco smoke, we hypothesize possible interaction mechanisms. The epidemiological and experimental evidence suggests that HR-HPV/EBV cooperation for developing a subset of HNCs is plausible and warrants further investigation.
RESUMO
Background: Several immunotherapy (IT) agents are FDA approved for treatment of melanoma and non-small-cell lung cancer (NSCLC). The addition of stereotactic radiosurgery (SRS) or stereotactic body radiation therapy (SBRT) to immunotherapy looks promising. A systematic review was conducted to evaluate the possible synergistic effects of immune checkpoints inhibitors (ICIs) and stereotactic radiation therapy in melanoma and NSCLC. Materials and methods: Pubmed databases from January 2010 to December 2020 were reviewed to identify English language studies reporting control of local and abscopal effect of the combination of ICI-SBRT/SRS in metastatic NSCLC and melanoma cancer. The inclusion criteria were followed according to PICO criteria. Results: Thirty-nine articles were included of the 2141 initial results. The reported rates for local control were 16.5-100% and 40-94% in brain and extracerebral metastases, respectively. Distant/abscopal response rates were 1-45% in extracerebral metastases. Abscopal effect could not be evaluated in brain metastases because it was not reported in studies. Treatments were well tolerated with few grade 4 toxicities and no grade 5. Conclusions: The combined treatment of ICI-SBRT/SRS achieves high local control and non-negligible abscopal response in patients with extracerebral metastases, with its benefit in cerebral metastases being more controversial. Clinical trials are needed to better characterize the potential synergism.
Assuntos
Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/radioterapia , Inibidores de Checkpoint Imunológico/farmacologia , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/radioterapia , Melanoma/tratamento farmacológico , Melanoma/radioterapia , Terapia Combinada/métodos , Humanos , Imunoterapia/métodos , Radiocirurgia/métodosRESUMO
BACKGROUND: Physical activity (PA) mitigated psychological distress during the initial weeks of the COVID-19 pandemic, yet not much is known about whether PA had effects on stress in subsequent months. We examined the relationship between change over time in COVID-related stress and self-reported change in PA between March and July 2020. METHODS: Latent growth modeling was used to examine trajectories of change in pandemic-related stress and test their association with self-reported changes in PA in an international sample (n = 679). RESULTS: The participants reported a reduction in pandemic-related stress between April and July of 2020. Significant linear (factor mean = -0.22) and quadratic (factor mean = 0.02) changes (Ps < .001) were observed, indicating a deceleration in stress reduction over time. Linear change was related to change in PA such that individuals who became less active during the pandemic reported less stress reduction over time compared with those who maintained or increased their PA during the pandemic. CONCLUSIONS: Individuals who experienced the greatest reduction in stress over time during the pandemic were those who maintained their activity levels or became more active. Our study cannot establish a causal relationship between these variables, but the findings are consistent with other work showing that PA reduces stress.
Assuntos
COVID-19 , Pandemias , Exercício Físico , Humanos , SARS-CoV-2 , AutorrelatoRESUMO
Breast cancer (BC) is the most commonly diagnosed malignancy in women worldwide as well as the leading cause of cancer-related death in this gender. Studies have identified that human papillomavirus (HPV) is a potential risk factor for BC development. While vaccines that protect against oncogenic HPVs infection have been commercially available, global disparities persist due to their high cost. Interestingly, numerous authors have detected an increased high risk (HR)-HPV infection in BC specimens when compared with non-tumor tissues. Therefore, it was suggested that HR-HPV infection could play a role in breast carcinogenesis in a subset of cases. Additional epidemiological and experimental evidence is still needed regarding the role of HR-HPV infection in the development and progression of BC.
RESUMO
To better understand risk management and mutual aid among American ranchers, we interviewed and mailed a survey to ranchers in Hidalgo County, New Mexico, and Cochise County, Arizona, focusing on two questions: (1) When do ranchers expect repayment for the help they provide others? (2) What determines ranchers' degrees of involvement in networks of mutual aid, which they refer to as "neighboring"? When needs arise due to unpredictable events, such as injuries, most ranchers reported not expecting to be paid back for the help they provide. When help is provided for something that follows a known schedule or that can be scheduled, such as branding, most ranchers did expect something in return for the help they provide. This pattern makes sense in light of computational modeling that shows that transfers to those in need without expectations of repayment pool risk more effectively than transfers that create debt. Ranchers reported helping other ranchers more often when they belonged to more religious and civic organizations, when they owned larger ranches, when they relied less on ranch vs. other income, and when they had more relatives in the area. Operators of midsize ranches reported helping other ranchers more frequently than did those on smaller and larger ranches. None of our independent variables predicted how many times ranchers reported receiving help from other ranchers. Although ranch culture in the American West is often characterized by an ethic of individualism and independence, our study suggests that this ethic stands alongside an ethic of mutual aid during times of need.
Assuntos
Fazendeiros , Humanos , Sudoeste dos Estados Unidos , Inquéritos e Questionários , Estados UnidosRESUMO
A fascinating pattern in nature is the uneven distribution of biodiversity among clades, some with low species richness and phenotypic variation in contrast to others with remarkable species richness and phenotypic diversity. In animals, communication signals are crucial for intra- and interspecific interactions and are likely an important factor in speciation. However, evidence for the association between the evolution of such signals and speciation is mixed. In hummingbirds, plumage coloration is an important communication signal, particularly for mate selection. Here, using reflectance data for 237 hummingbird species (â¼66% of total diversity), we demonstrate that color evolution rates are associated with speciation rates, and that differences among feather patches are consistent with an interplay between natural and sexual selection. We found that female color evolution rates of multiple plumage elements, including the gorget, were similar to those of males. Although male color evolution in this patch was associated with speciation, female gorget color evolution was not. In other patches, the relationship between speciation and color evolution rates was pervasive between sexes. We anticipate that future studies on animal communication will likely find that evolution of signaling traits of both sexes has played a vital role in generating signal and species diversity.