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1.
Evolutionary psychiatrists invariably consider schizophrenia to be a paradox: how come natural selection has not yet eliminated the infamous ‘genes for schizophrenia’ if the disorder simply crushes the reproductive success of its carriers, if it has been around for thousands of years already, and if it has a uniform prevalence throughout the world? Usually, the answer is that the schizophrenic genotype is subject to some kind of balancing selection: the benefits it confers would then outbalance the obvious damage it does. In this paper, however, I will show that the assumptions underlying such evolutionary accounts of schizophrenia are at least implausible, and sometimes even erroneous. First of all, I will examine some factual assumptions, in particular about schizophrenia’s impact on reproductive success, its genetics, its history, and its epidemiology. Secondly, I will take a critical look at a major philosophical assumption in evolutionary psychiatric explanations of schizophrenia. Indeed, evolutionary psychiatrists take it for granted that schizophrenia is a natural kind, i.e. a bounded and objectively real entity with discrete biological causes. My refutation of this natural kind view suggests that schizophrenia is in fact a reified umbrella concept, covering a heterogeneous group of disorders. Therefore, schizophrenia, as we now know it, simply doesn’t have an evolutionary history.  相似文献   

2.
Richardson SC 《Oecologia》2004,139(2):246-254
As exploiters of plant-pollinator mutualisms, nectar-robbers remove rewards (nectar) without providing pollination services. Though one might expect nectar-robbing to be costly to plants, it may instead benefit plants by indirectly increasing pollen dispersal. I investigated the direct effects of nectar-robbing bees (Xylocopa californica) on floral rewards and behaviors of pollinators visiting desert willow (Chilopsis linearis) and indirect effects of robbing on the reproductive success of the plant. Nectar-robbers reduced nectar; while unrobbed and robbed flowers were equally likely to contain nectar, nectar volumes were smaller in robbed flowers with nectar. Apis mellifera (honeybees), ineffective pollinators in terms of pollen deposition, avoided robbed flowers. In contrast, Bombus sonorus (bumblebees), effective pollinators, did not avoid robbed flowers. While bumblebees tended to spend less time in robbed flowers, the time that they spent in flowers was not correlated with pollen deposition. Using powder mimicking pollen, I found that on some days, powder was dispersed farther or to more flowers from robbed flowers, indicating that robbing may sometimes benefit plants by increasing male reproductive success. Powder movement suggested that the effect of robbing on male reproductive success ranged from costly to beneficial. The outcome for flowers that were marked early each morning was a function of prevalence of robbing and abundances of effective pollinators, but not a function of spatial variability among trees in prevalence of robbing or the abundance of ineffective honeybees. Unlike powder dispersal, female reproductive success, measured by fruit set and the number of pollen tubes growing in styles, was not affected by robbing. Thus, robbers did not reduce plants female reproductive success either directly by damaging flowers or indirectly by reducing pollen deposition by pollinators. Overall, this study indicates that nectar-robbers were not often costly to plants, and sometimes even benefited plants.  相似文献   

3.
Populations ofDrosophila melanogaster that had been subjected to long-term selection favoring either delayed or rapid senescence were compared with respect to age-specific components of male reproductive success involving sperm competition. These components of reproductive success were divided into those related to sperm defense (protection of sperm from other males), and into those related to sperm offense (ability to mate with previously mated females and to displace the sperm of other males). Males were tested at four ages ranging from 1–2d to 5–6 wk after eclosion. Several aspects of sperm defense capability showed clear evidence of senescent decline. Furthermore, males from populations selected for delayed senescence were superior to males from control (rapid senescence) populations with regard to components of sperm defense. The superiority of males from populations with delayed senescence either increased as a function of male age, or was present at all ages tested. These results indicate that the rate of reproductive senescence in maleD. melanogaster can be altered in predictable directions by artificial selection. There were no differences between selection regimes with regard to sperm offense, and most components of sperm offense did not show clear evidence of senescence. The improved late-age reproductive success of males from populations selected for delayed senescence did not appear to entail any cost or trade-off at early ages with respect to the reproductive traits examined in these experiments.  相似文献   

4.
In this article, I examine whether inter- and/or intraunit variation in ethnocentrism— a trait not automatically connected with mortality/natality rates—can be correlated with differential reproductive success. As a preliminary test of general theoretical models in the literature regarding the sociobiology of ethnocentrism, it was postulated that the more ethnocentric an ethnic unit is, the more important ethnocentrism is for the members of that unit. With the use of this postulate, hypotheses were generated and tested with empirical data obtained through field research among two ethnic units—Tamils and Gujaratis—in the city of Pune, India. It was concluded that: 1) if interunit aggression and kin selection were predominant characteristics of the early hominid environments of evolutionary adaptation, then from a sociobiological perspective, ethnocentrism can be explained as an evolved human trait, intimately linked to kin selection and interunit warfare; and, 2) under what I assumed to be novel environmental conditions ethnocentrism and reproductive success appear to be uncorrelated; and, 3) because the possibility exists that novel environmental contengencies were acting to level off reproductive variance upon which natural selection could have operated in my sample, only future research in a society similar in structure to those we tend to identify with early hominid environments of evolutionary adaptation will allow researchers to rule out the possibility that ethnocentrism is an evolved human “biocultural” trait.  相似文献   

5.
The murder of George Floyd sparked an awakening, long overdue, which reverberated throughout society. As science begins to acknowledge its role in perpetuating systematic racism, the voices of Black scientists, which have largely been absent, are now being called on. As we rightly begin to make space for diverse voices and perspectives in science, we all must think about what it is we are asking minoritized individuals to do.

It has been roughly 1 year since the murder of George Floyd, an unarmed Black man, who was killed over an alleged counterfeit 20 dollar bill in Minneapolis, Minnesota (Hill et al. 2020; Kaul, 2020; Levenson, 2021). In many ways, his murder was no different than the murders of thousands of other murders of Black people in this country (Thompson, 2020; Lett et al., 2021; Tate et al., 2021). However, what distinguishes George Floyd’s murder from many other high profile cases is that it was unambiguously captured on video (Alexander, 1994), an act of bravery by Darnella Frazier, a 17-year-old Black woman (Izadi, 2021), at a time when the world was mostly housebound by a raging global pandemic. As a result, his murder reverberated through society in a way that has not happened in my lifetime. While there have been other high profile cases of murders carried out by police (Treyvon Martin, Walter Scott, Breonna Taylor, and Philando Castile, among many others), these cases failed to fully sustain the attention of a national and international audience (Chan et al., 2020; Chughtai, 2021). The murder of George Floyd was fundamentally different, and for once, more than just Black people were paying attention. His murder sparked protests across the nation led by the Black Lives Matter (BLM) movement (Day, 2015; Taylor, 2016; Banks, 2018; Taylor, 2021), and the demands for change were so loud people could not help but hear.As a Black, gay man who is also a scientist, I was thrown into despair. All of my life I have thought if I just worked hard enough, if I am kind and unthreatening, if I play the game and keep my head down, maybe I can make it in academia. Maybe then I will be seen and accepted, not just by society, but by the scientific community. George Floyd’s murder reminded me, and many of my Black colleagues, that our degrees can’t protect us, that our privileged middle-class upbringing (if we had one) was not a shield. Our lives were not worth more than a counterfeit 20 dollar bill.Science, which has always been a product of society, was not impervious to these reverberations. By late June my inbox began to slowly fill with invitations to speak at several institutions for their seminar series, retreats, or special symposia. It felt as if the scientific community, for the first time, realized that there were Black scientists among them. In the throes of my own despair, and the feeling that I needed to be doing something for my community, I began to say “yes.” I was not going to participate in the nightly protests that occurred in my newly adopted hometown of Portland, Oregon. Aside from fearing I could be next to lose my life at the hands of the police (Edwards et al., 2019), these protests were happening in the backdrop of a global pandemic. I came to the conclusion that by accepting these invitations to speak, this could be my activism, my way of sparking change, increasing visibility, and being seen not only for my own sake but also for other Black scientists.Before I write anything else, I want to be clear: I am extremely thankful to all the institutions and organizations that invited me and gave me a platform. I am extremely proud of my students’ work and of the research we produce. I am sharing my experiences with the hope that they can be instructive to the greater scientific community, but if I am being frank, there is a bit of anger.I received over 15 invitations and gave an additional three or four interviews over the course of the year. Most of these came with the expectation that I would also talk about my work in Diversity, Equity, and Inclusion. But here’s the lowdown: prior to this year, I did not view myself as someone who did Diversity, Equity, and Inclusion work. I am co-chair of the LGBTQ+ committee of the American Society of Cell Biology and a member of the Diversity, Equity, and Inclusion committee of the Genetics Society of America. I volunteer for both of these committees because they speak to something I care deeply about, the advocacy for minoritized 1 scientists. I also embody both of these axes of diversity; so, in some way, I am only looking out for myself. This is far from being a scholar or doing “Diversity work.” I fully recognize that there are individuals who have dedicated their lives to this type of work with entire academic fields populated with accomplished scholars. So, I started this year of talks being invited because I am a Black, gay scientist at a time when science was grappling with its own systematic racism, under the guise of my nonexistent Diversity, Equity, and Inclusion work.What has this year actually taught me? The first thing it taught me is that I have been missing out. Prior to George Floyd’s murder, I had only received three seminar invitations from major research institutions and unfortunately all within a year of being posttenure. That is after nearly 6 years in my current position.In giving these talks I got the opportunity to meet with some of the giants in my field, people I have looked up to for years. I received reagents, offers to collaborate, and a litany of great ideas that will help drive my research program for years to come. I left some of these meetings truly inspired and excited to start experiments. These opportunities would have been invaluable to me, pretenure. One could argue, I did not need it. I made it even without this networking and the advantages these visits bring. Before you applaud my ability to persist and be resilient, we should take a deep look at the systems that have forced people who look like me to be doubly resilient. If George Floyd had not been murdered, would any of these invitations have happened? If the previous 6 years are any indication of a trend, I would have to say most certainly not. Why did it take a murder and the reignition of a Civil Rights movement for me to have the type of interactions I now know many of my straight, white counterparts have had from the very beginning of their independent careers? Let me be clear: this is a form of systematic racism, plain and simple.As I began to make the rounds, I was often asked to either share a bit of my journey or include my Diversity, Equity, and Inclusion work in my talks. This sometimes came at the expense of sharing my lab’s work. While I was very happy to do so, this was very much implicit in the invitations I received. At times it did feel that my inclusion was only checking a box, placating the graduate students so that they could see that their department or institution was responding to their demands. This also had the consequence of making me feel as though my science was merely performative. I was being invited to do the Diversity work institutions did not want to do. This is the tension I, and many other minoritized scientists, face. I want to share my experiences with the hopes that the next generation will have it better; but, my scholarly work is not in Diversity, Equity, and Inclusion. I fully recognize that it is my embodied diversity that is bringing me to the table; but, it is the science I want to share.On the first invitation to give a seminar, I promised myself that I was going to be honest. This meant that I would tell the truth about my experience and bare my soul over and over again. What I had not counted on was the emotional toll this would take on me. Reliving my own trauma, on a regular basis, left me emotionally drained after these visits. In one of my “stops” (I use quotes here because these “visits” were all virtual), I met with the queer, person of color (POC), graduate students. This session quickly turned into an emotional support group where I heard stories of mistreatment, racism, and discrimination. It was nearly impossible to maintain my composure. Diversity, Equity, and Inclusion work is clearly extremely important, but, maybe, we could just start by listening to the needs of the students and having a bit of humanity.The trial of Derek Chauvin has come and passed, and much to my surprise, and to the surprise of many other Black people nationwide, he was found guilty and was sentenced to prison (Arango, 2021; Cooper and Fiegel, 2021). This, of course, is not justice, not even close. Justice would mean that George Floyd is still alive and would get to live out his life in the way he chose. We are also at the beginning of the end of the pandemic. In 6 months or less, we may all be returning to life, more or less, as it was before George Floyd, before COVID-19. Does this mean we stop fighting? Does this mean that I, and many other Black scientists, suddenly disappear? For George Floyd, for countless other faceless Black people before him, I sincerely hope not. We need to continue to give Black scientists a platform. We need to ensure that they, too, are given the opportunity to network, collaborate, and interact with the larger scientific community. This means the invitations cannot stop. To further this, we need to ensure that Black scientists are included in every grant review panel, are included on speaker lists at every national and international meeting, are funded, and are in the room where funding, tenure, and other critical decisions are being made. We need to recognize that systematic racism has not gone away with Derek Chauvin’s conviction and sentencing. We need to continue to push forward. And, for all of you young, minoritized scientists (and allies) reading this, demand change and do not take "no" for an answer. I am truly sorry this has fallen on your shoulders, but enough is enough. The next generation of minoritized scientists should be recognized for their science without the additional burden of creating their own space.About the AuthorI am currently an Associate Professor of Biology at Reed College (https://www.reed.edu/biology/applewhite/index.html), which is located in Portland, Oregon. I arrived at Reed in 2014; prior to that, I was a postdoctoral fellow at the University of North Carolina, Chapel Hill. I received my PhD from Northwestern University in Cellular and Molecular Biology and a BS in Biology from the University of Michigan where I was also a 4-year letter winner in track and field. My research focuses on the cytoskeleton where I study cell motility and morphogenesis using Drosophila and Drosophila derived in tissue culture cells to explore actin, microtubules, and molecular motors. My current lab is composed of fierce, determined undergraduate students. I am a member of the American Society of Cell Biology (ASCB) and the current chair of the LGBTQ+ Committee (https://www.ascb.org/committee/lgbtq/). I am also a member of the Diversity, Equity, and Inclusion Committee for the Genetics Society of America (https://genetics-gsa.org/committees/). I also serve as an editor for MBoC’s Voices series.  相似文献   

6.
Observations on mating behaviours and strategies guide our understanding of mating systems and variance in reproductive success. However, the presence of cryptic strategies often results in situations where social mating system is not reflective of genetic mating system. We present such a study of the genetic mating system of a harem-forming bat Cynopterus sphinx where harems may not be true indicators of male reproductive success. This temporal study using data from six seasons on paternity reveals that social harem assemblages do not play a role in the mating system, and variance in male reproductive success is lower than expected assuming polygynous mating. Further, simulations reveal that the genetic mating system is statistically indistinguishable from promiscuity. Our results are in contrast to an earlier study that demonstrated high variance in male reproductive success. Although an outcome of behavioural mating patterns, standardized variance in male reproductive success (I(m)) affects the opportunity for sexual selection. To gain a better understanding of the evolutionary implications of promiscuity for mammals in general, we compared our estimates of I(m) and total opportunity for sexual selection (I(m) /I(f), where I(f) is standardized variance in female reproductive success) with those of other known promiscuous species. We observed a broad range of I(m) /I(f) values across known promiscuous species, indicating our poor understanding of the evolutionary implications of promiscuous mating.  相似文献   

7.
Summary I consider a general model of a fluctuating environment in which the environmental state each year is drawn at random from some given distribution. Each year organisms must choose what action to perform before the environmental state for that year is known. There is no interaction with kin. In this scenario, natural selection will tend to produce organisms which maximize their geometric mean fitness. In this paper I introduce the idea of the profile of a strategy. This function quantifies how the strategy peforms for each environmental state. I show that there is a unique profile such that a strategy is optimal if and only if it has this profile. I then give a characterization of the optimal profile which generalizes previous work by others in this area. The characterization of the optimal profile has a game theoretical interpretation. Motivated by this I introduce a game in which individuals play the field in a constant environment. This game may be interpreted as a cooperative game between kin. The key result of this paper shows that a strategy maximizes geometric mean fitness in the original fluctuating environment problem if and only if it is an evolutionarily stable strategy of the deterministic environment game. It is well known that an optimal strategy in a fluctuating environment may be mixed, involving adaptive coin-flipping. Others have previously noted that this may result in some individuals sacrificing individual reproductive success for the good of the genotype. My analysis shows that one may regain the concept of individual optimization if the quantity maximized is suitably defined. Under an optimal strategy every action taken maximizes the expected number of offspring produced, where this expectation is not calculated using the true distribution of environmental states, but a distribution modified to take account of the actions of kin.  相似文献   

8.
Physical attractiveness has been associated with mating behavior, but its role in reproductive success of contemporary humans has received surprisingly little attention. In the Wisconsin Longitudinal Study (1244 women, 997 men born between 1937 and 1940), we examined whether attractiveness assessed from photographs taken at age 18 years predicted the number of biological children at age 53–56 years. In women, attractiveness predicted higher reproductive success in a nonlinear fashion, so that attractive (second highest quartile) women had 16% and very attractive (highest quartile) women 6% more children than their less attractive counterparts. In men, there was a threshold effect so that men in the lowest attractiveness quartile had 13% fewer children than others who did not differ from each other in the average number of children. These associations were partly but not completely accounted for by attractive participants' increased marriage probability. A linear regression analysis indicated relatively weak directional selection gradient for attractiveness (β=0.06 in women, β=0.07 in men). These findings indicate that physical attractiveness may be associated with reproductive success in humans living in industrialized settings.  相似文献   

9.
No one maps out their tenure as a postdoc anticipating a life-altering tragedy. But mental health crises of all kinds affect academic trainees and staff at similar or higher levels than the general public. While the mental health resources available to trainees are often set by healthcare providers, all levels of university leadership can work to remove material and immaterial obstacles that render such resources out of reach. I describe how access to care via telemedicine helped me following a loss in my family.

Over the years, my siblings and close friends have sought mental health resources like therapy, psychoanalysis, or psychiatry, so I loosely understood their benefits. When I was a PhD student I went to therapy briefly, but my counselor and I decided I could do without it. Since I started my postdoc, stress manifested in some new ways but I managed it well with my usual coping strategies and support. That changed one bright December morning in 2019 while I was preparing for our weekly lab meeting. My phone rang indicating a call from my father, whom I had spoken to the night before to celebrate the news of my nephew’s birth. But the voice on the phone was that of a family friend, telling me that my father had died overnight of an undiagnosed heart condition. In the moment I couldn’t even understand what was happening, saying over and over, “but I talked to him last night.” Soon I was sitting at home, dazed, on a string of tearful calls with family and friends.I often read words like “lifted” or “buoyed” to describe the stabilizing support of a network of loved ones. In my case this network was tethering me to reality over the next few weeks, preventing me from spinning off the Earth’s surface in a storm of sorrow and anxiety. The trauma also took a strange physical form and convinced me that I was suffering from a cardiac condition of my own. I had a panic attack during which I went to urgent care convinced my own heart was about to give way. Night after night these physical symptoms prevented me from sleeping.Graced by many loving connections with my siblings, my boyfriend, and close friends, I was actually weathering the process as well as one can. My PI gave me a firm directive to take as much time off as I needed. These were two key elements early in my healing process: a supportive network and an understanding advisor. The third was getting professional help, which I soon realized I needed. Even if I felt OK one day, I didn’t trust that I’d be OK the next. My grief formed too thick and too broad a landscape for me to navigate without help.Deciding to seek mental health resources and realizing that one needs them are often the hardest parts. Connecting with those resources once the decision has been made should be as simple as possible. I called a mental health number, and a triage counselor noted my therapy needs and verified my insurance. She asked what times and locations I preferred and then searched for an open appointment with a therapist who accepted my insurance. She also informed me that my coverage allowed 12 sessions with no copay, which was a pleasant surprise. The therapist who agreed to see me had very few openings, in part because this all happened in December—the holidays are especially busy for therapists. I was aiming for a time after normal working hours, or in the morning before I would head to lab, but none of those times were available. I didn’t like interrupting my workday to trot off to therapy. Taking a long break once a week meant I couldn’t run experiments or mentor my student during that time. But I made the sacrifice because my highest priority was getting the help I needed. There was no shortcut. Prioritizing mental health over lab work is tough for researchers, and I would never have accepted that kind of weekly disruption before my dad’s passing. But as a wonderful mentor of mine used to say, “You are the most valuable reagent in the lab.” She wasn’t describing mental health at the time, but the phrase now provided a guiding principle for my recovery. My first few sessions were on Tuesdays at 2:00 pm.The afternoon break turned out to be less disruptive than I had feared, because I had recently come back to the lab and was working short days. Had she asked, I would have told my PI where I was on Tuesday afternoons, but she wasn’t normally abreast of my daily schedule, so I didn’t seek her approval beforehand. Coordinating experiments with lab members thankfully wasn’t an issue because my work was largely independent; I simply let lab members know that I’d would be out of the lab for a bit on those days.The weeks went by, and the benefits of therapy accrued, helping me in large and small ways as I grieved. In mid-March of 2020, my therapist followed public health guidelines and asked all her clients to transition to remote sessions. While this was easy and sensible, it was still a little disappointing. Therapists are professional empaths, among many other things, and doing away with the physical presence and exchange with her was a blow. Yet therapy via video felt less odd simply because most of my social interactions were now virtual. Thankfully I didn’t have to move out of state for the lockdown (as did many students living in campus housing), which meant I could stay with the same therapist without any insurance complications.A few weeks into lockdown, I asked my therapist whether we had reached the limit of my 12 sessions without a copay. She replied with the good news that my insurance provider had waived all copays for mental health costs due to the pandemic. By that time therapy had generated a platform and an outlet to explore areas of my grief beyond the trauma of my father’s passing. Without needing to weigh the costs and benefits of this resource, I saw my therapist for another 4 months. I slowly took stock of my upbringing in an unconventional family and the loss of my mother when I was 25 and waded through a series of difficult decisions regarding my father’s estate. My father’s death changed me at a depth that is untouched by any amount of therapy or treatment. I’m not “healed”: I feel aged, more brittle, and a little ground down compared with who I had been. But therapy guided me through the worst of my grief, past the acute trauma to help me grasp what I was going through.Since the pandemic began, the number of people reporting increased stress or mental health issues has steadily increased (information on the impact of COVID-19 measures on mental health: https://www.apa.org/workforce/publications/depression-anxiety-coronavirus.pdf) (also see Mental health resources for trainees). I am fortunate to have affordable health insurance and the support from my lab and my department. The ease of finding my institution’s phone number for mental health resources was itself an important benefit. I share these pieces of my story with humility and understanding that not everyone enjoys the privileges that I do and the knowledge that everyone weathers life’s tragedies in their own way. It is not lost on me that some benefits stemmed from a policy change made by a private insurance provider. The provider made the right decision to waive copays, freeing me from having to choose between cost and my mental health needs. Yet had I been a student who had to move out of state due to COVID-19, access to mental health resources might have been disrupted or cut off. The need for reduced out-of-pocket costs for healthcare is known and needs no repetition, but the benefits of telehealth should be a low-cost component of health plans offered to students and staff (information on telehealth recommendations: https://www.apaservices.org/advocacy/news/congress-patient-telehealth?_ga=2.231013471.1538013741.1619359426-1228006513.1619359425 and http://www.apaservices.org/practice/advocacy/state/leadership/telebehavioral-health-policies.pdf?_ga=2.3385904.1067518037.1620039082-1228006513.1619359425.I’m not a cloud of emotions attached to a pair of good pipetting hands, I’m a human who is choosing to spend my time doing research. This observation is easy to repeat, by trainees as much as by faculty and administrators, but much harder to act upon in the midst of conflicting priorities. Consider my story a success: Because I could access the resources I needed, I was able to prioritize my mental health in the midst of my ambitious research program even during the lockdown.MEET THE AUTHORI have been a postdoc in Stefani Spranger’s lab at MIT for 4 years. Supported by an Irvington Fellowship from the Cancer Research Institute, my work examines the behaviors of dendritic cells in tumors that contribute to productive or unproductive anti-tumor immune responses. My doctoral work examined modes of multicellular invasion controlled by the actin cytoskeleton with Margaret Gardel at the University of Chicago. Earlier I was a lab technician with Thea Tlsty at the University of California, San Francisco, which followed a bachelor’s degree in biology at the University of California, Santa Cruz. I serve on the Committee for Students and Postdocs at the American Society for Cell Biology, where I chair the Outreach Subcommittee.  相似文献   

10.
I am incredibly honored to receive the 2021 WICB Junior Award for Excellence in Research in WICB’s golden jubilee year. In this essay, I traverse my scientific journey starting with my PhD, highlighting the highs and the lows and how these intersect with luck, privilege, and bias.

V. AnanthanarayananMy pursuit for a PhD started with a hiccup—I had applied to several places in the United States, but barely got any offers due to the economic upheaval that happened that year (2008). I had to forgo any dreams of a PhD in the United States and remained in Bangalore, India to complete a project I had started with William (Bill) Thies at Microsoft Research India on a programming language for expressing biology protocols. Applying to U.S. schools was an expensive task, one which I was unwilling to put my family through again. So, a year later, when I recommenced my search for a PhD position, I set my sights on Europe. I had heard about the PhD program at the Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG ) at Dresden from a friend who had just joined the institute for her PhD. Fortunately, I received an interview call from MPI-CBG. At the end of a crucial interview week at Dresden, I “matched” with Iva Tolic´’s (now Institut Ruđer Boškovic´, Croatia) lab for my PhD. At the start of my PhD, I knew next to nothing about the cytoskeleton, motor proteins, or microscopy, but I found Iva and my lab members to be some of the warmest and most welcoming people. I made friends for life and graduated with a PhD in Biophysics, with a thesis focused on understanding the regulation of the motor protein cytoplasmic dynein. I was lucky to have been able to get a position at MPI-CBG and join Iva’s lab—of the other three places in Europe I had applied to for a PhD, only one other institute invited me for an interview, which also proved to be unsuccessful.On completing my PhD in 2014, I didn’t quite know what I wanted to do. Due to personal reasons, I had to return to India and was open to options in both industry and academia. But with my training in motor protein and cytoskeleton research, I had some ideas for exploring scientific questions related to dynein activation. However, most labs I approached for a postdoctoral position were not open to a project that was outside the realm of their research focus. Nonetheless, Iva, Nenad Pavin (University of Zagreb), and Jonathon (Joe) Howard (Yale University), who were members of my thesis advisory committee, gave me the courage to continue in academia. In my naïveté, I went ahead and applied for the INSPIRE Faculty Fellowship, which is targeted at fresh PhDs and junior postdoctoral fellows to establish their own independent group at an Indian institute. To my surprise, I ended up getting the fellowship. The next issue was finding a host institute that was preferably in Bangalore, where my partner was based. I applied at a few different places, but only after I attended IndiaBioscience’s Young Investigator Meeting in 2014 did I get the chance to meet representatives of potential host institutes, including the Indian Institute of Science (IISc). After a couple of research seminars at IISc, my application was assessed and I was offered the position of INSPIRE Faculty Fellow at the newly formed Centre for BioSystems Science and Engineering, IISc.While I did not have any additional start-up funding, I was given the infrastructure and the independence to pursue my research program. It was slow and frustrating at the start, not unlike most starting labs. I always wondered if it might have been easier if I had had a regular postdoctoral stint. During this time, I also started recognizing how hard it was to be a woman in Indian academia. As a woman principal investigator, one’s authority, expertise, and ability are constantly called into question. Justifying your presence in academia on a daily basis is an exhausting task. I had a great mentor in Sandhya Visweswariah (IISc) who helped me navigate the system. I also had an extremely supportive partner, who kept me going through some of the worst times. Eventually, my lab and I landed on our feet (more about this in “My INSPIRE’d Journey”). Our research has been recognized with grants and awards, but one of the most rewarding parts of the job is seeing other lab members discovering the joy of science (I wrote about my approach to mentorship recently [https://www.nature.com/articles/s41580-020-0256-6]).Three years into the faculty fellowship, I was able to transition to an Assistant Professor position in the same institute. However, this did not change my experience as a young woman in Indian science, and the implicit and explicit biases continued. In 2020, I accepted a fantastic opportunity to further my lab’s science as an EMBL Australia Group Leader at the Single Molecule Science Node at UNSW Sydney and made the move during a pandemic. My lab’s research focus is in understanding how stochastic and rare events pertaining to cytoskeleton and motor proteins give rise to complexity in intracellular organization. With this theme as the essence of our research, we ask specific questions about motor protein regulation to effect differential cellular trafficking, mitochondria-microtubule interactions, and their role in mitochondrial dynamics, and we aim to determine barcodes of global organelle positioning in health and disease.I have the privilege of being able-bodied, born in an upper middle-class family to college-educated parents who were extremely supportive of my choices. I have also inordinately benefitted from the fact that I was born to an Indian ‘upper caste’ family. I therefore had an undue head start in life. These were circumstances beyond my control and yet played a huge role in how my story turned out. I was embarrassingly ignorant of the rampant misogyny in academia until I had to contend with explicit and implicit gender-based biases myself when I started my independent research group in India. Women make up ∼40% of science PhDs awarded in India but represent only ∼13% of Indian academia (biaswatchindia.com), highlighting the stark gender biases at play in creating a leaky pipeline. While I tried my best to voice my discontent and affect changes to create an equitable environment within my department and institute, it was slow work. In 2020, when the pandemic hit and all conferences and meetings went virtual, conference posters advertised on social media made it immediately apparent just how much women were underrepresented in Indian STEM conferences. So, I teamed up with Shruti Muralidhar (now a scientist at Deep Genomics, Canada) to found BiasWatchIndia, an initiative to document women representation and combat gender-biased panels in Indian STEM conferences.BiasWatchIndia has been in existence for a little over a year now—we have achieved several milestones, but there’s still so much to do. “Manels” (conferences that feature only men) are still as rampant as they were when we first started—40% of all Indian STEM conferences are manels. And while we have just about started to tackle the underrepresentation of women in Indian STEM, we are conscious of the intersectionality of bias with gender, caste, ableism, and socioeconomic background and aim to understand how best we can advocate for all minorities.People who are in power in academia and who oppose equity, diversity, and inclusion initiatives and instead preach merit and equality as the gold standard need to introspect, because when options and opportunities are offered without consideration to the millennia of oppression based on gender, race, and background, it is not promoting equality but upholding values that will continue to oppress underrepresented groups. Still, I am optimistic and hope to see real changes that will result in equity in academia in my lifetime.  相似文献   

11.
Sexual selection is believed to play a major role in speciation processes of cichlid fishes in the East African Great Lakes, in particular Lakes Malawi and Victoria, by driving diversification in male nuptial coloration. In Lake Tanganyika, a high rate of color pattern diversification is found in the genus Tropheus, where more than 100, mostly allopatric, color morphs have been described. Whether color pattern differentiation in Tropheus could follow from sexual selection as well, has not yet been conclusively shown. Unlike typical sexually selected species, Tropheus are sexually monomorphic, establish temporary pair bonds and spawn monogamously. Variance in mating success among individuals would still allow for sexual selection, but due to their high population census sizes, parentage data from natural populations are difficult to obtain. Simulations designed according to existing data on mating behavior in Tropheus suggested that variance in male reproductive success can be substantial and lead to levels of opportunity for selection, which are similar to values estimated, for example, from natural populations of sexually dimorphic songbirds. Variance in male success was mostly affected by the way females perceived and reacted to differences between males, and to a lesser extent by the duration of components of the reproductive cycles of males and females. These results indicate that future work on the importance of sexual selection in Tropheus should concentrate on mate choice cues and female mate choice behavior, but does not depend critically on the acquisition of more detailed life history data.  相似文献   

12.
Despite evidence that some individuals achieve both superiorreproductive performance and high survivorship, the factorsunderlying variation in individual quality are not well understood.The compensation and increased-intake hypotheses predict thatbasal metabolic rate (BMR) influences reproductive performance;if so, variation in BMR may be related to differences in individualquality. We evaluated whether BMR measured during the incubationperiod provides a proximate explanation for variation in individualquality by measuring the BMRs and reproductive performance ofLeach's storm-petrels (Oceanodroma leucorhoa) breeding on KentIsland, New Brunswick, Canada, during 2000 and 2001. We statisticallycontrolled for internal (body mass, breeding age, sex) and external(year, date, time of day) effects on BMR. We found that maleswith relatively low BMRs hatched their eggs earlier in the seasonand that their chicks' wing growth rates were faster comparedto males with relatively high BMRs. Conversely, BMR was notrelated to egg volume, hatching date, or chick growth rate forfemales or to lifetime (23 years) hatching success for eithersex. Thus, for males but not for females, our results supportthe compensation hypothesis. This hypothesis predicts that animalswith low BMRs will achieve better reproductive performance thananimals with high BMRs because they have lower self-maintenancecosts and therefore can apportion more energy to reproduction.These results provide evidence that intraspecific variationin reproductive performance is related to BMR and suggest thatBMR may influence individual quality in males.  相似文献   

13.
The deceptive Iris lutescens (Iridaceae) shows a heritable and striking flower colour polymorphism, with both yellow‐ and purple‐flowered individuals growing sympatrically. Deceptive species with flower colour polymorphism are mainly described in the family Orchidaceae and rarely found in other families. To explain the maintenance of flower colour polymorphism in I. lutescens, we investigated female reproductive success in natural populations of southern France, at both population and local scales (within populations). Female reproductive success was positively correlated with yellow morph frequency, at both the population scale and the local scale. Therefore, we failed to observe negative frequency‐dependent selection (NFDS), a mechanism commonly invoked to explain flower colour polymorphism in deceptive plant species. Flower size and local flower density could also affect female reproductive success in natural populations. Pollinator behaviour could explain the positive effect of the yellow morph, and our results suggest that flower colour polymorphism might not persist in I. lutescens, but alternative explanations not linked to pollinator behaviour are discussed. In particular, NFDS, although an appealingly simple explanation previously demonstrated in orchids, may not always contribute to maintaining flower colour polymorphism, even in deceptive species.  相似文献   

14.
ABSTRACT.   The epaulets of male Red-winged Blackbirds ( Agelaius phoeniceus ) are frequently cited as a sexually selected plumage ornament, but a number of laboratory and field studies provide little evidence that they are currently experiencing sexual selection. We used hair dye to dull epaulets of free-living territorial males prior to pair formation to determine if manipulated males experienced disadvantages in comparison with control males. We found no differences between control males and males with dulled epaulets in territorial behavior (territory size, song rate, trespass rate, and loss of territory), paternal care (time spent on territory and in antipredator sentinel behavior, and response to a model crow to simulate the threat of predation), pairing success (number of social mates), apparent reproductive success (numbers of nesting attempts, eggs/nest, nestlings/egg, and fledglings/nestling), or realized reproductive success (numbers of within-pair, extra-pair, and total fledglings as determined by DNA fingerprinting). We then used a meta-analysis of 11 published studies of Red-winged Blackbirds to determine if there is an overall effect of epaulet color or size on male-male competition, female choice, or reproductive success. Our results show that epaulet size has a small positive effect on male reproductive success, but epaulet color has no effect on male-male competition, female choice, and male reproductive success. One explanation for the seeming contradiction between studies that show that epaulets are necessary for territory defense and those that conclude that epaulets are not currently under selection is that epaulets serve as one of several cues of species recognition, especially among males at close range. An alternative explanation proposes counter-balancing intersexual advantages and intrasexual disadvantages of epaulet expression. Additional studies are needed to test these alternatives.  相似文献   

15.
Experiments     
In this article, I have provided a brief history of my life. After tracing my family background and my early interest in physical sciences, I discuss how I entered biology under the influence of Robert Emerson. I have always enjoyed doing experiments and this led to new measurements and analyses of chlorophyll unit, efficiency of photosynthesis, excitation energy transfer, delayed light emission, thermoluminescence and electroluminescence in photosynthetic organisms. It is my view that discoveries are made because we follow our scientific curiosities.This article was written at the invitation of Govindjee.  相似文献   

16.
Prohl  Heike 《Behavioral ecology》2002,13(2):175-181
In this study I examined the relationship among abundance ofreproductive resources, population density, and adult sex ratioin the strawberry dart-poison frog, Dendrobates pumilio, andhow these variables in turn influence the mating system, malereproductive success, and sexual selection. I studied the matingbehavior in two populations of D. pumilio living in a primaryand secondary rainforest on the Caribbean slope of Costa Rica.The abundance of tadpole-rearing sites (reproductive resourcesfor females) was approximately 10-fold higher in the secondary forest. Accordingly, the population density was higher and theadult sex ratio was strongly female biased in the secondaryforest, whereas the adult sex ratio was even in the primaryforest. The female-biased sex ratio was associated with a higherlevel of polygyny and higher male mating and reproductive successin the secondary forest. In contrast, the level of polyandrydid not differ between habitats. As expected, the opportunityfor sexual selection on male mating success was lower in thesecondary forest, the habitat with high female density. Inconclusion, my results suggest that ecological variables suchas resource availability have a great impact on the matingsystem and sexual selection through their effect on population structure. Moreover, the results of this study give furtherevidence that the opportunity for sexual selection is influencedby the adult sex ratio and hence by the operational sex ratioin a population.  相似文献   

17.
18.

Background

We used behavioural and genetic data to investigate the effects of density on male reproductive success in the zebrafish, Danio rerio. Based on previous measurements of aggression and courtship behaviour by territorial males, we predicted that they would sire more offspring than non-territorial males.

Results

Microsatellite analysis of paternity showed that at low densities territorial males had higher reproductive success than non-territorial males. However, at high density territorial males were no more successful than non-territorials and the sex difference in the opportunity for sexual selection, based on the parameter I mates, was low.

Conclusion

Male zebrafish exhibit two distinct mating tactics; territoriality and active pursuit of females. Male reproductive success is density dependent and the opportunity for sexual selection appears to be weak in this species.  相似文献   

19.

Background

Effective mating between laboratory-reared males and wild females is paramount to the success of vector control strategies aiming to decrease disease transmission via the release of sterile or genetically modified male mosquitoes. However mosquito colonization and laboratory maintenance have the potential to negatively affect male genotypic and phenotypic quality through inbreeding and selection, which in turn can decrease male mating competitiveness in the field. To date, very little is known about the impact of those evolutionary forces on the reproductive biology of mosquito colonies and how they ultimately affect male reproductive fitness.

Methods

Here several male reproductive physiological traits likely to be affected by inbreeding and selection following colonization and laboratory rearing were examined. Sperm length, and accessory gland and testes size were compared in male progeny from field-collected females and laboratory strains of Anopheles gambiae sensu stricto colonized from one to over 25 years ago. These traits were also compared in the parental and sequentially derived, genetically modified strains produced using a two-phase genetic transformation system. Finally, genetic crosses were performed between strains in order to distinguish the effects of inbreeding and selection on reproductive traits.

Results

Sperm length was found to steadily decrease with the age of mosquito colonies but was recovered in refreshed strains and crosses between inbred strains therefore incriminating inbreeding costs. In contrast, testes size progressively increased with colony age, whilst accessory gland size quickly decreased in males from colonies of all ages. The lack of heterosis in response to crossing and strain refreshing in the latter two reproductive traits suggests selection for insectary conditions.

Conclusions

These results show that inbreeding and selection differentially affect reproductive traits in laboratory strains overtime and that heterotic ‘supermales’ could be used to rescue some male reproductive characteristics. Further experiments are needed to establish the exact relationship between sperm length, accessory gland and testes size, and male reproductive success in the laboratory and field settings.  相似文献   

20.
To determine the fitness consequences of communal nesting inwhite-footed mice, Peromyscus leucopus, and deer mice, P. maniculalus,I compared the reproductive success of field populations offemales nesting solitarily, in communal groups of more thanone female, in extended families of successive litters, andin communal groups with extended families. Mean first littersize of weanlings and juveniles 6 weeks old did not differ significantlyfor pups raised under the four nesting situations. Similarly,for pups born into extended families, litter sizes of pups fromsecond litters did not differ significantly from those of firstlitters or from pups born to solitarily nesting females. Delayeddispersal of juvenile females did not result in resource competitionor inhibition of reproduction. Thus, reproductive success offemales was not significantly affected by additional membersin the nest. At least 26 of 28 communally nesting females wereclose relatives. Solitary nesting is the common breeding patternin Peromyscus, and extended families and communal nesting arealternative reproductive tactics in response to limited space,delayed dispersal, and local grouping among related females.  相似文献   

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