biologists-from-the-united-states

"Flowers are organized into concentric s of s, s, s and s, with each of these floral organ types having a unique role in ... Sepals enclose and protect the flower bud, while petals can be large and showy so as to attract s (or people!). Stamens produce pollen grains that contain male gametes, while the carpels contain the ovules that when fertilized will produce the seeds. While the size, shape, number and elaboration of each of these organ types can be quite different, the same general organization of four floral organ types arranged in concentric whorls exists across all species. As I shall explain in this Primer, the ‘ABC model’ is a simple and satisfying explanation for how this conserved floral architecture is genetically specified. What is the ABC model? The ABC model was first explicitly articulated in 1991, in a seminal paper by and . Although s affecting floral organ identity had been known for centuries, it was the systematic analyses of these mutations, and of the phenotypes produced by double and triple mutants, that proved to be critical in developing the ABC model."

"As a graduate student, I encountered a book that still inspires me: Classic Papers in Genetics edited by . Sadly, it is now out of print, but it is a wonderful compendium of many groundbreaking papers,starting with Mendel’s ‘Experiments in Plant Hybridization’. It also includes several papers by my scientific hero, , who figured out the principle of as an undergraduate, and whose papers are a model of clarity and careful reasoning. I also really enjoy reading Peters’ prefaces to each paper, which place each work in its scientific and historical context."

"entails the regulation of , cell expansion, and , and patterning of the organ as a whole. s are ideally suited to dissecting these processes. Petals are dispensable for growth and reproduction, enabling varied manipulations to be carried out with ease. In ', petals have a simple laminar structure with a small number of cell types, facilitating the analysis of organogenesis. This review summarizes recent studies that have illuminated some of the complex interplay between the s controlling petal specification, growth and differentiation in Arabidopsis. These advances, coupled with the advantages of using petals as a model , provide an excellent platform to investigate the underlying mechanisms driving plant organogenesis."

"I asked whether —applies to microbes. I conducted a synthesis of empirical studies that tested relationships among microbial traits presumed to define the competitive, stress tolerance and ruderal, and other ecological strategies. There was broad support for Grime's triangle. However, the ecological strategies were inconsistently linked to shifts in under environmental changes like nitrogen and phosphorus addition, warming, , etc. We may be missing important ecological strategies that more closely influence microbial community composition under shifting environmental conditions. We may need to start by documenting changes in microbial communities in response to environmental conditions at fine spatiotemporal scales relevant for microbes. We can then develop empirically based ecological strategies, rather than modifying those based on . Synthesis. Microbes appear to sort into similar ecological strategies as plants. However, these microbial ecological strategies do not consistently predict how community composition will shift under environmental change. By starting ‘from the ground up’, we may be able to delineate ecological strategies more relevant for microbes."

"Nitrogen (N) enrichment is an element of that could influence the growth and abundance of many s. In this , I synthesized responses of microbial to N additions in 82 published field studies. I hypothesized that the biomass of , bacteria or the microbial community as a whole would be altered under N additions. I also predicted that changes in biomass would parallel changes in soil CO2 emissions. Microbial biomass declined 15% on average under , but fungi and bacteria were not significantly altered in studies that examined each group separately. Moreover, declines in abundance of microbes and fungi were more evident in studies of longer durations and with higher total amounts of N added. In addition, responses of microbial biomass to N fertilization were significantly correlated with responses of soil CO2 emissions. There were no significant effects of biomes, fertilizer types, ambient N deposition rates or methods of measuring biomass. Altogether, these results suggest that N enrichment could reduce microbial biomass in many ecosystems, with corresponding declines in soil CO2 emissions."

"When trees build wood, is incorporated. It takes a long time to decompose ... It’s a smaller scale in . Some of the material they make can be almost woody. The is tough to decompose. The cell walls stay in the soil, microscopically. ... It adds up to a lot ... twice as much carbon in the soil as in the , and much of that is in [fungi]."

"In this commentary, I advocate for more detailed incorporation of in , to improve our projections of . Current Earth system models display relatively low predictability of stocks, which limit our ability to estimate future climate conditions. A more explicit incorporation of microbial mechanisms can increase the accuracy of ecosystem-scale models that inform the larger-scale Earth system models. Of the numerous microbial groups that can influence soil C dynamics, AM fungi are particularly tractable for integration in models. Arbuscular mycorrhizal fungi are globally abundant and perform critical roles in , such as augmentation of net and soil C storage. Moreover, AM communities exhibit relatively low diversity within ecosystems, compared to other microbial groups. In addition, global datasets of AM ecology are available for use in model development. Thus, AM communities can be readily simulated in next-generation trait-based models that link microbial diversity to ecosystem function. Altogether, we are well-poised to incorporate the dynamics of individual AM taxa in ecosystem models, which can then be coupled to Earth system models. Hopefully, these efforts would advance our ability to predict and plan for future climate change."

"in the late 1970s led to the discovery of at s. More recently, sulphide deposits containing . In addition to metal-rich ores, hydrothermal vents host ecosystems based on . Although there has been considerable effort to study the biology and ecology of vent systems in the decades since these systems were first discovered, there has been limited attention paid to conservation issues. Three priority recommendations for conservation science at hydrothermal vent settings are identified here: (i) determine the natural conservation units for key species with differing life histories; (ii) identify a set of first principles for the design of preservation reference areas and conservation areas; (iii) develop and test methods for effective mitigation and restoration to enhance the recovery of biodiversity in sulphide systems that may be subject to open-cut mining."

"ecosystems have stimulated decades of and hold promise of mineral and genetic resources that also serve societal needs. Some endemic taxa thrive only in vent environments, and vent-associated organisms are adapted to a variety of natural disturbances, from tidal variations to earthquakes and volcanic eruptions. In this paper, physicochemical and biological impacts of a range of human activities at vents are considered. , albeit at a local scale, based on our current understanding of ecological responses to disturbance. Natural recovery from a single mining event depends on immigration and larval recruitment and colonization; understanding processes and dynamics influencing life-history stages may be a key to effective minimization and mitigation of mining impacts. Cumulative impacts on of several mining projects in a single region, without proper management, include possible species extinctions and shifts in community structure and function."

"and their were discovered in 1977. While the hot-water springs were predicted to occur at s, no one expected to find them colonized by exotic invertebrate faunas. Accustomed to a view of the deep sea as a food-limited environment, the puzzle of how lush communities could be maintained provoked biologists into a flurry of research activity. ... As field programs multiplied and more vent communities were discovered, biogeographic patterns in the distribution of faunas became apparent and ecological issues of requirements, , and began to be addressed. associated with diverse settings, from and s to . Massive bacterial blooms triggered by the release of nutrients during a volcanic eruption, rapid colonization of new vents by invertebrates, and burial of extant vent communities by lava flows demonstrate the dynamic nature of hydrothermal systems. Perhaps the most provocative consequence of the discovery of seafloor hydrothermal vents is the ."

"You can go for hundreds of meters along the and see nothing. But then you’ll get to a and it will be a garden of exotic creatures. The vents are like the . The seawater percolates down through cracks caused by earthquakes, and then it comes up through these underwater chimneys. There are lots of ores there like copper, gold, silver, and s. There’s so much life there, and it’s very different from what we’re used to seeing. Whenever scientists go down, we almost always find new creatures."

"The transition to that launched the evolution of animals from marks one of the most pivotal, and poorly understood, events in . Advances in and , and particularly the study of s, are yielding new insights into the biology of the unicellular progenitors of animals. and gene families critical for animal development (including s and s) evolved in protozoa before the origin of animals. Innovations in and expansions of certain gene families may have allowed the integration of cell behavior during the earliest experiments with multicellularity. The protozoan perspective on animal origins promises to provide a valuable window into the distant past and into the cellular bases of animal development."

"s have a secret. While our research is motivated by a desire to reconstruct , it can also provide novel insights into fundamental cellular mechanisms in modern s. Studies of evolution reveal how the cell's component parts were “assembled” over time, how and why cells are vulnerable to disease and death, the molecular mechanisms that are responsible for fundamental cellular processes, and those mechanisms that distinguish the and of different lineages of organisms from each other. Studies of “evolutionary cell biology” promise to deepen our understanding of how cells function."

"... in the closing line of Darwin's ', he remarked on 'endless forms most beautiful', and he was referring to the incredible diversity of s ... much of his research and thinking had to with trying to understand: How do we get this diversity of s? And, there's been a great deal of progress in this regard, largely from the work of s, s, and s working together to try to understand what are molecular mechanistic underpinnings of the diversification of animal body plans. ... Animals are united by their shared ancestry. They all share a common ancestor … And, in fact, we know relatively little about the nature of that organism."

"Effects from small plastic debris and sorbed chemicals may not be additive and future research is needed to identify the nature of the risks from this combination of s. It is likely that the risk to an will vary by type and size of plastic debris, which may affect its ability to concentrate chemicals from ambient water ... and in s … Risks may also vary over space and time due to the concentration of hazardous chemicals available for ... and the length of time the debris has interacted with ambient water and sunlight. of plastic increases surface area, and may enable greater accumulation of hazardous chemicals. Such complexity begs the initiation of research programs and risk assessments that are ecologically relevant ..."

"The impact of , , and, to a lesser extent , on the structure of the of large is explored in one fossil and four Recent communities. Two aspects are emphasized: (1) the number of species within each guild and (2) the extent of locomotor convergence as inferred from morphology among the constituent species. Locomotor behavior reflects habitat choice, hunting mode, and escape strategy, all of which appear to be important avenues of adaptive divergence among coexisting predators."

"Despite the repeated tendency of s to evolve s for hypercarnivory, a canid has yet to appear that is completely catlike, that is, without any post- s. This possible constraint on morphological evolution in canids is argued to have resulted, paradoxically, in increased flexibility over evolutionary time and a great potential for rapid diversification and clade survivorship. Finally, it is suggested that the iterative pattern of specialization of the lower molars for meat-slicing that is seen in all families of carnivores, past and present, is probably a result of intraspecific competition for food, perhaps among s. This intraspecific selective force is countered by competition among species, since there are limits on the number of hypercarnivorous species within a single community."

"For decades we have learned about the physical hazards associated with in the , but recently we are beginning to realize the s. Assessing hazards associated with plastic in is not simple, and requires knowledge regarding s that may be exposed, the exposure concentrations, the types of s comprising the debris, the length of time the debris was present in the aquatic environment (affecting the size, shape and fouling) and the locations and transport of the debris during that time period. Marine plastic debris is associated with a ‘cocktail of chemicals’, including chemicals added or produced during manufacturing and those present in the marine environment that accumulate onto the debris from surrounding . This raises concerns regarding: (i) the complex mixture of chemical substances associated with marine plastic debris, (ii) the environmental fate of these chemicals to and from plastics in our oceans and (iii) how this mixture affects wildlife, as hundreds of species ingest this material in nature."

"Research on (small particles of plastic <5 in size) has long focused on their largest sink: the ocean. More recently, however, researchers have expanded their focus to include freshwater and terrestrial environments. This is a welcome development, given that an estimated 80% of microplastic pollution in the ocean comes from land ... and that rivers are one of the dominant pathways for microplastics to reach the oceans ... Like other , such as s (PCBs), microplastics are now recognized as being distributed across the globe. Detailed understanding of the fate and impacts of this ubiquitous environmental contaminant will thus require a concerted effort among scientists with expertise beyond the marine sciences."

"Eaton (1979) was one of the first biologists to promote the importance of among coexisting large s. In his review, he focused on interspecific interactions over carcasses and noted that larger carnivores tended to displace smaller ones from carcasses and that grouping behavior could reverse this relationship. He noted as well that interspecific battles over kills occurred and often resulted in injury or death to one of the participants. In a study of adaptations to coexistence among carnivores, Van Valkenburg (1985) pointed out the additional pressure of interspecific predation among carnivores, noting that both juveniles and adults are killed but not always eaten."

"Over the last decade, it has become indisputable that small plastic debris contaminates s and wildlife globally. Of concern is that this material, which is ingested by hundreds of species across multiple trophic levels, is associated with a complex mixture of hazardous chemicals. Models, laboratory exposures, and field studies have all demonstrated that plastic debris can act as a source for hazardous chemicals to bioaccumulate in animals. This has been demonstrated with several plastic types, including , (PVC), , and , and for several different organic chemicals, including s, s, , , and . What remains less certain is the ecological importance of this transfer, i.e., the relative contribution of plastic as a source of chemicals to wildlife relative to other sources. ... Further research is warranted to better understand the mechanisms by which plastic-associated contaminants transfer to organisms and if the chemicals are biomagnified in higher trophic level animals leading to ecological consequences or even human health effects via consumption of contaminated seafood."

"Each year—as a result of , automobiles, , , and tropical —humankind spews some 8 billion tons of , , and other carbon-based pollutants into the atmosphere. The net effect, as we all know, has been an alarming rise in air pollutants—particularly carbon dioxide, which has increased by more than a third, from 280 to 380 parts per million (ppm), since the onset of the industrial era. Equally distressing is that these emissions are accelerating, because countries like the United States have failed to rein their burgeoning emissions and because rapidly developing countries like China, India, and Brazil are increasingly adopting the energy-consumptive lifestyles of industrial nations. From 1800 to 1960, for example, the average annual increase in atmospheric carbon dioxide concentrations was just 0.2 ppm, but this jumped to 1.4 ppm from 1960 to 2000 and has since risen to 2.3 ppm."

"Passing by the mountain village of —a quaint, artsy town known for its Saturday tourist markets—the changed abruptly to open . Stately rainforest trees were replaced by s, s and s, with a ground layer of punctuated by large, oddly shaped . s and s, their flowers shaped like bottle-brushes, grew in dense clumps along a few meandering creeks."

"In the , alters forest–climate interactions in diverse ways. On a local scale (less than 1 ), elevated desiccation and wind disturbance near fragment margins lead to sharply increased tree mortality, thus altering dynamics, composition, dynamics and . Fragmented forests are also highly vulnerable to edge–related fires, especially in regions with periodic droughts or strong dry seasons. At landscape to regional scales (10–1000 km), habitat fragmentation may have complex effects on forest–climate interactions, with important consequences for atmospheric circulation, water cycling and precipitation. Positive feedbacks among , regional climate change and fire could pose a serious threat for some tropical forests, but the details of such interactions are poorly understood."

"s are the most biologically diverse and ecologically complex of terrestrial ecosystems, and are disappearing at alarming rates. It has long been suggested that rapid forest loss and degradation in the , if unabated, could ultimately precipitate a wave of species extinctions, perhaps comparable to mass extinction events in the geological history of the Earth. However, a vigorous debate has erupted following a study by Wright and Muller-Landau that challenges the notion of large-scale tropical extinctions, at least over the next century."

"Humankind has dramatically transformed much of the Earth’s surface and its natural ecosystems. This process is not new—it has been ongoing for millennia—but it has accelerated sharply over the last two centuries, and especially in the last several decades. Today, the loss and degradation of natural history can be likened to a war of attrition. Many natural ecosystems are being progressively razed, bulldozed, and felled by axes or chainsaws, until only small scraps of their original extent survive. Forests have been hit especially hard: the global area of forests have been reduced by roughly half over the past three centuries. Twenty-five nations have lost virtually all of their forest cover, and another 29 more than nine-tenths of their forest ( 2005)."

"affects cabbage cultivars grown for , storage, and fresh market. The disease is caused by the '. This fungus can cause serious losses in the field, in storage, and under transit and market conditions. S. sclerotiorum is widely distributed in relatively cool and moist areas throughout the world. The fungus has a wide host range and is known to attack over 360 species of plants. In the family alone, it has been recorded on 18 genera and 32 species. In the fungus is capable of infecting many types of vegetables and is particularly serious on s. It also infects weeds such as , , and wild clover.."

"Tomato anthracnose is a serious disease of processing es caused by the ' and is a threat to tomatoes grown in . To minimize the mold count in processed tomato products, processors impose a strict limit on the amount of anthracnose acceptable on the raw product. ... The fungus survives the winter as seedlike structures called and as threadlike strands called e in infested tomato debris. In late spring the lower leaves and fruit may become infected by germinating sclerotia and spores in the soil debris. Infections of the lower leaves of tomato plants are important sources of spores for secondary infections throughout the growing season. Senescent leaves with early s and leaves with injury are especially important spore sources because the fungus can colonize C. coccodes and produce new spores in these wounded areas."

"s have contested for possession of the waters much as the have contended for supremacy on land, until it may be said that the dominant forage crop of our lakes, ponds, and s is to be found among the pondweeds, the s. Variety in form, adaptability to , and diversity in range have all contributed their share in giving prominence in this group and in furthering a natural resource whose propagation and control are vital factors in the economic relations of the life of inland waters."

"Collections of fish were made at weekly intervals and, if not examined at once in their fresh condition, were kept in an - preserving fluid until needed. In examining the food the method of (1918) was employed, that is, the food content of the digestive tract was pressed out upon a , moistened, and examined under the dissecting and compound microscopes."

"... ', one of the largest of the , was produced in enormous quantity by natural means. The blue-green alga, , contributed directly to its support and proved to be the most desirable food of a heavy, natural culture of Daphnia pulex. The author's first observation of this association in the pond occurred on June 21, 1918. At this time a "bloom" of the Aphanizomenon was approaching it maximum. It was so abundant that the water appeared blue-green and oily. A few hand strokes of the net would bring up a of it in concentrated form."

"I had to be all things to all fishes."

"The only way that I will be in charge of this [lab] group is if you let me run it my way and there’s no interference from anyone."

"From the tiniest single-celled organisms to complex microbial communities, microbes hold immense scientific value and hold the secrets to the origins of life."

"I’ve made many mistakes in my time,” she told her lab team. I expect you to make mistakes. I expect you to tell me what those mistakes are so we can correct them."

"By studying microbes, we can gain insights into our own biological processes and potentially unlock new therapeutic approaches."

"Microbiology is a field where curiosity meets application, paving the way for meaningful scientific advancements."

"From the most remote landscapes to the depths of the ocean, microbes are everywhere."

"Microbes are the ultimate survivors, capable of thriving in some of the most extreme environments on Earth."

"The ability of microbes to adapt and evolve is unparalleled in the natural world."

"Microbes hold the key to solving many of our pressing global challenges, from disease eradication to sustainable agriculture."

"Microbes provide the foundation for all life on Earth."

"Microbes have been shaping the course of evolution since the beginning of life."

"Through the study of microbes, we can unlock the secrets of life itself."

"The study of microbes is a never-ending journey of discovery."

"Microbial communities are like intricate ecosystems, with each member playing a unique role."

"The evolution of life forms required billions of years for the first steps."

"The biodiversity of microbes far exceeds that of all other organisms combined."

"We must recognize the interconnectedness of all living things if we are to truly understand life."

"The central dogma of molecular biology: DNA makes RNA makes protein."