‘The History of Hindu Chemistry’ is one of the rare, important books published in twentieth century. Sir Prafulla Chandra Ray, the author of this book, who was a chemist by profession, has contributed greatly to the field of Rasashastra in his own style. The book in two volumes is in English and has achieved international recognition. The work became the cause of enlightening people specially, the Westerners about Indian Alchemy which, they were till then unaware of. In a way, ‘globalization’ of the concepts of Rasashastra has its starting point in the works of Sir P.C.Ray. The author has touched almost every area of Rasashastra of course, from the standpoint of modern Chemistry. A critical analysis of his contributions, the narration of the contents of the book are detailed in the paper.
Though Gauchers disease (G.D.), a lipid storage disease is most commonly encountered by the hematologist but we present a case of G.D. type-3 which is rare in Indian subcontinent.
A 36-year-old Hindu, Indian male patient presented with bony pain, kyphosis, dragging sensation in the abdomen, dementia and ptosis of the left eyelid for one year. Clinical examination and history pointed to be a lipid storage disease. Radiological examination showed bilateral necrosis of the neck of femur. A final diagnosis of G.D. type-3 with bilateral necrosis of the femur neck was reported after examining the bone marrow smears. Unfortunately, we were unable to do the enzyme study as the patient was lost in the follow-up.
G.D. type-3 with bilateral necrosis of femur neck is rare in our sub-continent. We are adding a new case to stress the importance of early recognition by clinical manifestation and finding of G.C. which is hallmark in the diagnosis of G.D.
From 1972 to 1979, a total of 3392 patients with endoscopically proven ulcers were seen, in six ethnic groups. The distribution was as follows: Africans 456 males, 182 females; Muslim Gujerati Indians 206 males, 60 females; Hindu Hindi 433 males; total North Indians 639 males, 195 females; Hindu Tamils 593 males, 184 females; Hindu Telegu 179 males, 46 females; total South Indians 872 males, 230 females, and Whites 465 males, 303 females. In the continent of India, it is predominantly the South Indians who suffer from duodenal ulcer. In Durban, the number of North Indians with duodenal ulcers approximates that of those from the South (North: South ratio 0.83). The first question raised by this study is that the protective factors in North Indians in India are not genetic, and are lost when they emigrate to Natal. This may be due to changes in diet. A seasonal analysis indicates that, for females, there is a striking Autumn and Winter predominance in all Indian groups, reaching 80% in Muslims and Telegus but not in African females (52.7%). The second question raised by this study is that protective factors must be sought which operate in Indian females in the Spring and Summer months. The third question emanating from this study is that duodenal ulcers (and ischaemic heart disease) appear to increase in times of dietary and social change. This occurred in the West from 1890 to 1960, and is still occurring in the Third World. The restoration of dietary fibre and unsaturated fat, and the possible adjustment to stress in the West since 1960, has been accompanied by a fall in the incidence of these diseases. A 'changing factors' theory of duodenal ulcers and ischaemic heart disease is proposed. These conditions fall when a 'plateau situation' is reached.
The family history of patients identified during incidence studies in Leicestershire were investigated and the prevalence and comparative risks calculated; 1254 patients aged 15 to 80 years were sent a questionnaire about their family history. All cases with a positive family history were reviewed and confirmed cases included in the study. In Europeans the standardised prevalence of Crohn's disease was 75.8/10(5) and that of ulcerative colitis 90.8/10(5). The prevalence of Crohn's disease among South Asians was 33.2/10(5) and that of ulcerative colitis 135/10(5). The prevalence of Crohn's disease in Europeans was significantly greater than that in Hindus (chi 2 = 16, p < 0.001), while the prevalence of ulcerative colitis was significantly lower in Europeans than Hindus (chi 2 = 27, p < 0.001) and Sikhs (chi 2 = 4.4, p < 0.05). The comparative risk of developing ulcerative colitis in first degree relatives of Europeans patients with ulcerative colitis was increased by approximately 15, but the risk of Crohn's disease was not increased. The comparative risk of developing Crohn's disease among first degree relatives of patients with Crohn's disease was increased by up to 35, the comparative risk of ulcerative colitis was approximately 3. The risk among relatives of South Asian patients with Crohn's disease was not increased, but the risk of ulcerative colitis to relatives of patients with ulcerative colitis was. This study supports the view that Crohn's disease and ulcerative colitis arise in people with a genetic predisposition and exposed to some, as yet unknown, environmental factor.
Plant chloroplast originated, through endosymbiosis, from a cyanobacterium, but the genomic legacy of cyanobacterial ancestry extends far beyond the chloroplast itself, and persists in organisms that have lost chloroplasts completely.
The complete genome sequences of cyanobacteria and of the higher plant Arabidopsis thaliana leave no doubt that the plant chloroplast originated, through endosymbiosis, from a cyanobacterium. But the genomic legacy of cyanobacterial ancestry extends far beyond the chloroplast itself, and persists in organisms that have lost chloroplasts completely.
Personalized energy (PE) is a transformative idea that provides a new modality for the planet’s energy future. By providing solar energy to the individual, an energy supply becomes secure and available to people of both legacy and non-legacy worlds, and minimally contributes to increasing the anthropogenic level of carbon dioxide. Because PE will be possible only if solar energy is available 24 hours a day, 7 day a week, the key enabler for solar PE is an inexpensive storage mechanism. HX (X = halide or OH−) splitting is a fuel-forming reaction of sufficient energy density for large scale solar storage but the reaction relies on chemical transformations that are not understood at the most basic science level. Critical among these are multielectron transfers that are proton-coupled and involve the activation of bonds in energy poor substrates. The chemistry of these three italicized areas is developed, and from this platform, discovery paths leading to new HX and H2O splitting catalysts are delineated. For the case of the water splitting catalyst, it captures many of the functional elements of photosynthesis. In doing so, a highly manufacturable and inexpensive method has been discovered for solar PE storage.
62 out of 68 acute psychosis patients who were initially recruited from the Bikaner Centre in 1982 for the Indian Council of Medical Research (ICMR) study on "phenomenology and natural history of acute psychosis" were assessed after completion of 10 years in 1992-93 on SCAAPS and PSE with the objective of studying the long term course and outcome of acute psychosis. The results show that 35 (56.45%) patients of acute brief episode of psychosis never had any psychotic illness during the course of follow-up. Remission was significantly better in the young, the unmarried, in those who belonged to the Hindu religion and in those who developed the full blown psychosis abruptly within 48 hours. Other sociodemographic, personal history variables, and symptomatology could not distinguish this remitted group from the rest of the patients.
Acute non-organic psychosis; phenomenology; outcome
The Pleistocene glacial cycles left a genetic legacy on taxa throughout the world; however, the persistence of genetic lineages that diverged during these cycles is dependent upon levels of gene flow and introgression. The consequences of secondary contact among taxa may reveal new insights into the history of the Pleistocene’s genetic legacy. Here, we use phylogeographic methods, using 20 nuclear loci from regional populations, to infer the consequences of secondary contact following divergence in the Mountain Chickadee (Poecile gambeli). Analysis of nuclear data identified two geographically-structured genetic groups, largely concordant with results from a previous mitochondrial DNA (mtDNA) study. Additionally, the estimated multilocus divergence times indicate a Pleistocene divergence, and are highly concordant with mtDNA. The previous mtDNA study showed a paucity of sympatry between clades, while nuclear patterns of gene flow show highly varied patterns between populations. The observed pattern of gene flow, from coalescent-based analyses, indicates southern populations in both clades exhibit little gene flow within or between clades, while northern populations are experiencing higher gene flow within and between clades. If this pattern were to persist, it is possible the historical legacy of Pleistocene divergence may be preserved in the southern populations only, and the northern populations would become a genetically diverse hybrid species.
Fertility pattern has some influence on health of mother and child as well as it can resist population growth.
A cross sectional study on fertility perception among married women of reproductive age group, was carried out in 3 blocks and 2 municipality areas of Howrah District of West Bengal, India, covering 12 villages and 4 wards, selected by stratified multistage random sampling, for a period of 6 months from April to September 2009. Two thousand married women were the respondents.
Respondents were mainly belonged to poor and below poverty line groups (86.7%), one third (33.4%) were illiterate and just literate group, 66.8% of the respondents belonged to Hindu by religion and 63.4% had history of teen age pregnancy and more than 50% of the respondents were married early (below 18 years). The study revealed that perception about age of marriage, interval between marriage and 1st pregnancy and spacing were incorrect in case of 45.8%, 37.6% and 23% of the respondents, respectively. 22.3% and 13.1% of the respondents had no proper idea regarding desired no of children and Family Planning methods, respectively and their knowledge varied with literacy status, age and religion. Majority (67.5%) of the study population received information about family planning methods from health personnel.
Correct Knowledge regarding different components of fertility among Eligible Couples to be enhanced by intervention through Information, Education and Communication (Interpersonal Communication and Mass Media).
Eligible couple; family planning methods; fertility
India is a country with enormous social and cultural diversity due to its positioning on the crossroads of many historic and pre-historic human migrations. The hierarchical caste system in the Hindu society dominates the social structure of the Indian populations. The origin of the caste system in India is a matter of debate with many linguists and anthropologists suggesting that it began with the arrival of Indo-European speakers from Central Asia about 3500 years ago. Previous genetic studies based on Indian populations failed to achieve a consensus in this regard. We analysed the Y-chromosome and mitochondrial DNA of three tribal populations of southern India, compared the results with available data from the Indian subcontinent and tried to reconstruct the evolutionary history of Indian caste and tribal populations.
No significant difference was observed in the mitochondrial DNA between Indian tribal and caste populations, except for the presence of a higher frequency of west Eurasian-specific haplogroups in the higher castes, mostly in the north western part of India. On the other hand, the study of the Indian Y lineages revealed distinct distribution patterns among caste and tribal populations. The paternal lineages of Indian lower castes showed significantly closer affinity to the tribal populations than to the upper castes. The frequencies of deep-rooted Y haplogroups such as M89, M52, and M95 were higher in the lower castes and tribes, compared to the upper castes.
The present study suggests that the vast majority (>98%) of the Indian maternal gene pool, consisting of Indio-European and Dravidian speakers, is genetically more or less uniform. Invasions after the late Pleistocene settlement might have been mostly male-mediated. However, Y-SNP data provides compelling genetic evidence for a tribal origin of the lower caste populations in the subcontinent. Lower caste groups might have originated with the hierarchical divisions that arose within the tribal groups with the spread of Neolithic agriculturalists, much earlier than the arrival of Aryan speakers. The Indo-Europeans established themselves as upper castes among this already developed caste-like class structure within the tribes.
A three-month sabbatical allowed a superficial overview of Indian medical history and practice. As in Western nations, cost is a major determinant of health care delivery in India; poverty and fiscal shortages, however, deny care to many. The education of Indian physicians is similar to that in Western nations and a high level of clinical competence is seen. However, physician compensation is woefully low by Western standards. India possesses its own indigenous medical systems, purported to be the oldest in the world and predating Hippocrates by several millenia. Most Indians are cared for by native practitioners whose medical techniques are intricately related to the Hindu and Islamic religions. Many of their herbal medicines have been assimilated into contemporary Western practice. Diseases unknown to us except by textbooks are commonly seen and effectively treated. On the other hand, Western diseases such as coronary arteriosclerosis are not uncommon in a land of massive overpopulation and malnutrition. The humbling aspect of this experience is the realization that medical practice dating back several millenia can be made more modern and carried out competently by contemporary physicians. A Western physician working in India finds an unparalleled variety of disease in a totally different medical-religious environment allowing him to reorganize his priorities and to rediscover himself in the world within which he lives.
Cerebrovascular manifestations are uncommon presentations of scorpion sting in the Indian subcontinent. A prospective study was carried out on 42 patients with scorpion sting in the intensive care unit (ICU) of the Institute of Medical Sciences, Banaras Hindu University, Varanasi-05, INDIA, during the period of May 2005 to October 2007. In all the patients detailed history, physical examination with a specific neurological examination and routine biochemical testing and fundus examination were done. Computerized tomography and magnetic resonance imaging were done in cases with neurological deficit. All these patients also underwent a complete hematological, rheumatologic and cardiovascular work-up for stroke. Cerebrovascular involvement was noted in three patients (7.15%). Hemorrhagic stroke was noted in two patients (4.77%) and thrombotic stroke was noted in one patient (2.39%). The mean time of presentation of neurological symptoms was 3 days. Contrary to world literature, there have been no reports of cranial nerve palsies or neuromuscular involvement in our series.
Disseminated intravascular coagulation; scorpion sting; stroke
The present study was conducted in the Urban Health centre, Muthialpet, Pondicherry covering a population of 40000 from July to October 2007 by using a predesigned and pretested proforma to find out the risk of diabetes in general population by using Indian Diabetes Risk Score. A total of 616 respondents were studied comprising 325(53%) females and 290(47%) males. Majority 518(85%) were Hindus. Of them, 380 (62 %) had studied up to higher secondary and above, 539 (87%) belonged to upper middle and upper socioeconomic class. A large number of the subjects 422(68%) were above 35 years of age. Most of the respondents 558(90.50%) indulged in mild to moderate physical activity. Again, 422 (68.50%) had no family history of diabetes mellitus, 315 (51%) individuals were in the overweight category (>25 BMI), and 261 (83%) of high Diabetic Risk Score individuals were overweight. It is observed that chances of high diabetic score increase with the increase in BMI. Prevalence of diabetes in the studied population were 51 (8.27%), out of that 39 (76%) had high (>60) IDRS score. The relationship between BMI and IDRS shows that if BMI increases from under weight (<18.50) to obesity (>30) chances of risk for diabetes also increases significantly.
Diabetes mellitus; Indian Diabetes Risk score; obesity; risk factors; urban area
ACHN-490 is a neoglycoside, or “next-generation” aminoglycoside (AG), that has been identified as a potentially useful agent to combat drug-resistant bacteria emerging in hospitals and health care facilities around the world. A focused medicinal chemistry campaign produced a collection of over 400 sisomicin analogs from which ACHN-490 was selected. We tested ACHN-490 against two panels of Gram-negative and Gram-positive pathogens, many of which harbored AG resistance mechanisms. Unlike legacy AGs, ACHN-490 was active against strains expressing known AG-modifying enzymes, including the three most common such enzymes found in Enterobacteriaceae. ACHN-490 inhibited the growth of AG-resistant Enterobacteriaceae (MIC90, ≤4 μg/ml), with the exception of Proteus mirabilis and indole-positive Proteae (MIC90, 8 μg/ml and 16 μg/ml, respectively). ACHN-490 was more active alone in vitro against Pseudomonas aeruginosa and Acinetobacter baumannii isolates with AG-modifying enzymes than against those with altered permeability/efflux. The MIC90 of ACHN-490 against AG-resistant staphylococci was 2 μg/ml. Due to its promising in vitro and in vivo profiles, ACHN-490 has been advanced into clinical development as a new antibacterial agent.
Study of the 620 Asian immigrants with tuberculosis notified in the Wandsworth area of south London between 1973 and 1988 showed a bimodal pattern of tuberculosis notifications: in 1977 there was a peak among Asians from East Africa, and in 1981 a peak among those from the Indian subcontinent. There was a mean lag time of five years between clinical presentation and immigration. Logit analysis showed that, although overall more men had tuberculosis than women, glandular tuberculosis was more common among women of all groups, and pulmonary tuberculosis was more common among Hindu women than Hindu men. Both subgroups of Asians had a substantially higher incidence of tuberculosis than white people, particularly at extrapulmonary sites. Hindus were also at a significantly greater risk of tuberculosis at all sites than Muslims (Hindu:Muslim risk ratio 5.5 for women and 3.7 for men). The increased susceptibility to tuberculosis of Hindus, particularly Hindu women, may be related to a culturally acquired immunodeficiency caused by vegetarianism and associated vitamin deficiency.
A health level 7 (HL7)-conformant data link to exchange information between the mainframe hospital information system (HIS) of our hospital and our home-grown picture archiving and communications system (PACS) is a result of a collaborative effort between the HIS department and the PACS development team. Based of the ability to link examination requisitions and image studies, applications have been generated to optimise workflow and to improve the reliability and distribution of radiology information. Now, images can be routed to individual radiologists and clinicians; worklists facilitate radiology reporting; applications exist to create, edit, and view reports and images via the internet; and automated quality control now limits the incidence of “lost” cases and errors in image routing. By following the HL7 standard to develop the gateway to the legacy system, the development of a radiology information system for booking, reading, reporting, and billing remains universal and does not preclude the option to integrate off-the-shelf commercial products.
One-third of public school students are racial and/or ethnic minorities. Yet only 14 per cent of teachers represent these groups. Frequently lost in broader debates concerning this disparity is the paradoxical contribution of the 1954 Brown v. Board of Education decision. Schools were mandated under Brown to desegregate the student body. But the law did not necessarily protect the jobs of black teachers and administrators. Using a unique database of court orders, we examine the impact of mandated desegregation on black teachers. Findings indicate regional differences. Mandated desegregation created conditions that resulted in decreases in the black teaching force in the South. The opposite occurred in the nonsouth, with mandated desegregation positively associated with increases (although small) in the black teaching force. Our findings suggest that the legacy of mandated desegregation may have created broader institutional conditions in which black and other minority teachers remain underrepresented in the teaching force.
Education; United States; policy; black teachers; desegregation; public schools
To document the tobacco industry's litigation strategy to impede tobacco control media campaigns.
Data were collected from news and reports, tobacco industry documents, and interviews with health advocates and media campaign staff.
RJ Reynolds and Lorillard attempted to halt California's Media Campaign alleging that the campaign polluted jury pools and violated First Amendment rights because they were compelled to pay for anti‐industry ads. The American Legacy Foundation was accused of violating the Master Settlement Agreement's vilification clause because its ads attacked the tobacco industry. The tobacco companies lost these legal challenges.
The tobacco industry has expanded its efforts to oppose tobacco control media campaigns through litigation strategies. While litigation is a part of tobacco industry business, it imposes a financial burden and impediment to media campaigns' productivity. Tobacco control professionals need to anticipate these challenges and be prepared to defend against them.
advertising; public policy, youth smoking prevention
When, as a condition of the Master Settlement Agreement (MSA) in 1998, US tobacco companies disbanded the Council for Tobacco Research and the Center for Indoor Air Research, they lost a vital connection to scientists in academia and the private sector. The aim of this paper was to investigate two new research projects funded by US tobacco companies by analysis of internal tobacco industry documents now available at the University of California San Francisco (San Francisco, California, USA) Legacy tobacco documents library, other websites and the open scientific literature. Since the MSA, individual US tobacco companies have replaced their industry‐wide collaborative granting organisations with new, individual research programmes. Philip Morris has funded a directed research project through the non‐profit Life Sciences Research Office, and British American Tobacco and its US subsidiary Brown and Williamson have funded the non‐profit Institute for Science and Health. Both of these organisations have downplayed or concealed their true level of involvement with the tobacco industry. Both organisations have key members with significant and long‐standing financial relationships with the tobacco industry. Regulatory officials and policy makers need to be aware that the studies these groups publish may not be as independent as they seem.
Today, an unprecedented volume of primary biodiversity data are being generated worldwide, yet significant amounts of these data have been and will continue to be lost after the conclusion of the projects tasked with collecting them. To get the most value out of these data it is imperative to seek a solution whereby these data are rescued, archived and made available to the biodiversity community. To this end, the biodiversity informatics community requires investment in processes and infrastructure to mitigate data loss and provide solutions for long-term hosting and sharing of biodiversity data.
We review the current state of biodiversity data hosting and investigate the technological and sociological barriers to proper data management. We further explore the rescuing and re-hosting of legacy data, the state of existing toolsets and propose a future direction for the development of new discovery tools. We also explore the role of data standards and licensing in the context of data hosting and preservation. We provide five recommendations for the biodiversity community that will foster better data preservation and access: (1) encourage the community's use of data standards, (2) promote the public domain licensing of data, (3) establish a community of those involved in data hosting and archival, (4) establish hosting centers for biodiversity data, and (5) develop tools for data discovery.
The community's adoption of standards and development of tools to enable data discovery is essential to sustainable data preservation. Furthermore, the increased adoption of open content licensing, the establishment of data hosting infrastructure and the creation of a data hosting and archiving community are all necessary steps towards the community ensuring that data archival policies become standardized.
Legacy data from natural history collections contain invaluable and irreplaceable information about biodiversity in the recent past, providing a baseline for detecting change and forecasting the future of biodiversity on a human-dominated planet. However, these data are often not available in formats that facilitate use and synthesis. New approaches are needed to enhance the rates of digitization and data quality improvement. Notes from Nature provides one such novel approach by asking citizen scientists to help with transcription tasks. The initial web-based prototype of Notes from Nature is soon widely available and was developed collaboratively by biodiversity scientists, natural history collections staff, and experts in citizen science project development, programming and visualization. This project brings together digital images representing different types of biodiversity records including ledgers , herbarium sheets and pinned insects from multiple projects and natural history collections. Experts in developing web-based citizen science applications then designed and built a platform for transcribing textual data and metadata from these images. The end product is a fully open source web transcription tool built using the latest web technologies. The platform keeps volunteers engaged by initially explaining the scientific importance of the work via a short orientation, and then providing transcription “missions” of well defined scope, along with dynamic feedback, interactivity and rewards. Transcribed records, along with record-level and process metadata, are provided back to the institutions. While the tool is being developed with new users in mind, it can serve a broad range of needs from novice to trained museum specialist. Notes from Nature has the potential to speed the rate of biodiversity data being made available to a broad community of users.
Natural History Museums; Biodiversity; Open Source; Museum Collections; Citizen Science; Digitization; Transcription
This paper examines the changing methods, underlying motives, clienteles and controversy surrounding posthumous commemorations of Lord Lister in Britain. The importance of the commemorations for professional identity formation continues throughout the twentieth century, but World War I appears as a turning point. The constituencies commemorating Lister change from broadly international, national and civic with an emphasis on fundraising, to more narrowly professional; the use of religious imagery is notable after the war in the debates in the 1920s; and as his students, so central to the creation and preservation of his image, die, the focus begins to shift from the man and his achievements, ‘the great benefactor of mankind’, to his legacy in the current state of subjects related to his work. The changing nature of the commemorations suggests that although Lister's precise position in the history of surgery is contentious today, his importance as an iconic figure in the history of the medical profession is secure.
Lister; commemoration; Royal Society; museum; Sir Henry Wellcome; centenaries
Ethnic minorities in Northern Thailand, often referred to as Hill Tribes, are considered an ideal model to study the different genetic impact of sex-specific migration rates expected in matrilocal (women remain in their natal villages after the marriage and men move to their wife's village) and patrilocal societies (the opposite is true). Previous studies identified such differences, but little is known about the possible interaction with another cultural factor that may potentially affect genetic diversity, i.e. linguistic differences. In addition, Hill Tribes started to migrate to Thailand in the last centuries from different Northern areas, but the history of these migrations, the level of genetic legacy with their places of origin, and the possible confounding effects related to this migration history in the patterns of genetic diversity, have not been analysed yet. Using both original and published data on the Hill Tribes and several other Asian populations, we focused on all these aspects.
Genetic variation within population at mtDNA is lower in matrilocal, compared to patrilocal, tribes. The opposite is true for Y-chromosome microsatellites within the Sino-Tibetan linguistic family, but Hmong-Mien speaking patrilocal groups have a genetic diversity very similar to the matrilocal samples. Population divergence ranges between 5% and 14% at mtDNA sequences, and between 5% and 36% at Y- chromosomes STRs, and follows the sex-specific differences expected in patrilocal and matrilocal tribes. On the average, about 2 men and 14 women, and 4 men and 4 women, are exchanged in patrilocal and matrilocal tribes every generation, respectively. Most of the Hill Tribes in Thailand seem to preserve a genetic legacy with their likely geographic origin, with children adoption probably affecting this pattern in one tribe.
Overall, the sex specific genetic signature of different postmarital habits of residence in the Hill Tribes is robust. However, specific perturbations related to linguistic differences, population specific traits, and the complex migratory history of these groups, can be identified. Additional studies in different populations are needed, especially to obtain more precise estimates of the migration parameters.
Both the parental legacy and current environmental conditions can affect offspring life histories; however, their relative importance and the potential relationship between these two influences have rarely been investigated. We tested for the interacting effects of parental and juvenile environments on the early life history of the marine fish Acanthochromis polyacanthus. Juveniles from parents in good condition were longer and heavier at hatching than juveniles from parents in poor condition. Parental effects on juvenile size were evident up to 29 days post-hatching, but disappeared by 50 days. Offspring from good condition parents had higher early survival than offspring from poor-condition parents when reared in a low-food environment. By contrast, parental condition did not affect juvenile survival in the high-food environment. These results suggest that parental effects on offspring performance are most important when poor environmental conditions are encountered by juveniles. Furthermore, parental effects observed at hatching may often be moderated by compensatory mechanisms when environmental conditions are good.
coral reef fish; environmental variability; food availability; parental effects; compensatory mechanisms; intergenerational interactions
The diversity of functional and life-history traits of organisms depends on adaptation as well as the legacy of shared ancestry. Although the evolution of traits in macro-organisms is well studied, relatively little is known about character evolution in micro-organisms. Here, we surveyed an ancient and ecologically important group of microbial plant symbionts, the arbuscular mycorrhizal (AM) fungi, and tested hypotheses about the evolution of functional and life-history traits. Variation in the extent of root and soil colonization by AM fungi is constrained to a few nodes basal to the most diverse groups within the phylum, with relatively little variation associated with recent divergences. We found no evidence for a trade-off in biomass allocated to root versus soil colonization in three published glasshouse experiments; rather these traits were positively correlated. Partial support was observed for correlated evolution between fungal colonization strategies and functional benefits of the symbiosis to host plants. The evolution of increased soil colonization was positively correlated with total plant biomass and shoot phosphorus content. Although the effect of AM fungi on infection by root pathogens was phylogenetically conserved, there was no evidence for correlated evolution between the extent of AM fungal root colonization and pathogen infection. Variability in colonization strategies evolved early in the diversification of AM fungi, and we propose that these strategies were influenced by functional interactions with host plants, resulting in an evolutionary stasis resembling trait conservatism.
arbuscular mycorrhizal fungi; functional traits; symbiosis; phylogenetic trait conservatism