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1.
Orphanet J Rare Dis ; 18(1): 90, 2023 04 20.
Article in English | MEDLINE | ID: mdl-37081508

ABSTRACT

BACKGROUND: Patient-centered research has emerged as critically important for understanding the impact of treatments on key stakeholders. The subjective experience of quality of life (QOL) is increasingly recognized as fundamental to delineating treatment goals. The present study utilized content analysis of qualitative data and quantitative analysis to highlight important domains of disease burden and underlying reasons for their importance, and to characterize goals for new treatments for Duchenne Muscular Dystrophy (DMD). RESULTS: The study sample reflected the perspectives of DMD patients and caregivers representing ambulatory, transitional, and non-ambulatory stages of disability progression (n = 20 per category). Open-ended interviews were content-analyzed and non-parametric statistical tests were used to compare ambulation groups. As patients progressed in disability, the noted DMD burdens reflected some differences in functional areas. While daily functioning and sports/recreation remained the most important priority areas across ambulation groups, "health" became less prominent as the disability progressed from ambulatory to transitional to non-ambulatory phases of disability; whereas relationships became more prominent as one progressed to the non-ambulatory phase from the ambulatory or transitional phases (Kruskall Wallis H = 12.24 and 5.28, p = 0.002 and 0.02, respectively). When asked why their burdens were important to them and how it impacted their or their child's life, self-esteem/confidence was most important for ambulatory patients, and became less prominent for patients in the transitional and non-ambulatory phases of disability (Kruskall Wallis H = 9.46, p = 0.009). In contrast, independence was less important for ambulatory patients, and became increasing prominent for patients in the transitional and non-ambulatory phases of disability (Kruskall Wallis H = 7.35, p = 0.025). Emotional functioning was most prominent for all ambulation groups on their best and worst days. Goals for new DMD treatments focused on functional goals, general QOL goals, and concerns about safety, ease of use, and effectiveness. CONCLUSION: This study provides useful information about treatment goals for DMD from the perspective of patients and their caregivers. It highlights some consistent values across the disability trajectory, as well as introducing an evolution of priorities as the person with DMD becomes more disabled. Results provide a roadmap for patient-centered DMD drug development.


Subject(s)
Disabled Persons , Muscular Dystrophy, Duchenne , Patient-Centered Care , Child , Humans , Cost of Illness , Goals , Muscular Dystrophy, Duchenne/psychology , Muscular Dystrophy, Duchenne/therapy , Patient-Centered Care/methods , Quality of Life/psychology , Caregivers/psychology , Disease Progression , Disabled Persons/psychology
2.
J Med Entomol ; 60(1): 235-238, 2023 01 12.
Article in English | MEDLINE | ID: mdl-36394132

ABSTRACT

A variety of physiological, morphological, and behavioral changes occur throughout the life cycle of mosquitoes, which can be correlated with a shift from the aquatic to terrestrial environment. Aedes albopictus Skuse is an abundant invasive species from Asia that was introduced into the Americas in the 1980's and is responsible for transmitting several important human disease-causing pathogens. How physiological and anatomical changes within each instar and throughout the developmental stages are related to changes in carbon (C) and nitrogen (N) levels are an unexplored area of mosquito ecology. We hypothesized that these changes as well as stoichiometry (C:N) would vary with instar stage and larval diet. Cohorts of larvae were grown in three different diets: animal only (crickets), plant only (red maple leaves), and a mixture containing both types. Larval instars (1st-4th), pupae, and adults were raised in each diet and were separately analyzed for nutrient content (%C, %N) and stoichiometry (C:N). Significant changes in nutrient values occurred across the life cycle, with C:N values being lower in early instars versus adults or pupae, especially in animal only or mixed diets; few differences were detected in %C or %N across ontogeny. This knowledge may lead to a better understanding of mosquito ecology and pathogen transmission.


Subject(s)
Aedes , Culicidae , Humans , Animals , Aedes/physiology , Larva , Ecology , Diet , Nutrients
3.
J Pharm Pract ; 35(6): 874-878, 2022 Dec.
Article in English | MEDLINE | ID: mdl-33955282

ABSTRACT

BACKGROUND: The dramatic increase in the acquisition cost of injectable calcitonin led to creating a pharmacy-driven calcitonin protocol to improve the appropriate use of calcitonin and other treatment modalities for hypercalcemia. OBJECTIVE: This study aimed to characterize the use of calcitonin before and after implementation of a pharmacy-driven calcitonin protocol. METHODS: This was a multi-center, retrospective study of the use of injectable calcitonin in adult hospitalized patients with hypercalcemia. The study included patients treated with calcitonin from October 2014 to September 2016 and from October 2017 to September 2019. The primary outcomes were percentage of patients with a complete response, partial response, and non-responders. The secondary outcomes were time to relapse, duration of partial response, number of doses, and associated costs of calcitonin. RESULTS: Of the 131 patients included in this study, 93 were included in a pre-protocol group and 38 were included in a post-protocol group. The primary outcome of complete response by 3 days was met in 28% of patients in the pre-protocol group and 53% of patients in the post-protocol group (P = 0.007). Calcitonin spending in dollars in the pre-protocol group was $818,956 compared to $224,320 in the post-protocol group; a difference of $594,636. CONCLUSION: Implementation of a pharmacy-driven calcitonin protocol effectively improved calcium levels, reduced inappropriate calcitonin use, and reduced calcitonin spending during a period of 2 fiscal years.


Subject(s)
Calcitonin , Hypercalcemia , Pharmacy , Adult , Humans , Calcitonin/economics , Calcitonin/therapeutic use , Calcium/blood , Calcium-Regulating Hormones and Agents/genetics , Calcium-Regulating Hormones and Agents/therapeutic use , Hypercalcemia/diagnosis , Hypercalcemia/drug therapy , Retrospective Studies , Clinical Protocols
4.
Clin Gerontol ; 45(3): 681-695, 2022.
Article in English | MEDLINE | ID: mdl-34369313

ABSTRACT

OBJECTIVES: This study describes the person-centered experience and impact of symptoms and the treatment needs of dementia-related psychosis (DRP) from a patient and care partner perspective. METHODS: Qualitative interviews and a quantitative survey were used to collect patient experience data from persons with DRP or their care partners. RESULTS: Sixteen participants (1 person with DRP, 15 care partners) completed the qualitative interview; 212 participants (26 persons with DRP, 186 care partners) completed the quantitative survey. The most commonly reported symptoms were visual hallucinations, auditory hallucinations, persecutory delusions, and distortion of senses. The most common impacts were difficulty differentiating what is real from what is not real, increased anxiety, and effects on personal relationships. Current treatments were less than moderately helpful, and the ability to distinguish what is real from what is not real and overall symptom improvement were described as the most important benefits of an ideal treatment. CONCLUSIONS: Patient experience data provide insights into urgent therapeutic needs of patients by describing the nature, frequency, and severity of symptoms and the impacts they have on individuals' lives. CLINICAL IMPLICATIONS: Patient experience data demonstrate an unmet need for treatments to reduce the symptoms and impacts of DRP.


Subject(s)
Dementia , Psychotic Disorders , Delusions/diagnosis , Delusions/etiology , Delusions/therapy , Dementia/complications , Dementia/diagnosis , Dementia/therapy , Hallucinations/etiology , Hallucinations/therapy , Humans , Patient Outcome Assessment , Psychotic Disorders/complications , Psychotic Disorders/diagnosis , Psychotic Disorders/therapy
5.
Syst Med (New Rochelle) ; 3(1): 22-35, 2020.
Article in English | MEDLINE | ID: mdl-32226924

ABSTRACT

The First International Conference in Systems and Network Medicine gathered together 200 global thought leaders, scientists, clinicians, academicians, industry and government experts, medical and graduate students, postdoctoral scholars and policymakers. Held at Georgetown University Conference Center in Washington D.C. on September 11-13, 2019, the event featured a day of pre-conference lectures and hands-on bioinformatic computational workshops followed by two days of deep and diverse scientific talks, panel discussions with eminent thought leaders, and scientific poster presentations. Topics ranged from: Systems and Network Medicine in Clinical Practice; the role of -omics technologies in Health Care; the role of Education and Ethics in Clinical Practice, Systems Thinking, and Rare Diseases; and the role of Artificial Intelligence in Medicine. The conference served as a unique nexus for interdisciplinary discovery and dialogue and fostered formation of new insights and possibilities for health care systems advances.

7.
Nat Rev Drug Discov ; 19(2): 93-111, 2020 02.
Article in English | MEDLINE | ID: mdl-31836861

ABSTRACT

Most rare diseases still lack approved treatments despite major advances in research providing the tools to understand their molecular basis, as well as legislation providing regulatory and economic incentives to catalyse the development of specific therapies. Addressing this translational gap is a multifaceted challenge, for which a key aspect is the selection of the optimal therapeutic modality for translating advances in rare disease knowledge into potential medicines, known as orphan drugs. With this in mind, we discuss here the technological basis and rare disease applicability of the main therapeutic modalities, including small molecules, monoclonal antibodies, protein replacement therapies, oligonucleotides and gene and cell therapies, as well as drug repurposing. For each modality, we consider its strengths and limitations as a platform for rare disease therapy development and describe clinical progress so far in developing drugs based on it. We also discuss selected overarching topics in the development of therapies for rare diseases, such as approval statistics, engagement of patients in the process, regulatory pathways and digital tools.


Subject(s)
Drug Approval , Drug Development , Drug Repositioning/statistics & numerical data , Orphan Drug Production/statistics & numerical data , Rare Diseases/drug therapy , Humans
8.
Adv Ther ; 36(5): 997-1010, 2019 05.
Article in English | MEDLINE | ID: mdl-30879250

ABSTRACT

INTRODUCTION: The traditional model of evaluating treatments based primarily on primary outcome measures has stumbled in its application to rare disease. Rare disease clinical trials face the methodological challenges of small, heterogeneous patient populations and relatively few validated, disease-specific outcome measures. Incorporating qualitative research into rare disease clinical trials may help sponsors, regulators, payers, and prescribers to better understand the real-world and patient-specific impact of a potential therapy. This paper provides a methodologic overview of the use of Patient and Caregiver Perception of Change (PPC and CPC) Assessments utilizing patient and caregiver video interviews to complement the data captured by traditional endpoints in rare disease clinical trials. METHODS: Incorporating qualitative patient and caregiver video interviews into clinical trials allows for the rigorous capture of patient experiences and caregiver observations. Interview guides informed by input from key stakeholders provide the opportunity to solicit structured feedback on experiences before, during, and after the clinical trial. Patients and caregivers can complete their video interviews in a study mobile application, and interview transcripts are analyzed by independent coders. Themes are summarized by the treatment group and individual patient, which adds context to the clinical outcome measures of how patients feel and function, as well as elucidates the degree of change that is meaningful to patients and caregivers. The qualitative results can be compared to the data captured in clinical trials to assess data concordance. CONCLUSION: Capturing patient experience data with sufficient rigor allows it to contribute to the body of evidence utilized in regulatory, payer, and prescriber decision-making. Adding PPC and CPC Assessments to rare disease clinical trials offers an innovative and powerful way to tap into the unique insights of patients and their families to develop a fuller picture of the patient experience in the clinical trial. FUNDING: Stealth BioTherapeutics Inc.


Subject(s)
Caregivers/psychology , Clinical Trials as Topic/organization & administration , Patient Participation/psychology , Rare Diseases , Humans , Video Recording
9.
Ther Innov Regul Sci ; 52(2): 206-213, 2018 03.
Article in English | MEDLINE | ID: mdl-29714514

ABSTRACT

OBJECTIVE: To identify the elements necessary for successful collaboration between patient groups and academic and industry sponsors of clinical trials, in order to develop recommendations for best practices for effective patient group engagement. METHODS: In-depth interviews, informed by a previously reported survey, were conducted to identify the fundamentals of successful patient group engagement. Thirty-two respondents from 3 sectors participated: patient groups, academic researchers, and industry. The findings were presented to a multistakeholder group of experts in January 2015. The expert group came to consensus on a set of actionable recommendations for best practices for patient groups and research sponsors. RESULTS: Interview respondents acknowledged that not all patient groups are created equal in terms of what they can contribute to a clinical trial. The most important elements for effective patient group engagement include establishing meaningful partnerships, demonstrating mutual benefits, and collaborating as partners from the planning stage forward. Although there is a growing appreciation by sponsors about the benefits of patient group engagement, there remains some resistance and some uncertainty about how best to engage. Barriers include mismatched expectations and a perception that patient groups lack scientific sophistication and that "wishful thinking" may cloud their recommendations. CONCLUSIONS: Patient groups are developing diverse skillsets and acquiring assets to leverage in order to become collaborators with industry and academia on clinical trials. Growing numbers of research sponsors across the clinical trials enterprise are recognizing the benefits of continuous and meaningful patient group engagement, but there are still mindsets to change, and stakeholders need further guidance on operationalizing a new model of clinical trial conduct.


Subject(s)
Clinical Trials as Topic , Cooperative Behavior , Patient Participation , Biomedical Research , Drug Industry , Humans , Public-Private Sector Partnerships , Research Personnel , United States , United States Food and Drug Administration , Universities
10.
Proc Natl Acad Sci U S A ; 115(4): 732-737, 2018 01 23.
Article in English | MEDLINE | ID: mdl-29305556

ABSTRACT

Taxonomic diversity of benthic marine invertebrate shelf species declines at present by nearly an order of magnitude from the tropics to the poles in each hemisphere along the latitudinal diversity gradient (LDG), most steeply along the western Pacific where shallow-sea diversity is at its tropical maximum. In the Bivalvia, a model system for macroevolution and macroecology, this taxonomic trend is accompanied by a decline in the number of functional groups and an increase in the evenness of taxa distributed among those groups, with maximum functional evenness (FE) in polar waters of both hemispheres. In contrast, analyses of this model system across the two era-defining events of the Phanerozoic, the Permian-Triassic and Cretaceous-Paleogene mass extinctions, show only minor declines in functional richness despite high extinction intensities, resulting in a rise in FE owing to the persistence of functional groups. We hypothesize that the spatial decline of taxonomic diversity and increase in FE along the present-day LDG primarily reflect diversity-dependent factors, whereas retention of almost all functional groups through the two mass extinctions suggests the operation of diversity-independent factors. Comparative analyses of different aspects of biodiversity thus reveal strongly contrasting biological consequences of similarly severe declines in taxonomic diversity and can help predict the consequences for functional diversity among different drivers of past, present, and future biodiversity loss.


Subject(s)
Biodiversity , Classification/methods , Animals , Bivalvia/classification , Computer Simulation , Databases, Factual , Extinction, Biological , Fossils , Genetic Speciation , Geography , History, Ancient , Invertebrates , Models, Biological , Phylogeography/methods
11.
Am Nat ; 189(1): 1-12, 2017 Jan.
Article in English | MEDLINE | ID: mdl-28035884

ABSTRACT

An impediment to understanding the origin and dynamics of the latitudinal diversity gradient (LDG)-the most pervasive large-scale biotic pattern on Earth-has been the tendency to focus narrowly on a single causal factor when a more synthetic, integrative approach is needed. Using marine bivalves as a model system and drawing on other systems where possible, we review paleobiologic and biogeographic support for two supposedly opposing views, that the LDG is shaped primarily by (a) local environmental factors that determine the number of species and higher taxa at a given latitude (in situ hypotheses) or (b) the entry of lineages arising elsewhere into a focal region (spatial dynamics hypotheses). Support for in situ hypotheses includes the fit of present-day diversity trends in many clades to such environmental factors as temperature and the correlation of extinction intensities in Pliocene bivalve faunas with net regional temperature changes. Support for spatial dynamics hypotheses includes the age-frequency distribution of bivalve genera across latitudes, which is consistent with an out-of-the-tropics dynamic, as are the higher species diversities in temperate southeastern Australia and southeastern Japan than in the tropical Caribbean. Thus, both in situ and spatial dynamics processes must shape the bivalve LDG and are likely to operate in other groups as well. The relative strengths of the two processes may differ among groups showing similar LDGs, but dissecting their effects will require improved methods of integrating fossil data with molecular phylogenies. We highlight several potential research directions and argue that many of the most dramatic biotic patterns, past and present, are likely to have been generated by diverse, mutually reinforcing drivers.


Subject(s)
Biodiversity , Fossils , Phylogeny , Animals , Australia , Japan , Models, Theoretical
12.
J Vasc Surg ; 64(3): 692-7, 2016 Sep.
Article in English | MEDLINE | ID: mdl-27288103

ABSTRACT

OBJECTIVE: The Zenith (Cook Medical, Bloomington, Ind) fenestrated endovascular graft may be designed with single-wide scallops or large fenestrations to address the superior mesenteric artery (SMA). Misalignment of the SMA with an unstented scallop or a large fenestration is possible. This study assessed SMA outcomes after fenestrated endovascular aortic aneurysm repair (FEVAR). METHODS: During an 18-month period, 47 FEVARs were performed at a single institution. For analysis, patients were grouped according to unstented (n = 23) vs stented (n = 24) SMA scallops/fenestrations. The Institutional Review Board approved this single-institution observational study. Because this was a retrospective review of the data, patient consent was unnecessary for the study. RESULTS: Technical success for FEVAR was 100%. The median follow-up period was 7.7 months (range, 1-16 months). Nine of 21 patients (43%) in the unstented group had some degree of misalignment of the SMA (range, 9%-71%). Among these, four patients (44%) developed complications: three SMA stenoses and one occlusion. The mean peak systolic velocity in patients with and without SMA misalignment was 317.8 cm/s vs 188.4 cm/s (P < .08), respectively. No misalignment occurred in the stented group, and only one of 19 patients (5%) developed an SMA stenosis that required angioplasty. Overall, patients with unstented SMAs had significantly more adverse events directly attributable to SMA misalignment than the stented group (44% vs 5%, respectively; P < .05). CONCLUSIONS: Misalignment of the SMA with the use of unstented unreinforced scallops or fenestrations occurs frequently. Routine stenting of single-wide and large fenestrations, when feasible, may be a safer option for patients undergoing FEVAR.


Subject(s)
Aortic Aneurysm/surgery , Blood Vessel Prosthesis Implantation/adverse effects , Endovascular Procedures/adverse effects , Mesenteric Artery, Superior/surgery , Mesenteric Vascular Occlusion/etiology , Adult , Aged , Aged, 80 and over , Angioplasty , Aortic Aneurysm/diagnostic imaging , Blood Vessel Prosthesis , Blood Vessel Prosthesis Implantation/instrumentation , Blood Vessel Prosthesis Implantation/methods , Constriction, Pathologic , Endovascular Procedures/instrumentation , Endovascular Procedures/methods , Female , Humans , Male , Mesenteric Artery, Superior/diagnostic imaging , Mesenteric Vascular Occlusion/diagnostic imaging , Mesenteric Vascular Occlusion/therapy , Middle Aged , Prosthesis Design , Retrospective Studies , Stents , Texas , Time Factors , Treatment Outcome
14.
Bioorg Med Chem Lett ; 26(4): 1124-9, 2016 Feb 15.
Article in English | MEDLINE | ID: mdl-26821821

ABSTRACT

The central role of the biogenic monoamine serotonin (5-hydroxytryptamine, 5-HT) as a neurotransmitter with important cognitive and behavioral functions is well known. However, 5-HT produced in the brain only accounts for approximately 5% of the total amount of 5-HT generated in the body. At the onset of our work, it appeared that substituted phenylalanine derivatives or related aryl amino acids were required to produce potent inhibitors of TPH1, as significant losses of inhibitory activity were noted in the absence of this structural element. We disclose herein the discovery of a new class of TPH1 inhibitors that significantly lower peripherally 5-HT.


Subject(s)
Proline/analogs & derivatives , Tryptophan Hydroxylase/antagonists & inhibitors , Animals , Binding Sites , Brain/metabolism , Drug Design , Half-Life , Humans , Inhibitory Concentration 50 , Molecular Docking Simulation , Proline/chemical synthesis , Proline/pharmacokinetics , Protein Binding , Protein Structure, Tertiary , Rats , Serotonin/metabolism , Spiro Compounds/chemistry , Structure-Activity Relationship , Tryptophan Hydroxylase/metabolism
15.
Endocr Pract ; 22(6): 766, 2016 Jun.
Article in English | MEDLINE | ID: mdl-26720249
16.
Bioorg Med Chem Lett ; 25(22): 5352-6, 2015 Nov 15.
Article in English | MEDLINE | ID: mdl-26411795

ABSTRACT

A novel series of spirocyclic-diamine based, isoform non-selective inhibitors of acetyl-CoA carboxylase (ACC) is described. These spirodiamine derivatives were discovered by design of a library to mimic the structural rigidity and hydrogen-bonding pattern observed in the co-crystal structure of spirochromanone inhibitor I. The lead compound 3.5.1 inhibited de novo lipogenesis in rat hepatocytes, with an IC50 of 0.30 µM.


Subject(s)
Acetyl Coenzyme A/metabolism , Acetyl-CoA Carboxylase/antagonists & inhibitors , Drug Discovery , Hepatocytes/drug effects , Spiro Compounds/chemistry , Spiro Compounds/pharmacology , Animals , Enzyme Activation/drug effects , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , Hepatocytes/enzymology , Humans , Inhibitory Concentration 50 , Models, Biological , Molecular Structure , Rats , Small Molecule Libraries/chemistry , Small Molecule Libraries/pharmacology
17.
Proc Natl Acad Sci U S A ; 112(16): 4903-8, 2015 Apr 21.
Article in English | MEDLINE | ID: mdl-25901312

ABSTRACT

Paleontological data provide essential insights into the processes shaping the spatial distribution of present-day biodiversity. Here, we combine biogeographic data with the fossil record to investigate the roles of parallelism (similar diversities reached via changes from similar starting points), convergence (similar diversities reached from different starting points), and divergence in shaping the present-day latitudinal diversity gradients of marine bivalves along the two North American coasts. Although both faunas show the expected overall poleward decline in species richness, the trends differ between the coasts, and the discrepancies are not explained simply by present-day temperature differences. Instead, the fossil record indicates that both coasts have declined in overall diversity over the past 3 My, but the western Atlantic fauna suffered more severe Pliocene-Pleistocene extinction than did the eastern Pacific. Tropical western Atlantic diversity remains lower than the eastern Pacific, but warm temperate western Atlantic diversity recovered to exceed that of the temperate eastern Pacific, either through immigration or in situ origination. At the clade level, bivalve families shared by the two coasts followed a variety of paths toward today's diversities. The drivers of these lineage-level differences remain unclear, but species with broad geographic ranges during the Pliocene were more likely than geographically restricted species to persist in the temperate zone, suggesting that past differences in geographic range sizes among clades may underlie between-coast contrasts. More detailed comparative work on regional extinction intensities and selectivities, and subsequent recoveries (by in situ speciation or immigration), is needed to better understand present-day diversity patterns and model future changes.


Subject(s)
Aquatic Organisms/classification , Biodiversity , Fossils , Oceans and Seas , Animals , Bivalvia/classification , Extinction, Biological , North America , Phylogeny , Temperature
18.
Ther Innov Regul Sci ; 49(5): 680-697, 2015 Sep.
Article in English | MEDLINE | ID: mdl-30227043

ABSTRACT

BACKGROUND: This study serves as a follow-up to a March 2012 analysis conducted by Frank Sasinowski that reviewed the quantum of effectiveness evidence that is required to secure FDA approval of therapies for rare diseases, or orphan drugs, from the 1983 enactment of the Orphan Drug Act through June 30, 2010. The current study was designed to determine, over the 4 years since the original study, how frequently FDA has required marketing applications of drugs for rare diseases to provide the conventional level of proof of effectiveness that is ordinarily expected for most drugs for prevalent diseases. METHODS: This study employed methods similar to the original analysis, identifying the noncancer orphan drugs approved as new chemical entities by relying on FDA's publicly available documents for drugs approved by FDA from July 1, 2010, to June 30, 2014. These materials were used to identify the basis for each drug's approval, and each approval was analyzed and classified. RESULTS: The results of this study show that for just over two-thirds of all noncancer orphan drugs approved between July 1, 2010, and June 30, 2014, FDA did not require the orphan drug applications to provide the conventional level of proof of effectiveness that is ordinarily expected for drugs for prevalent diseases. This is consistent with the results of the 2012 analysis. CONCLUSIONS: The findings further support that FDA has demonstrated extraordinarily reasonable flexibility in its review of certain applications for orphan drugs and reinforce the need for FDA and drug companies to better understand and discuss the various types of flexibility.

19.
PLoS One ; 9(7): e101494, 2014.
Article in English | MEDLINE | ID: mdl-25036112

ABSTRACT

Global patterns in the functional attributes of organisms are critical to understanding biodiversity trends and predicting biotic responses to environmental change. In the first global marine analysis, we find a strong decrease in functional richness, but a strong increase in functional evenness, with increasing latitude using intertidal-to-outer-shelf bivalves as a model system (N = 5571 species). These patterns appear to be driven by the interplay between variation in origination rates among functional groups, and latitudinal patterns in origination and range expansion, as documented by the rich fossil record of the group. The data suggest that (i) accumulation of taxa in spatial bins and functional categories has not impeded continued diversification in the tropics, and (ii) extinctions will influence ecosystem function differentially across latitudes.


Subject(s)
Animal Migration , Aquatic Organisms , Biodiversity , Bivalvia , Animals , Aquatic Organisms/classification , Bivalvia/classification , Models, Statistical
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