Regional Distribution of 5-Methyltetrahydrofolate Dependent Dopamine-N-Methyl Transferase in Rat Brain and Its Presence in Human Brain

Since the introduction of the hypothesis that abnormal transmethylation of biogenic amines may be associated with mental illness, transmethylation processes have been shown to be important in the production of biologically active amine derivatives. Laduron has shown that dopamine can be N-methylated with an enzyme from rat brain that requires 5-methyltetrahydrofolic acid (5MTHF ) as a methyl donor. This study shows that the methylation reaction which produces epinine from dopamine is greatest with supernatant from homogenized caudate lobe as compared to the cerebellum, hippocampus, cortex, and raphe nucleus: the brains of male rats were dissected and homogenized, the supernatant was assayed for 5MTHF dependent dopamine-N-methyl transferase activity by incubation with dopamine and C14-5MTHF, separation of the catecholamines with alumina columns, counting radioactivity with a scintillation counter, and identification of epinine with Amberlite column chromatography. The medial forebrain bundle (DA containing neurons) and the raphe nucleus (5HT containing neurons) were lesioned. There was no significant change in enzyme activity in the caudate after these lesions. Human caudate tissue was assayed and found to have significant enzyme activity

Ecological selectivity and the evolution of mammalian substrate preference across the K-Pg boundary.

The Cretaceous-Paleogene (K-Pg) mass extinction 66 million years ago was characterized by a worldwide ecological catastrophe and rapid species turnover. Large-scale devastation of forested environments resulting from the Chicxulub asteroid impact likely influenced the evolutionary trajectories of multiple clades in terrestrial environments, and it has been hypothesized to have biased survivorship in favour of nonarboreal lineages across the K-Pg boundary. Here, we evaluate patterns of substrate preferences across the K-Pg boundary among crown group mammals, a group that underwent rapid diversification following the mass extinction. Using Bayesian, likelihood, and parsimony reconstructions, we identify patterns of mammalian ecological selectivity that are broadly similar to those previously hypothesized for birds. Models based on extant taxa indicate predominant K-Pg survivorship among semi- or nonarboreal taxa, followed by numerous independent transitions to arboreality in the early Cenozoic. However, contrary to the predominant signal, some or all members of total-clade Euarchonta (Primates + Dermoptera + Scandentia) appear to have maintained arboreal habits across the K-Pg boundary, suggesting ecological flexibility during an interval of global habitat instability. We further observe a pronounced shift in character state transitions away from plesiomorphic arboreality associated with the K-Pg transition. Our findings are consistent with the hypothesis that predominantly nonarboreal taxa preferentially survived the end-Cretaceous mass extinction, and emphasize the pivotal influence of the K-Pg transition in shaping the early evolutionary trajectories of extant terrestrial vertebrates.NS

Timing the extant avian radiation: The rise of modern birds, and the importance of modeling molecular rate variation

Unravelling the phylogenetic relationships among the major groups of living birds has been described as the greatest outstanding problem in dinosaur systematics. Recent work has identified portions of the avian tree of life that are particularly challenging to reconstruct, perhaps as a result of rapid cladogenesis early in crown bird evolutionary history (specifically, the interval immediately following the end-Cretaceous mass extinction). At face value this hypothesis enjoys support from the crown bird fossil record, which documents the first appearances of most major crown bird lineages in the early Cenozoic—in line with a model of rapid post-extinction niche filling among surviving avian lineages. However, molecular-clock analyses have yielded strikingly variable estimates for the age of crown birds, and conflicting inferences on the impact of the end-Cretaceous mass extinction on the extant bird radiation. This uncertainty has often been ascribed to a patchy avian fossil record, but the possibility of model misspecification in molecular divergence time analyses represents an important and relatively underexplored alternative hypothesis. Here, we highlight the necessity of further developing and using models that account for coordinated variation in rates of molecular evolution across a phylogeny (e.g. molecular early bursts) as a means of assessing support for a rapid post-Cretaceous radiation of crown birds. We discuss how relationships between life-history and substitution rates can mislead divergence time studies that do not account for directional changes in substitution rates over time, and suggest that these effects might have caused some of the variation in existing molecular date estimates for birds. We suggest multiple paths forward that could help resolve this and similar conflicts within other major eukaryotic clades.</jats:p

Recent divergence and lack of shared phylogeographic history characterize the diversification of neotropical savanna birds

Aim Neotropical savanna birds occur north and south of, but mostly not in the Amazon Basin, except for a few isolated savanna patches. Here, we investigate the phylogeography of 23 taxa of Neotropical savanna birds co-distributed across multiple isolated savanna patches to assess to what extent these species have a shared history of spatial diversification. We explore the role of the forested Amazon Basin as a vicariant barrier separating northern and southern populations, particularly focusing on the role of the coastal savannas of Amapa as a potential corridor of gene flow between northern and southern populations. Location Neotropical savannas. Taxon Aves. Method We employ 775 mtDNA samples of 24 co-distributed savanna bird taxa from all major savanna patches in South America to infer phylogeographic patterns. For this purpose, we use 24 genomic samples (UCEs) of a subset of 12 taxa in addition to the mtDNA samples to estimate timing of divergence across the Amazon Basin. We use phylogeographic concordance factors (PCF) to assess the level of phylogeographic congruence across co-distributed taxa. Finally, we assess to which level physical distance drives genetic structuring by estimating isolation-by-distance (IBD) effects. Results We find that although the study taxa generally do not share similar diversification patterns geographically, many have at least two distinct genetic groups, one north and one south of the Amazon Basin, that have only recently diverged. The timing of divergence between both areas is generally centered in the late Pleistocene, but somewhat variable, indicating there is no single vicariant event responsible for driving diversification. Main conclusions Variability in divergence times indicates that landscape processes have not led to shared phylogeographic responses, which indicates a relatively minor role for vicariance. Shallow divergences suggest that Neotropical grassland habitats may have recently been more connected or that gene flow has played an important role. We did not find evidence of a single dominant corridor of dispersal between savannas north and south of the forested Amazon Basin.Peer reviewe

Early Evolution of Modern Birds Structured by Global Forest Collapse at the End-Cretaceous Mass Extinction

The fossil record and recent molecular phylogenies support an extraordinary early-Cenozoic radiation of crown birds (Neornithes) after the Cretaceous-Paleogene (K-Pg) mass extinction [1–3 ]. However, questions remain regarding the mechanisms underlying the survival of the deepest lineages within crown birds across the K-Pg boundary, particularly since this global catastrophe eliminated even the closest stem-group relatives of Neornithes [4 ]. Here, ancestral state reconstructions of neornithine ecology reveal a strong bias toward taxa exhibiting predominantly non-arboreal lifestyles across the K-Pg, with multiple convergent transitions toward predominantly arboreal ecologies later in the Paleocene and Eocene. By contrast, ecomorphological inferences indicate predominantly arboreal lifestyles among enantiornithines, the most diverse and widespread Mesozoic avialans [5–7 ]. Global paleobotanical and palynological data show that the K-Pg Chicxulub impact triggered widespread destruction of forests [8, 9 ]. We suggest that ecological filtering due to the temporary loss of significant plant cover across the K-Pg boundary selected against any flying dinosaurs (Avialae [10 ]) committed to arboreal ecologies, resulting in a predominantly non-arboreal postextinction neornithine avifauna composed of totalclade Palaeognathae, Galloanserae, and terrestrial total-clade Neoaves that rapidly diversified into the broad range of avian ecologies familiar today. The explanation proposed here provides a unifying hypothesis for the K-Pg-associated mass extinction of arboreal stem birds, as well as for the post-K-Pg radiation of arboreal crown birds. It also provides a baseline hypothesis to be further refined pending the discovery of additional neornithine fossils from the Latest Cretaceous and earliest Paleogene.Also supported by:- a 50th Anniversary Prize Fellowship at the University of Bath.- a Smithsonian NMNH Deep Time Peter Buck Postdoctoral Fellowship.- NSF grants DGE-1650441 and DEB-1700786.</p

Genomic signature of an avian Lilliput Effect across the K-Pg Extinction

Survivorship following major mass extinctions may be associated with a decrease in body size-a phenomenon called the Lilliput Effect. Body size is a strong predictor of many life history traits (LHTs), and is known to influence demography and intrinsic biological processes. Pronounced changes in organismal size throughout Earth history are therefore likely to be associated with concomitant genome-wide changes in evolutionary rates. Here,we report pronounced heterogeneity in rates of molecular evolution (varying up to ∼20-fold) across a large-scale avian phylogenomic data set and show that nucleotide substitution rates are strongly correlated with body size and metabolic rate.We also identify potential body size reductions associated with the Cretaceous-Paleogene (K-Pg) transition, consistent with a Lilliput Effect in the wake of that mass extinction event.We posit that selection for reduced body size across theK-Pg extinction horizon may have resulted in transient increases in substitution rate along the deepest branches of the extant avian tree of life. This "hidden" rate acceleration may result in both strict and relaxed molecular clocks over-estimating the age of the avian crown group through the relationship between life history and demographic parameters that scale with molecular substitution rate. If reductions in body size (and/or selection for related demographic parameters like short generation times) are a common property of lineages surviving mass extinctions, this phenomenon may help resolve persistent divergence time debates across the tree of life. Furthermore, our results suggest that selection for certain LHTs may be associated with deterministic molecular evolutionary outcomes.</p

TEMPO AND MODE: USING GENOMIC, ANATOMICAL, AND LIFE-HISTORY DATA TO INTEGRATE THE MICRO- AND MACROEVOLUTION OF BIRDS

My research agenda as a Ph.D. Candidate has been primarily driven by a fascination with the boundary between micro- and macroevolution. While these intellectual domains are most commonly studied separately from of one another, I do not regard them as products of distinct phenomena; to me, they are different manifestations of the same underlying evolutionary processes. As such, I am motivated to understand the mechanisms linking microevolutionary processes to macroevolutionary patterns. Some of the questions that guide my research program include: What are the roles of evolutionary contingency and convergence in generating patterns of biodiversity? Why might certain modes of evolution predominate over others? What are the drivers and constraints on evolutionary change? Are there evolutionary ‘laws’? My first two dissertation chapters focus on evolutionary questions at relatively recent timescales. The most significant of these interests focuses on the biogeography and evolution of neotropical suboscine passerines, a speciose group of modern birds representing ~10% of living bird diversity. In particular, I focus on two South American avian clades, Cotingidae (Berv and Prum 2014), and Pipridae (forthcoming work, Berv et al 20xx), which are characterized by a fascinating diversity of plumages, vocalizations, and display behaviors. These works evaluate several hypotheses about the origins of diversity in the Amazonian and Andean regions of Latin America. While the first half of my dissertation reports on avian microevolution, I am also deeply fascinated by macroevolutionary patterns. Birds are one of the most broadly appreciated groups of living organisms, but the origins of modern birds are shrouded in mystery. After the Chicxulub asteroid struck the Yucután peninsula 66 million years ago (the K-Pg event), up to 75% of life on Earth was lost. It took millions of years for ecosystems to recover from this geologically instantaneous contingency. We know that at least a few early lineages of modern birds survived and rapidly diversified in the wake of this event—but how? My dissertation research in this area leverages advances in DNA sequencing to investigate the impact of the mass extinction on bird evolution. In one chapter, I worked with a team of researchers to construct a new phylogenetic framework for understanding bird diversification (Prum, Berv et al 2015). In my final chapter (Berv and Field 2018), I propose and evaluate a new hypothesis—that the K-Pg event drove a macroevolutionary shift in the rate of avian genome evolution

Supplementary Table 1

Life history data table formatted for input into the Coevol analytical software. Life history data were obtained from the AnAge senescence database Build 13 (De Magalhães, J.P. and Costa, J. 2009, Tacutu, R., Craig, T., et al. 2013). We collated the following data: (1) age at sexual maturity (days), (2) incubation time (days), (3) number of eggs laid per year, (4) mass at hatching (grams), (5) growth rate (1/days), (6), maximum recorded longevity (years), and (7) total metabolic rate (watts). Relative to the set of 198 avian taxa in (Prum, R.O., Berv, J.S., et al. 2015), when matching genera occurred in the AnAge database, we used averages at the genus level; otherwise, we used family-level averages. Body mass (grams, species average) data were collected from Dunning Jr, J.B. (1992). This yielded a data matrix with ~49% missing data overall (with no missing data for body mass)

SUPPLEMENTAL DATA: Genomic phylogeography of the White-crowned Manakin Pseudopipra pipra (Aves: Pipridae) illuminates a continental-scale radiation out of the Andes

SUPPLEMENTAL DATA FOR Genomic phylogeography of the White-crowned Manakin Pseudopipra pipra (Aves: Pipridae) illuminates a continental-scale radiation out of the Andes Author Affiliations: Jacob S. Berv (1,2,3), Leonardo Campagna (1,2), Teresa J. Feo (4), Ivandy Castro-Astor (5), Camila C. Ribas (6), Richard O. Prum (7), Irby J. Lovette (1,2) 1. Fuller Evolutionary Biology Program, Cornell Lab of Ornithology, 159 Sapsucker Woods Road, Ithaca, NY 14850, USA. 2. Department of Ecology and Evolutionary Biology, Cornell University, 215 Tower Road, Ithaca, NY 14853, USA. 3. Department of Ecology and Evolutionary Biology, and University of Michigan Museum of Paleontology, 1105 North University Avenue, Biological Sciences Building, Ann Arbor, MI 48109-1085, USA. 4. Department of Vertebrate Zoology, MRC-116, National Museum of Natural History, Smithsonian Institution, Washington, DC 20013, USA. 5. Department of Biology, City College of New York and CUNY Graduate Center, City University of New York, New York, NY 10031, USA 6. Coordenacão de Biodiversidade, Instituto Nacional de Pesquisas da Amazônia, Manaus, AM, Brazil 7. Department of Ecology and Evolutionary Biology, and Peabody Museum of Natural History, Yale University, New Haven, Connecticut, 06520, USA. Correspondence to Jacob S. Berv ([email protected]) LAST UPDATED 28 APRIL 2021 CODE WILL ALSO BE MADE AVAILABLE AT https://github.com/jakeberv The parent directory contains many data files related to the analyses presented in this manuscript. The top level file 'Pseudopipra_code.R' contains function definitions and code used for most of the analyses in this article. This code is annotated with descriptions throughout. Note that all files referenced within various subdirectories must be unzipped for the R code to work. Download "Supplemental Data.zip" to download the entire archive, or browse individual files for download. SEE README.TXT for additional informatio