Biology Commons^™

Seasonal Plasticity In Morphology And Metabolism Differs Between Migratory North American And Resident Costa Rican Monarch Butterflies, Ayşe Tenger-Trolander, Cole R. Julick, Wei Lu, Delbert André Green, Kristi L. Montooth, Marcus R. Kronforst

School of Biological Sciences: Faculty Publications

Environmental heterogeneity in temperate latitudes is expected to maintain seasonally plastic life-history strategies that include the tuning of morphologies and metabolism that support overwintering. For species that have expanded their ranges into tropical latitudes, it is unclear the extent to which the capacity for plasticity will be maintained or will erode with disuse. The migratory generations of the North American (NA) monarch butterfly Danaus plexippus lead distinctly different lives from their summer generation NA parents and their tropical descendants living in Costa Rica (CR). NA migratory monarchs postpone reproduction, travel thousands of kilometers south to overwinter in Mexico, and subsist …

Seasonal Plasticity In Morphology And Metabolism Differs Between Migratory North American And Resident Costa Rican Monarch Butterflies, Ayşe Tenger-Trolander, Cole R. Julick, Wei Lu, Delbert André Green, Kristi L. Montooth, Marcus R. Kronforst

School of Biological Sciences: Faculty Publications

Environmental heterogeneity in temperate latitudes is expected to maintain seasonally plastic life-history strategies that include the tuning of morphologies and metabolism that support overwintering. For species that have expanded their ranges into tropical latitudes, it is unclear the extent to which the capacity for plasticity will be maintained or will erode with disuse. The migratory generations of the North American (NA) monarch butterfly Danaus plexippus lead distinctly different lives from their summer generation NA parents and their tropical descendants living in Costa Rica (CR). NA migratory monarchs postpone reproduction, travel thousands of kilometers south to overwinter in Mexico, and subsist …

Evolution And Molecular Basis Of A Novel Allosteric Property Of Crocodilian Hemoglobin, Chandrasekhar Natarajan, Anthony V. Signore, Naim M. Bautista, Federico G. Hoffmann, Jeremy R.H. Tame, Angela Fago, Jay F. Storz

School of Biological Sciences: Faculty Publications

The extraordinary breath-hold diving capacity of crocodilians has been ascribed to a unique mode of allosterically regulating hemoglobin (Hb)-oxygenation in circulating red blood cells. We investigated the origin and mechanistic basis of this novel biochemical phenomenon by performing directed mutagenesis experiments on resurrected ancestral Hbs. Comparisons of Hb function between the common ancestor of archosaurs (the group that includes crocodilians and birds) and the last common ancestor of modern crocodilians revealed that regulation of Hb-O₂ affinity via allosteric binding of bicarbonate ions represents a croc-specific innovation that evolved in combination with the loss of allosteric regulation by ATP binding. …

Temperature Fluctuation Alters Optimal Predator Community Composition For Anticipated Biological Control, Amanda N. Laubmeier, Nusrat Tabassum, Brigitte Tenhumberg

School of Biological Sciences: Faculty Publications

Alongside pesticides and specialist predators, natural communities of generalist beetle and spider predators play an important role in suppressing agricultural pests. However, the predation pressure of natural communities can be unpredictable. Overall predation pressure is influenced by a dense network of potential intraguild interactions, which are further shaped by species traits and environmental factors. Understanding how these different influences combine to impact pest control is especially important in the context of changing global temperatures. Recent empirical studies have demonstrated that the foraging behavior of arthropod predators is influenced by an interaction between temperature and predator body size. To explore the …

Intraguild Predation Is Increased In Areas Of Low Prey Diversity In A Generalist Predator Community, Stella F Uiterwaal, Amber Squires, Bennett Grappone, Brian Dillard, Ariadne Castaneda, Sora L. Kim, John Delong

School of Biological Sciences: Faculty Publications

1. Niche differentiation and intraguild predation (IGP) can allow ecologically similar species to coexist, although it is unclear which coexistence mechanism predominates in consumer communities. Until now, a limited ability to quantify diets from metabarcoding data has precluded the use of sequencing data to determine the relative importance of these mechanisms.

2. Here, we pair a recent metabarcoding quantification approach with stable isotope analysis to examine diet composition in a wolf spider community.

3. We compare the prevalence of resource partitioning and IGP in these spiders and test whether factors that influence foraging performance, including individual identity, morphology, prey community …

Functionally Redundant Multimodal Predator Cues Elicit Changes In Prey Foraging Behavior, Fiona G. Shogren, Eileen Hebets, John Delong

School of Biological Sciences: Faculty Publications

Many prey species can assess the risk of predation from information acquired through different sensory systems. For many animals, this information is detected with sensory organs specialized for visual (sight) or chemical (smell or taste) stimuli. It is unclear; however, whether information acquired through multiple sensory systems is functionally redundant or interchangeable, especially if the message is the same. Here, we assess prey response to unimodal visual and chemical cues as well as multimodal (visual + chemical) cues. We specifically test if a foraging individual shows a stronger behavioral response to risk when they can perceive that risk through multimodal …

Predator Feeding Rates May Often Be Unsaturated Under Typical Prey Densities, Kyle E. Coblentz, Mark Novak, John Delong

School of Biological Sciences: Faculty Publications

Predator feeding rates (described by their functional response) must saturate at high prey densities. Although thousands of manipulative functional response experiments show feeding rate saturation at high densities under controlled conditions, it remains unclear how saturated feeding rates are at natural prey densities. The general degree of feeding rate saturation has important implications for the processes determining feeding rates and how they respond to changes in prey density. To address this, we linked two databases—one of functional response parameters and one on mass–abundance scaling—through prey mass to calculate a feeding rate saturation index. We find that: (1) feeding rates may …

Gene Regulatory Changes Underlie Developmental Plasticity In Respiration And Aerobic Performance In Highland Deer Mice, Rena M. Schweizer, Catherine M. Ivy, Chandrasekhar Natarajan, Graham R. Scott, Jay F. Storz, Zachary A. Cheviron

School of Biological Sciences: Faculty Publications

Phenotypic plasticity can play an important role in the ability of animals to tolerate environmental stress, but the nature and magnitude of plastic responses are often specific to the developmental timing of exposure. Here, we examine changes in gene expression in the diaphragm of highland deer mice (Peromyscus maniculatus) in response to hypoxia exposure at different stages of development. In highland deer mice, developmental plasticity in diaphragm function may mediate changes in several respiratory traits that influence aerobic metabolism and performance under hypoxia. We generated RNAseq data from diaphragm tissue of adult deer mice exposed to (1) life-long …

Longitudinal Variations In Antibody Responses Against Sars-Cov-2 Spike Epitopes Upon Serial Vaccinations, Dicle Yalcin, Sydney J. Bennett, Jared Sheehan, Amber J. Trauth, For Yue Tso, John T. West, Michael E. Hagensee, Alistair J. Ramsay, Charles Wood

School of Biological Sciences: Faculty Publications

The COVID-19 pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) impacted healthcare, the workforce, and worldwide socioeconomics. Multi-dose mono- or bivalent mRNA vaccine regimens have shown high efficacy in protection against SARSCoV- 2 and its emerging variants with varying degrees of efficacy. Amino acid changes, primarily in the receptor-binding domain (RBD), result in selection for viral infectivity, disease severity, and immune evasion. Therefore, many studies have centered around neutralizing antibodies that target the RBD and their generation achieved through infection or vaccination. Here, we conducted a unique longitudinal study, analyzing the effects of a three-dose mRNA vaccine …

Ecological Boundaries And Constraints On Viable Eco-Evolutionary Pathways [Pre-Print], Kyle E. Coblentz, John Delong

School of Biological Sciences: Faculty Publications

Evolutionary dynamics are subject to constraints ranging from limitations on what is physically possible to limitations on the pathways that evolution can take. One set of evolutionary constraints, known as ‘demographic constraints’, constrain what can occur evolutionarily due to the population demographic or population dynamical consequences of evolution leading to conditions that make populations susceptible to extinction. These demographic constraints can limit the strength of selection or rates of environmental change populations can experience while remaining extant and the trait values a population can express. Here we further hypothesize that the population demographic and population dynamical consequences of evolution also …

Metamorphosis Imposes Variable Constraints On Genome Expansion Through Effects On Development, R. Lockridge Mueller,, Clayton E. Cressler, R S. Schwartz, R A. Chong, M. Butler

School of Biological Sciences: Faculty Publications

Genome size varies ∼100,000-fold across eukaryotes and has long been hypothesized to be influenced by meta- morphosis in animals. Transposable element accumulation has been identified as a major driver of increase, but the nature of constraints limiting the size of genomes has remained unclear, even as traits such as cell size and rate of development co-vary strongly with genome size. Salamanders, which possess diverse metamorphic and non-metamorphic life histories, join the lung- fish in having the largest vertebrate genomes—3 to 40 times that of humans—as well as the largest range of variation in genome size. We tested 13 biologically-inspired hypotheses …

Viral Chemotaxis Of Paramecium Bursaria Altered By Algal Endosymbionts, Huy V.N. Ho, David Dunigan, Miranda E. Salsbery, Irina Agarkova, Zeina Al-Ameeli, James L. Van Etten, John Delong

School of Biological Sciences: Faculty Publications

Chemotaxis is widespread across many taxa and often aids resource acquisition or predator avoidance. Species interactions can modify the degree of movement facilitated by chemotaxis. In this study, we investigated the influence of symbionts on Paramecium bursaria’s chemotactic behavior toward chloroviruses. To achieve this, we performed choice experiments using chlorovirus and control candidate attractors (virus stabilization buffer and pond water). We quantified the movement of Paramecia grown with or without algal and viral symbionts toward each attractor. All Paramecia showed some chemotaxis toward viruses, but cells without algae and viruses showed the most movement toward viruses. Thus, the endosymbiotic …

Metamorphosis Imposes Variable Constraints On Genome Expansion Through Effects On Development, R. Lockridge Mueller, Clayton E. Cressler, R. S. Schwartz, R. A. Chong, M. A. Butler

School of Biological Sciences: Faculty Publications

Genome size varies ∼100,000-fold across eukaryotes and has long been hypothesized to be influenced by meta- morphosis in animals. Transposable element accumulation has been identified as a major driver of increase, but the nature of constraints limiting the size of genomes has remained unclear, even as traits such as cell size and rate of development co-vary strongly with genome size. Salamanders, which possess diverse metamorphic and non-metamorphic life histories, join the lung- fish in having the largest vertebrate genomes—3 to 40 times that of humans—as well as the largest range of variation in genome size. We tested 13 biologically-inspired hypotheses …

To What Extent Do Physiological Tolerances Determine Elevational Range Limits Of Mammals?, Jay F. Storz, Graham R. Scott

School of Biological Sciences: Faculty Publications

A key question in biology concerns the extent to which distributional range limits of species are determined by intrinsic limits of physiological tolerance. Here, we use common-garden data for wild rodents to assess whether species with higher elevational range limits typically have higher thermogenic capacities in comparison to closely related lowland species. Among South American leaf-eared mice (genus Phyllotis), mean thermogenic performance is higher in species with higher elevational range limits, but there is little among-species variation in the magnitude of plasticity in this trait. In the North American rodent genus Peromyscus, highland deermice (Peromyscus maniculatus) …

Modelling Pollinator And Nonpollinator Selection On Flower Colour Variation, Brigitte Tenhumberg, Agnes S. Dellinger, Stacey D. Smith

School of Biological Sciences: Faculty Publications

1. Flower colour variation is ubiquitous within and between populations, which is why it has long been a focal point for studies of natural selection. This body of work has uncovered a wide range of selective agents, including pollinators, herbivores, and various abiotic factors. Nevertheless, we lack an integrative framework for predicting the phenotypic outcome in terms of floral pigmentation when these forces act collectively and often in opposition. 2. We here present such a framework through a model that incorporates selection on pigmentation at the vegetative phase (i.e., through survival to reproduction) and at the flowering phase (i.e., on …

Intercontinental Comparisons Of Subterranean Host-Parasite Communities Using Bipartite Network Analyses, Altangerel Tsogtsaikhan Dursahinhan, Sebastian Botero-Cañola, Scott L. Gardner

Scott L. Gardner Publications

Rodents living in a subterranean ecotope face a unique combination of evolutionary and ecological pressures and while host species evolution may be driven by the selective pressure from the parasites they harbour, the parasites may be responding to the selective pressures of the host. Here we obtained all available subterranean rodent host-parasite records from the literature and integrated these data by utilizing a bipartite network analysis to determine multiple critical parameters to quantify and measure the structure and interactions of the organisms present in host-parasite communities. A total of 163 species of subterranean rodent hosts, 174 parasite species, and 282 …

Stochasticity Directs Adaptive Evolution Toward Nonequilibrium Evolutionary Attractors, John Delong, Clayton E. Cressler

School of Biological Sciences: Faculty Publications

Stochastic processes such as genetic drift may hinder adaptation, but the effect of such stochasticity on evolution via its effect on ecological dynamics is poorly understood. Here we evaluate patterns of adaptation in a population subject to variation in demographic stochasticity. We show that stochasticity can alter population dynamics and lead to evolutionary outcomes that are not predicted by classic eco-evolutionary modeling approaches. We also show, however, that these outcomes are governed by nonequilibrium evolutionary attractors— these are maxima in lifetime reproductive success when stochasticity keeps the ecological system away from the deterministic equilibrium. These NEEAs alter the path of …

The Consumption Of Viruses Returns Energy To Food Chains, John Delong, James L. Van Etten, Zeina Al-Ameeli, Irina Agarkova, David Dunigan

School of Biological Sciences: Faculty Publications

Viruses impact host cells and have indirect effects on ecosystem processes. Plankton such as ciliates can reduce the abundance of virions in water, but whether virus consumption translates into demographic consequences for the grazers is unknown. Here, we show that small protists not only can consume viruses they also can grow and divide given only viruses to eat. Moreover, the ciliate Halteria sp. foraging on chloroviruses displays dynamics and interaction parameters that are similar to other microbial trophic interactions. These results suggest that the effect of viruses on ecosystems extends beyond (and in contrast to) the viral shunt by redirecting …

Pathways Of Density Dependence And Natural Selection In Modern Humans, John Delong

School of Biological Sciences: Faculty Publications

Living things depend on a flow of energy and materials to grow, reproduce, and maintain their bodies. Populations are aggregations of individuals, so they too depend on resources. Humans use many fuels derived from the Earth’s photosynthetic energy, which in turn support a population that often occurs at unusually high densities for a mammal. Like most populations, growing human populations may experience negative feedbacks from population size unless the socio-economic system in which the population lives grows fast enough to maintain resource flows to individuals and to limit the downsides of high density. I map out a simple view of …

“Revisiting The Past”: A Redescription Of Physaloptera Retusa (Nemata, Physalopteridae) From Material Deposited In Museums And New Material From Amazon Lizards = “Revisitando O Passado”: Uma Redescrição De Physaloptera Retusa (Nemata, Physalopteridae) A Partir De Material Depositado Em Museus E Novo Material De Lagartos Amazônicos, Lílian Cristina Macedo, Yuri Willkens, Leandro Maurício Oliveira Da Silva, Scott Lyell Gardner, Francisco Tiago De Vasconcelos Melo, Jeannie Nascimento Dos Santos

Scott L. Gardner Publications

Abstract

Physaloptera Rudolphi, 1819 is a genus of nematodes that includes approximately 100 species parasitic in vertebrates around the world. From these, approximately 30 occur in the Neotropical region, with nine reported from neotropical reptiles. Physaloptera spp. are recognized by their distinct morphology of the apical end and characters of the reproductive system. However, despite the fact that the morphological characters for species diagnosis have been firmly established, we frequently find identification problems regarding poorly detailed descriptions and poorly preserved specimens. These may lead to taxonomic incongruencies. Physaloptera retusa (Rudolphi, 1819) is the most common species of the genus and …

Helminth And Protozoan Parasites Of Subterranean Rodents (Chordata, Mammalia, Rodentia) Of The World, Altangerel Tsogtsaikhan Dursahinhan, Daniel A. Kenkel, Scott Lyell Gardner

Scott L. Gardner Publications

Published studies and ten new unpublished records included herein reveal that approximately 174 species of endoparasites (helminths and protozoans) are known from 65 of 163 species of rodents that occupy the subterranean ecotope globally. Of those, 94 endoparasite species were originally described from these rodents. A total of 282 host-parasite associations are summarized from four major zoogeographic regions including Ethiopian, Palearctic/Oriental, Nearctic, and Neotropical. Thirty-four parasite records from the literature have been identified to only the level of the genus. In this summary, ten new records have been added, and the most current taxonomic status of each parasite species is …

Filling The Gap In Distribution Ranges And Conservation Status In Ctenomys (Rodentia: Ctenomyidae), Diego A. Caraballo, Sabrina Laura Lopez, Sebastian Botero-Cañola, Scott Lyell Gardner

Scott L. Gardner Publications

South American subterranean rodents of the genus Ctenomys (Rodentia, Ctenomyidae, tuco-tuco) are one of the most diverse genera among mammals. Recently described species, new taxonomic revisions, and new distribution range delimitation made the revision of distribution areas and conservation status of these mammals mandatory. Implementing the first part of the DAMA protocol (document, assess, monitor, act), here we compile updated sets of species distribution range maps and use these and the number of collection localities to assess the conservation status of ctenomyids. We integrate potential for conservation in protected areas, and levels of habitat transformation to revise previous conservation status …

Tapping Into Natural History Collections To Assess Latitudinal Gradients Of Parasite Diversity, Sebastian Botero-Cañola, Scott Lyell Gardner

Scott L. Gardner Publications

Parasites are key components of the biosphere not only due to their huge diversity, but also because they exert important influences on ecological processes. Nevertheless, we lack an understanding of the biogeographical patterns of parasite diversity. Here, we tap into the potential of biodiversity collections for understanding parasite biogeography. We assess species richness of supracommunities of helminth parasites infecting mammal assemblages in the Nearctic, and describe its relation to latitude, climate, host diversity, and land area. We compiled data from parasitology collections and assessed parasite diversity in Nearctic ecoregions for the entire parasite supracommunity of mammals in each ecoregion, as …

A New Species Of Mathevotaenia (Cestoda: Anoplocephalidae) From The Andean Tuco-Tuco, Ctenomys Opimus (Rodentia: Ctenomyidae), On The Altiplano Of Bolivia, Scott Lyell Gardner, Bennett A. Grappone, Alex Lai

Scott L. Gardner Publications

A new species of Mathevotaenia Akumyan, 1946 (Cestoda: Anoplocephalidae) is described from the Andean tuco-tuco, Ctenomys opimus Wagner 1848 (Rodentia: Ctenomyidae), collected in 1984 on the Altiplano of Bolivia. This is the second species of anoplocephalid cestode recorded from rodents of the genus Ctenomys, the first being Monoecocestus torresi Olsen 1976 from the Maule tuco-tuco, Ctenomys maulinus Philippi 1872, documented in southwestern Argentina. The new species of Mathevotaenia described here has more testes per segment than any other described species of the same genus from South America. The description of a new species from a decades-old specimen highlights the …

Antibody Epitope Profiling Of The Kshv Lana Protein Using Virscan, Sydney J. Bennett, Dicle Yalcin, Sara R. Privatt, Owen Ngalamika, Salum J. Lidenge, John T. West, Charles Wood

School of Biological Sciences: Faculty Publications

The humoral antibody response against Kaposi sarcoma-associated herpesvirus (KSHV) in infected individuals has been characterized demonstrating the latency-associated nuclear antigen (LANA) as the most antigenic KSHV protein. Despite the antigenicity of the protein, specific LANA epitopes have not been systematically characterized. Here, we utilized a bacteriophage T7 library, which displays 56-amino acid KSHV LANA peptides with 28-amino acid overlap (VirScan), to define those epitopes in LANA targeted by antibodies from a cohort of 62 sub-Saharan African Kaposi sarcoma (KS) patients and 22 KSHV-infected asymptomatic controls. Intra- and inter-patient breadth and magnitude of the anti-LANA responses were quantified at the peptide …

Droughts Reduce Growth Rates And Increase Vulnerability To Increasingly Frequent And Severe Drying Events In An Aquatic Ectotherm, Thomas M. Luhring, Lyndsie S. Wszola, Grant M. Connette, Christopher M. Schalk

School of Biological Sciences: Faculty Publications

Many aquatic organisms are experiencing increasingly severe and frequent droughts and drying events. Simultaneously, drought effects are carrying over to non-drought years as ecosystems remain in incomplete states of recovery. Aquatic organisms are thus faced with fewer sequential years under degraded environmental conditions to prepare for increasingly severe droughts and potential drying events. We assessed the effect of droughts and sex on the growth, mass, and mass-dependent estivation potential of long-lived aquatic salamanders (Greater Sirens, Siren lacertina) that estivate during drying events brought on by severe droughts. We calculated growth rates of S. lacertina based on mark–recapture data spanning …

Droughts Reduce Growth Rates And Increase Vulnerability To Increasingly Frequent And Severe Drying Events In An Aquatic Ectotherm, Thomas M. Luhring, Lyndsie S. Wszola, Grant M. Connette, Christopher M. Schalk

School of Biological Sciences: Faculty Publications

Many aquatic organisms are experiencing increasingly severe and frequent droughts and drying events. Simultaneously, drought effects are carrying over to nondrought years as ecosystems remain in incomplete states of recovery. Aquatic organisms are thus faced with fewer sequential years under degraded environmental conditions to prepare for increasingly severe droughts and potential drying events. We assessed the effect of droughts and sex on the growth, mass, and mass-dependent estivation potential of long-lived aquatic salamanders (Greater Sirens, Siren lacertina) that estivate during drying events brought on by severe droughts. We calculated growth rates of S. lacertina based on mark–recapture data spanning …

Social Networks And Instructional Reform In Stem: The Teaching‑Research Nexus, John Skvoretz, Katherine Kappelman, Ariel Marcy, Jacob D. Mcalpin, Jennifer E. Lewis, John P. Ziker, Karl Mertens, Brittnee Earl, Susan E. Shadle, Brian A. Couch, Stephanie Feola, Luanna B. Prevost, A. Kelly Lane, Blake Whitt, Marilyne Stains

School of Biological Sciences: Faculty Publications

Instructional reform in STEM aims for the widespread adoption of evidence based instructional practices (EBIPS), practices that implement active learning. Research recognizes that faculty social networks regarding discussion or advice about teaching may matter to such efforts. But teaching is not the only priority for university faculty – meeting research expectations is at least as important and, often, more consequential for tenure and promotion decisions. We see value in understanding how research networks, based on discussion and advice about research matters, relate to teaching networks to see if and how such networks could advance instructional reform efforts. Our research examines …

Context And Content Of Teaching Conversations: Exploring How To Promote Sharing Of Innovative Teaching Knowledge Between Science Faculty, A. Kelly Lane, Brittnee Earl, Stephanie Feola, Jennifer E. Lewis, Jacob D. Mcalpin, Karl Mertens, Susan E. Shadle, John Skvoretz, John P. Ziker, Marilyne Stains, Brian A. Couch, Luanna B. Prevost

School of Biological Sciences: Faculty Publications

Background: Change strategies may leverage interpersonal relationships and conversations to spread teaching innovations among science faculty. Knowledge sharing refers to the process by which individuals transfer information and thereby spread innovative ideas within an organization. We use knowledge sharing as a lens for identifying factors that encourage productive teaching-related conversations between individuals, characterizing the context and content of these discussions, and understanding how peer interactions may shape instructional practices. In this study, we interview 19 science faculty using innovative teaching practices about the teaching-focused conversations they have with different discussion partners.

Results: This qualitative study describes characteristics of …

Late Quaternary Biotic Homogenization Of North American Mammalian Faunas, Danielle Fraser, Amelia Villaseñor, Anikó B. Tóth, Meghan A. Balk, Jussi T. Eronen, W. Andrew Barr, A. K. Behrensmeyer, Matt Davis, Andrew Du, J. Tyler Faith, Gary R. Graves, Nicholas J. Gotelli, Advait M. Jukar, Cindy V. Looy, Brian J. Mcgill, Joshua H. Miller, Silvia Pineda-Munoz, Richard Potts, Alex B. Shupinski, Laura C. Soul, S. Kathleen Lyons

School of Biological Sciences: Faculty Publications

Biotic homogenization—increasing similarity of species composition among ecological communities—has been linked to anthropogenic processes operating over the last century. Fossil evidence, however, suggests that humans have had impacts on ecosystems for millennia. We quantify biotic homogenization of North American mammalian assemblages during the late Pleistocene through Holocene (~30,000 ybp to recent), a timespan encompassing increased evidence of humans on the landscape (~20,000–14,000 ybp). From ~10,000 ybp to recent, assemblages became significantly more homogenous (>100% increase in Jaccard similarity), a pattern that cannot be explained by changes in fossil record sampling. Homogenization was most pronounced among mammals larger than 1 …