Did Mammals Bring the First Mistletoes into the Treetops?
Abstract AbstractThe growth habit of mistletoes, the only woody, parasitic plants to infect host canopies, represents a key innovation. How this aerially parasitic habit originated is unknown; mistletoe macrofossils are relatively recent, from long after they adapted to canopy life and evolved showy, bird-pollinated flowers; sticky, bird-dispersed seeds; and woody haustoria diverting water and nutrients from host branches. Since the transition to aerial parasitism predates the origin of mistletoes' contemporary avian seed dispersers by 20-40 million years, this leaves unanswered the question of who the original mi...
Source: The American Naturalist - November 21, 2020 Category: Biology Authors: Watson DM Tags: Am Nat Source Type: research

The Enemy Within: How Does a Bacterium Inhibit the Foraging Aptitude and Risk Management Behavior of Allenby's Gerbils?
Abstract AbstractMicrobes inhabiting multicellular organisms have complex, often subtle effects on their hosts. Gerbillus andersoni allenbyi are commonly infected with Mycoplasma haemomuris-like bacteria, which may cause mild nutrient (choline, arginine) deficiencies. However, are there more serious ecological consequences of infection, such as effects on foraging aptitudes and risk management? We tested two alternatives: the nutrient compensation hypothesis (does nutrient deficiency induce infected gerbils to make up for the shortfall by foraging more and taking greater risks?) and (2) the lethargy hypothesis (do...
Source: The American Naturalist - November 21, 2020 Category: Biology Authors: Makin DF, Kotler BP, Brown JS, Garrido M, Menezes JFS Tags: Am Nat Source Type: research

Australian Rodents Reveal Conserved Cranial Evolutionary Allometry across 10 Million Years of Murid Evolution.
Abstract AbstractAmong vertebrates, placental mammals are particularly variable in the covariance between cranial shape and body size (allometry), with rodents being a major exception. Australian murid rodents allow an assessment of the cause of this anomaly because they radiated on an ecologically diverse continent notably lacking other terrestrial placentals. Here, we use 3D geometric morphometrics to quantify species-level and evolutionary allometries in 38 species (317 crania) from all Australian murid genera. We ask whether ecological opportunity resulted in greater allometric diversity compared with other ro...
Source: The American Naturalist - November 21, 2020 Category: Biology Authors: Marcy AE, Guillerme T, Sherratt E, Rowe KC, Phillips MJ, Weisbecker V Tags: Am Nat Source Type: research

Life-History Modeling Reveals the Ecological and Evolutionary Significance of Autotomy.
This study demonstrated the utility of the multimethod hierarchical-modeling approach for the quantitative understanding of the ecological and evolutionary processes of antipredator defenses in the wild. PMID: 33211560 [PubMed - in process] (Source: The American Naturalist)
Source: The American Naturalist - November 21, 2020 Category: Biology Authors: Hoso M, Shimatani IK Tags: Am Nat Source Type: research

Oxidative Stress Experienced during Early Development Influences the Offspring Phenotype.
Abstract AbstractOxidative stress (OS) experienced early in life can affect an individual's phenotype. However, its consequences for the next generation remain largely unexplored. We manipulated the OS level endured by zebra finches (Taeniopygia guttata) during their development by transitorily inhibiting the synthesis of the key antioxidant glutathione ("early-high-OS"). The offspring of these birds and control parents were cross fostered at hatching to enlarge or reduce its brood size. Independent of parents' early-life OS levels, the chicks raised in enlarged broods showed lower erythrocyte glutathion...
Source: The American Naturalist - November 21, 2020 Category: Biology Authors: Romero-Haro AA, Alonso-Alvarez C Tags: Am Nat Source Type: research

Adaptation and Latitudinal Gradients in Species Interactions: Nest Predation in Birds.
Abstract AbstractAre biotic interactions stronger in the tropics? Here, we investigate nest predation in birds, a canonical example of a strong tropical biotic interaction. Counter to expectations, daily rates of nest predation vary minimally with latitude. However, life-history traits that influence nest predation have diverged between latitudes. For example, tropical species have evolved a longer average nesting period, which is associated with reduced rates of nest attendance by parents. Daily nest mortality declines with nesting period length within regions, but tropical species have a higher intercept. Conseq...
Source: The American Naturalist - November 21, 2020 Category: Biology Authors: Freeman BG, Scholer MN, Boehm MMA, Heavyside J, Schluter D Tags: Am Nat Source Type: research

Simultaneous Wing Molt as a Catalyst for the Evolution of Flightlessness in Birds.
Abstract AbstractComplex features, such as vision, limbs, and flight, have been lost by many groups of animals. Some groups of birds are more prone to loss of flight than others, but few studies have investigated possible reasons for this variation. I tested the hypothesis that a rare strategy of flight feather replacement is involved in rate variation in the evolution of flightlessness in birds. This strategy involves a simultaneous molt of the flight feathers of the wing, resulting in a temporary flightless condition during molt. I hypothesized that adaptations for this flightless period may serve as preadaptati...
Source: The American Naturalist - November 21, 2020 Category: Biology Authors: Terrill RS Tags: Am Nat Source Type: research

Fluctuating Dynamics of Mate Availability Promote the Evolution of Flexible Choosiness in Both Sexes.
Abstract AbstractThe evolution of choosiness has a strong effect on sexual selection, as it promotes variance in mating success among individuals. The context in which choosiness is expressed, and therefore the associated gain and cost, is highly variable. An overlooked mechanism by current models is the rapid fluctuations in the availability and quality of partners, which generates a dynamic mating market to which each individual must optimally respond. We argue that the rapid fluctuations of the mating market are central to the evolution of optimal choosiness. Using a dynamic game approach, we investigate this h...
Source: The American Naturalist - November 21, 2020 Category: Biology Authors: Chevalier L, Labonne J, Galipaud M, Dechaume-Moncharmont FX Tags: Am Nat Source Type: research

Trends and Transitions in 150 Years of The American Naturalist.
Abstract AbstractThe American Naturalist recently passed its sesquicentennial. Throughout this long history, it regularly encountered moments of introspection and debate over its goals, mission, identity, and audience. Here, we chronicle the history of those debates and transitions at critical moments. The Naturalist began as a popular magazine for amateur naturalists in the late 1860s. In the late 1870s, it transitioned to an increasingly academic journal for professional scientists from all branches of the natural sciences. By the turn of the century, academic specialization led to increasing fragmentation of th...
Source: The American Naturalist - November 21, 2020 Category: Biology Authors: Smocovitis VB, Bolnick DI, Moore CM, Morse PL Tags: Am Nat Source Type: research

Secretary's Report, 2020 : American Society of Naturalists.
PMID: 33211566 [PubMed - in process] (Source: The American Naturalist)
Source: The American Naturalist - November 21, 2020 Category: Biology Authors: Fukami T Tags: Am Nat Source Type: research

Comparing the Indirect Effects between Exploiters in Predator-Prey and Host-Pathogen Systems.
In this study, we use two-predator-two-prey and two-host-two-pathogen models to compare the indirect effects between predators with the indirect effects between pathogens. We focus on how the indirect interactions between pathogens are affected by the competitive abilities of susceptible and infected hosts, whether the pathogens are specialists or generalists, and the transmission pathway (direct vs. environmental transmission). In many cases, indirect effects between pathogens and predators follow similar patterns, for example, more positive indirect effects with increased interspecific competition between victim species....
Source: The American Naturalist - November 21, 2020 Category: Biology Authors: Cortez MH, Duffy MA Tags: Am Nat Source Type: research

Treasurer's Report, 2019 : Statement of Activities For the year ending December 31, 2019.
PMID: 33211568 [PubMed - in process] (Source: The American Naturalist)
Source: The American Naturalist - November 21, 2020 Category: Biology Authors: McPeek MA Tags: Am Nat Source Type: research

Daily Nest Predation Rates Decrease with Body Size in Passerine Birds.
Abstract AbstractBody size evolution is generally framed by the benefits of being large, while costs are largely overlooked. An important putative cost of being large is the need to extend development periods, which should increase exposure to predation and potentially select against larger size. In birds, this selection pressure can be important because predation is the main source of offspring mortality and predators should more readily detect the larger nests associated with larger body sizes. Here, we show for diverse passerine birds across the world that counter to expectations, larger species suffer lower da...
Source: The American Naturalist - November 21, 2020 Category: Biology Authors: Unzeta M, Martin TE, Sol D Tags: Am Nat Source Type: research

Positive Feedback between Behavioral and Hormonal Dynamics Leads to Differentiation of Life-History Tactics.
In this study, we developed a simple mathematical model for the positive feedback between hormonal and behavioral dynamics, with the expectation of establishing multiple discrete clusters of hormone levels leading to differentiation of life-history tactics. The assumptions were that probability of winning in fighting depends both on the body size and hormone level of the two contestants. An individual with a higher hormone level would be more likely to win the competition, which further enhanced hormone production, forming a positive feedback loop between hormone level and fighting ability. If the positive feedback was str...
Source: The American Naturalist - November 21, 2020 Category: Biology Authors: Horita J, Iwasa Y, Tachiki Y Tags: Am Nat Source Type: research

Treasurer ’s Report, 2019: Statement of Activities; For the year ending December 31, 2019
The American Naturalist,Volume 196, Issue 6, Page 787-788, December 2020. (Source: The American Naturalist)
Source: The American Naturalist - November 19, 2020 Category: Zoology Authors: Mark A. McPeek Source Type: research

Secretary ’s Report, 2020: American Society of Naturalists
The American Naturalist,Volume 196, Issue 6, Page 785-786, December 2020. (Source: The American Naturalist)
Source: The American Naturalist - November 19, 2020 Category: Zoology Authors: Tadashi Fukami Source Type: research

Front and Back Matter
The American Naturalist,Volume 196, Issue 6, December 2020. (Source: The American Naturalist)
Source: The American Naturalist - November 19, 2020 Category: Zoology Source Type: research

Retraction
The American Naturalist, Ahead of Print. (Source: The American Naturalist)
Source: The American Naturalist - November 18, 2020 Category: Zoology Authors: James L. L. Lichtenstein Ambika Kamath Sarah Bengston Leticia Avil és Source Type: research

Observed Ecological Communities Are Formed by Species Combinations That Are among the Most Likely to Persist under Changing Environments
The American Naturalist, Ahead of Print. (Source: The American Naturalist)
Source: The American Naturalist - November 18, 2020 Category: Zoology Authors: Lucas P. Medeiros Karina Boege Ek del-Val Alejandro Zald ívar-Riverón Serguei Saavedra Source Type: research

Positive Feedback between Behavioral and Hormonal Dynamics Leads to Differentiation of Life-History Tactics
The American Naturalist, Ahead of Print. (Source: The American Naturalist)
Source: The American Naturalist - November 3, 2020 Category: Zoology Authors: Junnosuke Horita Yoh Iwasa Yuuya Tachiki Source Type: research

Simultaneous Wing Molt as a Catalyst for the Evolution of Flightlessness in Birds
The American Naturalist, Ahead of Print. (Source: The American Naturalist)
Source: The American Naturalist - October 30, 2020 Category: Zoology Authors: Ryan S. Terrill Source Type: research

Trends and Transitions in 150 Years of The American Naturalist
The American Naturalist, Ahead of Print. (Source: The American Naturalist)
Source: The American Naturalist - October 28, 2020 Category: Zoology Authors: Vassiliki Betty Smocovitis Daniel I. Bolnick Christopher M. Moore Patricia L. Morse Source Type: research

Did Mammals Bring the First Mistletoes into the Treetops?
The American Naturalist, Ahead of Print. (Source: The American Naturalist)
Source: The American Naturalist - October 28, 2020 Category: Zoology Authors: David M. Watson Source Type: research

Daily Nest Predation Rates Decrease with Body Size in Passerine Birds
The American Naturalist, Ahead of Print. (Source: The American Naturalist)
Source: The American Naturalist - October 28, 2020 Category: Zoology Authors: Mar Unzeta Thomas E. Martin Daniel Sol Source Type: research

Fluctuating Dynamics of Mate Availability Promote the Evolution of Flexible Choosiness in Both Sexes
The American Naturalist, Ahead of Print. (Source: The American Naturalist)
Source: The American Naturalist - October 23, 2020 Category: Zoology Authors: Louise Chevalier Jacques Labonne Matthias Galipaud Fran çois-Xavier Dechaume-Moncharmont Source Type: research

Oxidative Stress Experienced during Early Development Influences the Offspring Phenotype
The American Naturalist, Ahead of Print. (Source: The American Naturalist)
Source: The American Naturalist - October 22, 2020 Category: Zoology Authors: Ana Angela Romero-Haro Carlos Alonso-Alvarez Source Type: research

The Enemy Within: How Does a Bacterium Inhibit the Foraging Aptitude and Risk Management Behavior of Allenby ’s Gerbils?
The American Naturalist, Ahead of Print. (Source: The American Naturalist)
Source: The American Naturalist - October 22, 2020 Category: Zoology Authors: Douglas F. Makin Burt P. Kotler Joel S. Brown Mario Garrido Jorge F. S. Menezes Source Type: research

Life-History Modeling Reveals the Ecological and Evolutionary Significance of Autotomy
The American Naturalist, Ahead of Print. (Source: The American Naturalist)
Source: The American Naturalist - October 22, 2020 Category: Zoology Authors: Masaki Hoso Ichiro K. Shimatani Source Type: research

The Size, Symmetry, and Color Saturation of a Male Guppy's Ornaments Forecast His Resistance to Parasites.
Abstract AbstractSexually selected ornaments range from highly dynamic traits to those that are fixed during development and relatively static throughout sexual maturity. Ornaments along this continuum differ in the information they provide about the qualities of potential mates, such as their parasite resistance. Dynamic ornaments enable real-time assessment of the bearer's condition: they can reflect an individual's current infection status, or they can reflect resistance to recent infections. Static ornaments, however, are not affected by recent infection but may instead indicate an individual's genetically det...
Source: The American Naturalist - October 20, 2020 Category: Biology Authors: Stephenson JF, Stevens M, Troscianko J, Jokela J Tags: Am Nat Source Type: research

Understanding the Social Dynamics of Breeding Phenology: Indirect Genetic Effects and Assortative Mating in a Long-Distance Migrant.
Abstract AbstractPhenological traits, such as the timing of reproduction, are often influenced by social interactions between paired individuals. Such partner effects may occur when pair members affect each other's prebreeding environment. Partner effects can be environmentally and/or genetically determined, and quantifying direct and indirect genetic effects is important for understanding the evolutionary dynamics of phenological traits. Here, using 26 years of data from a pedigreed population of a migratory seabird, the common tern (Sterna hirundo), we investigate male and female effects on female laying date. W...
Source: The American Naturalist - October 20, 2020 Category: Biology Authors: Moiron M, Araya-Ajoy YG, Teplitsky C, Bouwhuis S, Charmantier A Tags: Am Nat Source Type: research

Janzen-Connell Effects Are a Weak Impediment to Competitive Exclusion.
Abstract AbstractA goal of ecology is to identify the stabilizing mechanisms that maintain species diversity in the face of competitive exclusion and drift. For tropical forest tree communities, it has been hypothesized that high diversity is maintained via Janzen-Connell effects, whereby host-specific natural enemies prevent any one species from becoming too abundant. Here we explore the plausibility of this hypothesis with theoretical models. We confirm a previous result that when added to a model with drift but no competitive exclusion-that is, a neutral model where intrinsic fitnesses are perfectly equalized a...
Source: The American Naturalist - October 20, 2020 Category: Biology Authors: Chisholm RA, Fung T Tags: Am Nat Source Type: research

Complex Relationship between Tunneling Patterns and Individual Behaviors in Termites.
Abstract AbstractThe nests built by social insects are complex group-level structures that emerge from interactions among individuals following simple behavioral rules. Nest patterns vary among species, and the theory of complex systems predicts that there is no simple one-to-one relationship between variation in collective patterns and variation in individual behaviors. Therefore, a species-by-species comparison of the actual building process is essential to understand the mechanism producing diverse nest patterns. Here, we compare tunnel formation of three termite sp ecies and reveal two mechanisms producing int...
Source: The American Naturalist - October 20, 2020 Category: Biology Authors: Mizumoto N, Bardunias PM, Pratt SC Tags: Am Nat Source Type: research

Fledging Mass Is Color Morph Specific and Affects Local Recruitment in a Wild Bird.
Abstract AbstractEarly-life conditions may have long-lasting effects on life history. In color polymorphic species, morph-specific sensitivity to environmental conditions may lead to differential fitness. In tawny owls (Strix aluco), pheomelanin-based color polymorphism is expected to be maintained because the brown morph has higher adult fitness in warmer environments, while selection favors the gray morph under colder conditions. Here we investigate body mass at fledging and its consequences until adulthood in a population at the species' cold range margin. Using 40 years of data (1979-2017), we show that brown ...
Source: The American Naturalist - October 20, 2020 Category: Biology Authors: Morosinotto C, Brommer JE, Lindqvist A, Ahola K, Aaltonen E, Karstinen T, Karell P Tags: Am Nat Source Type: research

Ant Collective Behavior Is Heritable and Shaped by Selection.
Abstract AbstractCollective behaviors are widespread in nature and usually assumed to be strongly shaped by natural selection. However, the degree to which variation in collective behavior is heritable and has fitness consequences-the two prerequisites for evolution by natural selection-is largely unknown. We used a new pharaoh ant (Monomorium pharaonis) mapping population to estimate the heritability, genetic correlations, and fitness consequences of three collective behaviors (foraging, aggression, and exploration), as well as of body size, sex ratio, and caste ratio. Heritability estimates for the collective be...
Source: The American Naturalist - October 20, 2020 Category: Biology Authors: Walsh JT, Garnier S, Linksvayer TA Tags: Am Nat Source Type: research

The Complexity of Social Complexity: A Quantitative Multidimensional Approach for Studies of Social Organization.
Abstract AbstractThe rapid increase in "big data" during the postgenomic era makes it crucial to appropriately measure the level of social complexity in comparative studies. We argue that commonly used qualitative classifications lump together species showing a broad range of social complexity and falsely imply that social evolution always progresses along a single linear stepwise trajectory that can be deduced from comparing extant species. To illustrate this point, we compared widely used social complexity measures in "primitively eusocial" bumble bees with "advanced eusocial" sting...
Source: The American Naturalist - October 20, 2020 Category: Biology Authors: Holland JG, Bloch G Tags: Am Nat Source Type: research

Miniaturization, Genome Size, and Biological Size in a Diverse Clade of Salamanders.
Abstract AbstractGenome size (C-value) can affect organismal traits across levels of biological organization from tissue complexity to metabolism. Neotropical salamanders show wide variation in genome and body sizes, including several clades with miniature species. Because miniaturization imposes strong constraints on morphology and development and because genome size is strongly correlated with cell size, we hypothesize that body size has played an important role in the evolution of genome size in bolitoglossine salamanders. If this hypothesis is correct, then genome size and body size should be correlated in thi...
Source: The American Naturalist - October 20, 2020 Category: Biology Authors: Decena-Segarra LP, Bizjak-Mali L, Kladnik A, Sessions SK, Rovito SM Tags: Am Nat Source Type: research

State-Dependent Decision-Making by Predators and Its Consequences for Mimicry.
Abstract AbstractThe mimicry of one species by another provides one of the most celebrated examples of evolution by natural selection. Edible Batesian mimics deceive predators into believing they may be defended, whereas defended Müllerian mimics have evolved a shared warning signal, more rapidly educating predators to avoid them. However, it may benefit hungry predators to attack defended prey, while the benefits of learning about unfamiliar prey depends on the future value of this information. Previous energetic state-dependent models of predator foraging behavior have assumed complete knowledge, while info...
Source: The American Naturalist - October 20, 2020 Category: Biology Authors: Aubier TG, Sherratt TN Tags: Am Nat Source Type: research

Proximate Causes of Infertility and Embryo Mortality in Captive Zebra Finches.
Abstract AbstractSome species show high rates of reproductive failure, which is puzzling because natural selection works against such failure in every generation. Hatching failure is common in both captive and wild zebra finches (Taeniopygia guttata), yet little is known about its proximate causes. Here we analyze data on reproductive performance (the fate of>23,000 eggs) based on up to 14 years of breeding of four captive zebra finch populations. We find that virtually all aspects of reproductive performance are negatively affected by inbreeding (mean r=-0.117); by an early-starting, age-related decline (mean ...
Source: The American Naturalist - October 20, 2020 Category: Biology Authors: Pei 裴一凡 Y, Forstmeier W, Wang 王代平 D, Martin K, Rutkowska J, Kempenaers B Tags: Am Nat Source Type: research

Evolution of Plasticity in Response to Ethanol between Sister Species with Different Ecological Histories (Drosophila melanogaster and D. simulans).
Abstract AbstractWhen populations evolve adaptive reaction norms in response to novel environments, it can occur through a process termed genetic accommodation. Under this model, the initial response to the environment is widely variable between genotypes as a result of cryptic genetic variation, which is then refined by selection to a single adaptive response. Here, I empirically test these predictions from genetic accommodation by measuring reaction norms in individual genotypes and across several time points. I compare two species of Drosophila that differ in their adaptation to ethanol (D. melanogaster and D. ...
Source: The American Naturalist - October 20, 2020 Category: Biology Authors: Signor SA Tags: Am Nat Source Type: research

Spite and the Geometry of Negative Relatedness.
Abstract AbstractSpite is the most surprising prediction of inclusive fitness theory because it suggests that a gene can be favored by natural selection despite causing harm to both the individuals that carry it and those around them. A gene for spite can only be favored because of negative relatedness, which means that the actor that carries the gene is less likely to share the gene for spite with the surrounding recipients than the random expectation. While positive relatedness can be simply reduced to the intuitive concept of kinship, negative relatedness is deeply counterintuitive. Here I clarify that negative...
Source: The American Naturalist - October 20, 2020 Category: Biology Authors: Madgwick PG Tags: Am Nat Source Type: research

Adaptation and Latitudinal Gradients in Species Interactions: Nest Predation in Birds
The American Naturalist, Ahead of Print. (Source: The American Naturalist)
Source: The American Naturalist - October 20, 2020 Category: Zoology Authors: Benjamin G. Freeman Micah N. Scholer Mannfred M. A. Boehm Julian Heavyside Dolph Schluter Source Type: research

Front and Back Matter
The American Naturalist,Volume 196, Issue 5, November 2020. (Source: The American Naturalist)
Source: The American Naturalist - October 16, 2020 Category: Zoology Source Type: research

Australian Rodents Reveal Conserved Cranial Evolutionary Allometry across 10 Million Years of Murid Evolution
The American Naturalist, Ahead of Print. (Source: The American Naturalist)
Source: The American Naturalist - October 16, 2020 Category: Zoology Authors: Ariel E. Marcy Thomas Guillerme Emma Sherratt Kevin C. Rowe Matthew J. Phillips Vera Weisbecker Source Type: research

Comparing the Indirect Effects between Exploiters in Predator-Prey and Host-Pathogen Systems
The American Naturalist, Ahead of Print. (Source: The American Naturalist)
Source: The American Naturalist - October 9, 2020 Category: Zoology Authors: Michael H. Cortez Meghan A. Duffy Source Type: research

Proximate Causes of Infertility and Embryo Mortality in Captive Zebra Finches
The American Naturalist, Ahead of Print. (Source: The American Naturalist)
Source: The American Naturalist - September 27, 2020 Category: Zoology Authors: Yifan Pei ( 裴一凡) Wolfgang Forstmeier Daiping Wang ( 王代平) Katrin Martin Joanna Rutkowska Bart Kempenaers Source Type: research

High Preservation Potential of Paleogeographic Range Size Distributions in Deep Time.
Abstract AbstractReconstructing geographic range sizes from fossil data is a crucial tool in paleoecology, elucidating macroecological and macroevolutionary processes. Studies examining links between range size and extinction risk may also offer a predictive tool for identifying species most vulnerable in the "sixth mass extinction." However, the extent to which paleogeographic ranges can be recorded reliably in the fossil record is unknown. We perform simulation-based extinction experiments to examine (1) the fidelity of paleogeographic range size preservation in deep time, (2) the relative performance ...
Source: The American Naturalist - September 26, 2020 Category: Biology Authors: Darroch SAF, Casey MM, Antell GS, Sweeney A, Saupe EE Tags: Am Nat Source Type: research

Mating Preference for Novel Phenotypes Can Be Explained by General Neophilia in Female Guppies.
Abstract AbstractUnderstanding how genetic variation is maintained in ecologically important traits is a fundamental question in evolutionary biology. Male Trinidadian guppies (Poecilia reticulata) exhibit extreme genetic diversity in color patterns within populations, which is believed to be promoted by a female mating preference for rare or novel patterns. However, the origins of this preference remain unclear. Here, we test the hypothesis that mating preference for novel phenotypes is a by-product of general neophilia that evolved in response to selection in nonmating contexts. We measured among-female variatio...
Source: The American Naturalist - September 26, 2020 Category: Biology Authors: Daniel MJ, Koffinas L, Hughes KA Tags: Am Nat Source Type: research

Multiple Environmental Stressors Induce an Adaptive Maternal Effect.
Abstract AbstractEvolution of adaptation requires predictability and recurrence of functional contexts. Yet organisms live in multifaceted environments that are dynamic and ever changing, making it difficult to understand how complex adaptations evolve. This problem is particularly apparent in the evolution of adaptive maternal effects, which are often assumed to require reliable and discrete cues that predict conditions in the offspring environment. One resolution to this problem is if adaptive maternal effects evolve through preexisting, generalized maternal pathways that respond to many cues and also influence ...
Source: The American Naturalist - September 26, 2020 Category: Biology Authors: Potticary AL, Duckworth RA Tags: Am Nat Source Type: research

Predicting Multivariate Responses of Sexual Dimorphism to Direct and Indirect Selection.
Abstract AbstractSexual dimorphism is often assumed to result from balancing the strength of antagonistic selection in favor of dimorphism against the degree of constraint imposed by the shared genome of the sexes, reflected in the B matrix of genetic intersexual covariances. To investigate the totality of forces shaping dimorphism, we reparameterized the Lande equation to predict changes in trait averages and trait differences between the sexes. As genetic constraints on the evolution of dimorphism in response to antagonistic selection become larger, dimorphism will tend to respond more rapidly to concordant sele...
Source: The American Naturalist - September 26, 2020 Category: Biology Authors: Cheng 成常德 C, Houle D Tags: Am Nat Source Type: research

Evolution of Reproduction Periods in Seasonal Environments.
Abstract AbstractMany species are subject to seasonal cycles in resource availability, affecting the timing of their reproduction. Using a stage-structured consumer-resource model in which juvenile development and maturation are resource dependent, we study how a species' reproductive schedule evolves, dependent on the seasonality of its resource. We find three qualitatively different reproduction modes. First, continuous income breeding (with adults reproducing throughout the year) evolves in the absence of significant seasonality. Second, seasonal income breeding (with adults reproducing unless they are starving...
Source: The American Naturalist - September 26, 2020 Category: Biology Authors: Sun Z, Parvinen K, Heino M, Metz JAJ, de Roos AM, Dieckmann U Tags: Am Nat Source Type: research