Dietary conservatism may facilitate the initial evolution of aposematism

Oikos ◽  
2003 ◽  
Vol 101 (3) ◽  
pp. 458-466 ◽  
Author(s):  
R. J. Thomas ◽  
N. M. Marples ◽  
I. C. Cuthill ◽  
M. Takahashi ◽  
E. A. Gibson
Keyword(s):  
Initial Evolution ◽  
Dietary Conservatism

Aposematism

2018 ◽  
Author(s):  
Graeme D. Ruxton ◽  
William L. Allen ◽  
Thomas N. Sherratt ◽  
Michael P. Speed
Keyword(s):  
Secondary Effects ◽  
Warning Coloration ◽  
Common Features ◽  
Initial Evolution ◽  
The Common ◽  
Aposematic Signals

Aposematism is the pairing of two kinds of defensive phenotype: an often repellent secondary defence that typically renders prey unprofitable to predators if they attack them and some evolved signal that indicates the presence of that defence. Aposematic signals often work to modify the behaviours of predators both before and during attacks. Warning coloration, for example, may increase wariness and hence improve the chances that a chemically defended prey is released unharmed after an attack. An aposematic signal may therefore first tend to reduce the probability that a predator commences attack (a primary defence) and then (as a component of secondary defence) reduce the probability that the prey is injured or killed during any subsequent attack. In this chapter we will consider both the primary and the secondary effects of aposematic signals on prey protection. We begin first by describing the common features of aposematic signals and attempting to show the wide use to which aposematic signalling is deployed across animals (and perhaps plants too). We then review the interesting evolutionary issues aposematic signals raise, including their initial evolution and their integration with sexual and other signals. We also discuss important ecological, co-evolutionary, and macroevolutionary consequences of aposematism.

scholarly journals A warm jet in a cold ocean

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jennifer A. MacKinnon ◽  
Harper L. Simmons ◽  
John Hargrove ◽  
Jim Thomson ◽  
Thomas Peacock ◽  
...  
Keyword(s):  
The Arctic ◽  
Bering Strait ◽  
Near Surface ◽  
Ice Melt ◽  
Beaufort Gyre ◽  
The Pacific ◽  
Climate Simulations ◽  
Initial Evolution ◽  
Forecast Models

AbstractUnprecedented quantities of heat are entering the Pacific sector of the Arctic Ocean through Bering Strait, particularly during summer months. Though some heat is lost to the atmosphere during autumn cooling, a significant fraction of the incoming warm, salty water subducts (dives beneath) below a cooler fresher layer of near-surface water, subsequently extending hundreds of kilometers into the Beaufort Gyre. Upward turbulent mixing of these sub-surface pockets of heat is likely accelerating sea ice melt in the region. This Pacific-origin water brings both heat and unique biogeochemical properties, contributing to a changing Arctic ecosystem. However, our ability to understand or forecast the role of this incoming water mass has been hampered by lack of understanding of the physical processes controlling subduction and evolution of this this warm water. Crucially, the processes seen here occur at small horizontal scales not resolved by regional forecast models or climate simulations; new parameterizations must be developed that accurately represent the physics. Here we present novel high resolution observations showing the detailed process of subduction and initial evolution of warm Pacific-origin water in the southern Beaufort Gyre.

scholarly journals The emergence and selection of reputation systems that drive cooperative behaviour

2018 ◽  
Vol 285 (1886) ◽  
pp. 20181508 ◽  
Author(s):  
Alain Schlaepfer
Keyword(s):  
Computer Simulations ◽  
Relevant Information ◽  
Reputation Systems ◽  
Cooperative Behaviour ◽  
Social Image ◽  
Reputation Mechanism ◽  
Initial Evolution ◽  
Group Members ◽  
Number Of Individuals ◽  
Selection Of

Reputational concerns are believed to play a crucial role in explaining cooperative behaviour among non-kin humans. Individuals cooperate to avoid a negative social image, if being branded as defector reduces pay-offs from future interactions. Similarly, individuals sanction defectors to gain a reputation as punisher, prompting future co-players to cooperate. But reputation can only effectively support cooperation if a sufficient number of individuals condition their strategies on their co-players' reputation, and if a sufficient number of group members are willing to record and transmit the relevant information about past actions. Using computer simulations, this paper argues that starting from a pool of non-cooperative individuals, a reputation system based on punishment is likely to emerge and to be the driver of the initial evolution of cooperative behaviour. However, once cooperation is established in a group, it will be sustained mainly through a reputation mechanism based on cooperative actions.

Initial Evolution Results on CAM-Brain Machines (CBMs)

2001 ◽  
pp. 814-819
Author(s):  
Hugo de Garis ◽  
Andrzej Buller ◽  
Leo de Penning ◽  
Tomasz Chodakowski ◽  
Derek Decesare
Keyword(s):  
Initial Evolution

The formation and initial evolution of protostellar disks

1990 ◽  
Vol 358 ◽  
pp. 515 ◽  
Author(s):  
Douglas N. C. Lin ◽  
John E. Pringle
Keyword(s):  
Protostellar Disks ◽  
Initial Evolution

scholarly journals The initial evolution of millisecond magnetars: an analytical solution

2020 ◽  
Vol 496 (2) ◽  
pp. 2183-2190
Author(s):  
S Çıkıntoğlu ◽  
S Şaşmaz Muş ◽  
K Yavuz Ekşi
Keyword(s):  
Dipole Moment ◽  
Analytical Solution ◽  
Magnetic Dipole ◽  
Inclination Angle ◽  
Magnetic Dipole Moment ◽  
Gamma Ray ◽  
Plateau Phase ◽  
Central Engine ◽  
Initial Evolution ◽  
Order Of Magnitude

ABSTRACT Millisecond magnetars are often invoked as the central engine of some gamma-ray bursts (GRBs), specifically the ones showing a plateau phase. We argue that an apparent plateau phase may not be realized if the magnetic field of the nascent magnetar is in a transient rapid decay stage. Some GRBs that lack a clear plateau phase may also be hosting millisecond magnetars. We present an approximate analytical solution of the coupled set of equations describing the evolution of the angular velocity and the inclination angle between rotation and magnetic axes of a neutron star in the presence of a corotating plasma. We also show how the solution can be generalized to the case of evolving magnetic fields. We determine the evolution of the spin period, inclination angle, magnetic dipole moment, and braking index of six putative magnetars associated with GRB 091018, GRB 070318, GRB 080430, GRB 090618, GRB 110715A, and GRB 140206A through fitting, via Bayesian analysis, the X-ray afterglow light curves by using our recent model. We find that within the first day following the formation of the millisecond magnetar, the inclination angle aligns rapidly, the magnetic dipole moment may decay by a few times, and the braking index varies by an order of magnitude.

scholarly journals Triparental inheritance inDictyostelium

2019 ◽  
Vol 116 (6) ◽  
pp. 2187-2192 ◽  
Author(s):  
Gareth Bloomfield ◽  
Peggy Paschke ◽  
Marina Okamoto ◽  
Tim J. Stevens ◽  
Hideko Urushihara
Keyword(s):  
High Frequency ◽  
Genetic Material ◽  
Mitochondrial Genomes ◽  
Genome Wide ◽  
Organelle Genomes ◽  
Initial Evolution ◽  
Sexual Progeny ◽  
Sexual Inheritance ◽  
Social Amoebae

Sex promotes the recombination and reassortment of genetic material and is prevalent across eukaryotes, although our knowledge of the molecular details of sexual inheritance is scant in several major lineages. In social amoebae, sex involves a promiscuous mixing of cytoplasm before zygotes consume the majority of cells, but for technical reasons, sexual progeny have been difficult to obtain and study. We report here genome-wide characterization of meiotic progeny inDictyostelium discoideum. We find that recombination occurs at high frequency in pairwise crosses between all three mating types, despite the absence of the Spo11 enzyme that is normally required to initiate crossover formation. Fusions of more than two gametes to form transient syncytia lead to frequent triparental inheritance, with haploid meiotic progeny bearing recombined nuclear haplotypes from two parents and the mitochondrial genome from a third. Cells that do not contribute genetically to theDictyosteliumzygote nucleus thereby have a stake in the next haploid generation.D. discoideummitochondrial genomes are polymorphic, and our findings raise the possibility that some of this variation might be a result of sexual selection on genes that can promote the spread of individual organelle genomes during sex. This kind of self-interested mitochondrial behavior may have had important consequences during eukaryogenesis and the initial evolution of sex.

scholarly journals Spontaneous Healing in complete ACL ruptures: results at eight-year mean follow-up

2018 ◽  
Vol 6 (12_suppl5) ◽  
pp. 2325967118S0018
Author(s):  
Matias Costa-Paz ◽  
Ignacio Garcia-Mansilla ◽  
Miguel Ayerza ◽  
D. Luis Muscolo
Keyword(s):  
Cruciate Ligament ◽  
Sport Activity ◽  
Scar Tissue ◽  
Long Term Results ◽  
Return To Sports ◽  
Spontaneous Healing ◽  
Initial Evolution ◽  
Anterior Cruciate ◽  
Tissue Rupture

Objectives: The injured anterior cruciate ligament (ACL) has a limited healing capacity leading to persisting instability. Although several studies have reported spontaneous healing of torn ACLs, it is difficult to determine its healing potential and whether patients will be able to return to sports activities. In 2011, we published a series of 14 patients with spontaneous healing following a complete ACL rupture, the mean follow up was 30 months (range 25-36 months). The purpose of this study was to evaluate the long-term results of spontaneous healing in complete ACL ruptures in the same group of patients. Methods: We retrospectively reviewed a cohort of 14 patients with acute ACL injury established by physical examination and MRI (proximal third in eight patients and the midligament in six). Twelve patients were male and average age at injury was 31 years (range, 23-41 years), All patients were athletically active before the injury and suffered the lesion during a sport activity. Surgery was indicated in all patients, but it was postponed for different reasons, including related labor problems, need to travel, illnesses, planned holidays, and the patient’s personal decision not to undergo surgery. Most of the patients let the injury run its course with no bracing and unspecific rehabilitation protocol. The primary outcomes of this study were rerupture rate and time between injury and surgery. Results: Twelve patients out of 14 were reevaluated (86%), with a mean follow up of 8 years (3-14). Ten were men, with a mean age of 38 years (range, 25-51 years). Five patients had an ACL reconstruction during follow-up, with a mean time between injury and surgery of 5 years (range 3-14). Initial injury was located in the proximal third in two patients and in the midligament in three. Conclusion: Although favorable initial evolution at 30 months after a complete ACL lesion, our series show a re-rupture rate or “scar tissue” rupture of 40% at a mean follow-up of 8 years.

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