scholarly journals Does a Simple Cope's Rule Mechanism Overlook Predators?

2007 ◽  
Vol 2007 ◽  
pp. 1-2
Author(s):  
Vincenzo Penteriani ◽  
Robert Kenward
Keyword(s):  
Large Body ◽  
General Increase ◽  
Predator Species ◽  
Animal Groups ◽  
Individual Fitness ◽  
Large Size ◽  
High Fitness ◽  
Body Sizes ◽  
Cope’S Rule

The Cope’s rule predicts a tendency for species to evolve towards an increase in size. Recently, it has been suggested that such a tendency is due to the fact that large body sizes provide a general increase in individual fitness. Here we highlight evidence that predator species do not always fit the large-size = high-fitness mechanism for Cope’s rule. Given the specific requirements of predators and the complexity of prey-predator relationships, any analysis that does not take into account all animal groups may overlook a significant portion of evolutive trends. Generalisations may not be possible regardless of taxa.

Using the research on intergroup conflict in nonhuman animals to help inform patterns of human intergroup conflict

2019 ◽  
Vol 42 ◽  
Author(s):  
Amanda R. Ridley ◽  
Melanie O. Mirville
Keyword(s):  
Large Body ◽  
Nonhuman Animal ◽  
Intergroup Conflict ◽  
Costs And Benefits ◽  
Animal Groups ◽  
Interesting Article ◽  
Nonhuman Animals

Abstract There is a large body of research on conflict in nonhuman animal groups that measures the costs and benefits of intergroup conflict, and we suggest that much of this evidence is missing from De Dreu and Gross's interesting article. It is a shame this work has been missed, because it provides evidence for interesting ideas put forward in the article.

scholarly journals Cope's Rule and Romer's theory: patterns of diversity and gigantism in eurypterids and Palaeozoic vertebrates

2009 ◽  
Vol 6 (2) ◽  
pp. 265-269 ◽  
Author(s):  
James C. Lamsdell ◽  
Simon J. Braddy
Keyword(s):  
Body Size ◽  
Environmental Factors ◽  
Feeding Strategy ◽  
Large Body ◽  
Large Body Size ◽  
Causal Mechanisms ◽  
Family Level ◽  
Cope’S Rule ◽  
Abiotic Environmental Factors

Gigantism is widespread among Palaeozoic arthropods, yet causal mechanisms, particularly the role of (abiotic) environmental factors versus (biotic) competition, remain unknown. The eurypterids (Arthropoda: Chelicerata) include the largest arthropods; gigantic predatory pterygotids (Eurypterina) during the Siluro-Devonian and bizarre sweep-feeding hibbertopterids (Stylonurina) from the Carboniferous to end-Permian. Analysis of family-level originations and extinctions among eurypterids and Palaeozoic vertebrates show that the diversity of Eurypterina waned during the Devonian, while the Placodermi radiated, yet Stylonurina remained relatively unaffected; adopting a sweep-feeding strategy they maintained their large body size by avoiding competition, and persisted throughout the Late Palaeozoic while the predatory nektonic Eurypterina (including the giant pterygotids) declined during the Devonian, possibly out-competed by other predators including jawed vertebrates.

scholarly journals Phenology of hatching, emergence, and end-of-season body size in young-of-year coho salmon in thermally contrasting streams draining the Copper River Delta, Alaska

2019 ◽  
Vol 76 (2) ◽  
pp. 185-191 ◽  
Author(s):  
Emily Y. Campbell ◽  
Jason B. Dunham ◽  
Gordon H. Reeves ◽  
Steve M. Wondzell
Keyword(s):  
Body Size ◽  
Environmental Variability ◽  
Coho Salmon ◽  
Growing Season ◽  
Early Life History ◽  
Growth And Survival ◽  
Individual Fitness ◽  
Marked Variability ◽  
Thermal Regimes ◽  
Body Sizes

Phenology can be linked to individual fitness, particularly in strongly seasonal environments where the timing of events has important consequences for growth, condition, and survival. We studied the phenology of coho salmon (Oncorhynchus kisutch) hatching and emergence in streams with contrasting thermal variability but in close geographic proximity. Following emergence, we tracked body sizes of cohorts of young-of-year fish until the end of the growing season. Hatch and emergence occurred at the same time among streams with marked variability in thermal regimes. We demonstrate that this can be explained in part by the thermal units accumulated during embryo development. At the end of the first growing season, there were some differences in body size, but overall fish size was similar among streams despite strong differences in thermal regimes. Collectively, these results provide novel insights into the interactions between environmental variability and the early life-history stages of coho salmon, furthering our understanding of the consequences of phenology on growth and survival for individuals within the critical first summer of life.

Remarkable new species of epedanid from Vietnam (Arachnida: Opiliones: Laniatores: Epedanidae)

Zootaxa ◽  
2020 ◽  
Vol 4858 (3) ◽  
pp. 427-437
Author(s):  
ALEKSEY N. TCHEMERIS
Keyword(s):  
New Species ◽  
Large Body ◽  
Dorsal Surface ◽  
Distal Segment ◽  
Southern Vietnam ◽  
The Family ◽  
Body Sizes ◽  
Males And Females ◽  
First Time ◽  
Latin Letter

The genus Euepedanus of the family Epedanidae is recorded from Vietnam for the first time. Euepedanus vietnamicus sp. nov. (males and females) is diagnosed, figured and described. The main characteristics that distinguish this species from other species Euepedanus are quite large body sizes, structure of the distal segment of the chelicerae, armament of palps and on the dorsal surface of body with a pattern resembling the Latin letter X. The only known locality of the new E. vietnamicus sp. nov. in southern Vietnam, is mapped. 

Reproductive dynamics of a turtle (Pseudemys scripta) population in a reservoir receiving heated effluent from a nuclear reactor

1970 ◽  
Vol 48 (4) ◽  
pp. 881-885 ◽  
Author(s):  
J. Whitfield Gibbons
Keyword(s):  
South Carolina ◽  
Growth Rates ◽  
Nuclear Reactor ◽  
Large Body ◽  
Reproductive Rate ◽  
Hot Water ◽  
Trophic Levels ◽  
Body Sizes ◽  
Pseudemys Scripta ◽  
Growth Differences

Individual yellow-bellied turtles (Pseudemys scripta) in Par Pond, a thermally polluted reservoir on the Savannah River Plant, Aiken, South Carolina, U.S.A., reach exceedingly large body sizes and maintain extraordinary juvenile growth rates when compared with turtles of this species from other populations in the vicinity. Increased water temperatures are not directly responsible for the observed size and growth differences. Diet differences resulting from increased productivity at lower trophic levels as a result of the hot-water effluent may be the cause of the observed growth and size phenomena. The increased growth rates and larger body sizes in the Par Pond turtles result in changes in reproductive rate which may have interesting consequences on the demography of the population.

Life-history and the evolution of ontogeny in the ostracode genus Cyprideis

Paleobiology ◽  
1990 ◽  
Vol 16 (2) ◽  
pp. 107-125 ◽  
Author(s):  
Peter N. Schweitzer ◽  
G. P. Lohmann
Keyword(s):  
Life History ◽  
Fossil Record ◽  
Large Body ◽  
Life History Evolution ◽  
Age At Maturity ◽  
Geological Time ◽  
Large Size ◽  
Fourth Species ◽  
History Evolution ◽  
Duration Of Development

A large body of paleontological literature concerns the importance of ontogeny as a source of morphological variation for evolution; morphologies that appear during one stage of an organism's development are made available for use in another simply by modifying the developmental program. Paleontologists need to know why this occurs, so they can study the process of evolution in extinct animals and so they can discuss the fossil record in terms that are applicable to modern forms. If most cases of heterochrony can be attributed to life-history evolution then the fossil record provides evidence of the nature of selection (in particular the age-specific mortality) that extinct animals experienced. The hypothesis of interest here is that species in which maturity is accelerated will also show generalized morphology and small size, while those with delayed maturity will have more specialized morphology and large size.Four species of the ostracode genus Cyprideis were studied to determine whether differences in age at maturity are correlated with heterochrony in the expected manner. For each species the changes in size and shape through geological time were evaluated in the statistical context of modern geographic and seasonal variation. Living populations were sampled regularly to detect differences in seasonality and to estimate the duration of development.Evolution of ontogeny is apparent at the level of species in this group, but it is not simply related to differences in life-history. In comparisons among species, we find evidence of heterochrony where there is no difference in the age at maturity, and a difference in age at maturity where there is no heterochrony. Similarly, three of the four species show the expected positive correlation between size and age at maturity, yet the fourth species is relatively large and matures rapidly. Cyprideis does not support the generalization that life-history evolution causes heterochrony, and casts doubt on the inference of life-history evolution from heterochrony where the data are drawn exclusively from extinct forms.

Trichodorus arasbaranensis n. sp. (Nematoda: Trichodoridae) from a natural forest in Arasbaran, north-west Iran

Nematology ◽  
2009 ◽  
Vol 11 (2) ◽  
pp. 243-252 ◽  
Author(s):  
Gholamreza Niknam ◽  
Akbar Karegar ◽  
Ebrahim Zahedi ◽  
Wilfrida Decraemer
Keyword(s):  
New Species ◽  
Excretory Pore ◽  
Large Body ◽  
Lateral View ◽  
Large Body Size ◽  
Pharyngeal Bulb ◽  
North West ◽  
Large Size ◽  
Cervical Papilla ◽  
Males And Females

AbstractTrichodorus arasbaranensis n. sp. is described from the rhizosphere of Carpinus betulus growing in forests in Arasbaran, north-west Iran. The new species is characterised by its large body length (1020-1520 μm in males; 1100-1500 μm in females), cuticle abnormally swollen upon fixation, onchiostyle medium-sized (41-66 μm in males; 49-65 μm in females) and secretory-excretory pore at level of pharyngeal bulb. Males have a single ventromedian cervical papilla varying in position from anterior to posterior to secretory-excretory pore, sperm cells with sausage-shaped nucleus, large (74-110 μm), smooth, ventrally curved spicules, manubrium wide, not offset from lamina, lamina narrowed in mid-region and with a distal ventral velum, and gubernaculum 25.5-34.5 μm long. Females have a short, but well developed, rounded vagina with large, rounded, triangular to oval-shaped, sclerotised vaginal pieces in lateral view. Because of its large body size, the new species most closely resembles T. magnus, T. elegans, T. obtusus, T. californicus and T. nanjingensis, from which the female can be differentiated by the short vagina length in relation to the corresponding body diam. and large size of the vaginal sclerotised pieces, and the male by the longer and differently shaped spicule which bears a velum. A key to the males and females of the Trichodorus spp. recorded from Iran is provided.

scholarly journals Size- and sex-specific predation on dung flies by amphibian and arthropod predators – size match matters

2019 ◽  
Author(s):  
Wolf U. Blanckenhorn ◽  
Gabriele Cozzi ◽  
Gregory Jäggli ◽  
Juan Pablo Busso
Keyword(s):  
Body Size ◽  
Sexual Size Dimorphism ◽  
Rana Temporaria ◽  
Large Body ◽  
Mechanistic Study ◽  
Mating Activity ◽  
Size Dimorphism ◽  
Arthropod Predators ◽  
Body Sizes ◽  
Predation Rates

Because predator-prey interactions in nature are multifarious, linking phenomenological predation rates to the underlying behavioural or ecological mechanisms is challenging. Size- and sex-specific predation has been implicated as a major selective force keeping animals small, affecting the evolution of body size and sexual size dimorphism. We experimentally assessed predation by various amphibian (frogs and toads) and arthropod predators (bugs, flies, spiders) on three species of dung flies with similar ecology but contrasting body sizes, sexual size dimorphism and coloration. Predators were offered a size range of flies in single- or mixed-sex groups. As expected based on optimal foraging theory, some anurans (e.g. Bufo bufo) selected larger prey, thus selecting against large body size of the flies, while others (Bombina variagata and Rana esculenta) showed no such pattern. Small juvenile Rana temporaria metamorphs, in contrast, preferred small flies, as did all arthropod predators, a pattern that can be explained by larger prey being better at escaping. The more mobile males were not eaten more frequently or faster than the cryptic females, even when conspicuously colored. Predation rates on flies in mixed groups permitting mating activity were not higher, contrary to expectation, nor was predation generally sex-specific. We conclude that the size-selectivity of predators, and hence the viability selection pattern exerted on their prey, depends foremost on the relative body sizes of the two in a continuous fashion. Sex-specific predation by single predators appears to contribute little to sexual dimorphism. Therefore, the mechanistic study of predation requires integration of both the predator’s and the prey’s perspectives, and phenomenological field studies of predation remain indispensable.

scholarly journals Sound Analysis to Predict the Growth of Turkeys

Animals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 866 ◽  
Author(s):  
El-Sayed M. Abdel-Kafy ◽  
Samya E. Ibraheim ◽  
Alberto Finzi ◽  
Sabbah F. Youssef ◽  
Fatma M. Behiry ◽  
...  
Keyword(s):  
Negative Correlation ◽  
Large Body ◽  
Growth Period ◽  
Significant Negative Correlation ◽  
Peak Frequency ◽  
Sound Signal ◽  
Sound Analysis ◽  
Body Sizes ◽  
The Relationship

Protocols for manual weighing of turkeys are not practical on turkey farms because of the large body sizes, heavy weights and flighty nature of turkeys. The sounds turkeys make may be a proxy for bird weights, but the relationship between turkey sounds and bird weights has not been studied. The aim of this study was to correlate peak frequency (PF) of vocalization with the age and weight of the bird and examine the possibility using PF to predict the weight of turkeys. The study consisted of four trials in Egypt. Sounds of birds and their weights were recorded for 11 days during the growth period in each trial. A total 2200 sounds were manually analyzed and labelled by extracting individual and general sounds on the basis of the amplitude and frequency of the sound signal. The PF of vocalizations in each trial, as well as in pooled trails, were evaluated to determine the relationship between PF and the age and weight of the turkey. PF exhibited a highly significant negative correlation with the weight and age of the turkeys showing that PF of vocalizations can be used for predicting the weight of turkeys. Further studies are necessary to refine the procedure.

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