Effect of population density on relationship between pre- and postcopulatory sexual traits

2019 ◽  
Vol 69 (3) ◽  
pp. 281-292 ◽  
Author(s):  
Yun Lin Cai ◽  
Chun Lan Mai ◽  
Xin Yu ◽  
Wen Bo Liao
Keyword(s):  
Population Density ◽  
Sexual Size Dimorphism ◽  
Sexual Selection Theory ◽  
Sexual Traits ◽  
Taxonomic Groups ◽  
Sperm Size ◽  
The Relationship ◽  
Comparative Phylogenetic Analysis ◽  
Testis Mass ◽  
Varying Population

Abstract Sexual selection theory states that the premating (ornaments and armaments) sexual traits should trade off with the postmating (testes and ejaculates) sexual traits, assuming that growing and maintaining these traits is expensive and that total reproductive investments are limited. Male-male competition and sperm competition are predicted to affect how males allocate their finite resources to these traits. Here, we studied relative expenditure on pre- and postmating sexual traits among 82 species for three mammalian orders with varying population density using comparative phylogenetic analysis. The results showed that population density affected sexual size dimorphism (SSD) in both Artiodactyla and Carnivora, but not in Primates. However, relative testis mass and sperm size were not affected by population density. Moreover, we did not find associations between the SSD and testis mass or sperm size in three taxonomic groups. The interspecific relationships between pre- and postcopulatory sexual traits did not change with increased population density. Our findings suggest that population density did not affect variation in the relationship between pre- and postcopulatory sexual traits for these three mammalian orders.

Evolution of vertebrate brain size is associated with sexual traits

2020 ◽  
Vol 70 (4) ◽  
pp. 401-416
Author(s):  
Mao Jun Zhong ◽  
Long Jin ◽  
Jian Ping Yu ◽  
Wen Bo Liao
Keyword(s):  
Sexual Size Dimorphism ◽  
Brain Size ◽  
Finite Energy ◽  
Energy Resources ◽  
Testis Size ◽  
Vertebrate Brain ◽  
Sexual Traits ◽  
The Relationship ◽  
The Brain ◽  
Expensive Tissue Hypothesis

Abstract The expensive tissue hypothesis predicts a trade-off between investments in the brain and other energetically costly organs due to the costs associated with their growth and maintenance within the finite energy resources available. However, few studies address the strength of relationships between brain size and investments in precopulatory (ornaments and armaments) and postcopulatory (testes and ejaculates) sexual traits. Here, in a broad comparative study, we tested the prediction that the relationship between brain size and investment in sexual traits differs among taxa relative to the importance of sperm competition within them. We found that brain size was negatively correlated with sexual size dimorphism (SSD) in anurans and primates, and it tended to decrease with SSD in ungulates and cetaceans. However, brain size did not covary significantly with armaments (e.g., canine length, horn, antler, and muscle mass). Brain size was not correlated with postcopulatory sexual traits (testes and ejaculates). The intensity of covariance between brain size and precopulatory sexual traits decreased with increasing relative testis size.

scholarly journals Sperm competition and sperm midpiece size: no consistent pattern in passerine birds

2006 ◽  
Vol 274 (1609) ◽  
pp. 561-568 ◽  
Author(s):  
Simone Immler ◽  
Tim R Birkhead
Keyword(s):  
Sperm Competition ◽  
Positive Association ◽  
Striking Difference ◽  
Significant Positive Association ◽  
Sperm Midpiece ◽  
Sperm Morphometry ◽  
Taxonomic Groups ◽  
And Function ◽  
The Relationship ◽  
Testis Mass

Sperm competition is thought to be a major force driving the evolution of sperm shape and function. However, previous studies investigating the relationship between the risk of sperm competition and sperm morphometry revealed inconclusive results and marked differences between taxonomic groups. In a comparative study of two families of passerines (Fringillidae and Sylviidae) and also across species belonging to different passerine families, we investigated the relative importance of the phylogenetic background on the relationship between sperm morphometry and the risk of sperm competition. The risk of sperm competition was inferred from relative testis mass as an indicator of investment in sperm production. We found: (i) a significant positive association between both midpiece length and flagellum length and relative testis mass in the Fringillidae, (ii) a significant negative association between sperm trait dimensions and relative testis mass in the Sylviidae, and (iii) no association across all species. Despite the striking difference in the patterns shown by the Sylviidae and the Fringillidae, the relationship between midpiece length and flagellum length was positive in both families and across all species with positive allometry. Reasons for the differences and similarities between passerine families are discussed.

Population Density and Occurrence of Accidents in Finland

2002 ◽  
Vol 17 (4) ◽  
pp. 206-208 ◽  
Author(s):  
Seppo Nieminen ◽  
Olli-Pekka Lehtonen ◽  
Miika Linna
Keyword(s):  
Population Density ◽  
Emergency Services ◽  
Social Activity ◽  
Healthcare Services ◽  
Trauma Patients ◽  
Emergency Visits ◽  
Increased Risk ◽  
The Relationship ◽  
Varying Population ◽  
Population Numbers

AbstractIntroduction:About one million accidents occur yearly in Finland (population 5.2 million), resulting in over 3,000 deaths, annually. The governmental and municipal authorities are responsible for the healthcare services that respond to these accidents. So far, resources for these services have been allocated according to regional equality, or in some cases, on the basis of population numbers. However, economical and effective resource allocation should be based on detailed risk analysis of the accidents.Hypothesis:In areas with more dense populations, the level of social activity is greater, which leads to an increased risk for accidents (traffic, civil disturbance, etc.).Methods:The number of accidents was estimated on the basis of registered emergency trauma patients using the Finnish healthcare statistics for the year 1999. The emergency visits were compared to the populations and populations’ densities of the regional sub-units. The rate of emergency injuries was analysed by regression analysis according to varying population density in Finland.Results:The number of accidents per inhabitants was related directly to population density. There was a correlation between emergency visits per inhabitant and population density (p <0.0001). According to estimates, each 1% increase in population density is associated with a 0.4% increase in the risk of accidents.Conclusion:The relationship between population density and rate of emergency visits is decisive for the planning of emergency services. Services should be placed in areas of high population densities where there are more people with greater risk of accidents.

Letters to the Editor

PEDIATRICS ◽  
1963 ◽  
Vol 31 (6) ◽  
pp. 1058-1059
Author(s):  
WILLIAM A. SILVERMAN
Keyword(s):  
Population Density ◽  
Nosocomial Infections ◽  
Specific Recommendation ◽  
Letters To The Editor ◽  
Airborne Infection ◽  
The Relationship

I was saddened to read that Doctor Harvie thinks the Committee on Fetus and Newborn has contributed to creeping authoritarianism by making a specific recommendation after evaluating evidence concerning the relationship between "spacing out" and airborne infection in hospital nurseries. Moreover I think he has misinterpreted the Committee's recommendations if he believes that they have advised nurseries to place sole reliance on reducing population density in order to minimize the risk of nosocomial infections. As Doctor Harvie comments, different modes of spread may be involved in the various types of infection that can be acquired in a newborn nursery.

Past and recent biodiversity profiling in ancient Lake Chalco Mexico by a metagenomics analysis

2021 ◽  
Author(s):  
Bárbara Moguel ◽  
Liseth Pérez ◽  
Luis David Alcaraz ◽  
Socorro Lozano-García ◽  
Luis Herrera-Estrella ◽  
...  
Keyword(s):  
Volcanic Belt ◽  
Environmental Dna ◽  
Radiocarbon Dates ◽  
The Past ◽  
Mexican Volcanic Belt ◽  
History Of ◽  
High Throughput Dna Sequencing ◽  
High Altitude Lake ◽  
Taxonomic Groups ◽  
The Relationship

&lt;p&gt;For decades, paleoecological studies in lake sediments have focused on reconstructing the environments of the past and explaining phenomena linked to climatic variations. Recent advances in high-throughput DNA sequencing have allowed access to environmental DNA (eDNA) and ancient sedimentary DNA (sedaDNA) as a new and efficient proxy for past and present biodiversity. The basin of Mexico (BM) is located in the central part of the Trans-Mexican Volcanic Belt at 2,200 m a.s.l.; with the southern portion harboring the Chalco sub-basin. Lake Chalco is one of the last remaining natural aquatic ecosystems within the ever-expanding urban area surrounding Mexico City. The paleoenvironmental history of this lake has been previously characterized using sedimentological and geochemical proxies, as well as preserved microfossils (diatoms, pollen) with a temporal framework based on multiple radiocarbon dates. However, information for the remaining taxonomic groups and metabolic pathways remained unexplored. Here, we present the first metagenomics-based study for the Holocene in a high-altitude lake in Central Mexico &amp;#8211;Lake Chalco. We explored the relationship between the lake&amp;#8217;s paleoenvironmental condition and estimations of taxonomic and metabolic profiles across the sedimentary sequence (2.5 meters long). Multiple biological and abiotic variables revealed three main environmental phases: 1) a cool freshwater lake (FW1: 11,500-11,000 cal years BP), 2) a warm hyposaline lake (HS2: 11,000-6,000 cal years BP), and 3) a temperate, subsaline lake (SS3, &lt;6,000 cal years BP). We describe the structure of the microbiota community and taxonomy richness turnover in the three Holocene paleoenvironmental phases. During the past 12 000 years BP the most abundant domains in Lake Chalco sediments were Bacteria, followed by Archaea, and Eukarya (36,722 genera). The analysis of functional proteins showed high biodiversity with a total of 27,636,243 proteins identified, but it was only possible to annotate 3,227,398 of them. Also, we identified several genes associated with some relevant pathways, such as methanogenesis. Altogether, this study allowed us to reconstruct the natural history of lake Chalco and its surroundings.&lt;/p&gt;

Influence of fruit age of the Brazilian Green Dwarf coconut on the relationship between Aceria guerreronis population density and percentage of fruit damage

2017 ◽  
Vol 72 (4) ◽  
pp. 329-337 ◽  
Author(s):  
André Silva Guimarães Sousa ◽  
Poliane Sá Argolo ◽  
Manoel Guedes Correa Gondim ◽  
Gilberto José de Moraes ◽  
Anibal Ramadan Oliveira
Keyword(s):  
Population Density ◽  
Aceria Guerreronis ◽  
Fruit Damage ◽  
The Relationship

scholarly journals Relationship between macrofauna, mineralogy and exchangeable calcium and magnesium in Cerrado Oxisols under pasture

2009 ◽  
Vol 44 (8) ◽  
pp. 996-1001 ◽  
Author(s):  
Pedro Rodolfo Siqueira Vendrame ◽  
Robélio Leandro Marchão ◽  
Osmar Rodrigues Brito ◽  
Maria de Fátima Guimarães ◽  
Thierry Becquer
Keyword(s):  
Total Carbon ◽  
Soil Macrofauna ◽  
Exchangeable Calcium ◽  
Exchangeable Ca ◽  
Calcium Magnesium ◽  
Distrito Federal ◽  
Calcium And Magnesium ◽  
Taxonomic Groups ◽  
The Relationship ◽  
Soil Groups

The objective of this work was to assess the relationship between macrofauna, mineralogy and exchangeable calcium and magnesium in Cerrado Oxisols under pasture. Twelve collection points were chosen in the Distrito Federal and in Formosa municipality, Goiás state, Brazil, representing four soil groups with varied levels of calcium + magnesium and kaolinite/(kaolinite + gibbsite) ratios. Soil macrofauna was collected in triplicate at each collection point, and identified at the level of taxonomic groups. Macrofauna density showed correlation with contents of kaolinite, gibbsite and exchangeable Ca + Mg in the soils. Mineralogy and exchangeable Ca + Mg had significant effects on taxonomic groups and relative density of soil macrofauna. The termites (Isoptera) were more abundant in soils with low exchangeable Ca + Mg; earthworms (Oligochaeta), in soils with high levels of kaolinite; and Hemiptera and Coleoptera larvae were more abundant in gibbsitic soils with higher contents of total carbon.

scholarly journals Reproduction and population structure of the sea cucumber Holothuria tubulosa in the Dardanelles Strait, Turkey

2015 ◽  
Vol 17 (1) ◽  
pp. 47 ◽  
Author(s):  
H. DERELİ ◽  
S. TÜRK ÇULHA ◽  
M. ÇULHA ◽  
B. H. ÖZALP ◽  
A. A. TEKİNAY
Keyword(s):  
Population Density ◽  
Gonadosomatic Index ◽  
Morphological Characteristics ◽  
Environmental Parameters ◽  
Population Characteristics ◽  
High Positive Correlation ◽  
Mediterranean Populations ◽  
Reproductive Patterns ◽  
First Time ◽  
The Relationship

In this study, Holothuria tubulosa Gmelin 1791 was investigated from April 2013 to March 2014 in the Dardanelles Strait, to outline the morphological characteristics, reproductive patterns and the relationship between population characteristics and environmental parameters. Between 15 and 30 individuals of this species were sampled monthly from three stations. There was a negative allometry between length and weight, being gutted weight the most reliable measurement for this species. Reproductive patterns of the species were identified the first time for Turkish coasts. By macroscopic examination of the gonads, smallest sizes (gutted length) were measured as 8.4 and 8.1 cm for female and male, respectively. Sex ratio was calculated as 1: 1.1 with differences between seasons. The reproduction of sea cucumbers occurred between August and September after Gonadosomatic Index (GSI) values reached their maximum in July. The species was found down to 10 m depth with a population density of 0.21 / m2, which was rather low compared to previously reported values for Mediterranean populations of this species. There was a high positive correlation between population density and GSI of the species. The highest population density was observed where the largest sea grass meadows are found.

scholarly journals Emergence ecology of the critically endangered Urothemis edwardsii in a new colonized site in El Kala National Park (Algeria): conservation implications

2019 ◽  
pp. 137-142
Author(s):  
Baaloudj Affef
Keyword(s):  
Body Size ◽  
Sex Ratio ◽  
Sexual Size Dimorphism ◽  
The Body ◽  
Microhabitat Selection ◽  
Conservation Implications ◽  
And Behavior ◽  
The Relationship ◽  
The Vertical Distribution ◽  
Dragonfly Species

Urothemis edwardsii is one of the most threatened dragonfly species in the Mediterranean. Recent investigations and conservation efforts have increased the local geographic distribution of the species in Northeast Algeria, where a new population (named El Graeate) has been discovered. In the absence of information about the biology and behavior of U. edwardsii in this new site, a study was conducted on the emergence ecology of the species taking into account the temporal pattern of emergence, sex ratio, body size and microhabitat selection. Emergence, which was quite asynchronous, lasted for 50 days, with 50% of the population emerging within the first half of the period. Sex ratio at emergence was slightly female biased despite the absence of sexual size dimorphism, suggesting that size is not the only driving force behind mortality bias during the larval stage. There was a slight seasonal increase in the body size of exuviae (exoskeletons) in both sexes. Microhabitat selection, assessed as the vertical stratification of exuviae at ecdysis, was positively correlated with the height of supporting plants, but the relationship reached a plateau suggesting that there are predetermined limits to the vertical distribution of exuviae. These data will be essential for the future species protection, restoration and management attempts in the region.

scholarly journals Controversial approach to wolf management in the Czech Republic

2021 ◽  
Vol 67 (No. 1) ◽  
pp. 1-10
Author(s):  
Jana Lososová ◽  
Jindřiška Kouřilová ◽  
Nikola Soukupová
Keyword(s):  
Czech Republic ◽  
Population Density ◽  
Preventive Measures ◽  
Management Programme ◽  
Wolf Population ◽  
Public Funds ◽  
The Czech Republic ◽  
Wolf Management ◽  
Key Issues ◽  
The Relationship

Expansion of the wolf in the Czech Republic results in an increasing conflict between nature conservationists and other landscape users. In March 2020, the Ministry of the Environment of the Czech Republic issued the "Wolf Management Programme". The document provoked negative reactions from organisations of farmers, breeders, and hunters. The article deals with the key issues triggered by the conflict and the attitudes of actors involved. We want to clarify to what extent the solutions designed by individual parties help to mitigate the conflict and how the financial demands related to this issue have been evolving. The problem may seem marginal in the Czech Republic, but the wolf population density in some regions may already be close to its bearable maximum. Key problems are the identification of specific target numbers of wolves, the absence of zoning as a future option, and clear rules for dealing with direct encounters of wolves with humans. The benefit of wolf management is primarily the sum of preventive measures it aims to address, but the relationship with other main actors and the area of education and promotion is debatable as it represents a further increase in the absorption of public funds without guarantees of effectiveness.

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