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Mate Competition
In ethology, male-male intrasexual competition occurs when two males of the same species compete for the opportunity to mate with a female. Sexually dimorphic traits, size, sex ratio, and the social situation may all play a role in the effects male-male competition has on the reproductive success of a male and the mate choice of a female. Larger males tend to win male-male conflicts due to their sheer strength and ability to ward off other males from taking over their females. For instance, in the fly ''Dryomyza anilis'', size shows the strongest correlation to the outcome of male-male conflicts over resources like territory and females. Influencing factors Sex ratio There are multiple types of male-male competition that may occur in a population at different times depending on the conditions. Competition variation occurs based on the frequency of various mating behaviours present in the population. One factor that can influence the type of competition observed is the popula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethology
Ethology is a branch of zoology that studies the behavior, behaviour of non-human animals. It has its scientific roots in the work of Charles Darwin and of American and German ornithology, ornithologists of the late 19th and early 20th century, including Charles Otis Whitman, Charles O. Whitman, Oskar Heinroth, and Wallace Craig. The modern discipline of ethology is generally considered to have begun during the 1930s with the work of the Dutch biologist Nikolaas Tinbergen and the Austrian biologists Konrad Lorenz and Karl von Frisch, the three winners of the 1973 Nobel Prize in Physiology or Medicine. Ethology combines laboratory and field science, with a strong relation to neuroanatomy, ecology, and evolutionary biology. Etymology The modern term ''ethology'' derives from the Greek language: wikt:ἦθος, ἦθος, ''ethos'' meaning "character" and , ''wikt:-logia, -logia'' meaning "the study of". The term was first popularized by the American entomologist William Mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dryomyza Anilis
''Dryomyza anilis'' is a common fly from the family (biology), family Dryomyzidae. The fly is found through various areas in the Northern Hemisphere, Northern hemisphere and has brown and orange coloration with distinctive large red eyes. The life span of the fly is not known, but laboratory-reared males can live 28–178 days. ''D. anilis'' has recently been placed back in the genus ''Dryomyza'', of which it is the type species. ''Dryomyzidae'' were previously part of ''Sciomyzidae'' but are now considered a separate family with two subfamilies. Male ''D. anilis'' engage in territorial behavior, guarding carcasses to attract potential mates. Males also guard females, and conflicts over females are frequent. Females typically mate with multiple males. Mating occurs through several rounds of Copulation (zoology), copulation and Oviparity, egg-laying. During mating, males engage in a series of "tapping" rituals where they use their claspers to tap the female's genitals, increasing t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Female Intrasexual Competition
Female intrasexual competition in humans, is competition between women over a Mate choice, potential mate. Such competition might include self-promotion, derogation of other women, and direct and indirect Aggression#Evolutionary explanations, aggression toward other women. Factors that influence female intrasexual competition include the genetic quality of available mates, hormone levels, and Interpersonal relationship, interpersonal dynamics. There are two modes of sexual selection: intersexual selection and intrasexual selection. Intersexual selection includes the display of desirable sexual characteristics to attract a potential mate. Intrasexual selection is competition between members of the same sex other over a potential mate. Compared to males, females tend to prefer subtle rather than overt forms of intrasexual competition. Self-promotion tactics Self-promotion tactics are one of the main strategies that can be used during intrasexual competition for mates. It is often p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Winner And Loser Effects
The winner and loser effect is an aggression phenomenon in which the winner effect is the increased probability that an animal will win future aggressive interactions after experiencing previous wins, while the loser effect is the increased probability that an animal will lose future aggressive interactions after experiencing previous losses. Overall these effects can either increase or decrease an animal's aggressive behaviour, depending on what effect affects the species of concern. Animals such as ''Agkistrodon contortrix'', Mangrove rivulus, ''Rivulus marmoratus'', and Blue-footed booby, ''Sula nebouxii'' show either both or one of these effects. The outcomes of winner and loser effects help develop and structure Hierarchy, hierarchies in nature and is used to support the game theory model of aggression. Causation A theory underlying the causation of the winner and loser effect deals with an animals perception on its own and other members resource holding potential. Essentia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhacophorus Omeimontis
''Zhangixalus omeimontis'' is a species of frog in the family Rhacophoridae endemic to China. Its common name is Omei whipping frog or Omei treefrog, in reference to its type locality, Mount Emei () in Sichuan. It is found in southern and central China in Yunnan, Sichuan, Guangxi, Guizhou, Hunan, and Hubei provinces. It has been observed between 200 and 700 meters above sea level. It is a relatively common frog that inhabits forests, and sometimes farmland. It breeds in still water (pools and ponds). Agriculture and logging are threats to this species. Description ''Zhangixalus omeimontis'' are moderately large frogs: males grow to a snout–vent length of about and females to . Maximum sizes can be even higher, reaching at least in males and in females. They tend to be bigger and older at cooler sites (i.e., at higher altitudes). Maximum age is at least eight years. Tadpoles are up to in length. Reproduction ''Zhangixalus omeimontis'' breed between mid-April and late July ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Japanese Rice Fish
The Japanese rice fish (''Oryzias latipes''), also known as the medaka, is a member of genus ''Oryzias'' (ricefish), the only genus in the subfamily Oryziinae. This small (up to about ) native of Japan is a denizen of rice paddies, marshes, ponds, slow-moving streams and tide pools. It is euryhaline, occurring in both brackish and freshwater. It became popular as an aquarium fish because of its hardiness and pleasant coloration: its coloration varies from creamy-white to yellowish in the wild to white, creamy-yellow, or orange in aquarium-bred individuals. Bright yellow, red or green transgenic populations, similar to GloFish, have also been developed, but are banned from sale in the EU. The medaka has been a popular pet since the 17th century in Japan. After fertilization, the female carries her eggs attached anterior to the anal fin for a period before depositing them on plants or similar things. Ecology Medaka live in small ponds, shallow rivers, and rice fields. They can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Resource (biology)
In biology and ecology, a resource is a substance or object in the environment required by an organism for normal growth, maintenance, and reproduction. Resources can be consumed by one organism and, as a result, become unavailable to another organism. For plants key resources are light, nutrients, water, and space to grow. For animals key resources are food, water, and territory. Key resources for plants Terrestrial plants require particular resources for photosynthesis and to complete their life cycle of germination, growth, reproduction, and dispersal: * Carbon dioxide * Microsite (ecology) * Nutrients * Pollination * Seed dispersal * Soil * Water Key resources for animals Animals require particular resources for metabolism and to complete their life cycle of gestation, birth, growth, and reproduction:Smith, T.M., and R.L. Smith. 2008. Elements of ecology, 7th ed. Benjamin Cummings, San Francisco, CA. * Foraging * Territory * Water Resources and ecological processes R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mate Choice
Mate choice is one of the primary mechanisms under which evolution can occur. It is characterized by a "selective response by animals to particular stimuli" which can be observed as behavior.Bateson, Paul Patrick Gordon. "Mate Choice." Mate Choice, Cambridge University Press, 1985 In other words, before an animal engages with a potential mate, they first evaluate various aspects of that mate which are indicative of quality—such as the resources or phenotypes they have—and evaluate whether or not those particular Phenotypic trait, trait(s) are somehow beneficial to them. The evaluation will then incur a response of some sort. These mechanisms are a part of evolutionary change because they operate in a way that causes the qualities that are desired in a mate to be more frequently passed on to each generation over time. For example, if female peacocks desire mates who have a colourful plumage, then this trait will increase in frequency over time as male peacocks with a colourful ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Male
Male (Planet symbols, symbol: ♂) is the sex of an organism that produces the gamete (sex cell) known as sperm, which fuses with the larger female gamete, or Egg cell, ovum, in the process of fertilisation. A male organism cannot sexual reproduction, reproduce sexually without access to at least one ovum from a female, but some organisms can reproduce both sexually and Asexual reproduction, asexually. Most male mammals, including male humans, have a Y chromosome, which codes for the production of larger amounts of testosterone to develop male reproductive organs. In humans, the word ''male'' can also be used to refer to gender, in the social sense of gender role or gender identity. Overview The existence of separate sexes has evolved independently at different times and in different lineage (evolution), lineages, an example of convergent evolution. The repeated pattern is sexual reproduction in isogamy, isogamous species with two or more mating types with gametes of identic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reproductive Success
Reproductive success is an individual's production of offspring per breeding event or lifetime. This is not limited by the number of offspring produced by one individual, but also the reproductive success of these offspring themselves. Reproductive success is different from fitness in that individual success is not necessarily a determinant for adaptive strength of a genotype since the effects of chance and the environment have no influence on those specific genes. Reproductive success turns into a part of fitness when the offspring are actually recruited into the breeding population. If offspring quantity is not correlated with quality this holds up, but if not then reproductive success must be adjusted by traits that predict juvenile survival in order to be measured effectively. Quality and quantity is about finding the right balance between reproduction and maintenance. The disposable soma theory of aging tells us that a longer lifespan will come at the cost of reproduction ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sex Ratio
A sex ratio is the ratio of males to females in a population. As explained by Fisher's principle, for evolutionary reasons this is typically about 1:1 in species which reproduce sexually. However, many species deviate from an even sex ratio, either periodically or permanently. These include parthenogenic and androgenetic species, periodically mating organisms such as aphids, some eusocial wasps, bees, ants, and termites. Types In most species, the sex ratio varies according to the age profile of the population. It is generally divided into four subdivisions: * — ratio at fertilization * — ratio at birth * — ratio in sexually mature organisms ** The tertiary sex ratio is equivalent to the (ASR), which is defined as the ratio of adult males to females in a population. ** The operational sex ratio (OSR) is the ratio of ''sexually active'' males to females in a population, and is therefore derived from a subset of the individuals included when calculating the ASR. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
