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Genetic Incompatibility
Genetic incompatibility describes the process by which mating yields offspring that are nonviable, prone to disease, or genetically defective in some way. In nature, animals can ill afford to devote costly resources for little or no reward, ergo, mating strategies have evolved to allow females to choose or otherwise determine mates which are more likely to result in viable offspring. Polyandry, for instance, when a female mates with two or more males during a period of sexual receptivity, reduces the chance that a singular mate is genetically incompatible. Exactly how females determine compatible genes prior to mating is not completely understood, but various mechanisms have been proposed, such as pheromones and male appearance and/or courtship behavior. It is also surmised that sexual selection can continue after copulation, the so called 'cryptic female choice', so named because it takes place within the body and cannot be directly observed. In this scenario, incompatible male s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyandry
Polyandry (; ) is a form of polygamy in which a woman takes two or more husbands at the same time. Polyandry is contrasted with polygyny, involving one male and two or more females. If a marriage involves a plural number of "husbands and wives" participants of each gender, then it can be called polygamy, group marriage, group or conjoint marriage. In its broadest use, polyandry refers to sexual relations with multiple males within or without marriage. Of the 1,231 societies listed in the 1980 Ethnographic Atlas, 186 were found to be monogamous, 453 had occasional polygyny, 588 had more frequent polygyny, and 4 had polyandry.''Ethnographic Atlas Codebook'' derived from George P. Murdock's ''Ethnographic Atlas'' recording the marital composition of 1,231 societies from 1960 to 1980. Polyandry is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptic Female Choice
Cryptic female choice is a form of mate choice which occurs both in pre and post copulatory circumstances when females in certain species use physical or chemical mechanisms to control a male's success of fertilizing their ova or ovum; i.e. by selecting whether sperm are successful in fertilizing their eggs or not. It occurs in internally-fertilizing species and involves differential use of sperm by females when sperm are available in the reproductive tract. The present understanding of cryptic female choice is largely thanks to the extensive research and analysis done by William G. Eberhard. The term ‘cryptic’ according to Eberhard is meant to describe an internal and thereby hidden choice some female organisms are able to make following insemination with regards to sperm selection. In male species with intromittent organs, during copulation, a male inserts his reproductive organ into that of a female's so as to inseminate her with his genetic material. Through the developmen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drosophila Melanogaster
''Drosophila melanogaster'' is a species of fly (the taxonomic order Diptera) in the family Drosophilidae. The species is often referred to as the fruit fly or lesser fruit fly, or less commonly the "vinegar fly" or "pomace fly". Starting with Charles W. Woodworth's 1901 proposal of the use of this species as a model organism, ''D. melanogaster'' continues to be widely used for biological research in genetics, physiology, microbial pathogenesis, and life history evolution. As of 2017, five Nobel Prizes have been awarded to drosophilists for their work using the insect. ''D. melanogaster'' is typically used in research owing to its rapid life cycle, relatively simple genetics with only four pairs of chromosomes, and large number of offspring per generation. It was originally an African species, with all non-African lineages having a common origin. Its geographic range includes all continents, including islands. ''D. melanogaster'' is a common pest in homes, restaurants, and othe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhodeus Ocellatus Ocellatus-m
''Rhodeus'' is a genus of cyprinid fish, consisting of 23 species called bitterlings. The scientific name is derived from the Greek word ', meaning "rose". Most species in the genus are restricted to Asia, but two species are found in Europe (''R. amarus'' and ''R. meridionalis''). Bitterlings are short-lived species, generally surviving only about five years. Their maximum size is 11 cm, but they are usually much shorter. Bitterlings inhabit slow-flowing or still waters, such as ponds, lakes, marshes, muddy and sandy pools, and river backwaters. Because they depend on freshwater mussels to reproduce, their range is restricted. Bitterlings are omnivorous, feeding on both invertebrates and plants. Bitterlings have a remarkable reproduction strategy where parents transfer responsibility for the care of their young to various species of freshwater mussels (Unionidae and Margaritiferidae). The female extends her long ovipositor into the mantle cavity of the mussel and deposi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rosy Bitterling
The rosy bitterling or Tairiku baratanago (''Rhodeus ocellatus'') is a small freshwater fish belonging to the family Cyprinidae (carp), native to East Asia from the Amur River basin to the Pearl River (China), Pearl River basin. Females are about long and males are . Their bodies are flat with an argent-colored luster. However, males change to a reddish (sometimes purple) color during the spawning season (March to September) which functions to attract females. This reddish color is similar to the color of a red rose, which is why it is called a rosy bitterling. Ecology and reproductive system Rosy bitterlings live in ponds (reservoirs) where freshwater mussels are abundant. Farm ponds are an important habitat for not only rosy bitterlings, but also mussels and plankton. Freshwater mussels play an important role in rosy bitterling reproduction. The female rosy bitterling has a unique pipe about the same length as its own body, used for laying eggs on a specific spot of mussels. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mus Musculus Domesticus
''Mus musculus domesticus'', the Western European house mouse, is a subspecies of the house mouse (''Mus musculus''). Some laboratory mouse strains, such as C57BL/6, are domesticated from ''M. m. domesticus''. Distribution In Europe, ''M. m. domesticus'' lives in Western and Northern Europe, while another subspecies, the Eastern European house mouse (''M. m. musculus'') lives in Eastern and Southern Europe. The area from Scandinavia to the Black Sea is a secondary hybrid zone for ''M. m. domesticus'' and ''M. m. musculus''. Habitats of ''M. m. domesticus'' also exist in the Middle East, Southern Asia, North Africa, North America, and some areas of Latin America and Oceania. Relations with humans ''M. m. domesticus'' is harmful to humans, for they can damage vegetation and field crops. It is also one of many invasive species An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most int ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gouldian Finch
The Gouldian finch (''Chloebia gouldiae''), also known as the Lady Gouldian finch, Gould's finch or the rainbow finch, is a colourful passerine bird that is native to Australia. Taxonomy The Gouldian finch was described by British ornithological artist John Gould in 1844 as ''Amadina gouldiae'', in honour of his deceased wife Elizabeth. The specimens were sent to him by Benjamin Bynoe although they had been described some years before by Jacques Bernard Hombron and Honoré Jacquinot. It is also known as the rainbow finch, Gould's finch, or the Lady Gouldian finch and sometimes just Gould. The Gouldian finch is sister to the parrotfinches in the genus '' Erythrura''. Description Both sexes are brightly coloured with black, green, yellow, and red markings. The females tend to be less brightly coloured. One major difference between the sexes is that the male's chest is purple, while the female's is a lighter mauve. Gouldian finches are about 125–140 mm long. Gouldian f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Selfish Genetic Element
Selfish genetic elements (historically also referred to as selfish genes, ultra-selfish genes, selfish DNA, parasitic DNA and genomic outlaws) are genetic segments that can enhance their own transmission at the expense of other genes in the genome, even if this has no positive or a net negative effect on organismal fitness. Genomes have traditionally been viewed as cohesive units, with genes acting together to improve the fitness of the organism. However, when genes have some control over their own transmission, the rules can change, and so just like all social groups, genomes are vulnerable to selfish behaviour by their parts. Early observations of selfish genetic elements were made almost a century ago, but the topic did not get widespread attention until several decades later. Inspired by the gene-centred views of evolution popularized by George Williams and Richard Dawkins, two papers were published back-to-back in ''Nature'' in 1980 – by Leslie Orgel and Francis Crick and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sterile Insect Technique
The sterile insect technique (SIT) is a method of biological insect control, whereby overwhelming numbers of sterile insects are released into the wild. The released insects are preferably male, as this is more cost-effective and the females may in some situations cause damage by laying eggs in the crop, or, in the case of mosquitoes, taking blood from humans. The sterile males compete with fertile males to mate with the females. Females that mate with a sterile male produce no offspring, thus reducing the next generation's population. Sterile insects are not self-replicating and, therefore, cannot become established in the environment. Repeated release of sterile males over low population densities can further reduce and in cases of isolation eliminate pest populations, although cost-effective control with dense target populations is subjected to population suppression prior to the release of the sterile males. The technique has successfully been used to eradicate the screw-wo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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