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Mating Systems
A mating system is a way in which a group is structured in relation to sexual behaviour. The precise meaning depends upon the context. With respect to animals, the term describes which males and females mating, mate under which circumstances. Recognised systems include Monogamy in animals, monogamy, Animal sexual behaviour#Polygamy, polygamy (which includes Polygyny in animals, polygyny, Polyandry in animals, polyandry, and polygynandry), and Promiscuity#Other animals, promiscuity, all of which lead to different mate choice outcomes and thus these systems affect how sexual selection works in the species which practice them. In plants, the term refers to the degree and circumstances of outcrossing. In human sociobiology, the terms have been extended to encompass the formation of relationships such as marriage. In plants The primary mating systems in plants are outcrossing (cross-fertilisation), autogamy (self-fertilisation) and apomixis (asexual reproduction without fertilization, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animals
Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia (). With few exceptions, animals consume organic material, breathe oxygen, have myocytes and are able to move, can reproduce sexually, and grow from a hollow sphere of cells, the blastula, during embryonic development. Animals form a clade, meaning that they arose from a single common ancestor. Over 1.5 million living animal species have been described, of which around 1.05 million are insects, over 85,000 are molluscs, and around 65,000 are vertebrates. It has been estimated there are as many as 7.77 million animal species on Earth. Animal body lengths range from to . They have complex ecologies and interactions with each other and their environments, forming intricate food webs. The scientific study of animals is known as zoology, and the study of animal behaviour is known as ethology. The animal kingdom is divided into five major clades, namely Porifera, Ctenophora, P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Effective Selfing Model
The effective selfing model is a mathematical model that describes the mating system of a plant population in terms of the degree of self-fertilisation present. Overview It was developed in the 1980s by Kermit Ritland, as an alternative to the simplistic mixed mating model. The mixed mating model assumes that every fertilisation event may be classed as either self-fertilisation, or outcrossing with a completely random mate. That is, it assumes that inbreeding is caused solely by self-fertilisation. This assumption is often violated in wild plant populations, where inbreeding may be due to outcrossing between closely related plants. For example, in dense stands, mating often occurs between plants in close proximity; and in plants with short seed dispersal In spermatophyte plants, seed dispersal is the movement, spread or transport of seeds away from the parent plant. Plants have limited mobility and rely upon a variety of dispersal vectors to transport their seeds, including bot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DNA Fingerprinting
DNA profiling (also called DNA fingerprinting and genetic fingerprinting) is the process of determining an individual's deoxyribonucleic acid (DNA) characteristics. DNA analysis intended to identify a species, rather than an individual, is called DNA barcoding. DNA profiling is a forensic technique in criminal investigations, comparing criminal suspects' profiles to DNA evidence so as to assess the likelihood of their involvement in the crime. It is also used in paternity testing, to establish immigration eligibility, and in genealogical and medical research. DNA profiling has also been used in the study of animal and plant populations in the fields of zoology, botany, and agriculture. Background Starting in the mid 1970s, scientific advances allowed the use of DNA as a material for the identification of an individual. The first patent covering the direct use of DNA variation for forensicsUS5593832A was filed by Jeffrey Glassberg in 1983, based upon work he had done while ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Communal Breeding
Cooperative breeding is a social system characterized by alloparental care: offspring receive care not only from their parents, but also from additional group members, often called helpers. Cooperative breeding encompasses a wide variety of group structures, from a breeding pair with helpers that are offspring from a previous season, to groups with multiple breeding males and females ( polygynandry) and helpers that are the adult offspring of some but not all of the breeders in the group, to groups in which helpers sometimes achieve co-breeding status by producing their own offspring as part of the group's brood. Cooperative breeding occurs across taxonomic groups including birds, mammals, fish, and insects. Costs for helpers include a fitness reduction, increased territory defense, offspring guarding and an increased cost of growth. Benefits for helpers include a reduced chance of predation, increased foraging time, territory inheritance, increased environmental conditions and an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polygynandry
Polygynandry is a mating system in which both males and females have multiple mating partners during a breeding season. In sexually reproducing diploid animals, different mating strategies are employed by males and females, because the cost of gamete production is lower for males than it is for females. The different mating tactics employed by males and females are thought to be the outcome of stochastic reproductive conflicts both ecologically and socially. Reproductive conflicts in animal societies may arise because individuals are not genetically identical and have different optimal strategies for maximizing their fitness; and often it is found that reproductive conflicts generally arise due to dominance hierarchy in which all or a major part of reproduction is monopolized by only one individual. In the wasp '' Polistes carolina'', the dominant queen amongst female wasps is determined by whoever arrives at the nest first rather than the largest foundress, who is expected to be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Western Honey Bee
The western honey bee or European honey bee (''Apis mellifera'') is the most common of the 7–12 species of honey bees worldwide. The genus name ''Apis'' is Latin for 'bee', and ''mellifera'' is the Latin for 'honey-bearing' or 'honey-carrying', referring to the species' production of honey. Like all honey bee species, the western honey bee is Eusociality, eusocial, creating Beehive, colonies with a single fertile female (or "Queen bee, queen"), many normally non-reproductive females or "workers", and a small proportion of fertile males or "Drone (bee), drones". Individual colonies can house tens of thousands of bees. Colony activities are organized by Bee learning and communication, complex communication between individuals, through both pheromones and the waggle dance. The western honey bee was one of the first Domestication, domesticated insects, and it is the primary species maintained by beekeepers to this day for both its honey production and pollination activities. With h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyandry In Nature
In behavioral ecology, polyandry is a class of mating system where one female mates with several males in a breeding season. Polyandry is often compared to the polygyny system based on the cost and benefits incurred by members of each sex. Polygyny in nature, Polygyny is where one male mates with several females in a breeding season (e.g., lions, deer, some primates, and many systems where there is an Alpha (biology), alpha male). A common example of polyandrous mating can be found in the field cricket (''Gryllus bimaculatus'') of the insect order Orthoptera (containing crickets, grasshoppers, and groundhoppers). Polyandrous behavior is also prominent in many other insect species, including honeybees, the red flour beetle, the Callosobruchus chinensis, adzuki bean weevil, and the species of spider ''Stegodyphus lineatus''. Polyandry also occurs in some mammals including primates such as marmosets and the marsupial genera ''Antechinus'' and bandicoots, and in around 1% of all bird ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xylocopa Micans
Carpenter bees are species in the genus ''Xylocopa'' of the subfamily Xylocopinae. The genus includes some 500 bees in 31 subgenera. The common name "carpenter bee" derives from their nesting behavior; nearly all species burrow into hard plant material such as dead wood or bamboo. The main exceptions are species in the subgenus '' Proxylocopa'', which dig nesting tunnels in suitable soil. Characteristics Many species in this enormous genus are difficult to tell apart; most species are all black, or primarily black with some yellow or white pubescence. Some differ only in subtle morphological features, such as details of the male genitalia. Males of some species differ confusingly from the females, being covered in greenish-yellow fur. The confusion of species arises particularly in the common names; in India, for example, the common name for any all-black species of ''Xylocopa'' is ''bhanvra'' (or ''bhomora'' - ভোমোৰা - in Assamese), and reports and sightings ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grayling (butterfly)
The grayling or rock grayling (''Hipparchia semele'') is a species in the brush-footed butterfly family Nymphalidae. Although found all over Europe, the grayling mostly inhabits coastal areas, with inland populations declining significantly in recent years. The grayling lives in dry and warm habitats with easy access to the sun, which helps them with body temperature regulation. A grayling goes through four stages in its life cycle. The eggs hatch around August, and larvae grow in four instars from August to the following June. By June, the larvae begin to pupate by spinning a silk cocoon below the surface of the ground. The adult grayling emerges around August. The grayling migrates in small groups of two or three butterflies throughout most of August, typically moving southeast. ''H. semele'' engages in cryptic coloring, with their tan and brown colored wings helping them camouflage into their surroundings. The grayling exposes the eyespots on its wings when it believes to have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vespula Squamosa
''Vespula squamosa'', or the southern yellowjacket, is a social wasp. This species can be identified by its distinctive black and yellow patterning and orange queen. This species is typically found in eastern North America, and its territory extends as far south as Central America. Within these territories, they create enormous, multiple-comb nests.MacDonald, John F., Matthews, R. W. "Nesting Biology of the Southern Yellowjacket, ''Vespula squamosa'' (Hymenoptera: Vespidae): Social Parasitism and Independent Founding", " Journal of the Kansas Entomological Society", January 1984. The colonies may be either annual or perennial depending on the climate, and in many perennial nests, polygyny takes place. In addition, this species uses pheromones both as a sexual attractant and an alarm signal.Landoldt, P. J. and Heath, R. R. "Alarm Pheromone Behavior of Vespula Squamosa (Hymenoptera: Vespidae)", "Florida Entomologist". June 1987. This species feeds on insects and animal carcasses; i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vertebrates
Vertebrates () are animals with a vertebral column (backbone or spine), and a cranium, or skull. The vertebral column surrounds and protects the spinal cord, while the cranium protects the brain. The vertebrates make up the subphylum Vertebrata with some 65,000 species, by far the largest ranked grouping in the phylum Chordata. The vertebrates include mammals, birds, amphibians, and various classes of fish and reptiles. The fish include the jawless Agnatha, and the jawed Gnathostomata. The jawed fish include both the Chondrichthyes, cartilaginous fish and the Osteichthyes, bony fish. Bony fish include the Sarcopterygii, lobe-finned fish, which gave rise to the tetrapods, the animals with four limbs. Despite their success, vertebrates still only make up less than five percent of all described animal species. The first vertebrates appeared in the Cambrian explosion some 518 million years ago. Jawed vertebrates evolved in the Ordovician, followed by bony fishes in the Devonian. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polygyny In Nature
Polygyny (; from Neo-Greek , ) is a mating system in which one male lives and mates with multiple females but each female only mates with a single male. Systems where several females mate with several males are defined either as promiscuity or polygynandry. Lek mating is frequently regarded as a form of polygyny, because one male mates with many females, but lek-based mating systems differ in that the male has no attachment to the females with whom he mates, and that mating females lack attachment to one another.Clutton-Brock T.H. (1989). ‘Review lecture: mammalian mating systems.' ''Proceedings of the Royal Society of London''. Series B, Biological Sciences 236: 339–372. Polygyny is typical of one-male, multi-female groupsBoyd, R., & Silk, J. B. (2009). How Humans Evolved (preferably the downloadable pdf version): WW Norton & Company, New York. and can be found in many species including: elephant seal, spotted hyena, gorilla, red-winged prinia, house wren, hamadryas baboo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
