Asexual reproduction is a type of reproduction that does not involve the fusion of gametes or change in the number of chromosomes. The offspring that arise by asexual reproduction from either unicellular or multicellular organisms inherit the full set of genes of their single parent and thus the newly created individual is genetically and physically similar to the parent or an exact clone of the parent. Asexual reproduction is the primary form of reproduction for single-celled organisms such as archaea and bacteria. Many eukaryotic organisms including plants, animals, and fungi can also reproduce asexually. In vertebrates, the most common form of asexual reproduction is parthenogenesis, which is typically used as an alternative to sexual reproduction in times when reproductive opportunities are limited. Komodo dragons and some monitor lizards can reproduce asexually.
Budding or blastogenesis is a type of asexual reproduction in which a new organism develops from an outgrowth or bud due to cell division at one particular site. For example, the small bulb-like projection coming out from the yeast cell is known as a bud. Since the reproduction is asexual, the newly created organism is a clone and excepting mutations is genetically identical to the parent organism. Organisms such as hydra use regenerative cells for reproduction in the process of budding.
Cheating is a term used in behavioral ecology and ethology to describe behavior whereby organisms receive a benefit at the cost of other organisms. Cheating is common in many mutualistic and altruistic relationships. A cheater is an individual who does not cooperate but can potentially gain the benefit from others cooperating. Cheaters are also those who selfishly use common resources to maximize their individual fitness at the expense of a group. Natural selection favors cheating, but there are mechanisms to regulate it. The stress gradient hypothesis states that facilitation, cooperation or mutualism should be more common in stressful environments, while cheating, competition or parasitism are common in benign environments.
Plant reproduction is the production of new offspring in plants, which can be accomplished by sexual or asexual reproduction. Sexual reproduction produces offspring by the fusion of gametes, resulting in offspring genetically different from either parent. Asexual reproduction produces new individuals without the fusion of gametes, resulting in clonal plants that are genetically identical to the parent plant and each other, unless mutations occur.
The European paper wasp is one of the most common and well-known species of social wasps in the genus Polistes. Its diet is more diverse than those of most Polistes species—many genera of insects versus mainly caterpillars in other Polistes—giving it superior survivability compared to other wasp species during a shortage of resources.
An organism is defined in a medical dictionary as any living thing that functions as an individual. Such a definition raises more problems than it solves, not least because the concept of an individual is also difficult. Many criteria, few of them widely accepted, have been proposed to define what is an organism. Among the commonest is that an organism has autonomous reproduction, growth, and metabolism. This would exclude viruses, despite the fact that they evolve like organisms. Other problematic cases include colonial organisms; a colony of eusocial insects is organised adaptively, and has germ-soma specialisation, with some insects reproducing, others not, like cells in an animal's body. The body of a siphonophore, a jelly-like marine animal, is composed of organism-like zooids, but the whole structure looks and functions much like an animal such as a jellyfish, the parts collaborating to provide the functions of the colonial organism.
Eusociality is the highest level of organization of sociality. It is defined by the following characteristics: cooperative brood care, overlapping generations within a colony of adults, and a division of labor into reproductive and non-reproductive groups. The division of labor creates specialized behavioral groups within an animal society which are sometimes referred to as 'castes'. Eusociality is distinguished from all other social systems because individuals of at least one caste usually lose the ability to perform behaviors characteristic of individuals in another caste. Eusocial colonies can be viewed as superorganisms.
Ropalidia marginata is an Old World species of paper wasp. It is primitively eusocial, not showing the same bias in brood care seen in other social insects with greater asymmetry in relatedness. The species employs a variety of colony founding strategies, sometimes with single founders and sometimes in groups of variable number. The queen does not use physical dominance to control workers; there is evidence of pheromones being used to suppress other female workers from overtaking queenship.
Polistes chinensis is a polistine vespid wasp in the cosmopolitan genus Polistes, and is commonly known as the Asian, Chinese or Japanese paper wasp. It is found in East Asia, in particular China and Japan. The subspecies P. chinensis antennalis is an invasive species in New Zealand, having arrived in 1979.
Polistes annularis is a species of paper wasp found throughout the eastern half of the United States. This species of red paper wasp is known for its large size and its red-and-black coloration and is variably referred to as a ringed paper wasp or jack Spaniard wasp. It builds its nest under overhangs near bodies of water that minimize the amount of sunlight penetration. It clusters its nests together in large aggregations, and consumes nectar and other insects. Its principal predator is the ant, although birds are also known to prey on it. Unlike other wasps, P. annularis is relatively robust in winter conditions, and has also been observed to store honey in advance of hibernation. This species has also been used as a model species to demonstrate the ability to use microsatellite markers in maternity assignment of social insects.
Polistes metricus is a wasp native to North America. In the United States, it ranges throughout the southern Midwest, the South, and as far northeast as New York, but has recently been spotted in southwest Ontario. A single female specimen has also been reported from Dryden, Maine. P. metricus is dark colored, with yellow tarsi and black tibia. Nests of P. metricus can be found attached to the sides of buildings, trees, and shrubbery.
Within the insect order Hymenoptera, the Halictinae are the largest, most diverse, and most recently diverged of the four halictid subfamilies. They comprise over 2400 bee species belonging to the five taxonomic tribes Augochlorini, Thrinchostomini, Caenohalictini, Sphecodini, and Halictini, which some entomologists alternatively organize into the two tribes Augochlorini and Halictini.
Polistes fuscatus, whose common name is the dark or northern paper wasp, is widely found in eastern North America, from southern Canada through the southern United States. It often nests around human development. However, it greatly prefers areas in which wood is readily available for use as nest material, therefore they are also found near and in woodlands and savannas. P. fuscatus is a social wasp that is part of a complex society based around a single dominant foundress along with other cofoundresses and a dominance hierarchy.
Synalpheus regalis is a species of snapping shrimp that commonly live in sponges in the coral reefs along the tropical West Atlantic. They form a prominent component of the diverse marine cryptofauna of the region. For the span of their entire lives, they live in the internal canals of the host sponge, using it as a food resource and shelter. It has been shown that colonies contain over 300 individuals, but only one reproductive female. Also, larger colony members, most of which apparently never breed, defend the colony against heterospecific intruders. This evidence points towards the first known case of eusociality in a marine animal.
Polistes carolina is one of two species of red paper wasp found in the eastern United States and is noted for the finer ridges on its propodeum. It is a social wasp in the family Vespidae and subfamily Polistinae. The species is native to the United States from Texas to Florida, north to New York, and west to Nebraska. The wasp's common name is due to the reddish-brown color of its head and body. P. carolina prefer to build their nests in protected spaces.
Ropalidia fasciata, a common paper wasp, is a wide-ranging species that is distributed from India to the Lesser Sunda Islands, Palawan, and Ryukyu Islands, occupying the northern edge of Ropalidia's larger distribution. These primitively eusocial wasps are unique in that they do not exhibit the strict matrifilial, single-queen social structure found in many species of social insects. Instead, colonies are founded based on associations between several females, or 'foundresses'.
Polistes dorsalis is a species of social wasps that can be found throughout various parts of North America. It is classified under the Vespidae within the genus of Polistes. Male Polistes dorsalis wasps can be distinguished from other Polistes species by their distinctly prominent median tubercle of sternum 7. Both sexes can also be recognized due to their v- shaped yellow markings on their head. They are distributed widely across North America and can be found in sheltered nests, typically closer to the ground. These wasps live in a dominance hierarchy in which the queen's role differs from that of ordinary workers. When threatened, these wasps can deliver moderately painful stings. Their venom might also be of human interest for their antimicrobial uses.
Halictus sexcinctus, commonly referred to as the six-banded furrow bee, is a species of sweat bee found throughout Europe and as far east as Asian Turkey and Iraq. The H. sexcinctus can be easily confused with the closely related species, Halictus scabiosae, due to very similar morphological features. H. sexcinctus show a social polymorphism in which different colonies can exhibit solitary, communal, or eusocial structure. Due to this large variance in social organization, it was suspected that it was not one species at all, but rather multiple, cryptic species. However, genetic analysis was able to confirm these varying populations as one species. H. sexcinctus will forage from multiple flower species, but prefers plant species with wide-open flowers. Their nests can be found dug into the ground in loamy or sandy soil.
Social immunity is any antiparasite defence mounted for the benefit of individuals other than the actor. For parasites, the frequent contact, high population density and low genetic variability makes social groups of organisms a promising target for infection: this has driven the evolution of collective and cooperative anti-parasite mechanisms that both prevent the establishment of and reduce the damage of diseases among group members. Social immune mechanisms range from the prophylactic, such as burying beetles smearing their carcasses with antimicrobials or termites fumigating their nests with naphthalene, to the active defenses seen in the imprisoning of parasitic beetles by honeybees or by the miniature 'hitchhiking' leafcutter ants which travel on larger worker's leaves to fight off parasitoid flies. Whilst many specific social immune mechanisms had been studied in relative isolation, it was not until Sylvia Cremer et al.'s 2007 paper "Social Immunity" that the topic was seriously considered. Empirical and theoretical work in social immunity continues to reveal not only new mechanisms of protection but also implications for understanding of the evolution of group living and polyandry.
In biology, Gonozooids are any of the reproductive individuals of Tunicates, Bryozoan, or Hydrozoan colonies that produce gametes. Gonozooids may play a role in labour division or in alternation of generations. A gonozooid typically has hardly any other function than reproduction, amounting to little more than a motile gonad.
