A clade, also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, the equivalent Latin term cladus is often used in taxonomical literature.
In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor and all of its lineal descendants. Monophyletic groups are typically characterised by shared derived characteristics (synapomorphies), which distinguish organisms in the clade from other organisms. An equivalent term is holophyly.
Symbiosis is any type of a close and long-term biological interaction between two different biological organisms, be it mutualistic, commensalistic, or parasitic. The organisms, each termed a symbiont, must be of different species. In 1879, Heinrich Anton de Bary defined it as "the living together of unlike organisms". The term was subject to a century-long debate about whether it should specifically denote mutualism, as in lichens. Biologists have now abandoned that restriction.
Chronobiology is a field of biology that examines timing processes, including periodic (cyclic) phenomena in living organisms, such as their adaptation to solar- and lunar-related rhythms. These cycles are known as biological rhythms. Chronobiology comes from the ancient Greek χρόνος, and biology, which pertains to the study, or science, of life. The related terms chronomics and chronome have been used in some cases to describe either the molecular mechanisms involved in chronobiological phenomena or the more quantitative aspects of chronobiology, particularly where comparison of cycles between organisms is required.
The Linnean Society of London is a learned society dedicated to the study and dissemination of information concerning natural history, evolution, and taxonomy. It possesses several important biological specimen, manuscript and literature collections, and publishes academic journals and books on plant and animal biology. The society also awards a number of prestigious medals and prizes.
Cladogenesis is an evolutionary splitting of a parent species into two distinct species, forming a clade.
Anagenesis is the gradual evolution of a species that continues to exist as an interbreeding population. This contrasts with cladogenesis, which occurs when there is branching or splitting, leading to two or more lineages and resulting in separate species. Anagenesis does not always lead to the formation of a new species from an ancestral species. When speciation does occur as different lineages branch off and cease to interbreed, a core group may continue to be defined as the original species. The evolution of this group, without extinction or species selection, is anagenesis.
The Zoological Journal of the Linnean Society is a monthly peer-reviewed scientific journal covering zoology published by Oxford University Press on behalf of the Linnean Society. The editor-in-chief is Maarten Christenhusz. It was established in 1856 as the Journal of the Proceedings of the Linnean Society of London. Zoology and renamed Journal of the Linnean Society of London, Zoology in 1866. It obtained its current title in 1969.
Zoogeography is the branch of the science of biogeography that is concerned with geographic distribution of animal species.
Walter Maurice Elsasser was a German-born American physicist, a developer of the presently accepted dynamo theory as an explanation of the Earth's magnetism. He proposed that this magnetic field resulted from electric currents induced in the fluid outer core of the Earth. He revealed the history of the Earth's magnetic field by the study of the magnetic orientation of minerals in rocks. He was also the first to suggest that the wave-like nature of matter might be investigated by electron scattering experiments using crystalline solids.
In phylogenetics, a sister group or sister taxon comprises the closest relative(s) of another given unit in an evolutionary tree.
Nematothallus is a form genus comprising cuticle-like fossils. Some of its constituents likely represent red algae, whereas others resemble lichens.
The Botanical Journal of the Linnean Society is a scientific journal publishing original papers relating to the taxonomy of all plant groups and fungi, including anatomy, biosystematics, cytology, ecology, ethnobotany, electron microscopy, morphogenesis, palaeobotany, palynology and phytochemistry.
James Mallet is an evolutionary zoologist specialising in entomology.
In biology, a phylum is a level of classification or taxonomic rank below kingdom and above class. Traditionally, in botany the term division has been used instead of phylum, although the International Code of Nomenclature for algae, fungi, and plants accepts the terms as equivalent. Depending on definitions, the animal kingdom Animalia contains about 31 phyla, the plant kingdom Plantae contains about 14 phyla, and the fungus kingdom Fungi contains about 8 phyla. Current research in phylogenetics is uncovering the relationships between phyla, which are contained in larger clades, like Ecdysozoa and Embryophyta.
Edward Stuart Russell OBE FLS was a Scottish biologist and philosopher of biology.
Grace Coleridge Frankland known as Mrs Percy Franklandnée Grace Toynbee was an English microbiologist. She was one of the nineteen female scientists who wrote the 1904 petition to the Chemical Society to request that they should create some female fellows of the society.
Pachymerium ferrugineum is a species of centipede in the family Geophilidae that can be found in Central Europe, the Iberian Peninsula, Scandinavia, Asian countries such as Japan and Turkey, and on African islands such as the Azores, Canary Islands and Crete. It is also distributed in Alaska and Mexico.
Rhabdocoela is an order of flatworms in the class Rhabditophora with about 1700 species described worldwide. Most of rhabdocoels are free-living organisms, but some live symbiotically with other animals.
Nonadaptive radiations are a subset of evolutionary radiations that are characterized by diversification that is not driven by resource partitioning. The species that are a part of a nonadaptive radiation will tend to have very similar niches, and in many cases will be morphologically similar. Nonadaptive radiations are driven by nonecological speciation. In many cases, this nonecological speciation is allopatric, and the organisms are dispersal-limited such that populations can be geographically isolated within a landscape with relatively similar ecological conditions. For example, Albinaria land snails on islands in the Mediterranean and Batrachoseps salamanders from California each include relatively dispersal-limited, and closely related, ecologically similar species often have minimal range overlap, a pattern consistent with allopatric, nonecological speciation. In other cases, such as certain damselflies and crickets from Hawaii, there can be range overlap in closely related species, and it is likely that sexual selection plays a role in maintaining species boundaries.
