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Amniote

The amniotes are a taxonomic group of animals: all the tetrapods except the amphibians. They are the land vertebrates which lay cleidoic eggs. Two super-groups make up the amniotes: the Synapsida Pelycosaurs, Theriodonts and mammals and the Sauro ...

                                               

Antibiotic resistance

Antibiotics kill certain types of bacteria. Over time, those bacteria change to develop a resistance to the antibiotics. Called antibiotic resistance, this is one of the most serious problems facing modern surgery and medicine. It is also one of ...

                                               

Appendix (anatomy)

In human anatomy, the appendix is a blind ended tube connected to the cecum. The caecum is a pouch-like part of the colon. The appendix is near the junction of the small intestine and the large intestine. The term "vermiform" comes from Latin and ...

                                               

Basal

Basal is a term in biology for primitive or ancestral. Basal is preferred because it is neutral and non-judgmental. This terminology came into use with cladistics. The term is used in evolution and classification to mean the group which gave rise ...

                                               

Biological species concept

The biological species concept gives an explanation of how species form. A biological species is a group of individuals that can breed together. However, they cannot breed with other groups. In other words, the group is reproductively isolated fr ...

                                               

Cambrian explosion

The Cambrian explosion is when many animal phyla first appeared in the fossil record. It happened 541 million years ago. Probably most had evolved before then, but that was their first appearance as fossils. Before about 580 mya it seems that mos ...

                                               

Cline

In biology, a cline, or ecocline, describes a series of connected populations in a species. These populations show a continuous gradient of traits and genetics. The term was coined by the English evolutionary biologist Julian Huxley in 1938. He d ...

                                               

Common descent

In evolutionary biology, a group of organisms have common descent if they have a common ancestor. "There is strong quantitative support, by a formal test" for the theory that all living organisms on Earth are descended from a common ancestor. Cha ...

                                               

Cro-Magnon

The earliest known Cro-Magnon remains are between 35.000 and 45.000 years old, based on radiometric dating. The oldest remains, from 43.000 – 45.000 years ago, were found in Italy and Britain. Other remains also show that Cro-Magnons reached the ...

                                               

DNA barcoding

DNA barcoding is a form of genetic analysis. It is part of molecular biology. Scientists use DNA barcoding to tell different species apart from each other. Scientists use DNA barcoding to tell which species are related to each other or evolved fr ...

                                               

Eusociality

Eusociality is a term in animal behaviour for the more complex kinds of social organisation. The term "eusocial" was introduced in 1966 by Suzanne Batra. E.O. Wilson gave it a more precise meaning.

                                               

Evolution of cetaceans

The Cetaceans are mammalian marine descendants of land mammals. Their terrestrial origins are indicated by: Their need to breathe air from the surface. The vertical movement of their spines, characteristic more of a running mammal than of the hor ...

                                               

Evolutionary grade

An evolutionary grade is a group of species at the same level of organisation. It refers to a group of animals or plants which are very similar, but which are not a clade. They have a similar morphological or physiological complexity, and they ar ...

                                               

Evolutionary psychology

Evolutionary psychology is a branch of psychology which investigates behaviour which has evolved. It is similar in this respect to ethology, which has always used ideas from evolutionary biology. It seeks to identify which human psychological tra ...

                                               

Evolutionary suicide

Evolutionary suicide is not a standard term in evolutionary biology. It is not used in any standard textbook on evolution. It is the incorrect idea that the adaptation of an individual animal works in such a way that an entire species dies out. T ...

                                               

Extinction

Extinction is when a species of animal, plant, or other organisms are no longer living. Extinction is one of the major features of evolution. All species become extinct sooner or later. The end of a species may happen for many reasons. It may be ...

                                               

Fitness

Fitness in biology is the relative ability of an organism to survive and pass on its genes to the next generation. p160 It is a central idea in evolutionary theory. Fitness is usually equal to the proportion of the individuals genes in all the ge ...

                                               

Halteres

Halteres are small knobbed structures modified from the hind wings in flies. They vibrate during flight, and help the insect fly better. The halteres evolved from wings. Ancestral flying insects had two pairs of wings, like dragonflies, hymenopte ...

                                               

Hardy–Weinberg law

The Hardy–Weinberg law was developed independently by an English mathematician, G.H. Hardy, and a German doctor, Wilhelm Weinberg. This concept is also known as the Hardy–Weinberg equilibrium, Hardy–Weinberg theorem or Hardy–Weinberg principle. S ...

                                               

Island dwarfism

Island dwarfism, or insular dwarfism, is the reduction in size of large animals over a number of generations. The same process can happen in evolution on a mainland: an example is the evolution of the dwarfed marmosets and tamarins among New Worl ...

                                               

Kin selection

Kin selection or kin altruism is a form of natural selection. Some animals cooperate with relatives, even if this brings risk to themselves. The classic example of this is seen in the family life of mammals, or in colonial insects such as ants. M ...

                                               

Lactase

Lactase is an enzyme which acts on lactose, breaking it down so it can be digested. Mammals in their infancy usually make lactase: they need it for digesting the lactose found in their mothers milk. Mammalian adults usually lose the capacity to p ...

                                               

Megaevolution

Megaevolution is a term which describes the most dramatic events in evolution. By that is not meant a different kind of evolution, rather, it means evolution which produces a tremendous effect. It is not suggested that the evolutionary processes ...

                                               

Molecular evolution

Molecular evolution is the process of evolution in DNA, RNA, and proteins. Molecular evolution emerged as a scientific field in the 1960s as researchers from molecular biology, evolutionary biology and population genetics sought to understand the ...

                                               

Mosaic evolution

In mosaic evolution some characters in a transitional form are basal, while others are remarkably advanced. Apparently, evolutionary change takes place rapidly in some body parts or systems without simultaneous changes in other parts. Another def ...

                                               

Origin of birds

The origin of birds is one of the most interesting questions in palaeontology and evolution. Birds evolved from theropod dinosaurs during the Mesozoic era. Thomas Henry Huxley "Darwins bulldog", who was a comparative anatomist, made a study of th ...

                                               

Ossicles

The ossicles are the three smallest bones in the human body. They may be called ear bones or auditory ossicles. They are in the auditory system of all mammals. They are contained within the middle ear space and serve to transmit sounds from the a ...

                                               

Paleontology

Palaeontology or Paleontology is the study of fossils of living things, and their phylogeny. It depends on basic sciences such as zoology, botany and historical geology. The term palaeobiology implies that the study will investigate the palaeoeco ...

                                               

Peppered moth evolution

The evolution of the peppered moth has been studied in detail over the last 150 years. At first, almost all of the moths were light coloured. This gave them camouflage against the light-coloured trees and lichens where they rested during the day. ...

                                               

Phylogeny

A phylogeny is a proposal of how organisms are related by their evolutionary history. p336 It is based on the evidence that all living things are related by common descent. The evidence for phylogeny comes from palaeontology, comparative anatomy, ...

                                               

Pleiotropism

Pleiotropism is a central term in developmental genetics. In pleiotropism, a single gene affects a number of phenotypic traits in the same organism. These pleiotropic effects often seem to be unrelated to each other. The usual underlying mechanis ...

                                               

Reproductive isolation

Reproductive isolation refers to the situation where different species may live in the same area, but properties of individuals prevent them from interbreeding. The things which stop species or groups of organisms reproducing sexually are called ...

                                               

Rolling and wheels in the natural world

There are two ways that natural and man-made things can use rotation to move around. One way is for the entire thing to roll. The other way is for part of the thing to turn while the rest does not, like a wheel or a propeller. Some living things ...

                                               

Sequence analysis

Sequence analysis in molecular biology involves identifying the sequence of nucleotides in a nucleic acid, or amino acids in a peptide or protein. Once a sample has been obtained, DNA sequences may be produced automatically by machine and the res ...

                                               

Sexual conflict

Sexual conflict is a term in evolutionary biology. It occurs in a species when what benefits the females is different from what benefits the males. The word benefit here means what benefits the reproduction of the females or males genes. It is ex ...

                                               

Sexual selection

Sexual selection is a special kind of natural selection. It is a theory of Charles Darwin that certain traits can be explained by competition within a species. Darwin defined sexual selection as the effects of the "struggle between the individual ...

                                               

Social darwinism

Social darwinism is a term used for different movements. Charles Darwin was one of the main proponents of evolution. Evolution is a concept from biology that tries to explain how different life-forms change over time. It basically says that becau ...

                                               

Struggle for existence

The struggle for existence is a natural history. It refers to the competition between living things to survive. This, and the similar phrase struggle for life, were used over 40 times by Charles Darwin in the Origin of Species, and the phrase is ...

                                               

Systematics

Systematics is one of the main fields in biology. It is closely related to taxonomy. Systematics is the study of the diversification of life on the planet Earth, both past and present, and the relationships among living things through time. Relat ...

                                               

Trait

A trait or character in biology is a feature of a living thing. It is part of an organisms phenotype. Every living thing, from tiny organisms like bacteria, to plants, animals and humans, has some characteristics which make it special. Thus an el ...

                                               

Transitional fossil

Transitional fossils are the fossilised remains of lifeforms that show features typical of two distinct groups. It may be a rare fossil, such as Archaeopteryx, which shows early features of a group which later becomes widespread. The rarity of tr ...

                                               

Transposon

A transposon is a sequence of DNA that can move to new positions within the genome of a single cell. The press called them jumping genes, but it is not correct to call them genes. Transposons were first found by Barbara McClintock while working o ...

                                               

Tree of life (biology)

The tree of life is a metaphor which expresses the idea that all life is related by common descent. Charles Darwin was the first to use this metaphor in modern biology. It had been used many times before for other purposes. The evolutionary tree ...

                                               

Vestigial organ

Vestigial organs are organs of the body which are smaller and simpler than those in related species. They have lost, or almost lost their original feature. Vestigiality is evidence for evolution, since they only make sense if evolution has occurr ...

                                               

Genetics

Genetics is a discipline of biology. It is the science of heredity. This includes the study of genes, and the inheritance of variation and traits of living organisms. In the laboratory, genetics proceeds by mating carefully selected organisms, an ...

                                               

Alternative splicing

Alternative splicing allows DNA to code for more than one protein. It varies the exon make-up of the messenger RNA. In alternative splicing the exons of the pre-messenger RNA produced by transcription are reconnected in different ways during RNA ...

                                               

Antisuppressor

Antisuppressor is a mutation with the response against suppression effects of nonsense suppression or suppression chemicals. In 1976, Rieger, Michaelis, and Green have been stated: antisuppressor – a mutation which countreacts suppressor effects ...

                                               

Apomixis

Apomixis is reproduction where only one parent passes genes to the offspring. Apomictically produced offspring are genetically identical to the parent. The method is most seen in plants, especially flowering plants. Brambles blackberry are apomic ...

                                               

Celera

Celera is a corporation registered in California, U.S.A. It was founded to discover and sell information about DNA sequence analysis, especially the human genome. The company is now wholly owned by Quest Diagnostics, a corporation which runs clin ...

                                               

Conserved sequence

Conserved sequences are similar or identical sequences which occur in DNA, and cause sequences in RNA, proteins and carbohydrates. These sequences occur across species. This shows that the sequences has been maintained in evolution despite specia ...

Encyclopedic dictionary

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Pino - logical board game which is based on tactics and strategy. In general this is a remix of chess, checkers and corners. The game develops imagination, concentration, teaches how to solve tasks, plan their own actions and of course to think logically. It does not matter how much pieces you have, the main thing is how they are placement!

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