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William D. Hamilton
William Donald Hamilton (1 August 1936 – 7 March 2000) was a British evolutionary biologist, recognised as one of the most significant evolutionary theorists of the 20th century. Hamilton became known for his Theoretical biology, theoretical work expounding a rigorous Genetics, genetic basis for the existence of altruism (biology), altruism, an insight that was a key part of the development of the gene-centered view of evolution. He is considered one of the forerunners of sociobiology. Hamilton published important work on sex ratios and the evolution of sex. From 1984 to his death in 2000, he was a Royal Society Research Professor at Oxford University. Early life Hamilton was born in 1936 in Cairo, Egypt, the second of seven children. His parents were from New Zealand; his father A.M. Hamilton was an engineer, and his mother B.M. Hamilton was a physician. The Hamilton family settled in Kent. During the Second World War, Hamilton was evacuated to Edinburgh. He became interes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cairo
Cairo ( ; ar, القاهرة, al-Qāhirah, ) is the capital of Egypt and its largest city, home to 10 million people. It is also part of the largest urban agglomeration in Africa, the Arab world and the Middle East: The Greater Cairo metropolitan area, with a population of 21.9 million, is the 12th-largest in the world by population. Cairo is associated with ancient Egypt, as the Giza pyramid complex and the ancient cities of Memphis and Heliopolis are located in its geographical area. Located near the Nile Delta, the city first developed as Fustat, a settlement founded after the Muslim conquest of Egypt in 640 next to an existing ancient Roman fortress, Babylon. Under the Fatimid dynasty a new city, ''al-Qāhirah'', was founded nearby in 969. It later superseded Fustat as the main urban centre during the Ayyubid and Mamluk periods (12th–16th centuries). Cairo has long been a centre of the region's political and cultural life, and is titled "the city of a thousand m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linnean Medal
The Linnean Medal of the Linnean Society of London was established in 1888, and is awarded annually to alternately a botanist or a zoologist or (as has been common since 1958) to one of each in the same year. The medal was of gold until 1976, and is for the preceding years often referred to as "the Gold Medal of the Linnean Society", not to be confused with the official Linnean Gold Medal which is seldom awarded. The engraver of the medal was Charles Anderson Ferrier of Dundee, a Fellow of the Linnean Society from 1882. On the obverse of the medal is the head of Linnaeus in profile and the words Carl Linnaeus, "Carolus Linnaeus", on the reverse are the arms of the society and the legend ''"Societas Linnaeana optime merenti"''; an oval space is reserved for the recipient's name.Gage A.T. and Stearn W.T. (1988) ''A Bicentenary History of the Linnean Society of London'', Linnean Society of London, p. 80 Linnean medallists 19th century *1888: Joseph Dalton Hooker, Sir Joseph D. Hoo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evolution Of Sex
Sexual reproduction is an adaptive feature which is common to almost all multicellular organisms and various unicellular organisms, with some organisms being incapable of asexual reproduction. Currently the adaptive advantage of sexual reproduction is widely regarded as a major unsolved problem in biology. As discussed below, one prominent theory is that sex evolved as an efficient mechanism for producing variation, and this had the advantage of enabling organisms to adapt to changing environments. Another prominent theory, also discussed below, is that a primary advantage of outcrossing sex is the masking of the expression of deleterious mutations. Additional theories concerning the adaptive advantage of sex are also discussed below. Sex does, however, come with a cost. In reproducing asexually, no time nor energy needs to be expended in choosing a mate. And if the environment has not changed, then there may be little reason for variation, as the organism may already be wel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sex Ratio
The sex ratio (or gender ratio) is usually defined as the ratio of males to females in a population. As explained by Fisher's principle, for evolutionary reasons this is typically about 1:1 in species which reproduce sexually. Many species deviate from an even sex ratio, either periodically or permanently. Examples include parthenogenic species, periodically mating organisms such as aphids, some eusocial wasps, bees, ants, and termites. The human sex ratio is of particular interest to anthropologists and demographers. In human societies, sex ratios at birth may be considerably skewed by factors such as the age of mother at birth and by sex-selective abortion and infanticide. Exposure to pesticides and other environmental contaminants may be a significant contributing factor as well. As of 2014, the global sex ratio at birth is estimated at 107 boys to 100 girls (1,000 boys per 934 girls).. Types In most species, the sex ratio varies according to the age profile of the populat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sociobiology
Sociobiology is a field of biology that aims to examine and explain social behavior in terms of evolution. It draws from disciplines including psychology, ethology, anthropology, evolution, zoology, archaeology, and population genetics. Within the study of human societies, sociobiology is closely allied to evolutionary anthropology, human behavioral ecology, evolutionary psychology, and sociology. Sociobiology investigates social behaviors such as mating patterns, territorial fights, pack hunting, and the hive society of social insects. It argues that just as selection pressure led to animals evolving useful ways of interacting with the natural environment, so also it led to the genetic evolution of advantageous social behavior. While the term "sociobiology" originated at least as early as the 1940s, the concept did not gain major recognition until the publication of E. O. Wilson's book '' Sociobiology: The New Synthesis'' in 1975. The new field quickly became the subject of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene-centered View Of Evolution
With gene defined as "not just one single physical bit of DNA utall replicas of a particular bit of DNA distributed throughout the world", the gene-centered view of evolution, gene's eye view, gene selection theory, or selfish gene theory holds that adaptive evolution occurs through the differential survival of competing genes, increasing the allele frequency of those alleles whose phenotypic trait effects successfully promote their own propagation. The proponents of this viewpoint argue that, since heritable information is passed from generation to generation almost exclusively by DNA, natural selection and evolution are best considered from the perspective of genes. Proponents of the gene-centered viewpoint argue that it permits understanding of diverse phenomena such as altruism and intragenomic conflict that are otherwise difficult to explain from an organism-centered viewpoint. The gene-centered view of evolution is a synthesis of the theory of evolution by natural sele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Altruism (biology)
In biology, altruism refers to behaviour by an individual that increases the fitness of another individual while decreasing the fitness of the agent. Altruism in this sense is different from the philosophical concept of altruism, in which an action would only be called "altruistic" if it was done with the conscious intention of helping another. In the behavioural sense, there is no such requirement. As such, it is not evaluated in moral terms—it is the consequences of an action for reproductive fitness that determine whether the action is considered altruistic, not the intentions, if any, with which the action is performed. The term altruism was coined by the French philosopher Auguste Comte in French, as ''altruisme'', for an antonym of egoism. He derived it from the Italian ''altrui'', which in turn was derived from Latin ''alteri'', meaning "other people" or "somebody else". Altruistic behaviours appear most obviously in kin relationships, such as in parenting, but may als ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetics
Genetics is the study of genes, genetic variation, and heredity in organisms.Hartl D, Jones E (2005) It is an important branch in biology because heredity is vital to organisms' evolution. Gregor Mendel, a Moravian Augustinian friar working in the 19th century in Brno, was the first to study genetics scientifically. Mendel studied "trait inheritance", patterns in the way traits are handed down from parents to offspring over time. He observed that organisms (pea plants) inherit traits by way of discrete "units of inheritance". This term, still used today, is a somewhat ambiguous definition of what is referred to as a gene. Trait inheritance and molecular inheritance mechanisms of genes are still primary principles of genetics in the 21st century, but modern genetics has expanded to study the function and behavior of genes. Gene structure and function, variation, and distribution are studied within the context of the cell, the organism (e.g. dominance), and within the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theoretical Biology
Mathematical and theoretical biology, or biomathematics, is a branch of biology which employs theoretical analysis, mathematical models and abstractions of the living organisms to investigate the principles that govern the structure, development and behavior of the systems, as opposed to experimental biology which deals with the conduction of experiments to prove and validate the scientific theories. The field is sometimes called mathematical biology or biomathematics to stress the mathematical side, or theoretical biology to stress the biological side. Theoretical biology focuses more on the development of theoretical principles for biology while mathematical biology focuses on the use of mathematical tools to study biological systems, even though the two terms are sometimes interchanged. Mathematical biology aims at the mathematical representation and modeling of biological processes, using techniques and tools of applied mathematics. It can be useful in both theoretical and prac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
A Devil's Chaplain
''A Devil's Chaplain: Reflections on Hope, Lies, Science, and Love'' is a 2003 book of selected essays and other writings by Richard Dawkins. Published five years after Dawkins's previous book ''Unweaving the Rainbow'', it contains essays covering subjects including pseudoscience, genetic determinism, memetics, terrorism, religion and creationism. A section of the book is devoted to Dawkins' late adversary Stephen Jay Gould. The book's title is a reference to a quotation of Charles Darwin, in a letter to J.D. Hooker dated 13 July 1856, made in reference to Darwin's lack of belief in how "a perfect world" was designed by God (and a reference to Reverend Robert Taylor): "What a book a devil's chaplain might write on the clumsy, wasteful, blundering low and horridly cruel works of nature!" Reception Robin McKie reviewed the book for ''The Observer'' and stated that the book contained a mixture of touching essays and "the good, old knockabout stuff at which Dawkins excels". ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evolution
Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation tends to exist within any given population as a result of genetic mutation and recombination. Evolution occurs when evolutionary processes such as natural selection (including sexual selection) and genetic drift act on this variation, resulting in certain characteristics becoming more common or more rare within a population. The evolutionary pressures that determine whether a characteristic is common or rare within a population constantly change, resulting in a change in heritable characteristics arising over successive generations. It is this process of evolution that has given rise to biodiversity at every level of biological organisation, including the levels of species, individual organisms, and molecules. The theory of evolution by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evolutionary Biologist
Evolutionary biology is the subfield of biology that studies the evolutionary processes (natural selection, common descent, speciation) that produced the diversity of life on Earth. It is also defined as the study of the history of life forms on Earth. Evolution is based on the theory that all species are related and they gradually change over time. In a population, the genetic variations affect the physical characteristics i.e. phenotypes of an organism. These changes in the phenotypes will be an advantage to some organisms, which will then be passed onto their offspring. Some examples of evolution in species over many generations are the Peppered Moth and Flightless birds. In the 1930s, the discipline of evolutionary biology emerged through what Julian Huxley called the modern synthesis of understanding, from previously unrelated fields of biological research, such as genetics and ecology, systematics, and paleontology. The importance of studying Evolutionary biology is ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
