Glossary A phenotypic characteristic, acquired during growth and development, that is not genetically based and therefore cannot be passed on to the next generation (for example, the large muscles of a weightlifter). Also used to describe the process of genetic change within a population, as influenced by natural selection. Peaks on the landscape correspond to genotypic frequencies at which the average fitness is high, valleys to genotypic frequencies at which the average fitness is low. Also called a fitness surface. A behavior has adaptive logic if it tends to increase the number of offspring that an individual contributes to the next and following generations. If such a behavior is even partly genetically determined, it will tend to become widespread in the population. Then, even if circumstances change such that it no longer provides any survival or reproductive advantage, the behavior will still tend to be exhibited - - unless it becomes positively disadvantageous in the new environment. The friends famously started performing together as students at Cambridge before launching themselves as a TV double act that could take on anything from comedy. Enter your details below to login. If you are an existing member of The Times and The Sunday Times enjoying the full benefits of thetimes.co.uk, then simply.
I am writing to express my satisfaction with a recent purchase from Sam Ash and to sing the praises of 'Big Jim' in the guitar department. I stopped in last week. The diversification, over evolutionary time, of a species or group of species into several different species or subspecies that are typically adapted to different ecological niches (for example, Darwin's finches). The term can also be applied to larger groups of organisms, as in . Species adapt when succeeding generations emphasize beneficial characteristics. A person who believes that the existence of a god or creator and the nature of the universe is unknowable. The term has no direct taxonomic significance. Algae range from macroscopic seaweeds such as giant kelp, which frequently exceeds 3. The Solar cooler goes wherever you do; Save Time. No need to stop for ice, just pack up and go! Plug right in and let the sun provide a.Spirogyra and Chlorella. One of the alternative forms of a gene. For example, if a gene determines the seed color of peas, one allele of that gene may produce green seeds and another allele produce yellow seeds. In a diploid cell there are usually two alleles of any. Within a population there may be many different alleles of a gene; each has a unique nucleotide sequence. For example, an allometric relation exists between brain size and body size, such that (in this case) animals with bigger bodies tend to have bigger brains. Allometric relations can be studied during the growth of a single organism, between different organisms within a species, or between organisms in different species. Speciation that occurs when two or more populations of a species are geographically isolated from one another sufficiently that they do not interbreed. Compare with sympatry. The unit molecular building block of proteins, which are chains of amino acids in a certain sequence. There are 2. 0 main amino acids in the proteins of living things, and the properties of a protein are determined by its particular amino acid sequence. A series of amino acids, the building blocks of proteins, usually coded for by DNA. The group of reptiles, birds, and mammals. These all develop through an embryo that is enclosed within a membrane called an amnion. The amnion surrounds the embryo with a watery substance, and is probably an adaptation for breeding on land. The class of vertebrates that contains the frogs, toads, newts, and salamanders. The amphibians evolved in the Devonian period (about 3. They have moist scaleless skin which is used to supplement the lungs in gas exchange. The eggs are soft and vulnerable to drying, therefore reproduction commonly occurs in water. Amphibian larvae are aquatic, and have gills for respiration; they undergo metamorphosis to the adult form. Most amphibians are found in damp environments and they occur on all continents except Antarctica. Structures in different species that look alike or perform similar functions (e. Contrast with homologous structures. Note: The recent discovery of deep genetic homologies has brought new interest, new information, and discussion to the classical concepts of analogous and homologous structures. Compare with derived homology. A member of the group of primates made up of monkeys, apes, and humans. Substances that destroy or inhibit the growth of microorganisms, particularly disease- causing bacteria. A heritable trait in microorganisms that enables them to survive in the presence of an antibiotic. Of a camera, the adjustable opening through which light passes to reach the film. The diameter of the aperture determines the intensity of light admitted. The pupil of a human eye is a self- adjusting aperture. The study of human history and prehistory through the excavation of sites and the analysis of physical remains, such as graves, tools, pottery, and other artifacts. The original form or body plan from which a group of organisms develops. The process by which humans breed animals and cultivate crops to ensure that future generations have specific desirable characteristics. In artificial selection, breeders select the most desirable variants in a plant or animal population and selectively breed them with other desirable individuals. The forms of most domesticated and agricultural species have been produced by artificial selection; it is also an important experimental technique for studying evolution. A type of reproduction involving only one parent that ususally produces genetically identical offspring. Asexual reproduction occurs without fertilization or genetic recombination, and may occur by budding, by division of a single cell, or by the breakup of a whole organism into two or more new individuals. The tendency of like to mate with like. Mating can be assortative for a certain genotype (e. AA tend to mate with other individuals of genotype AA) or phenotype (e. A small rocky or metallic body orbitting the Sun. About 2. 0,0. 00 have been observed, ranging in size from several hundred kilometers across down to dust particles. The doctrine or belief that there is no god. Mendelian inheritance is an atomistic theory because in it, inheritance is controlled by distinct genes. A group of bipedalhominidspecies belonging to the genus. Australopithecus that lived between 4. An early australopithecine species that was bipedal; known fossils date between 3. Lucy). Of, relating to, or characteristic of birds (members of the class Aves). Tiny, single- celled, prokaryotic organisms that can survive in a wide variety of environments. Some cause serious infectious diseases in humans, other animals, and plants. The DNA molecule is a chain of nucleotide units; each unit consists of a backbone made of a sugar and a phosphate group, with a nitrogenous base attached. The base in a unit is one of adenine (A), guanine (G), cytosine (C), or thymine (T). In RNA, uracil (U) is used instead of thymine. A and G belong to the chemical class called purines; C, T, and U are pyrimidines. An extinct marine invertebrate that was related to squid, octopi, and chambered nautiluses. We know from the fossil record that belemnites were common in the Jurassic period and had bullet- shaped internal skeletons. Ecosystem diversity describes the variety of habitats present; species diversity is a measure of the number of species and the number of individuals of each species present; genetic diversity refers to the total amount of genetic variability present. Name given by Haeckel to recapitulation. The study of patterns of geographical distribution of plants and animals across Earth, and the changes in those distributions over time. The concept of species, according to which a species is a set of organisms that can interbreed among each other. Compare with cladistic species concept, ecological species concept, phenetic species concept, and recognition species concept. The quantitative study of characters of organisms. The part of Earth and its atmosphere capable of sustaining life. Of hominids, walking upright on two hind legs; more generally, using two legs for locomotion. Bivalves include clams, oysters, scallops, mussels, and other shellfish. A recent book, The Meme Machine, offers an introduction to the subject of memes. Compare with Mendelian inheritance. A scientist who studies plants. Much of his work concentrates on the coevolutionary arms race between newts that posess tetrodotoxin, one of the most potent known toxins, and the resistant garter snakes who prey on them. A biologist recognized internationally for his work on the evolution of mechanisms in amphibians that allow them to avoid predators. These mechanisms include toxins carried in skin secretions, coloration, and behavior. When an organism dies, however, it no longer takes up carbon from the atmosphere, and the carbon- 1. By measuring the carbon- 1. Because most carbon- 1. It cannot be used to determine the age of Earth, for example. Developmental geneticist with the Howard Hughes Medical Institute and professor at the University of Wisconsin- Madison. From the large- scale changes that distinguish major animal groups to the finely detailed color patterns on butterfly wings, Dr. Carroll's research has centered on those genes that create the . Coauthor, with Jennifer Grenier and Scott Weatherbee, of From DNA to Diversity: Molecular Genetics and the Evolution of Animal Design. A scientist and writer fascinated with the workings of nature. Her best- known publication, Silent Spring, was written over the years 1. The book looks at the effects of insecticides and pesticides on songbird populations throughout the United States. The publication helped set off a wave of environmental legislation and galvanized the emerging ecological movement. His Genetics of Domestic Rabbits, published in 1. Harvard University Press, covers such topics as the genes involved in determining the coat colors of rabbits and associated mutations. Cell size varies, but most cells are microscopic. Cells may exist as independent units of life, as in bacteria and protozoans, or they may form colonies or tissues, as in all plants and animals. Each cell consists of a mass of protein material that is differentiated into cytoplasm and nucleoplasm, which contains DNA. The cell is enclosed by a cell membrane, which in the cells of plants, fungi, algae, and bacteria is surrounded by a cell wall.
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