What is "natural selection" in evolution?
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Natural selection involves mechanisms such as competition or predation to kill off some members of a species, allowing members that have certain genetic traits that make them stronger or better-suited for survival, and those traits will be passed on to future generations of that species.
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let's see...\nAccording to Darwin, natural selections is when species born with a trait that's slightly different from what they are supposed to be turn out to have a bigger advantage in life. Because it's successful, it breeds, and the trait is passed on to the next generation. Eventually, that trait dominates the species in a way that we identiy them as a new or different species. \nIn the case of hummingbirds, the flowers they feed on also evolve with the birds. As we all know, hummingbirds have prett long beaks. To 'protect' their nector (or something), flowers start to grow more in a 'tube' shape, which prevents species like bees to get the nector. In response, hummingbirds evolve by growing longer beaks so they can still get their food (drink?)
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Evolutionary biologists have written extensively about how natural selection could produce new species. For instance, in the model called allopatry, developed by Ernst Mayr of Harvard University, if a population of organisms were isolated from the rest of its species by geographical boundaries, it might be subjected to different selective pressures. Changes would accumulate in the isolated population. If those changes became so significant that the splinter group could not or routinely would not breed with the original stock, then the splinter group would be reproductively isolated and on its way toward becoming a new species. Natural selection is the best studied of the evolutionary mechanisms, but biologists are open to other possibilities as well. Biologists are constantly assessing the potential of unusual genetic mechanisms for causing speciation or for producing complex features in organisms. Lynn Margulis of the University of Massachusetts at Amherst and others have persuasively argued that some cellular organelles, such as the energy-generating mitochondria, evolved through the symbiotic merger of ancient organisms. Thus, science welcomes the possibility of evolution resulting from forces beyond natural selection. Yet those forces must be natural; they cannot be attributed to the actions of mysterious creative intelligences whose existence, in scientific terms, is unproved.\n\nSpeciation is probably fairly rare and in many cases might take centuries. Furthermore, recognizing a new species during a formative stage can be difficult, because biologists sometimes disagree about how best to define a species. The most widely used definition, Mayr’s Biological Species Concept, recognizes a species as a distinct community of reproductively isolated populations—sets of organisms that normally do not or cannot breed outside their community. In practice, this standard can be difficult to apply to organisms isolated by distance or terrain or to plants (and, of course, fossils do not breed). Biologists therefore usually use organisms’ physical and behavioral traits as clues to their species membership. Nevertheless, the scientific literature does contain reports of apparent speciation events in plants, insects and worms. In most of these experiments, researchers subjected organisms to various types of selection—for anatomical differences, mating behaviors, habitat preferences and other traits—and found that they had created populations of organisms that did not breed with outsiders. For example, William R. Rice of the University of New Mexico and George W. Salt of the University of California at Davis demonstrated that if they sorted a group of fruit flies by their preference for certain environments and bred those flies separately over 35 generations, the resulting flies would refuse to breed with those from a very different environment. \n\nSome Creationists say that evolutionists cannot point to any transitional fossils—creatures that are half reptile and half bird, for instance. Actually, paleontologists know of many detailed examples of fossils intermediate in form between various taxonomic groups. One of the most famous fossils of all time is Archaeopteryx, which combines feathers and skeletal structures peculiar to birds with features of dinosaurs. A flock’s worth of other feathered fossil species, some more avian and some less, has also been found. A sequence of fossils spans the evolution of modern horses from the tiny Eohippus. Whales had four-legged ancestors that walked on land, and creatures known as Ambulocetus and Rodhocetus helped to make that transition [see “The Mammals That Conquered the Seas,” by Kate Wong; Scientific American, May]. Fossil seashells trace the evolution of various mollusks through millions of years. Perhaps 20 or more hominids (not all of them our ancestors) fill the gap between Lucy the australopithecine and modern humans. Creationists, though, dismiss these fossil studies. Th
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The term comes from oldish genetics vocabulary and it refers to the most common allele (in terms of proportion) for a given gene in a population. \nBefore modern population genetics research, it was believed that most genes (and associated characteristics) usually had one "normal" form (that would be the wild-type allele, present in most individuals) and another "mutant" form (the least common one). \nNow we know that natural populations are polymorphic (have usually several alleles) for any given gene, and there may be one or more than one more frequent alleles.
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Evolutionary fitness is a measure of reproductive success no matter how efficient (or whatever) you are. The more healthy, offspring you produce, the more of your genes are passed on to the next generation, and the more evolutionarily fit you are. Of course these offspring have to reproduce as well to validate your fitness. Individuals that do not reproduce have a fitness of zero no matter how efficient (or whatever) they are.
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Genetics and evolution.
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"In biology, evolution is the measurable change in the heritable traits (allele frequency) of a population over successive generations. Evolution is ultimately the source of the vast diversity of the biological world. Over time, it may result in the origin of new species (speciation). Contemporary species are related to each other through common descent, products of evolution and speciation over billions of years." translation organisms change over time due to adapting to their environment and selective breeding, though natural selection plays the largest role in evolution, in natural selection the animal that is best fit to live in  and survive in its environment will be able to live on and reproduce. Also known as "survival of the fittest"
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NatBoCheck: Well for starters even creationists believe in microevolution, but then you probably don't know what that is.\n\nGive me a few mins...\n\n"The process of evolution can be summarized in three sentences: Genes mutate. [gene: a hereditary unit] Individuals are selected. Populations evolve."\n\n"The mechanisms of evolution are mutation, natural selection, genetic drift, recombination and gene flow."\n\nMutation\n\nThe cellular machinery that copies DNA sometimes makes mistakes. These mistakes alter the sequence of a gene. This is called a mutation. There are many kinds of mutations. A point mutation is a mutation in which one "letter" of the genetic code is changed to another. Lengths of DNA can also be deleted or inserted in a gene; these are also mutations. Finally, genes or parts of genes can become inverted or duplicated. Typical rates of mutation are between 10-10 and 10-12 mutations per base pair of DNA per generation. \n\nNatural Selection\n\nSome types of organisms within a population leave more offspring than others. Over time, the frequency of the more prolific type will increase. The difference in reproductive capability is called natural selection. Natural selection is the only mechanism of adaptive evolution; it is defined as differential reproductive success of pre- existing classes of genetic variants in the gene pool.\n\nThe most common action of natural selection is to remove unfit variants as they arise via mutation. [natural selection: differential reproductive success of genotypes] In other words, natural selection usually prevents new alleles from increasing in frequency. This led a famous evolutionist, George Williams, to say "Evolution proceeds in spite of natural selection."\n\nNatural selection can maintain or deplete genetic variation depending on how it acts.\n\nGenetic Drift\n\nAllele frequencies can change due to chance alone. This is called genetic drift. Drift is a binomial sampling error of the gene pool. What this means is, the alleles that form the next generation's gene pool are a sample of the alleles from the current generation. When sampled from a population, the frequency of alleles differs slightly due to chance alone.\n\nAlleles can increase or decrease in frequency due to drift. The average expected change in allele frequency is zero, since increasing or decreasing in frequency is equally probable. A small percentage of alleles may continually change frequency in a single direction for several generations just as flipping a fair coin may, on occasion, result in a string of heads or tails. A very few new mutant alleles can drift to fixation in this manner.\n\nRecombination\n\nEach chromosome in our sperm or egg cells is a mixture of genes from our mother and our father. Recombination can be thought of as gene shuffling. Most organisms have linear chromosomes and their genes lie at specific location (loci) along them. Bacteria have circular chromosomes. In most sexually reproducing organisms, there are two of each chromosome type in every cell. For instance in humans, every chromosome is paired, one inherited from the mother, the other inherited from the father. When an organism produces gametes, the gametes end up with only one of each chromosome per cell. Haploid gametes are produced from diploid cells by a process called meiosis.\n\nIn meiosis, homologous chromosomes line up. The DNA of the chromosome is broken on both chromosomes in several places and rejoined with the other strand. Later, the two homologous chromosomes are split into two separate cells that divide and become gametes. But, because of recombination, both of the chromosomes are a mix of alleles from the mother and father.\n\nRecombination creates new combinations of alleles. Alleles that arose at different times and different places can be brought together. Recombination can occur not only between genes, but within genes as well. Recombination within a gene can fo
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Evolution is a scientific theory that explains the origin of the diversity of species (note that it does not, and is not intended to explain the origin of life). The basic idea of evolution is that mutations result in genetic diversity in a population, and consequently different traits, and different selective pressures favor certain traits over others. In a diverse population, some individuals are better suited to the environment than others, and the individuals that are better suited are more likely to survive to reproduce and thus pass their genes on to the next generation. Consequently, the next generation will have more of the "good" genes and fewer of the "bad" genes than the generation before it. Because the environment is constantly changing, the definition of "good" and "bad" genes is also constantly changing. Something that used to be an advantage can become a disadvantage, and vice versa. More often, however, neutral traits will become either good or bad. Changes in environment can include not only changes in weather or resources, but also competition from other species.\n\nAs the environmental pressures change, the population of organisms changes with it. Over time, the little changes start to add up, and eventually the population will be so different from the ancestral state that it will be considered a different species. The diversity of species results from splitting of populations. If a population is separated by some geographical or reproductive barrier, the two subpopulations will likely evolve in different ways, to become two separate species. Eventually the two species may be reunited, but they will no longer be able to interbreed. Instead, they will compete with each other, and likely diverge even more.\n\nThe theory of evolution is supported by considerable scientific evidence, and is accepted by the vast majority of the scientific community. It is the ONLY scientific theory currently in existence that explains the diversity of species. Some people claim that "intelligent design" is an alternative theory for the origin of species. However, intelligent design is not a theory in the scientific sense. It is not supported by scientific evidence and can never be tested experimentally (not because we don't have the tools yet, but because it is theoretically impossible). Intelligent design provides an alternative to science, not an alternative scientific theory.\n\nScience is not about finding a single piece of evidence to conclusively prove a theory. It's about constructing theories to fit the existing evidence and gathering new evidence that supports or refutes existing theories. Evolution is supported by a preponderance of evidence. While no one point conclusively proves it, when all the evidence is considered in the context of existing scientific knowledge evolution is a well substantiated theory. Intelligent design is not.  What follows are brief explanations of some of the evidence that supports the theory of evolution.\n\n1. Vestigial structures\n\nOne example of a vestigial structure in humans is the appendix. It has no function. Removing it is harmful only in so far as any surgery is associated with certain risks (so I wouldn't have it removed just for fun, but it's because of the surgery not the absence of the appendix). An appendix is found in several mammals. In humans it is small and has no known function. In rabbits and many other herbivores it is large and is used in the digestion of cellulose.\n\nAnother example of a vestigial structure is the hipbones of snakes. Snakes evolved from quadrupeds, and some species still retain not on pelvises, but tiny protrusions of bone in a location that corresponds to the location of the legs in other quadrupeds.\n\n2. Microevolution can be observed in both a controlled laboratory setting and in nature.\n\nCreationists will tell you that microevolution does not prove macroevolution.  This is true.
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This refers to the idea in Evolution that new species form very quickly, then things remain more or less unchanged for a relatively long period of time.\n\nThis is used to explain the lack of "missing links".  If the changes occur very quickly, and then everything returns to "normal" (hence the equilibrium), then there should be very few transitional species, or missing links.
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genetic drift actually refers to the tendancy for weaker alleles to disappear naturally over time.\n\nSelective breeding and eugenics are purposely removing (or preventing the succession) of those alleles in the population
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Evolution.\n\nEvolution is a scientific theory that explains the origin of the diversity of species (note that it does not, and is not intended to explain the origin of life). The basic idea of evolution is that mutations result in genetic diversity in a population, and consequently different traits, and different selective pressures favor certain traits over others. In a diverse population, some individuals are better suited to the environment than others, and the individuals that are better suited are more likely to survive to reproduce and thus pass their genes on to the next generation. Consequently, the next generation will have more of the "good" genes and fewer of the "bad" genes than the generation before it. Because the environment is constantly changing, the definition of "good" and "bad" genes is also constantly changing. Something that used to be an advantage can become a disadvantage, and vice versa. More often, however, neutral traits will become either good or bad. Changes in environment can include not only changes in weather or resources, but also competition from other species.\n\nAs the environmental pressures change, the population of organisms changes with it. Over time, the little changes start to add up, and eventually the population will be so different from the ancestral state that it will be considered a different species. The diversity of species results from splitting of populations. If a population is separated by some geographical or reproductive barrier, the two subpopulations will likely evolve in different ways, to become two separate species. Eventually the two species may be reunited, but they will no longer be able to interbreed. Instead, they will compete with each other, and likely diverge even more.\n\nThe theory of evolution is supported by considerable scientific evidence, and is accepted by the vast majority of the scientific community. It is the ONLY scientific theory currently in existence that explains the diversity of species. Some people claim that "intelligent design" is an alternative theory for the origin of species. However, intelligent design is not a theory in the scientific sense. It is not supported by scientific evidence and can never be tested experimentally (not because we don't have the tools yet, but because it is theoretically impossible). Intelligent design provides an alternative to science, not an alternative scientific theory.\n\nScience is not about finding a single piece of evidence to conclusively prove a theory. It's about constructing theories to fit the existing evidence and gathering new evidence that supports or refutes existing theories. Evolution is supported by a preponderance of evidence. While no one point conclusively proves it, when all the evidence is considered in the context of existing scientific knowledge evolution is a well substantiated theory. Intelligent design is not.  What follows are brief explanations of some of the evidence that supports the theory of evolution.\n\n1. Vestigial structures\n\nOne example of a vestigial structure in humans is the appendix. It has no function. Removing it is harmful only in so far as any surgery is associated with certain risks (so I wouldn't have it removed just for fun, but it's because of the surgery not the absence of the appendix). An appendix is found in several mammals. In humans it is small and has no known function. In rabbits and many other herbivores it is large and is used in the digestion of cellulose.\n\nAnother example of a vestigial structure is the hipbones of snakes. Snakes evolved from quadrupeds, and some species still retain not on pelvises, but tiny protrusions of bone in a location that corresponds to the location of the legs in other quadrupeds.\n\n2. Microevolution can be observed in both a controlled laboratory setting and in nature.\n\nCreationists will tell you that microevolution does not prove macroevolution.
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Evolution is a dynamic, ongoing process that can have direct, important impacts on human welfare. The evolution of insecticide resistance by pest species of insects and other arthropods provides a spectacular example.1 \n\nSince World War II, synthetic insecticides have been used to control insects and mites that cause immense crop losses, and by carrying malaria and other diseases, pose major threats to public health. However, many chemical control programs are failing or have failed altogether, because the pest species have evolved resistance. \nMore than 500 species have evolved resistance to at least one insecticide. Many pest species are now resistant to all, or almost all, of the available insecticides. Moveover, some species that had been uncommon have become serious pests, because insecticide use has extinguished their natural enemies. As insects have become more resistant, farmers have applied ever higher levels of insecticide to their crops, so that more than one billion pounds per year are now applied in the United States. Resistance has made it necessary to develop new insecticides, each at an average cost of 8 to 10 years and $20 to $40 million in research and development. Hence insect evolution has imposed a huge economic burden (about $118 million per year, just in the United States), and an increasing environmental burden of chemicals that can endanger human health and natural ecosystems. \nInsect resistance evolves rapidly because natural selection increases the rare mutations that are not advantageous under normal conditions, but happen to provide protection against harmful chemicals. Entomologists trained in evolutionary genetics have developed strategies for delaying the evolution of resistance. The most effective strategy, based both on evolutionary models and on evidence, is to provide the pest species with pesticide-free "refuges" in which susceptible genotypes can reproduce, thus preventing resistant genotypes from taking over. The intuitively appealing opposite strategy – trying to overwhelm the insect population with "saturation bombing" – simply hastens the evolution of resistance, because it increases the strength of natural selection. \nAlthough evolution of resistance can be delayed, it is probably inevitable in most cases. Thus modern pest management strategies combine pesticides with other tactics. For example, spider mites in almond orchards have been controlled by applying both a pesticide and predatory mites that had been selected for pesticide resistance in the laboratory. Crop varieties that are genetically resistant to certain insects have been developed both by traditional methods of selection and by genetic engineering. For instance, strains of several crops have been engineered to carry a bacterial gene for a protein (Bt-toxin) that is toxic to certain insects. Pest-resistant crop varieties have often been economically very profitable, but history has shown that if they are planted widely, the insect pest eventually evolves the capacity to attack them, so that it becomes necessary to develop new genetic strains that the pest is not yet adapted to. At least one pest species, the diamondback moth, has already adapted to Bt-toxin. Thus, the "arms race" between the insect evolution and human ingenuity presents a continuing challenge
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Here's a little known fact - the theory of natural selection - very few on YA can describe it correctly yet it's very simple:\nThere are just 3 assumptions:\n\n1. Individual members of a species are not always exactly alike. A population of similar organisms displays variability.\n\n2. Organisms possess some mechanism by which offspring tend to be like their parents. That is, individual traits are heritable.\n\n3. Totally unrestricted breeding doesn't happen. No population can reproduce forever without limit. So clearly there must be some force at work to reduce populations.\n\nFrom these assumptions Darwin concluded the theory of natural selection - some of the variations between individuals are inherited by their offspring, and, in a world where not everyone can survive, some of these inherited characteristics give some individuals a better chance of survival.
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THE EVOLUTION\n\n“I know that the word of “Evolution” has become an obsolete and worthless word in some circles of the people___ and they do frown even on it’s simple reference.\n\nYou will however surprise to know that I, not only, respect these friends and their feelings, rather, I agree to their viewpoint, to some extent, in the light of the current knowledge. Because they apprehend “Evolution” in terms of material or mechanical evolution whereas material or mechanical evolution is far different from that of the creative evolution.\n\nAn important source of Evolution is the Nature’s process of selection. Which is originally one of the laws of nature and a secondary cause, like the other laws of nature, as it’s Creator is again God.\n\nAll the species generated by this process are again the indirect creation of God as the Nature’s process of selection, itself, is not capable to create any specie. It simply admits some species to be nourished, leaving aside the others, to be withered and this process works under some hereditary variations. So___ the survival or removal of a specific specie, is never accidental as it is presumed by the believers of material or mechanical evolution”.\n\nThis very statement of Edward Luther Castle positively removes that superstition. Which has captured, not only, the materialists but the religious leaders as well. Who are still in it’s captivity even after the lapse of so many years. Dr. George Erl Devis, the physicist, writes:\n\n“As much as the knowledge is flourishing and the superstitions are being unveiled___ importance & inevitability of the critical study of religion & ethics___ is increasing day by day in the same scale.”\n\nThe physicist is hinting upon the urge of the “quest for truth and the specific process” which may bring forth, a suitable solution for the problems of life. Of course, we can not lead the life in a particular way unless we come to know the origin of life. What is the actual and factual truth? Only after positive cognition of the same, we can learn to lead the real life. And__ the same learning may, in turn, lead us to the aim of life.\n\nGeorge Erl Devis writes further:\n\n“The surprising scientific discoveries have produced certain indispensable questions. Though not so new, but their nature has become more changed, on account of___ the receipt of detailed information about cosmic system. And___ in any case____ man can not be held as excluded thereform. Among these questions, is the most important question___ upon whose answer is depending___  our aim of life and the system of our moral values. And___ that is the same old question that:\n\nIs there any Supreme and Sublime Source who is the Creator of whole cosmos and who could be surnamed as God?\n\nAnd___ thereby arises the other question, that if God has created us then who has created God? This question is usually raised by the children, in a highly logical air.\n\nWe can not deny the fact, that science has no convincing reply of the question that God is existing or not? Rather, science can never bring forth a scientific proof thereof.\n\nWe are breathing in such a physical universe which is running smoothly in terms of the pre-ordained laws of it’s complexed system. But, it does not mean that we can ever derive some information, through this very universe, about a thing, which is existing outside to this universe. Our universe is just like a room without any doors and windows. And even if it is having the same, then, such glasses are fixed therein that to see & understand the outside thereform is totally impossible. Whereas to see inside from the outside__  is almost possible.”\n\nAs we can not prove the existence or non-existence of God on the basis of science. So it is the all-alone way for us, that whatsoever stock of information we have, about this universe. We should derive a reasonable result therefrom. Such a reasonable result___ which could never be objected on logic
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I don't think you will get a satisfying answer becausae you worded your question in a rather confusing fashion.\n\nIf you don't want to discuss natural selection, don't use the word evolution at all.  Ask about Big Bang Cosmologies instead.
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Evolution is the gradual change in a group of organisms based on surroundings and circumstances that make one population more favorable. Since we do not know what future events might select for homo sapiens, we cannot predict how they will evolve. For example, if we had a full out nuclear war, perhaps a small group of humans would survive that were very tolerant to radiation. There is no way to know. That being said, humans have somewhat overcome evolution because of our advanced medicine- we can let people live who would otherwise be selected against, like people with debilating diseases.