How genetic variability in frogs population advantages over frogs with less variability?
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Genetic variability allows a group to adapt to changes in habitat, climate, etc- so, for example, if it became suddenly dry for many years, frogs that carried genes that helped them adapt to that would survive, and thus save that population of frogs.  If you look, for example, at humans- some humans are extremely efficient at storing fat- in days gone by, there were probably periods when there was no food for months.  Most people would have died, but these people (who nowadays are obese and have a hard time) would have survived and saved that population of humans.  Diversity is the single best strategy for dealing with environmental stresses that would otherwise wipe out a population.\n*edit* in response to your email- There are a lot of genes that are there for sepcific stress conditions- times when things are not normal, like a period when there isn't any food, or water, or a long period of cold, or apecific diseases.  The more of these kinds of genes a population has in it, the better the chance that at least  few of the population will survive.  For example, say there are 100 diseases that can kill frogs.  There are a thousand frogs in the population- say each frog only has a few of the 100 genes that protect from the diseases.  So, if you have a major disease come through, maybe half the population will die (the ones that didnt have the gene to protect against that disease).  Now, right away, there is a period of drought, and another half die (cause they didnt have the gene to help them survive drought)...and on and on- you can see how, having a lot of different genes (high diversity) would help the whole population survive getting hit with different environmental stresses like disease, parasites, hot and cold weather, etc.  If a population of frogs had only the genes they needed to live in their little pond, in exactly the right weather, with exactly the right amount of food (in other words, they had low genetic diversity) then if any disease, or drought or cold snap came through, it would wipe them out.
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Wikipedia has a good summary:\nhttp://en.wikipedia.org/wiki/Origin_of_species\n\nAn extract from this wikipedia page:\nDarwin's theory of evolution is based on five key observations and inferences drawn from them, as summarized by the biologist Ernst Mayr:\n\nSpecies have great fertility. They make more offspring than can grow to adulthood. \nPopulations remain roughly the same size, with modest fluctuations. \nFood resources are limited, but are relatively constant most of the time. From these three observations it may be inferred that in such an environment there will be a struggle for survival among individuals. \nIn sexually reproducing species, generally no two individuals are identical. Variation is rampant. \nMuch of this variation is heritable. \nFrom this Darwin infers: In a world of stable populations where each individual must struggle to survive, those with the "best" characteristics will be more likely to survive, and those desirable traits will be passed to their offspring; and that these advantageous characteristics are inherited by following generations, becoming dominant among the population through time. This is natural selection.\n\nDarwin did not suggest that every variation and every character must have a selection value. However, he pointed out that, because of our ignorance of animal physiology and its relationship with the environment, it was extremely rash to set down any characters as valueless to their owners. It is even more important to notice that he did not suggest that every individual with a favorable variation must be selected, or that the selected or favored animals were better or higher, but merely that they were more adapted to their surroundings.\n\nDarwin further infers that natural selection, if carried far enough, makes changes in a population, eventually leading to new species. He puts forward myriad observations as demonstrations of this, and also claims that the fossil record can be interpreted as supporting these observations. Darwin imagined it might be possible that all life is descended from an original species from ancient times. Modern DNA evidence is consistent with this idea.
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Toads and frogs are BOTH amphibians.  Frogs have more permeable skin so lose more water through their skin and need a wetter environment.  Toads have dryer, wartier skin and are generally darker in color. Frogs lay eggs in clusters on water, toads lay eggs in strings. Frogs jump farther and have longer legs, toads hop. Frogs have tiny teeth, toads do not have teeth.
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Over the last several decades a significant decline in frog populations all over the world have been noticed, they are just not moving to diffrent locations.  Right now thousands of species are considered endangered or extinct.\n\nFrogs have been on this planet for more the three hundred millions years.  They were around at the time of the dinosaurs and out lived them.  They belong to the class amphibia, meaning double life.  This name fits them because they spend part of their life in the water and part of their life on land.  Unlike reptiles amphibians as a whole rely on water a lot more and can never move far from it.  Today there are almost 5900 species of known amphibians, which 4800 are frog species.  Frogs and toads (which are a type of frog) belong to the order anura.  Of this order there are 29 different families.  Many biologists question why frogs are in a state of decline, an answer with more the one apparent culprit.  It seems to be a combination of problems such as habit destruction, cattle grazing, agriculture, pollution, climate change, UV radiation, pesticides, invasive species, and even road traffic.\n\nHumans have caused much destruction to the natural environment.  We reduce the number of habitats suitable for many species to thrive in, causing them to migrate elsewhere, adapt to us, or die off.  Frogs are very fragile creatures that adapt slowly to major change.  They always must maintain wet, moist skin and due to their dependency on water they are unable to migrate long distances to find suitable habitat.  If we destroy the only pond in an area where will the frogs go?  We forget that they are small animals and a distance of a mile might be too much for them.  \n\nForest fragmentation of a few hundred feet is enough to wipe out an entire population of frogs.  Something as simple as a road can devastate a species’ numbers.  If a road blocks them from their mating ground it can be an impossible task to cross it.  Many times on a warm sunny day the road will get very hot, and the frog’s skin will dry out while crossing it, resulting in its death.    Along with forest fragmentation comes the edge effect.  With the edge effect a once cool shaded area can change dramatically.  The edge effect causes greater changes in temperature and moisture that can be unsuitable for many frog species.   Microhabitats can dry out and temperatures inside the forest fragment can become increasing cold due wind patterns.  Along the edge different vegetation can take over resulting in invasive species of both plant and animal.  In Brazil an Amazonian frog species has shown great decline and forest fragmentation seems to play a key role.  Adult survival was not effected by fragmentation but mean clutch size was reduced by 17%.  By experiments it has been shown that the fragmentation of the forest causes increase predation, increase in interspecific competition, and slower growth rate resulting in delayed reproduction.  \n\nNot just forest fragmentation causes frog decline but also other human alterations to habitats is causing declines worldwide.  Wetlands are the homes of many species of frogs and humans over the years have in some way changed the landscape.  The wetting and drying of the wetlands has great influence on many organisms and frogs are no different.  The Murray-Darling Basin of Australia has been modified for irrigation flow and has reduced the overbank flooding into flood plain wetlands.  This degradation of the wetlands has caused all frog species in the area to decline by an average of 23%.\n\nAgriculture is also another way in which humans alter the habitat.  Both rangeland and cropland reduces the population size of frogs.  Cattle grazing greatly alters the habitat.  First off the habitat many times must be made suited for grazing.  This means frog habitat can be destroyed causing a direct effect or the cattle can interfere with frog migration, causing an indirect effect.  By the grazing of livestock migrat
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Each nucleotide contains roughly 13 atoms. There are two nucleotides per base pair. There are roughly 10,000 - 100,000 base pairs in an average gene. That's 260,000 - 2,600,000 atoms in each gene. Assuming no gene duplications, there are 2 copies of a given gene in each cell. Since atoms behave in a probabilistic manner, it is a given that DNA replication will not occur with 100% fidelity; errors (or, as we call them, mutations) occur.\n\nEvery modern organism we've observed has sophisticated methods to minimize the errors, reducing the background rate of mutation to about 1 per 1,000,000,000 base pairs.\nOf course, even simple bacteria have genomes of several million base pairs, and humans have 6,000,000,000 base pairs per cell (meaning that, on average, every cell in your body has ~6 mutations).\nVarious other factors, known as mutagens, can increase this background rate, and many of these are found in nature.\n\nAs for why genes should be variable, that is not a very precise question. Genes are observed to be variable. Variability in genes is a good thing for organisms, too. If every organism had the exact same genes, (well, first of all, there would only be one type of organism on Earth, but, more relevantly...) every organism of a species would have the exact same weaknesses. Anything that could wipe out one could wipe out all of them. Not a very good survival strategy; indeed, it would be the proverbial "placing all your eggs in one basket".\n\nOh, and one other thing. Gene variability is NOT essential for Darwinism. At the time Darwin formulated his concept of evolution (not the modern concept of evolution, of which genetic variability IS an essential component), genes were not yet known* (nor was DNA). However, Darwin predicted that, whatever the mechanism of heredity was, it would have variability in it. Further, many properties of genes (and, later, DNA) were predicted by Darwinian evolution**.\n\n\n*On the Origin of Species was published in 1859. Gregor Mendel was still conducting his experiments on pea plants, which lasted through 1863, and published nothing until 1866. It was forgotten about shortly thereafter, and not rediscovered for over 30 years, in 1900. This is when the terms "gene", "allele", and "genetics" originated.\n\n\n** Darwin called his model of heredity "pangenesis", and it was published in the late 1860's. It turned out to be incorrect, but the fundamental ideas of transmission and development of inheritable/inherited characteristics were so useful that they were incorporated, along with mendelian genetics, into the modern synthesis.
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Variablility is important in fighting epidemics.  Something that can make one individual animal sick might not make another sick, provided that other animal is unique.  Similar genes means similar genetic bases for immunity--a disease that afflicts one can afflict all.\n\nTraditional agriculture is also based on the idea of artificial selection, which improves the livestock over generations.  Cloning means no variation, which retards the idea of improving the qualities of livestock.\n\nFinally, it's pointlessly expensive.  Why get a cell biologist to transfect genes when a bull will do it for free?
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Not usually. Tree frogs do but many don't. There are so many varieties of frogs that you can't really make a generalization about all of them except maybe that they're amphibians.
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I'd never heard of grassfrogs, but I've done some reading about them.\nThis site:\nhttp://www.goldlinksweb.com/growlinggrassfrog/aboutfrog.html\nis a good resource for learning about them.  It doesn't say anything about tadpoles flying, but it does say that grassfrogs can travel over a long distance with no water.\nIt also says that the grassfrogs are rare, a protected species in Victoria, as a matter of fact.\n\nAnother site:\nhttp://www.studiocinqo.com/p_veenvliet/2_5_midwintertadpoles.htm\nmentions that though many grassfrogs hatched there aren't many tadpoles around.  He says that predators have eaten the tadpoles.  That might be your answer.\n\nHere's what another site said.  It again says that this is a threatened species.  \nThreats \nChytridiomycosis is an emerging infectious disease of frogs skin caused by the chytrid fungus, Batrachochytrium dendrobatidis and has been linked with continuing amphibian population declines in the western USA, Central America, Europe, Africa, and Australia. Ongoing studies suggest a correlation between resistance to lethal infection by B. dendrobatidis and synthesis (production) of antimicrobial peptides by the host amphibian. Further research is needed to define better the role of antimicrobial peptides in protection of amphibian populations and the effect of environmental factors upon antimicrobial peptide synthesis (Rollins-Smith & Conlon 2005). \n\nPhysical and environmental impacts include direct loss of habitat through removal of aquatic and riparian vegetation particularly by allowing grazing to the water edge. Draining of wetlands, lowing of freshwater groundwater through pumping and increased salinity from run-off and altered hydrological systems can all alter Growling Grass Frog habitat. \n\nPredator species such as the introduced Mosquito Fish Gambusia affinis can impact on tadpoles, Mosquito Fish are prolific breeders producing off spring three or four times per year. They can tolerate poor water quality and can inhabit waters otherwise unsuitable to many of the native freshwater fishes, which increases their capacity to prey on tadpoles. \n\nElevated nitrate and phosphate concentrations have been identified as a impact. Historical and experimental evidence suggests that in New South Wales the decline of Green and Golden Bell Frog L. aurea in its former range was due to high nutrient run off events. Fertilizers may also increase the nutrient status of waterbodies and thereby initiate eutrophication, resulting in lowered dissolved oxygen levels that do not support tadpoles (Hamer et al 2004). \n\n\nhttp://bird.net.au/bird/index.php?title=Growling_Grass_Frog\nCan the frogs be moved somehow?  Discouraged with sounds?  I don't really know the answer, but I hope these sites will help you.  You could also call the natural resources organization in your area. They might have some good ideas for you.
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Perhaps, the time of birthing and mating is in the spring.  They can not lay their eggs on land.  So, if they do not have water to deposit them in, then new frogs can not be born.  Hence, the population declines.  What do you think?
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try these sites...could be helpful!\n\n\nhttp://curry.edschool.virginia.edu/go/frog/\nhttp://www.science.mcmaster.ca/Biology/Harbour/SPECIES/FROGS/FROG10.HTM
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You would get two different genotypes and phenotypes.\nIf you were crossing a tall, heterozygous plant, Tt with a short plant, tt, you would get 50% Tt and 50% tt.
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The advantage is seen in the fishes who could slightly breathe through their skin.  When the pond dries up millions of times over hundreds of millions of years the descendants with better breathing could eventually stay ashore and ponder these questions.  The advantage of asexual reproduction is that you don't have to be cute.
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The process of adaptation cannot be appreciated in a single organism, but only in a population. This is because adaptation is a RELATIVE condition, that is, relative with respect to a particular environment, and with respect to other individuals/species. \nNatural selection acts on the variation that arises naturally and randomly in each generation of individuals, so that those individuals best adapted to the extant environmental conditions leave more offspring which, presumably, will inherit these characteristics (assuming they're at least partly hereditary). Thus those "more adaptive" traits will spread in the population, and the population as a whole will be better adapted. \nHowever, as environmental conditions vary, some traits that were "better" may become "worse", and the population will evolve in a different direction.. or become extinct.\nThe changes in individuals that occur during their lifetime are _not_ adaptation, but a different phenomenon called ACCLIMATION.
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If an entire species has the same gene, they would all be the same. So if the species was hit with a disease they are vulnerable to, all of them would die because none of them could develop an immunity against it. Gene difference also allows more changes for mutation which is important for long term survival.
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The difference is only a very slight genetic difference. There is no difference in their physical appearance.\n\nAccording to my sources:\n\n"The scientists found no genetic differences between the samples from peninsular Malaysia and eastern Sumatra, slight differences between the eastern and western Sumatran populations, and larger differences between the Bornean rhino and the other populations. The findings indicate the Bornean rhino has been separated from the other subpopulations for a longer period of time, Professor Melnick said, allowing the development of genetic distinctions, which are probably both adaptations to local conditions and neutral mutations."
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Not to mention, a 3 percent difference in genetics is a vast difference.  Enough to render a separate and distinct species.
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Darwin's Theory of Natural Selection, in a nutshell:\n\nThere are three observations about life\n1) Variation: Individuals of a species are not all identical.  \n2) Competition: More individuals are born than can possibly survive to reproduce.  \n3) Inheritance: Individuals pass on traits to their offspring.  \nGiven these three things, those individuals in a species that have traits that help them survive better and produce more offspring, will pass those very traits on to those offspring.  So in this way, beneficial traits become more frequent a population, and produce an overall change in the species over time.  \n\nThat's it.\n\nAs for the creation of new species:  If two subpopulations of a species get separated for long enough, then they will change in separate directions, and will eventually lose the ability to interbreed, resulting in (now) two separate species that will continue to change (evolve) in different directions.\n\nThe catchphrase "survival of the fittest" summarizes this idea ... but use it with caution.  It's not just about "surviving" but "surviving to reproduce."  For example, a peacock's tail doesn't really help him "survive" better ... in fact it probably makes him an easier prey for predators ... but it does attract the ladies.  So it makes those individuals with the flashiest tail more "fit" then their homelier cousins.\n\n-------------- A warning about 'tiffany g's answer ---------------\n\nBe careful with answers like 'tiffany g' who copy-paste web pages instead of giving you a link to them, and without giving you the source, so you can check it out.  She is copying from the web-site allaboutscience.org, a thinly disguised Christian/Creationist site.  \n\nMy objection is not with people presenting the Creationist side ... but rather the attempt to hide that fact.  For example, it is deliberately misleading for a site to call itself "allaboutscience.org" when it does not address science topics in general, but only topics like the Big Bang, Evolution, and evidence for the existence of Jesus.  (Watch out for "allaboutphilosophy.org" as well.)\n\nAs a glaring example of intellectual dishonesty, the citation/page finishes with Darwin's famous quote about the eye ... famous because it is always quoted out of context and omits Darwin's very next sentence.  Darwin did indeed write that the evolution of the eye "seems, I freely confess, absurd in the highest degree."  (Note the word "seems".)  But then Darwin continues ... "Yet reason tells me, that if numerous gradations from a perfect and complex eye to one very imperfect and simple, each grade being useful to its possessor, can be shown to exist; if further, the eye does vary ever so slightly, and the variations be inherited, which is certainly the case; and if any variation or modification in the organ be ever useful to an animal under changing conditions of life, then the difficulty of believing that a perfect and complex eye could be formed by natural selection, though insuperable by our imagination, can hardly be considered real."  (See second source, Darwin, Ch. 6.)\n\nIn other words, Darwin immediately refutes the "irreducible complexity" argument, by pointing out that all we need to do is show that the eye can come about through small, incremental changes that each confers a small advantage, no matter how small.  Every single case of "irreducible complexity" yet offered by Creationists has always been shown (usually quite easily) to be fully "reducible."\n\nCreationists love to quote out-of-context from Darwin's Chapter 6, because this is the chapter where Darwin considers possible objections or "difficulties" with the theory, and then refutes them. The Creationists love to quote Darwin's own-words description of the "difficulty", but then omit his