why organisms of the same specie can be different from one to another?
336439
Mutation generates differences.  Most mutations are deleterious and natural selection tends to eliminate them quickly.  Many are neutral and are retained to some degree because there's nothing weeding them out.  A few are positive and variation is also lost in that case because selection will eliminate the other variations.\n\nThere is a process called frequency dependent selection whereby a trait is advantageous but only if its rare.  For example since hosts adapt to a certain kind of parasite, it is advantageous for a parasite to have rare characteristics.  That way the host is unlikely to have seen that model before and the parasite is likely to be successful.  In that case selection actually favors a lot of versions in a species because as soon as anything become really numerous it becomes deleterious.
855495
very simple\n\nBecause sexual reproduction involves 2 species(man and woman) which entails 2 different genetic make-up. Therefore,\nthe offspring that will be produced will be based from the resulting gene of the mother and the father\n\nwhile asexual reproduction do not involve a 2nd party and so naturally it will produce another organism which is identical since it is organically within its genetic make-up
591012
well...\nu could talk about how little we know about whether organisms like bacteria and viruses have consicousness and a probable effect that might happen if we change their genomes . we dont really know whether those kind of organisms have an "individuality" or anything, so thats where i would start off from.\nhope this helped
694287
fundamentally they will be the same plant but genetic they will be different they will have the same features but those features will appear in a varied state...the environment has a lot to do with how they appear
477885
If you were to think about it biologically, one answer is the genetic code. All animals- monkeys, insects, bacteria, cows, snakes, sharks, cats, dogs, and humans have very similiar genetic codes.
728283
The male and female reproductive "tracts" are homologous.  This means that they're similar in structure and evolutionary origin, but are different in function.
748122
Yes.  Consider dogs, which are all considered to be the same species.  Yet, it would be difficult to cross a Great Dane with  a Yorkshire Terrier (no silly jokes about stepladders please - this is Science!!).  Because of th edimorphism, these are effectively two different species - often called "Ring species".  You can look that term up on the web.
422256
I have all the respect in the world to Darwin. He is a good scientist, and even though evolution does indeed occur; it occurs withIN one species. So, in effect, an insect can evolve into an 'evolved' insect, but it can't evolve into a fish! Primates might 'seem' similar, but I do not hold them in the same 'species' as humans. In other words, I do not believe that WE evolved from monkeys, and therefore, we have no 'relatives' from the animal kingdom. If primates evolved into anything; I think it is into bigfoot, but not humans.
1166645
Only clones or identical twins have identical DNA. Genetic drift and diversity are necessary for natural selection to take place - there has to be a variety of traits to select from. An example is the mutation that enables adults to produce lactase. This adaptation is very common in populations of traditional milk drinkers, but uncommon in regions where dairy is not part of the traditional diet.
918447
The variation, could be frankly anything, because it arises from mutations. It could be anything from a different shell colour for a beetle, to a different beak shape for a bird.\n\nHow does it spread? Well, through mating. Organisms mate, they produce offspring. Some will have the mutation. Others won't. The mutation will only take a hold in the population, if it gives the particular organisms that have it, an advantage. So, it doesn't so much as spread, as that it outlasts the other variations.\n\nOf course, even this description doesn't do it justice. I suggest you really, look into the below sources and remember that the Wikipedia article is open to vandalism by Creationists and IDers that don't know what they're talking about.
831468
An existing organism is born with certain genes.  Those genes determine how that organism will develop during its life.  Those genes cannot change ... there is no mechanism in life to alter the genes for the entire organism (individual cells yes ... e.g. cancer, but not the entire organism).\n\nSo even if that single organism lived for centuries (like a redwood tree), it cannot change (evolve) in ways not dictated by its genes.\n\nNew life (offspring) is a brand new set of genes ... a new mixture from each of its parents.  \n\nSo each offspring can be different from either one of its parents ... better or worse in some characteristics, or all characteristics, from either parent.\n\nSo over the entire group of individuals in a species ... you have many individuals with slight improvements over their parents.  Those will produce more offspring than those who have fewer improvements (or are slightly worse adapted) than their parents.\n\nThe result is evolution.  Many many tiny improvements in genes, over many many generations.  You cannot have that evolution, without the opportunity for new genes with every new life.
580432
The problem that creations have with evolution is that they think of evolution as a ladder. You need to view it as a tree, each branch as smaller branches that are similar.\nFor example dogs and wolves are very similar. \nLions, tigers, and house cats are similar.\nall animals come from a single organism.\n\nDidn't you learn this in biology class???
117488
Each of the microbes performs a limited number of tasks (so to speak) in maintaining soil structure; some of the tasks are, I suspect, mutually exclusive of others...\n\nIt is actually impossible to be sure why there are so many diverse organisms, beyond that: we weren't there when the structure was put together, and the best we can do besides make this humble observation is make scientific, wild-eyed guesses based on whatever theory we prefer...
1032840
OK.  Instances of evolution (speciation, not just adaptation to pesticides or antibiotics through selection):\n\nEvening Primrose (Oenothera gigas)\n\nWhile studying the genetics of the evening primrose, Oenothera lamarckiana, de Vries (1905) found an unusual variant among his plants. O. lamarckiana has a chromosome number of 2N = 14. The variant had a chromosome number of 2N = 28. He found that he was unable to breed this variant with O. lamarckiana. He named this new species O. gigas.\n\nRaphanobrassica\n\nThe Russian cytologist Karpchenko (1927, 1928) crossed the radish, Raphanus sativus, with the cabbage, Brassica oleracea. Despite the fact that the plants were in different genera, he got a sterile hybrid. Some unreduced gametes were formed in the hybrids. This allowed for the production of seed. Plants grown from the seeds were interfertile with each other. They were not interfertile with either parental species. Unfortunately the new plant (genus Raphanobrassica) had the foliage of a radish and the root of a cabbage.\n\nStephanomeira malheurensis\n\nGottlieb (1973) documented the speciation of Stephanomeira malheurensis. He found a single small population (< 250 plants) among a much larger population (> 25,000 plants) of S. exigua in Harney Co., Oregon. Both species are diploid and have the same number of chromosomes (N = 8). S. exigua is an obligate outcrosser exhibiting sporophytic self-incompatibility. S. malheurensis exhibits no self-incompatibility and self-pollinates. Though the two species look very similar, Gottlieb was able to document morphological differences in five characters plus chromosomal differences. F1 hybrids between the species produces only 50% of the seeds and 24% of the pollen that conspecific crosses produced. F2 hybrids showed various developmental abnormalities.\n\nDobzhansky and Pavlovsky (1971) reported a speciation event that occurred in a laboratory culture of Drosophila paulistorum sometime between 1958 and 1963. The culture was descended from a single inseminated female that was captured in the Llanos of Colombia. In 1958 this strain produced fertile hybrids when crossed with conspecifics of different strains from Orinocan. From 1963 onward crosses with Orinocan strains produced only sterile males. Initially no assortative mating or behavioral isolation was seen between the Llanos strain and the Orinocan strains. Later on Dobzhansky produced assortative mating (Dobzhansky 1972).\n\nApple Maggot Fly (Rhagoletis pomonella)\n\nRhagoletis pomonella is a fly that is native to North America. Its normal host is the hawthorn tree. Sometime during the nineteenth century it began to infest apple trees. Since then it has begun to infest cherries, roses, pears and possibly other members of the rosaceae. Quite a bit of work has been done on the differences between flies infesting hawthorn and flies infesting apple. There appear to be differences in host preferences among populations. Offspring of females collected from on of these two hosts are more likely to select that host for oviposition (Prokopy et al. 1988). Genetic differences between flies on these two hosts have been found at 6 out of 13 allozyme loci (Feder et al. 1988, see also McPheron et al. 1988). Laboratory studies have shown an asynchrony in emergence time of adults between these two host races (Smith 1988). Flies from apple trees take about 40 days to mature, whereas flies from hawthorn trees take 54-60 days to mature. This makes sense when we consider that hawthorn fruit tends to mature later in the season that apples. Hybridization studies show that host preferences are inherited, but give no evidence of barriers to mating. This is a very exciting case. It may represent the early stages of a sympatric speciation event (considering the dispersal of R. pomonella to other plants it may even represent the beginning of an adaptive radiation). It is important to note that some of the leading researchers on this question are urging c
962657
I can think of a few:\n\nFungi are actually more closely related to animals. They get their food from living matter.\nHowever, they are different from animals because:\n\nThey absorb their food instead of ingesting it.\n\nThey have cell walls.\n\nThey are stationary, like plants.\n\nThey are different from plants because:\n\nThey are heterotrophs.\n\nThey lack roots.
1073987
like die?  Transplants can only be done between creatures with similar dna.
892480
True, in fact observations that the offspring from parents of different species (where offspring are possible) are sterile was one of the key lines of evidence that lead Darwin to evolution by natural selection. ie. that once two populations of the same species become different enough, they can't interbreed thus stay separate.  \n\nIt is now established though, through many observations, that bacteria have and do pick up chunks of DNA from unrelated species of bacteria. A lot of their DNA is very mobile. I guess it depends on what you call 'kind'.