Can anyone explain.. while it is true that divergent species can't interbreed to produce viable offspring?
953716
http://www.blackboard.com/company                                                        ^v^.
56353
It is good for a species to utilise varied gene pools (non close relatives) when reproducing in order to continually evolve and strengthen their DNA.  However, it doesn't hurt a particular person to mate with a relative (only if they have kids).
748748
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.
684738
There are two conceptual models that overshadow current theories related to the production of diversification within organisms. Darwinian evolutionists propose that genetic variability is the result of random mutations that have accumulated gradually over millions of years. In contrast, creationists generally assume that God made all useful genetic information during the creation of the world. Both largely agree that groups such as the Family Canidae evolved from a common ancestor, and the rapid development of variety during the domestic dog breeding, was simply the result of shuffling preexisting genes. This common genetic theory fails to explain the rapid production of the significant diversity when presented with the assertion that the wolf was a pure breed while in nature. A purebred organism is a genetic homozygote for the characteristics in question, and will therefore pass its traits to every offspring produced. In other words, wolves only give birth to wolf pups, but from them a tremendous genetic and morphologically diverse number of dogs have been isolated in a relatively short period of time. Explaining this conundrum cuts to the very heart of the creation vs. evolution controversy.\n\nThe canine baramin (Biblical kind) likely speciated rapidly following the flood of Noah during geographic radiation, and each new population was then naturally selected until varieties such as the wolf, fox, hyena, jackal, etc., each became purebred. Selection is the process of inbreeding specific genes from a diverse genotype until alternate variations of genes (alleles) are eliminated, and the bloodline will only then breed true. As a result, the purebred organism is genetically limited, and in many respects the wolf should be considered no different in its ability to produce offspring diversity than any of the dog breeds we have today. Although speculative for some time, genetic studies have now thoroughly established that dogs were bred from domesticated gray wolves.1 It is also a matter of historic fact that most breeds have been selected to purity within the last few hundred years. However, when compared to the wolf, the domestic dogs are found to have divergent sequences not possessed by their progenitors. Due to these findings some geneticists now believe that wolf domestication must have begun more than 100,000 years ago despite the fact that archaeological findings can not verify their existence beyond 14,000 years.2\n\nIf one believes that the Biblical flood of Noah was a recent and global event, then another problem presents itself. Genes have fixed locations within the genome called loci, and sexually reproducing organism only carry two alleles (variation of a gene) per locus.(Figure 1) If the number of breeding pairs released from the ark can be taken as accurate data for this recent genetic bottleneck, then the maximum number of original alleles is known. According to the Bible, no more than seven breeding pairs were preserved for each baramin, and these 14 individuals can only carry 28 alleles per locus. Since only 8 people were alive following the flood, there should be a maximum of 16 alleles at any given locus in humans. However, it is now clear that many genes exist within populations as hundreds or even thousands of alleles. For example, 240 alleles have already been discovered in the human HLA-B locus. In spite of such concrete evidence, most creationists still tend to assume there is no mechanism for generating new genetic information,3 and indeed the following quote may be exemplary of the current state of thinking regarding intelligently designed genetic heredity. "Recombination explains why children look different from their parents. This shuffling of the genes can produce superior combinations of different genes. However, because we see that mutations are incapable of supplying useful variation, the useful genes that are there to be shuffled must have been created at the beginning.\n\n\nThis might do it
519495
Theoretically yes, but there would be so many mutations required that it would take decades of manipulation and the result would end up being of one species or another.  \n\nLast year, scientists finally succeeded (reportedly) in the birth of a mouse with two mothers and no father.  It took them many long years, and although published in Science magazine the method is still questioned.
408714
you can't, it's impossible. they are not of the same species or genius let alone class. good luck trying to even get them to mate.
936422
.  It's the sort of achievement that is so interesting and scientifically valuable that, if it were possible through and techniques yet developed, it would have been done; and it hasn't.\n.  If there were a tissue specimen from an extinct species which were well enough preserved that there were intact cell nuclei and intact chromosomes, it should be possible to clone a near match to the extinct animal, using an egg ell from a closely related species.  This 'clone' would not have the same mitochondrial DNA as the extinct animal, s it is not known if it would have the same metabolic performance, but it should be close enough.\n.  Unfortunately, it takes quite a lot of care to preserve cell nuclei and chromosomes.  The only extinct animals for whom such care has been taken are a few who have gone extinct while observed by scientists.  These are species which were watched closely as their population dwindled to a few individuals and, when the last few passed, tissue samples were taken in the hope that they might be cloned.  The amount of such tissue material preserved is very limited, and the time does not seem right to risk that limited tissue in an effort at cloning in which there is not yet great confidence.
1069568
Ligers and Tigons are sterile from birth, so there would be no offspring.  However, if one were to unlock the secrets behind genetic recombination, you could sample DNA from both animals and possbly splice a new, third hybrid ... perhaps a Tigron.  Sadly, natural pathways for an enhanced hybrid from these two creatures is impossible.
622375
'Survival of the fittest' works to a lesser degree in the opposite direction too; just as animals with features that allow them to adapt better to their environment are more likely to successfully reproduce, animals with features that are not necessary might find them impeded by them and, thus, might find themselves less able to survive long enough to reproduce.\n\nIf you will, imagine a village of our distant ancestors. As we're not hanging from trees anymore (if we ever did), our tail has no practical purpose, but it's still hanging around (pun partly intended). Now, through random mutation protohuman A's tail turns out to be a little shorter than protohuman B's tail. So when a big predator comes chasing after them, A has an advantage because 1) the tail is not getting in the way of his running as much and 2) the predator has more difficulty seizing on to protohuman A. So protohuman B becomes a predator's lunch and protohuman A gets to pass his short-tailed genes onto his children.\n\nNow, you might say 'well, how can that possibly be enough? A 1- or 2mm difference from one generation to the next?' but there also is a concept of a 'feedback loop', which is quite logical to perceive. It's that, frankly, tails ain't sexy.\n\nAll of the predators munching on long-tailed protohumans might have developed a sense among the protowomenfolk that a long tail does not a good father make (you know, motion of the ocean etc.) So then, through the development of this biological preference (call it 'taste' or 'fashion'), the longtailed boys become the wallflowers - always the bridesmaid, never the mixed metaphor.\n\nIn short, every generation, the shorttails are more popular and have more children, and for all I know strut in a manly way around the longtails. This seriously alters the 'genetic lottery' of DNA, with the result that, over countless generations, we're down to the tiny stub that we have today (excepting the unfortunate).
901776
It is E\n\nThe reason: \na) Reproductive variations lead to the "better producer" making more offspring and thus leading to more chances for their offspring to reproduce.  For this one, think of gorillas...the dominant Male (silverback) will mate with the females so it is his offspring who carry the genetics into the next generation, and the other males in the group dont pass on their genes. \n\nb) There has to be some offspring that simply don't survive...this is the whole "don't interfere and let nature take its course" thing.  This means that after the "unhealthy" individuals die, the rest (on average) will be better suited to their environment.  Think of it like this... a  human family has three babies but one of them dies; the one that died may have had a defect that shouldn't have been passed on.  Since the parents had two other babies, they have replaced themselves in the population so there will not be a net loss of population when they eventually die. \n\nc) There has to be variations in the genetics of the offspring.  This is due to the fact that for us to become better suited to our environment, there has to be a change in our genetics to produce that change.  If we were exactly like our parents, no changes could occur.\n\nd) Inheritance is hugely important.  Think about it like this: If a beneficial change develops (such as opposable thumbs), what good would it be if it couldnt be passed on to the next generation?  There must be a mechanism to pass the benefit on.  \n\ne) Even though there have been many catastrophic events that have allowed for natural selection, it is not required.  A large eruption may cause the animals who can eat more diverse variety of plants to do better than ones that can't but they may be able to out-compete the other animals anyway.
411955
If the two different populations are unable to mate and create fertile offspring, then they are different species.
87033
The answer is either “No” with a but or “Yes” with an and.\n\nRobins and chickens are totally separate species of birds. They are no more closely related than humans are to baboons. You wouldn’t expect a human and a baboon to be able to mate and produce babies would you? So no, robins and chickens can’t interbreed.\n\nHowever there are many different species of animal that CAN interbreed and produce offspring. But the different species need to be fairly closely related, far more closely than human and baboon… or a chicken and a robin.\n\nFor example we can interbreed horses and donkeys to produce baby mules, and we can breed cattle and buffalo, or camels and llamas. \n\nAnd the same is true of birds. While chickens can’t be bred with robins they are often bred with guinea fowl and pheasants for example, and occasionally bred with turkeys (see links below). \n\n\nSo to answer the question, yes different types of bird can mate and produce chicks, there's no doubt about that. But chickens and robins are not two types that are capable of it. Chickens and turkeys or chickens and pheasants are.\n\n\n>>>>>A robin and a chicken might be a stretch, but how about\n>>>>>two different types of sparrows? \n\nYes, in fact the various sparrow species are amongst the most likely to hybridise.\n\n>>>>>>Does it ever happen in the wild?\n\nRegularly. See the last two links.\n\n__________________________\n\nAddenda\n\nScientist said: "Only organisms of the same species can produce viable offspring"\n\nThat is simply not true. \n\nI know they teach you that in school, but it has no factual basis whatsoever and is not accepted by any biologist anywhere on the planet.\n\nJust to name a few examples cattle and bison, wolves and coyotes and fin and blue whales are all perfectly capable of breeding. They all interbreed commonly in the wild and the offspring are all perfectly fertile and have young themselves. \n\nEven lions and tigers will produce offspring that are capable of producing cubs, though most are not, and there have been at least 2 documented cases of mules having foals.\n\n\nUnless someone wants to argue that cattle and buffalo are the same species then ability to produce fertile offspring doesn't prevent two animals being seperate species in any way.\n\n\nSal said: "There are different kinds of chickens that can interbreed with each other. But a chicken can't breed with a turkey."\n\nA total lie with no basis in reality. I just provided links which prove that turkeys can breed with chickens.\n\nSal also said"This is one of thousands of examples as to why the theory of evolution is hard to swallow. If animals can change into other kinds of animals, you would be able to see at least a slight form of interbreeding betweeen different species, but you dont."\n\nWell since I have proved this belief completely wrong, and Sal now knosw that interspecies breding is common, even in the wild, I guess Sal will now accept evolution?\n\nYeah, right. Like facts and evidence played any part his belief.
181890
Defining a species of virus is problematic because many biologists do not consider them to be alive.  It's the "organism" part of the species definition (any species definiton) that's a problem.\n\nDefining a species of bacteria under the biological species concept is problematic because the BSC defines a species as a collection of organisms that can reproduce only with other members of the same species.  Bacteria reproduce asexually, so they're not reproducing WITH anyone.  However, there are other problems with the BSC. For example, lions and tigers are clearly separate species, but they can interbreed.  So biologists tend to favor other species definitions (like the morphological species concept), which can effectively classify lions and tigers (as well as several other species that are able to interbreed).  These species definitions have no trouble classifying bacteria.
539495
Species. In a strict technical sense all would classify as "reproductively isolated" (since, for example, a mammal cannot mate with a reptile- mammals and reptiles belong to separate classes.) But when we say "species" we are really saying reproductively isolated populations.\n\nThere are various definitions of "species", some that require complete biological reproductive isolation while others that require simply that the populations do not have the opportunity to normally reproduce (perhaps because they are isolated on separate islands and can't get to one another).  For example, the wolf and coyote can interbreed and have viable (living) offspring, but they are still separate species because populations of wolves and coyotes do not normally interbreed (in a funny way you might even say that maybe they don't "like" each other).  In the wolf/coyote case, the two are able to reproduce from a biological standpoint, but they still don't reproduce for whatever reason, and therefore they are still reproductively isolated.\n\nIf you would like to learn more about how "species" are defined, take a look at the following informative link:\n\nhttp://research.amnh.org/ornithology/crossbills/species.html
1110389
Species do not evolve, individuals show variation and sometimes that variation is pro reproductive, (not necessarily pro long and happy life)  In that case a pool of individuals with that trait grows and reinforces it.  Such variation tends to be absorbed in a large mobile population and cause no long term divergence, so our own mobility and global success works against a new variety of human emerging.  \n\nOne can anticipate however that our science will progress far faster then any normal evolution and in a short time a group of therapies will be available that will offer longer life, greater vitality and sexual enjoyment, improved health in general and whatever appearance is desired.  The trend to these things already exists.  The factor that will isolate this group of advantaged humans may already exist as well, since it is likely that such biological tinkering will be available only to those who can afford it.  We may see the very rich diverging as a virtual new type of human in the next fifty years, followed by the middle class in places like America.  The difference in lifespan between a wealthy nation and a third world one is now twenty five years or more, it may stretch to a century.  A pretty big issue putting wealth and experience against endless numbers...
270479
Ignoring the fact that both domestic dogs and wolves are Canis Familiaris, speciation does not imply extinction of the ancestral species. In parapatric speciation, a group of members of a population enter a new niche without leaving the territory of the ancestral population, and are reproductively isolated over time as a result.\n\nHowever, dogs and wolves have not yet speciated; they can still breed and produce fertile offspring, which is usually the demarcation criteria for animal species (see: biological species concept). However, there are good odds that they could become reproductively isolated in the relatively near future; for example, consider the difficulty of a chihuahua and a wolf attempting to breed. This is known as a prezygotic barrier, and could result in reproductive isolation, or something akin to a ring species (although such are typically a result of geographic isolation).\n\nIndeed, the diversity of canis familiaris is strong evidence for just how much diversity can be produced from a common ancestor (in only ~50,000 years, no less!).
17522
I would have to disagree with David to some extent. To evolve into a different species we would have changed enough so that different subpopulations of humans could no longer interbreed. Humans display a range of social and technological aptitudes and capacities throughout earth, the majority of which haven't even heard a dialtone let alone participated in any form of advanced travel or communications processes. However, none of these people are incabable of doing so if provided with the appropriate education needed. This suggest that there hasn't been any change in our molecular (genetic) makeup that provides us with these advanced technologies -- which is where the changes are needed to happen for biological evolution to occur. Even if you wanted to argue that social evolution has distinguished industrialized man from our primitive brethern enough to warrant a new species distinction, I would argue that we still haven't met one of the key requirements for doing so, there are no subgroups of humans on earth that are incapable of interbreeding with one another. Until that happens, no we haven't evolved from Homo sapiens sapiens to Homo sapiens futura. \n\nHowever, we will evolve into someting different! This is a certainty -- as long as our species doesn't become extint before that can happen! But don't expect that Homo sapiens will evolve into just one different species. Depending on what our environment(s) dictates, humans could evolve into numerous other species. Through the process of evolution, it is inevitable, but at the same time it is not predictable.