What is Lamarack's hypothesis regarding evolution?
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Lamarckism is a term used for Lamarckian evolution, a theory put forward by the French biologist Jean-Baptiste Pierre Antoine de Monet, Chevalier de Lamarck, based on heritability of acquired characteristics, the once widely accepted idea that an organism can acquire characteristics during its lifetime and pass them on to its offspring, in contrast to the now commonly accepted Darwinian theory of Natural selection; the idea that individual organisms which possess genetic variations giving them advantageous heritable traits are more likely to survive and reproduce and, in doing so, to increase the frequency of such traits in subsequent generations.
63723
unfortunatly there is none for the emergance of species that can be observed. natural selection can be observed and has been but there is no conclusive evidence that evolution took place.
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If we talk about Evolution Theory, a number of them have been formulated till now, for instance, by Lean Bapist Lamark, by Charles Robert Darwin, by Earnest Hackel, by Hugos de Veries....\nBut in general, the probable evidences, which might have stimulated these gentlemen to formulate their Evolution Theory are,\n1) Fossils - Missing links, and connecting links\n2) Homologous organs\n3) Analogous organs\n4) Vestigial organs\n5) Embryology\n\nAnd apart from these, we can take into consideration, "Physiology ".
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According to Darwin, it's due to the accumulation of random point mutations in the genetic code of a primitive ancestor, one that's related to all the great apes. As these mutations accumulated, some individuals were removed from the gene pool (by the death or non-reproductive status of the mutant organism), others showed no change and therefore didn't compete for resources in any improved manner, and lastly, some showed mutations that were beneficial and allowed that individual to reproduce more efficiently (either by more efficient energy usage or mating habits, etc., whatever would give that individual and advantage over it's peers).\n\nThere are other more esoteric theories on evolution/development that may or may not contribute to this process, but Darwin's Theory is the universally accepted one.
199584
"Macro-evolution" is a theory inasmuch as evolutionary events that have purportedly occured over millions of years and resulted in the appearance of new species can not be experimentally reproduced or observed. In contrast, "Micro-evolution," which describes genetic change within a particular species, has been observed and can be witnessed over and over again. \n\nThe mechanics of micro-evolution are most evident in lower order organisms such as bacteria, viruses, insects, etc. Just think about cockroaches and how quickly, in a matter of a few generations they can adapt to certain pesticides and become immune to them. \n\nThe reason why macro-evolution has been readily accepted as fact when it really isn't is because the principles of micro-evolution have been extrapolated to the illogical conclusion that species can go through so many minor genetic changes that they eventually become entirely new species. This has not been proven and unless you are able to live millions of years or be able to maintain documentation that lasts that long, macro-evolution can NEVER be proven.
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No. Darwin's theory of evolution hasn't been proven,in fact most evidence proves otherwise.A lot of scientists don't believe in evolution.There is no more evidence to support Darwin's theory of evolution today than there was when Darwin came up with the theory.I don't see how anyone could believe in evolution.There isn't enough evidence to support it.Science itself refutes Darwinism.\n\n• According to the theory of evolution, at some time in the distant past there was no life in the universe -- just elements and chemical compounds. Somehow, these chemicals combined and came to life.\n\n• However, scientists don't really know how life came to be. Even Stanley Miller, whose experiments are cited in most biology text books, says that the origin of life is still unknown. The idea that dead material can come to life all by itself is not consistent with scientific observation.\n\n• The leading mathematicians in the century met with some evolutionary biologists and confronted them with the fact that, according to mathematical statistics, the probabilities for a cell or a protein molecule coming into existence were nil. They even constructed a model on a large computer and tried to figure out the possibilities of such a cell ever happening. The result was zero possibility! - Wistar Institute\n\n• Professor Edwin Conklin observed, "The probability of life originating from accident is comparable to the probability of the Unabridged Dictionary resulting from an explosion in a printing shop."\n\n• Under normal circumstances, creatures give birth to the same kind of creatures. It is established scientific fact that like begets like. On rare instances, the DNA in an embryo is damaged, resulting in a mutant child that differs in some respect from its parent. Although a few mutations have been scientifically observed that are beneficial, most mutations produce inferior offspring. For the theory of evolution to be true, there must be a fantastic number of creative mutations that produce new kinds of offspring which are better suited for survival, and therefore are favored by natural selection.\n\n• Darwinists claim that the reptile-to-mammal evolution is well documented. But for reptiles to evolve into mammals at least some of these transformations must have happened: \n• Scales had to have mutated into hair. \n• Breasts had to have evolved from nothing. \n• Externally laid eggs had to evolve into soft-shelled eggs that were nourished by an umbilical cord and placenta in a womb. \n\n• It has never been observed in any laboratory that mutations can cause one species to turn into another. Despite this, evolutionists believe that given enough time, some animals will eventually evolve into other creatures. \n\n• Evolutionists claim that although we have not actually observed these things happening, that does not mean that they are impossible. They say it simply means they are extremely improbable. Evolutionists think the world has been around long enough for all these highly improbable things to happen.\n\n• Sir Fred Hoyle, of Cambridge University stated that statistically the chances of one cell evolving was the same as a tornado passing through a junkyard and giving you a fully functional Boeing 747.\nhttp://www.straight-talk.net/evolution/arguments.shtml\n\n* Scientific evidence casts serious doubts on the theory of evolution, for example:\n\n* The Fossil Record (Updated 3 July, 2005)\nhttp://www.straight-talk.net/evolution/fossil.htm\n\n* Living "Fossils"\nhttp://www.straight-talk.net/evolution/living.htm\n\n* The Cambrian Explosion\nhttp://www.straight-talk.net/evolution/explosion.htm\n\n• New T.Rex Discoveries (Updated 10 June, 2005)\nhttp://www.straight-talk.net/evolution/t-rex.htm\n\n* "Missing Links"\nhttp://www.straight-talk.net/evolution/misslinks.htm \n\n* The Big Bang\n http://www.straight-talk.net/evolution/bigbang.htm\n\n* Anthropic Principle\nhttp:/
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Von Baer studied the development of embryos and found that all embryos follow a similar developmental pattern.  Darwin used this as evidence in his book (On the Origin of Species) suggesting that the reason for this similiarity was due to a common ancestor.
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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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Genetics. And Darwins theory.
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Oh no, not this question again. Why doesn't anybody use the Search button?\nLet me address two separate issues (the first part is modified from another answer):\n1) The pattern of evolutionary processes that can be seen (in the fossil record and living species)can be of two types: \nIn _anagenetic_ (meaning "that generate upward movement") events, an entire population evolves in one direction and becomes so different that at some point the people who study it give it a different name. This is encountered in paleontological research and the decision to separate one from the other is ultimately arbitrary. \n_Cladogenetic_ (meaning "that generates branches") events entail a population that splits into different sub-groups; each of these then evolves independently from the others. We share A COMMON ANCESTOR with living apes, but we have not evolved from them directly. \nOur direct ancestors are fossil hominid species. \nAll the species that are living today have their separate evolution and history; also they all (including humans) share common ancestors from which they (we) have inherited our common traits. And apes have their own ancestors that are closer to them than to Homo sapiens; the fact that apes are our closest living relatives does not exclude the existence of more related _extinct_ relatives.\n\n2) What you're stating is one of the arguments that many creationist use, namely, that change within a species (adaptation, i.e. microevolution) is possible (they are astute in not denying this, because the proofs are overwhelming!), but a species cannot transform into another (macroevolution). \nThis is based on a mistaken concept of "species". Most people think in terms of the biological species concept, which is based on reproductive isolation. That is, individuals of each species cannot hybridize succesfully with individuals of other species. However, there is not a single path for the rise of the mechanisms for recognition or isolation that we perceive as the "real boundaries" of a species (see second link for an interesting discussion here at Y!Answers). What the taxonomist calls a species may respond to different species concepts (such as morphological, evolutionary, biological (isolation), paleontological, recognition, etc,), and there are many examples of populations in which speciation (total isolation) is on the way, and there's a thin line between "subspecies" or "geographical races" and valid species (just ask an expert in systematics, which I am not). \nEvolutionary processes are long-term phenomena, and it may seem that there are "evolutionary leaps" from one species to the other. But although there are particular cases of "instantaneous speciation", most of the "leaps" are due to the fragmentary nature of the fossil record. So many populations become extinct or become something else and their former existence is not recorded anywhere! But although the record is fragmentary, life is continuous.\n\nSorry for the lengthy answer, I hope you find it useful.
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THEORIES OF EVOLUTION\n\nEvolution in one sense, means growth or development--literally, unrolling or unfolding. It is difficult to give a clear definition that will apply to each of the various theories that are held. Theories differ vastly in the extent of their application, as held by their various advocates, resulting in great confusion of terms:\n\n1. The atheists believe that there is no God. Hence, matter was not created, but was eternal, or came by chance. Only a mere handful of the whole human race have ever yet believed such an untenable doctrine. The existence of a Creator, is doubted or denied by extreme atheistic evolutionists, who would dethrone God, "exalt the monkey, and degrade man."\n\n2. The first of modern scientific men to adopt the theory that all plants and animals, including man, are developed from certain original simple germs, was Lamarck a French naturalist, in 1809. He conceded that God created matter--nothing more. He believed in spontaneous generation, which scientific investigation has utterly disproved.\n\n3. Darwin goes a step further and concedes there may have been a Creator of matter, and of one, or at most, a few germs, from which all vegetation and all animals came by evolution--all orders, classes, families, genera, species, and varieties. He differs from Lamarck, by allowing the creation of one germ, possibly a few more. He says in his "Origin of Species," "I believe that animals are descended from at most only four or five progenitors; and plants from an equal or lesser number . Analogy would lead me one step further, namely, to the belief that all animals and plants are descended from one prototype...All the organic beings, which have ever lived on the earth, may be descended from some one primordial form." Darwin, because of his great scholarship, fairness, and candor, won for his theory more favor than it inherently deserves. Darwin taught that, "The lower impulses of vegetable life pass, by insensible gradations, into the instinct of animals and the higher intelligence of man," without purpose or design. None of these three hypotheses can admit the creation of man.\n\n4. Other evolutionists, believing in the evolution of both plants and animals, nevertheless refuse to believe in the evolution of man--the most baneful application of the whole theory. Even if there were convincing proof of the evolution of plants and animals from one germ, there is no real proof of the evolution of man. To prove this is the chief purpose of this book.\n\n5. A fifth theory of evolution is held by many. It is called polyphyletic evolution, which means that God created numerous stocks, or beginnings of both plant and animal life, which were subject to change and growth, deterioration and development, according to his plan and purpose. So much of evolution in this sense as can be proved, is in harmony with the Bible account of the creation of plants, animals and man. The false theory of evolution is called the monophyletic, which teaches that al1 species of plants and animals including man, developed from one cell or germ which came by creation or spontaneous generation. Evolution is used throughout this book in this latter sense, unless otherwise indicated by the context. God does not create by evolution, for it can only develop what already exists.\n\nThis book is divided into three parts: In Part One, material evolution, especially the evolution of the human body, is disproved. In Part Two, the alleged proofs of evolution are examined and refuted. In Part Three, the evolution of the soul is shown to be impossible. There are in all fifty numbered arguments, including answers to the arguments of evolutionists.
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Evolution is still happening today, so it is observable. However, it takes many generations for any adaptation to become part of the genetic code of a species, and therefore, only in a great many generations will there be any concrete proof. Scientists do not claim to have proved it, at least, none of the scientists I've consulted on this matter. They say there is a lot of evidence to substantiate the theory of evolution and none to disprove it, which I believe to be true. Because of this, it's a theory that has ceased to be contested. However, it is still a theory, with lots of evidence in it's favor but no proof.
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Adaptation? Evolution?
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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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There is an enormous amount of evidence supporting evolution, and none I have seen disputing it at all- There are gaps in the evidence, but there is no evidence directly *against* the theory.  Originally it was thought that evolution happened in a slow, steady, manner-but fossil evidence mounted that disputed that view, and thus the theory was refined, so that now we know it generally occurs more rapidly when there is major climactic change, leaving different environments, creating new ones, killing off of existing species which creates empty niches for new animals to fill.  Most arguments against evolution depend on areas where there is lack of evidence, not on evidence that disputes the theory.  \nThe first evidence was Darwin's observations that birds adapted genetically to different environments, a process that is, in fact, slow and steady.\nThen the geological and physical evidence that the Earth was actually billions, not thousands, of years old meant that there was plenty of time for evolution.\nThen the morphilogical evidence of relatedness.\nThis theory also explained the many vestigial structures found in animals, such as the tiny hipbones in snakes\nIt was well documented and accepted by the early 1900's-THis theory predicted that there would be a close correlation of genetic patterns with morphology, and predicted that there would be vestigial genes in animals.  It also predicted that all forms of life would share certain genes, and that closely related species would have closely related, but slightly different, genes.  All of these predictions were shown to be true.\nEvolution also predicted that structure such as wings would have evolved at some point with a different function, since evolutionary mutations that are beneficial (less than 1 in 100,000) would tend to make small changes, and one could not expect a lizard to bear baby lizards with full-blown wings.  THus, the structures that become wings would be expected to have had some other function, and eventually evolved into wings.  For many structures, such as wings and eyes, these early purposes have been determined.\nRapid evolution, especially under conditions of stress, is seen in bacteria and other one-celled animals.  Because the theory states that it would require thousands of generations to observe evolution in action, only bacteria and other very rapidly dividing organisms can be tested for evolutionary changes that we can actually see.\nThus, the theory effectively explains animal and plant diversity, the predictions that the theory made were shown to be true, the fossil, genetic, and morphological data from the past support the theory, and it has been demonstrated to occur in the only animals that it could be demonstrated in, bacteria.\nFor a theory about how things have occurred over the last few billion years, when we cannot actually "see" it occuring, when it has happened over a span of time far beyond our historical records, this is an overwhelming and nearly indisputable amount of evidence.\n\nThe theory does not predict that animals will become "better" over time, just that any genetic mutation which increase the viability and number of offspring will tend to change the species- Remember, the theory of evolution is only one of biochemistry, genetics, and environmental interactions- It is not a philosophy, religion, or value system- Evolution does not make value judgements, does not plan or think or even care- it is merely a physical process like a rock falling down a hill.
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For the most part they do not understand the theory of evolution, or the scientific meaning of the word "theory."  I see people all the time who think they can refute evolution with questions like "If people came from monkeys why are there still monkeys?"\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.  However, it does provide evidence that macroevolution may be possible. Taken in the context of the other evidence for evolution, microevolution provides a mechanism by which macroevolution could occur. On its own, it doesn't prove that macroevolution occurs, but it does suggest that it is possible.\n\n3. The fossil record.\n\nAlthough the fossil record does not provide a “complete” record as fossils form only under certain conditions, it does show a gradual change in the morphology of species as well as numerous extinct species.  There are a number of methods used to date fossils, and the time period from which a fossil comes can be determined with reasonable accuracy.\n\n4. Imperfect structures (the blind spot of the mammalian eye, for example).\n\nI want to mention the bind-spot of the mammalian eye specifically because creationists often hold up the human eye up as an example of something that is too perfect to occur by "chance" (i.e. as the result of the natural selection of beneficial changes among random mutations).\n\nThere are also numerous examples where the morphology of a species is constrained by similar patterns in its ancestors (quadrupeds, vertebrates, etc.).\n\n5. Developmental biology reflects evolutionary lineage.\n\nCreationists like to bring up a man named Haeckel in response to this argument.  Haeckel suggested that development reflects evolutionary origin.  It was later discovered that several of the sketches he used as evidence over-exaggerated certain features, and some were of different embryos all together. However, many of his sketches do accurately reflect the morphology of the embryo. Haeckel's methods were sometimes wrong and his ethics were poor, but it just so happens that his theory turned out to be fairly accurate.\n\nAny developmental biologist can tell you that embryos of related species show similar morphology in the early stages of development. The point at which their development begins to diverge shows a strong correlation with the relative point at which the evolution of the two species diverged. Human embryos look similar to chimpanzee embryos for a lot longer than they look similar to cat embry
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For those who said Darwin or Russell, sorry. Both fail. Not only did Lamarck's theory of evolution predate both in modern times but the first theory of evolution was proposed around 2500 years earlier than any of them.\n\nThe first theory of evolution that I know of was proposed by Empedocles around 450BC. \n\nFollow the second link for a full verbatim quote of the theory as it was originally written down.\n\n\nCaveat. I don't claim this is the first theory of evolution. It is just the earliest that I am aware of. It is certainly much earlier than Darwin or Wallace.