Talk:Evolution
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Many of these questions are rephrased objections to evolution that users have argued should be included in the text of Evolution. The reason for their exclusion is discussed below. The main points of this FAQ can be summarized as:
More detail is given on each of these points, and other common questions and objections, below. To view the response to a question, click the [show] link to the right of the question. Q1: Why won't you add criticisms or objections to evolution in the Evolution article?
A1: This is essentially mandated by Wikipedia's official neutral point of view policy. This policy requires that articles treat views on various subjects proportionally to those views' mainstream acceptance in the appropriate academic field. For example, if two contradictory views in physics are held by roughly an equal number of physicists, then Wikipedia should give those views "equal time". On the other hand, if one view is held by 99% of physicists and the other by 1%, then Wikipedia should favor the former view throughout its physics articles; the latter view should receive little, if any, coverage. To do otherwise would require, for example, that we treat belief in a Flat Earth as being equal to other viewpoints on the figure of the Earth.
Due to the enormous mainstream scientific consensus in support of modern evolutionary theory, and pursuant to Wikipedia's aforementioned policies, the Evolution article references evolution as an observable natural process and as the valid explanation for the diversity of life on Earth. Although there are indeed opposing views to evolution, such as Creationism, none of these views have any support in the relevant field (biology), and therefore Wikipedia cannot, and should not, treat these opposing views as being significant to the science of evolution. On the other hand, they may be very significant to sociological articles on the effects of evolutionary theory on religious and cultural beliefs; this is why sociological and historical articles such as Rejection of evolution by religious groups give major coverage to these opposing views, while biological articles such as Evolution do not. Q2: Evolution is controversial, so why won't you teach the controversy?
A2: As noted above, evolution is at best only controversial in social areas like politics and religion. The fact that evolution occurs and the ability of modern evolutionary theory to explain why it occurs are not controversial amongst biologists. Indeed, numerous respectable scientific societies, such as the American Association for the Advancement of Science and the National Academy of Sciences, have issued statements supporting evolution and denouncing creationism and/or ID.[1] In 1987 only about 0.15% of American Earth and life scientists supported creationism.[2]
Thus, as a consequence of Wikipedia's policies, it is necessary to treat evolution as mainstream scientific consensus treats it: an uncontroversial fact that has an uncontested and accurate explanation in evolutionary theory. There are no scientifically supported "alternatives" for this view. However, while the overall theory of evolution is not controversial in that it is the only widely-accepted scientific theory for the diversity of life on Earth, certain aspects of the theory are controversial or disputed in that there actually are significant disagreements regarding them among biologists. These lesser controversies, such as over the rate of evolution, the importance of various mechanisms such as the neutral theory of molecular evolution, or the relevance of the gene-centered view of evolution, are, in fact, covered extensively in Wikipedia's science articles. However, most are too technical to warrant a great deal of discussion on the top-level article Evolution. They are very different from the creation–evolution controversy, however, in that they amount to scientific disputes, not religious ones. Q3: Why is evolution described as though it's a fact? Isn't evolution just a theory?
A3: That depends on if you use the words evolution, theory, and fact in their scientific or their colloquial sense. Unfortunately, all of these words have at least two meanings. For example, evolution can either refer to an observed process (covered at evolution), or, as a shorthand for evolutionary theory, to the explanation for that process (covered at modern evolutionary synthesis). To avoid confusion between these two meanings, when the theory of evolution, rather than the process/fact of evolution, is being discussed, this will usually be noted by explicitly using the word theory.
Evolution is not a theory in the sense used on Evolution; rather, it is a fact. This is because the word evolution is used here to refer to the observed process of the genetic composition of populations changing over successive generations. Because this is simply an observation, it is considered a fact. Fact has two different meanings: in colloquial usage, it refers to any well-supported proposition; in scientific usage, it refers to a confirmed observation. For example, in the scientific sense, "apples fall if you drop them" is a fact, but "apples fall if you drop them because of a curvature in spacetime" is a theory. Gravity can thus either refer to a fact (the observation that objects are attracted to each other) or a theory (general relativity, which is the explanation for this fact). Evolution is the same way. As a fact, evolution is an observed biological process; as a theory, it is the explanation for this process. What adds to this confusion is that the theory of evolution is also sometimes called a "fact", in the colloquial sense—that is, to emphasize how well supported it is. When evolution is shorthand for "evolutionary theory", evolution is indeed a theory. However, phrasing this as "just a theory" is misleading. Theory has two different meanings: in colloquial usage, it refers to a conjecture or guess; in scientific usage, it refers to a well-supported explanation or model for observed phenomena. Evolution is a theory in the latter sense, not in the former. Thus, it is a theory in the same sense that gravity and plate tectonics are theories. The currently accepted theory of evolution is known as the modern evolutionary synthesis. Q4: But isn't evolution unproven?
A4: Once again, this depends on how one is defining the terms proof and proven. Proof has two meanings: in logic and mathematics, it refers to an argument or demonstration showing that a proposition is completely certain and logically necessary; in other uses, proof refers to the establishment and accumulation of experimental evidence to a degree at which it lends overwhelming support to a proposition. Therefore, a proven proposition in the mathematical sense is one which is formally known to be true, while a proven proposition in the more general sense is one which is widely held to be true because the evidence strongly indicates that this is so ("beyond all reasonable doubt", in legal language).
In the first sense, the whole of evolutionary theory is not proven with absolute certainty, but there are mathematical proofs in evolutionary theory. However, nothing in the natural sciences can be proven in the first sense: empirical claims such as those in science cannot ever be absolutely certain, because they always depend on a finite set of facts that have been studied relative to the unproven assumptions of things stirring in the infinite complexity of the world around us. Evolutionary science pushes the threshold of discovery into the unknown. To call evolution "unproven" in this sense is technically correct, but meaningless, because propositions like "the Earth revolves around the Sun" and even "the Earth exists" are equally unproven. Absolute proof is only possible for a priori propositions like "1 + 1 = 2" or "all bachelors are unmarried men", which do not depend on any experience or evidence, but rather on definition. In the second sense, on the other hand, evolutionary theory is indeed "proven". This is because evolution is extremely well supported by the evidence, has made testable confirmed predictions, etc. For more information, see Evidence of evolution. Q5: Has evolution ever been observed?
A5: Evolution, as a fact, is the gradual change in forms of life over several billion years. In contrast, the field of evolutionary biology is less than 200 years old. So it is not surprising that scientists did not directly observe, for example, the gradual change over tens of millions of years of land mammals to whales.[3] However, there are other ways to "observe" evolution in action.
Scientists have directly observed and tested small changes in forms of life in laboratories, particularly in organisms that breed rapidly, such as bacteria and fruit flies.[4] A famous experiment was developed in 1992 that traced bacterial evolution with precision in a lab. This experiment has subsequently been used to test the accuracy and robustness of methods used in reconstructing the evolutionary history of other organisms with great success.[5][6] Evolution has also been observed in the field, such as in the plant Oenothera lamarckiana which gave rise to the new species Oenothera gigas,[7] in the Italian Wall Lizard,[8] and in Darwin's finches.[9] Scientists have observed significant changes in forms of life in the fossil record. From these direct observations scientists have been able to make inferences regarding the evolutionary history of life. Such inferences are also common to all fields of science. For example, the neutron has never been observed, but all the available data supports the neutron model. The inferences upon which evolution is based have been tested by the study of more recently discovered fossils, the science of genetics, and other methods. For example, critics once challenged the inference that land mammals evolved into whales. However, later fossil discoveries illustrated the pathway of whale evolution.[3] So, although the entire evolutionary history of life has not been directly observed, all available data supports the fact of evolution. Q6: Why is microevolution equated with macroevolution?
A6: The article doesn't equate the two, but merely recognizes that they are largely or entirely the same process, just on different timescales. The great majority of modern evolutionary biologists consider macroevolution to simply be microevolution on a larger timescale; all fields of science accept that small ("micro") changes can accumulate to produce large ("macro") differences, given enough time. Most of the topics covered in the evolution article are basic enough to not require an appeal to the micro/macro distinction. Consequently, the two terms are not equated, but simply not dealt with much.
A more nuanced version of the claim that evolution has never been observed is to claim that microevolution has been directly observed, while macroevolution has not. However, that is not the case, as speciations, which are generally seen as the benchmark for macroevolution, have been observed in a number of instances. Q7: What about the scientific evidence against evolution?
A7: To be frank, there isn't any. Most claimed "evidence against evolution" is either a distortion of the actual facts of the matter, or an example of something that hasn't been explained yet. The former is erroneous, as it is based on incorrect claims. The latter, on the other hand, even when accurate, is irrelevant. The fact that not everything is fully understood doesn't make a certain proposition false; that is an example of the argument from ignorance logical fallacy. Examples of claimed evidence against evolution:
Q8: How could life arise by chance?
A8: If by "arise", one means "develop from non-organic matter through abiogenesis", then this is a question that is not answered by evolutionary theory. Evolution only deals with the development of pre-existing life, not with how that life first came to be. The fact that life evolves is not dependent upon the origin of life any more than the fact that objects gravitate towards other objects is dependent upon the Big Bang.
On the other hand, if by "arise" one means "evolve into the organisms alive today", then the simple answer is: it didn't. Evolution does not occur "by chance". Rather, evolution occurs through natural selection, which is a non-random process. Although mutation is random, natural selection favors mutations that have specific properties—the selection is therefore not random. Natural selection occurs because organisms with favored characteristics survive and reproduce more than ones without favored characteristics, and if these characteristics are heritable they will mechanically increase in frequency over generations. Although some evolutionary phenomena, such as genetic drift, are indeed random, these processes do not produce adaptations in organisms. If the substance of this objection is that evolution seems implausible, that it's hard to imagine how life could develop by natural processes, then this is an invalid argument from ignorance. Something does not need to be intuitive or easy to grasp in order to be true.Past discussions For further information, see the numerous past discussions on these topics in the archives of Talk:Evolution: The article is not neutral. It doesn't mention that evolution is controversial.
The article should mention alternative views prominently, such as in a criticism section.
Evolution is just a theory, not a fact.
There is scientific evidence against evolution. References
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WARNING: This is not the place to discuss any alleged controversy or opinion about evolution and its related subjects. This page is for discussing improvements to the article, which is about evolution (not creation science, not creationism, and not intelligent design to name a few), and what has been presented in peer-reviewed scientific literature about it. See Wikipedia:No original research and Wikipedia:Talk page guidelines. Some common points of argument are addressed in the FAQ above, which represents the consensus of editors here. If you are interested in discussing or debating over evolution itself, you may want to visit talk.origins or elsewhere. |
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Evolution has many definitions
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It should be specified that in common parlance AND scientific journals the word 'evolution' is shorthand for the THEORY of evolution. Evolution is not really ' the change in alleles'. This was stated in better previous versions of this article. I don't know why it has deteriorated so much. John.r.r (talk) 13:45, 1 September 2015 (UTC)
McSly, I read Q3 and it really does not pertain to what I am saying. The article at the start should be clear that the word evolution is MOST often used to mean the theory. Rarely is it used to mean 'alleles over time' To put that first is misleading and deceptive. Previous better versions did not make that mistake. Can you tell me where those WP rules are located like WP:NPV etc??? John.r.r (talk) 14:48, 1 September 2015 (UTC)
Simply want many parts of this article to return to the way it was years ago. And many others feel the same way. How can consensus develop to change it if you stamp out all those who want to change it?????? Not very democratic. Very dictatorial! By stamping out discussion you are turning evolution into a pseudoscience: Attacking the motives or character of anyone who questions the claims. John.r.r (talk) 22:40, 1 September 2015 (UTC)
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Semi-protected edit request on 2 September 2015
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This sentence is awkward because it lacks parallel construction:
Understanding of evolution has made significant contributions to humanity, including preventing and treating human disease, new agricultural products, industrial innovations, a subfield of computer science and rapid advances in life sciences.[21][22][23]
Here's a suggested modification:
Understanding evolution has advanced humanity. It has led to innovation in fields such as healthcare, agriculture, computer science and life sciences.[21][22][23]
12.238.88.5 (talk) 21:39, 2 September 2015 (UTC)
- I made a slightly smaller revision to get the phrases lined up. —Torchiest talkedits 02:26, 3 September 2015 (UTC)
Variation
in the sentence "A substantial part of the variation in phenotypes in a population is caused by the differences between their genotypes" what does 'their' refer to? I would suggest replacing this sentence with something along the lines of "A substantial part of the phenotypic variation in a population is caused by genotypic variation". 129.127.101.245 (talk) 07:21, 22 September 2015 (UTC)
- "Their" refers to the phenotypes. The sentence is clear, direct and easy to understand. Proposed construction is clumsy. - Nick Thorne talk 11:14, 23 September 2015 (UTC)
- phenotyes don't have genotypes. individuals have genotypes and phenotypes. What is clumsy about the proposed construction? I would posit that the current construction is clumsy. The proposed construction replaces 'variation in phenotypes in a population' with 'phenotypic variation' -- clearly less convoluted and 'clumsy', and in the proposed construction there is also no ambiguity about what 'their' refers to (phenotypes don't have genotypes so the current construction doesn't even make sense).129.127.101.245 (talk) 05:09, 25 September 2015 (UTC)
- It seems there are no further objections, so I will go ahead and ask for the proposed change to be made.129.127.101.245 (talk) 01:57, 29 September 2015 (UTC)
lead sentence
"Evolution is change in the heritable traits of biological populations over successive generations."
"over successive generations" is not necessary. Heritable traits of biological populations change within generations, e.g. when an individual dies -- this is still evolution. Not to mention, a generation is extremely difficult to define in most cases. "Change" already implies an element of time.
It may also be helpful to define heritable traits in brackets based on the most common definitions and in line with the terminology used in definitions for natural selection and genetic drift (two important evolutionary forces). E.g. heritable traits (alleles, phenotypes)129.127.101.245 (talk) 06:30, 25 September 2015 (UTC)
- It seems there are no objections, so I will go ahead and ask for the proposed change to be made.129.127.101.245 (talk) 02:07, 29 September 2015 (UTC)
Semi-protected edit request on 29 September 2015
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please change "A substantial part of the variation in phenotypes in a population is caused by the differences between their genotypes." to "A substantial part of the phenotypic variation in a population is caused by genotypic variation." The current construction is clumsy. The proposed construction replaces 'variation in phenotypes in a population' with 'phenotypic variation' -- clearly less convoluted, and in the proposed construction there is also no ambiguity about what 'their' refers to (phenotypes don't have genotypes so the current construction doesn't make sense). 129.127.101.245 (talk) 02:05, 29 September 2015 (UTC)
- Agreed and Done, though I didn't include the wikilinks as those terms are linked earlier. Thanks, Adrian J. Hunter(talk•contribs) 13:22, 29 September 2015 (UTC)
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please change the lead sentence "Evolution is change in the heritable traits of biological populations over successive generations." to "Evolution is change in the heritable traits (alelles, phenotypes) of biological populations." "over successive generations" is not necessary. Heritable traits of biological populations change within generations, e.g. when an individual dies -- this is still evolution. Not to mention, a generation is extremely difficult to define in most cases. "Change" already implies an element of time. It may also be helpful to define heritable traits in brackets based on the most common definitions and in line with the terminology used in definitions for natural selection and genetic drift (two important evolutionary forces). E.g. heritable traits (alleles, phenotypes) 129.127.101.245 (talk) 02:11, 29 September 2015 (UTC)
- I'll await a second opinion on this one. I don't like "heritable traits (alleles, phenotypes)", as that wording could be misunderstood to imply "alleles" is a synonym of "traits". It's no true that "change" implies time; for example, the diameter of that tree trunk changes from 2 m at ground level to 1 m higher up. But I take your point about "generations" being unnecessary, and think "Evolution is change in the heritable traits of biological populations over
successive generationstime" would be an improvement. Adrian J. Hunter(talk•contribs) 13:32, 29 September 2015 (UTC)- I think the sentence is fine and very descriptive-individuals don't evolve-populations do and over successive generations (population genetics). Successive generations refers to asexual reproduction and "sex" which is instrumental in evolution (Mendelian inheritance and recombination and the expression and distribution of traits within a population)) , and implied that different proportions of a trait will be expressed over generations in a specific pattern (in equilibrium) unless random mutation or outside forces-natural selection, drift, gene flow, etc. alter that Hardy-Weinberg equilibrium to produce an evolutionary change. A successive generation will be a different time interval for any given species so "time" really isn't the info we want to express but reproduction and offspring of a "successive generation". Even if an individual expressed a novel mutation and trait if they don't reproduce no evolution has occurred. Then too fruit flies resistance to synthetic pesticides is from a transposon mutation that occurred some 30,000 years ago (that isn't evolution), but not until recent times has evolution taken place with the advent of synthetic pesticides such the mutation found a function in resistance to the pesticide and then through successive generations that evolution has taken place such a change has occurred in the population that now high numbers express this new novel trait because of selective pressure from synthetic pesticides. . Now 80% of the world's fruit flies express this mutation from natural selection acting on the cryptic jumping gene and trait that floated around the population for thousands of years until now and evolution produced a change in the population that now high numbers of the population expresses this novel new trait. Regards, GetAgrippa (talk) 15:31, 29 September 2015 (UTC)
Not done: After checking the wiktionary entry and a few other dictionaries[1][2][3], I would say that the wording is fine. Inomyabcs (talk) 23:08, 29 September 2015 (UTC)
References
- @ Adrian J. I agree with you that having "heritable traits (alleles, phenotypes)" is not a good idea, and I also see your point re: change and time. I agree that "time" is a good replacement for "generations".
- @ GetAgrippa I disagree. As I mentioned, heritable traits of biological populations change within generations, e.g. when an individual dies -- this *is* evolution; it changes the frequency of traits in the population. Also, in your fruit fly example, when the mutation occurred, that *is* evolution (it sounds like you're confusing evolution and natural selection here). Using "generations" is too restrictive; yes, it implies reproduction, which plays an important role in evolution, but it also excludes a bunch of things like mutation (the only source of new variation) and death (integral in both drift and selection). Having "heritable traits" should be enough to imply inheritance and therefore reproduction. Not to mention, "generation" has a very ambiguous definition (actually many) and in most cases cannot be defined for a population, which poses problems if evolution occurs at the population-level. On the other hand, time is inclusive of all processes. 129.127.101.245 (talk) 06:12, 30 September 2015 (UTC)
Not done: please establish a consensus for this alteration before using the {{edit semi-protected}}
template. Once consensus is reached, any autoconfirmed editor can edit the article, or the request can be reopened if needed. Thanks, ‑‑ElHef (Meep?) 13:29, 30 September 2015 (UTC)
- I disagree I think you are confusing molecular evolution with biological evolution. Molecular evolution took place with the mutation but the actual biological evolution didn't occur till pesticides were an environmental agent of natural selection-a process of biological evolution. The mutation had no trait (not every mutation is meaningful nor is evolution-mutation isn't evolution) till it jumped into a position to alter a cytochrome P450 gene =the emergent property of the gene interactions is the trait-resistance to pesticides that then natural selection acted on to alter the distribution in the population through successive generations. Individual alway die within a population-that is a given-but it may not change the distribution of traits within the population so no it doesn't equate to evolution always. If the death of individuals randomly or selectively alters the traits of the population so it is no longer in Hardy Weinberg equilibrium then you have evolution. . Death of individuals is a given it doesn't necessarily change the distribution of traits within a population for that generation. Death is due to any number of factors such as chaotic events such as is genetic drift, natural selection of individuals that survive so others die, or a neighboring population migrated in and killed all but a few individuals-gene flow (then too if the two population hybridize more gene flow. Then too those that survive have to reproduce so if only a fraction of individuals reproduce then that will alter the distribution of traits of the population. The population is considered individuals that survive to reproduce-hence fitness. You can predict the distribution of genotypes and phenotypes/traits of a breeding population under the assumptions of Hardy-Weinberg. Anything that alters that equilibrium is Evolution. So the death of individuals randomly in genetic drift will alter it, or selectively with natural selection such certain ones more likely to die will alter it, or say a neighboring population migrates in and kills all but a few individual so gene flow that alter the equilibrium and traits of the population then too hybridization between population can occurs so more gene flow. Then too as you mentioned a random mutation can alter the populations trait too but only if the individual with the mutation reproduces to pass on the trait=a single individual with a trait that isn't propagated isn't evolution Sexual recombination acts generationally to create new combinations of alleles within a population too. It isn't the time that is important more so than generational change-descent with modification. Without "successive generations" you leave out descent which is more important than time. You seem to equate death to evolution which is like equating extinction to evolution both play a role in evolution but aren't evolution. Wikipedia defines Generation as" the act of producing offspring. In kinship terminology, it is a structural term designating the parent-child relationship. It is also known as biogenesis, reproduction, or procreation in the biological sciences." So Evolution is the change in traits of a population through successive generations. How are the traits changed=through successive generations or reproduction=descent with modification. Regards GetAgrippa (talk) 00:17, 1 October 2015 (UTC)
- Here is a better example-take the Linski longterm E. Coli experiment following the evolution of a cloned bacteria. If you take the first generation of bacteria and froze them in storage-they are alive but aren't evolving because they aren't reproducing-time can continue ad infinitum. Only with successive generations does evolution take place and the time interval per generation may be different as it evolves so time isn't important. The bacteria is a great example too as the citrate trait that evolved did so with multiple mutations and multiple steps but not every mutation was significant. It is generation-reproduction that is most important not time. GetAgrippa (talk) 00:29, 1 October 2015 (UTC)
- wow, are you trying to bury this under a wall of text? You've hardly addressed any of the points I made, and when you've attempted, you've failed.
- first, I'll address some of the points you made:
- The bacteria example really doesn't support your point (but then no example will, because your point is flawed). Nowhere in the proposed definition (using 'time' instead of 'generations') does it state that time is all that is required for evolution -- it is change in heritable traits of biological populations over time; therefore, change in heritable traits is also required. The proposed definition is perfectly applicable to that scenario.
- "and the time interval per generation may be different as it evolves so time isn't important" -- this doesn't make sense. Time is clearly important -- can you have generations without time? You're argument seems to be assuming that 'time' should be interpreted as some arbitrarily set time span, whereas the proposed definition doesn't state a set time span, just time. It is broad and as such allows flexibility, and it's not meaningless because it is in the context of the rest of the definition.
- "The mutation had no trait [snip] till it jumped into a position to alter a cytochrome P450 gene" -- well that's just another mutation.
- "You seem to equate death to evolution" -- no. nowhere have I said death = evolution.
- Horizontal gene transfer also puts a hole in your argument. This can transfer traits without reproduction. Just another process on top of mutation and death that can change heritable traits of biological populations without needing reproduction. Remember that I'm not arguing that reproduction isn't important in evolution, just that the current definition excludes all the processes of evolution that operate within generations, whereas the proposed definition will be inclusive of all processes. Let me try to highlight my point with a hypothetical example -- if there was a population that had very neat generation times of, let's say 2 years, and you study the traits in the population in one year and find 12 individuals have big ears and 8 have small ears (it's not a big population, and let's assume that ear size is a heritable trait). You return the next year before breeding (i.e. same generation) and you find that there are now 8 individuals with big ears and 8 individuals with small ears. Would you conclude that evolution hasn't occurred? By the current definition, you'd have to, but does that really make sense? What purpose does an arbitrary line on what change is considered to be evolution or not serve?
- Successive generations doesn't negate HGT??? I think you are conflating ideas. Evolution is change in the heritable traits of biological populations over successive generations. How the heritable traits change is by numerous mechanism-that is explained in text. Because life is a continuum of life reproducing life it is in successive generations we see the changes. The change maybe a new mutation, maybe drift, selection, gene flow-which includes HGT, etc. Simple definition that is common to other sources. 75.76.251.115 (talk) 15:00, 1 October 2015 (UTC)
- Now I'll reiterate some of my main points so they're not lost under this wall of text:
- Using "generations" is too restrictive; it excludes a bunch of things like mutation (the only source of new variation) and death (integral in both drift and selection). The use of 'heritable' in the definition implies heredity -- (according to wikipedia) the passing on of physical or mental characteristics genetically from one generation to another -- so the importance of reproduction is still accounted for if 'generations' is changed to 'time'.
- That makes no sense-generations doesn't exclude anything just conveys the heritable traits change through generations. How does "time" capture all you state? GetAgrippa (talk) 14:39, 1 October 2015 (UTC)
- And again, "generation" has a very ambiguous definition (actually many) and in most cases cannot be defined for a population, which poses problems if evolution occurs at the population-level. How can you define evolution if you can't define a generation?129.127.101.245 (talk) 04:23, 1 October 2015 (UTC)
- Actually it isn't ambiguous-successive generations is very informative and is defined??? It explains life is a continuum with successive generations and that life has been modified through this descent. Evolutionary biologist can't define a species (7 definitions) so I don't see your point-that's why they usually speak in terms of populations.
- Successive generations: (not just generation you are taking it out of its context) isn't ambiguous nor does it exclude anything. No more than evolution is-which has different meanings, or genetic drift-drift can be ambiguous too. You state successive generations doesn't take into account mutations or HGT (which is common in microbes and plants) but how does "time"? Besides all that is addressed in the body of article and this is suppose to a short concise definition. Here is a common dictionary definition: "Biology. change in the gene pool of a population from generation to generation by such processes as mutation, natural selection, and genetic drift." Encyclopedia Britannica:"Evolution, theory in biology postulating that the various types of plants, animals, and other living things on Earth have their origin in other preexisting types and that the distinguishable differences are due to modifications in successive generations." So I would argue it isn't ambiguous and would vote no on your suggestion. It isn't my definition btw mine was years ago with the standard gene centric Dobzhansky definition of shifts in alleles etc. This definition was hammered by numerous editors and I still support it. GetAgrippa (talk) 12:54, 1 October 2015 (UTC)
- Your example is evolution as the definition states-change in traits of a population through successive generations. Life is a continuum. The generation before gave birth to your generation of rabbits with 12 long ears and 8 short ears=if the population were not evolving then the proportion of the traits in successive generations won't change if it is a simple Mendelian trait of dominant and recessive and it will be in equilibrium for generations (if no recombination). Now you have changed the population due to natural selection, random death, or migration so the population of 12 big ears and 8 small ears is now equal numbers of both that will now reproduce. These mechanisms act on the variation within the population. The proportion of individuals with the traits has changed that generation from past generations and will for subsequent generations=evolution. Lastly from your response about the fruit flies I think you are conflating ideas. Mutations aren't synonymous with evolution. The mutation has to have an effect and emerge as a biological trait. The initial mutation event had no appreciable trait (it wasn't evolution) and it was only till synthetic pesticides were invented that the mutation emerged as trait. The mutation was meaningless till then and wasn't a "trait". Populations have variation because of a random mutation, or gene flow, or most often genetic recombination during reproduction and then the mechanisms of natural selection, drift, gene flow, etc. can alter that variation in a population such that the traits change over successive generations. GetAgrippa (talk) 13:21, 1 October 2015 (UTC)
- Successive generations: (not just generation you are taking it out of its context) isn't ambiguous nor does it exclude anything. No more than evolution is-which has different meanings, or genetic drift-drift can be ambiguous too. You state successive generations doesn't take into account mutations or HGT (which is common in microbes and plants) but how does "time"? Besides all that is addressed in the body of article and this is suppose to a short concise definition. Here is a common dictionary definition: "Biology. change in the gene pool of a population from generation to generation by such processes as mutation, natural selection, and genetic drift." Encyclopedia Britannica:"Evolution, theory in biology postulating that the various types of plants, animals, and other living things on Earth have their origin in other preexisting types and that the distinguishable differences are due to modifications in successive generations." So I would argue it isn't ambiguous and would vote no on your suggestion. It isn't my definition btw mine was years ago with the standard gene centric Dobzhansky definition of shifts in alleles etc. This definition was hammered by numerous editors and I still support it. GetAgrippa (talk) 12:54, 1 October 2015 (UTC)
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