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This paragraph in section 5.2 needs to be fixed up, because it doesn't make sense at the moment.
The second sentence doesn't make sense. I'm not going to touch it because I don't know what it's trying to say, but someone more versed in the matter might be able to fix it up. Maelin ( Talk | Contribs) 04:40, 5 February 2007 (UTC)
at Evolutionary theory of sex-- Filll 23:09, 26 July 2007 (UTC)
This is a worthy article. However, it confuses the evolution of sex and the evolution of recombination. I would be happy to help edit the article, but wanted to get some agreement on how to proceed. This article is mostly about the advantages of recombination and the disdvantages of sex, both of interest, but somewhat conflated. More careful parsing of the effects of recombination (two parents) and sex (males and females) is in order. Worth noting, a proper accounting of the dis/advantages makes explaining sex more difficult.
Shall I have a go at it or is more coordination required?
Here it is again. A discussion of “why sex?” that covers every base except what is probably the most important: sexual selection. Just about every lay introduction to natural selection will utilize as prime examples traits such as opposable thumbs and beak shapes. I would argue that sexual selection is of crucial importance to evolution and over the last 100 thousand years has been of far greater importance than traits developed through interaction with purely physical forces such as heat, cold, and resistance to bacteriological elements. In sexual selection, the woman will typically prefer men with a good balance of strength and gentleness, being cognisant that she expects him to help rear their children. As a result, women characteristically are attracted to strength, but not to sadism, to affluence, but not to meanness, to a sense of humour, because a man with a sense of humour will be more likely to be charmed by the activities of their children, and so on. In an oral society, a well-spoken man will receive preferential treatment when compared to one who is tongue-tied. A man who has “people-skills” and can handle and lead people will attain personal power that others will not. Traditionally, people who attain privileged positions have greater choices available to them, in terms of who they marry, in terms of provision for their children. In this way, such behavioural and personality traits can become fixed in a community through the simple functioning of selection pressure via sexual and cultural selection. Yet these mechanisms are given short shrift in the literature of evolution. Sexual attraction between the genders is the next best thing to direct phenome to genome transfer. In effect, a strong, intelligent man is given his procreational advantages on credit, as it were, just as a fertile, intelligent woman is given hers. I often wonder why these HUGE affects are forgotten by writers, in favour of such piddling ones as resistance to parasites. Is it because evolutionary pressure from within society sounds less “scientific”? Myles325a 05:49, 16 August 2007 (UTC)
Has the mystery of sex been explained at last? http://www.newscientist.com/article/mg20227121.600-has-the-mystery-of-sex-been-explained-at-last.html?full=true Stikko ( talk) 12:30, 15 June 2009 (UTC)
There are fallacies in the picture as well as in the description:
Well, doh. If each individual were to contribute to double the number, the sexual population also doubles in size. They can do that because they are twice as many individuals, sharing the cost.
No, it doesn't.
Note that I don't comment on whether or not the basic premise is true, just that the explanations are fallacious. -- 91.55.208.202 ( talk) 00:09, 27 January 2010 (UTC)
This should probably be reworded to something along the lines of "each individual/pair contributing to the next generation". Within sexual reproduction you obviously need two individuals. If this pair then to produce two offspring then they each produce a single "replacement", as it were. Within asexual reproduction, the individual merely divides creating two "offspring", in essence creating one "replacement" and a second offspring which adds to the next generation. So we have sexual reproduction as 1+1(2)>2, number of offspring=number of breeding individuals vs. assexual reproduction as 1>1+1(2), number of offspring=2*(number of breeding individuals). The initial statement could easily be misread and does need to be made clearer. -
Wikim3 04:11, 24 February 2010 (UTC) —Preceding
unsigned comment added by
89.241.186.67 (
talk)
Fallacies I see in "Cost of sex": The long term replacement rate for every species on Earth is one. Because if not, you would get exponential growth and earth couldn’t support this. Beside this the number of offspring, who reach the phase of adulthood, is more dependent on the resources and perils of the environment. And not on the number of offspring produced by the parents.
The only disadvantage I see for sexual reproduction is, that a pair of individuals has to meet each other to reproduce. —Preceding unsigned comment added by 77.185.82.62 ( talk) 20:21, 18 March 2010 (UTC)
Although your premise that one would get exponential growth if the long-term replacement rate is not one, your conclusion is invalid. This is because having one child (if you are asexual) or two (if you are sexual) does not gaurantee that in the long-term, your genes will be preserved, albeit in different organisms in case of sexual reproduction. The individual with the largest number of healthy, fertile offspring has the largest chance of being represented in the gene-pool in the long-run. To make this clear, it has been found that 1 in 200 men are direct descendents of Genghis Khan [1], who lived about a 1000 years ago. Your conclusion would make sense only if there were only 200 men at the time. — Preceding unsigned comment added by 118.151.208.163 ( talk) 19:49, 20 April 2015 (UTC)
This section does have several weaknesses, already noted. I think one basic issue is that the term "two-fold cost of sex" is misleading, albeit popular in the literature. I prefer the original term, which is the cost of males - it more precisely identifies the problem as the presence of a significant proportion of the adult population that is required for reproduction to occur, but does not itself reproduce; although Maynard Smith did show that this advantage is two-fold under the assumptions of his example, it can safely be assumed that this cost will vary depending upon a number of factors, such as mating system specifics, presence of hermaphroditism, prevalence of sex in the life cycle (i.e. if it is not obligate), etc.
And on that note, the combination of the reference to Maynard Smith being the first to mathematically describe the cost of males is juxtaposed with a nonsense graphic that, first of all, bears no resemblance at all to the schematic that accompanied his mathematical description, and second of all, erroneously gives the impression that a sexual population does not increase in size at all! "Two-fold" implies that the rate of increase is twice as great for the asexuals; the figure does not illustrate this. Maynard Smith's own diagram can be found in his book, which is in any decent science library.
Sexual selection is completely out of place in this section; the costs of sexual selection are completely irrelevant to the specifics of the two-fold cost of sex/cost of males. Sexual selection is worthy of attention, but it is a separate matter. Changing the section title to "Disadvantages/Costs of Sex" would make the inclusion more appropriate, along with the other disadvantages.
The paragraph claiming that evidence that the cost of sex can be overcome comes from George C. Williams makes no sense; the evidence that the sex can be overcome is that sex is utterly dominant as a reproductive mechanism in multicellular eukaryotes. One of Maynard Smith's major points in describing the cost of males was in contrasting the ubiquity and obvious success of sex, which evolutionary biologists had heretofore taken largely for granted, with the fact that it simply does not work according to standard population genetics. The paragraph describes a specific hypothetical advantage to sexual reproduction, which is often referred to as the "lottery ticket argument," since that was the analogy Williams used to make the point.
I apologize, because these points will seem "old-fogeyish," though I wish to return to make these edits, if someone does not beat me to it.
-colbyg 98.87.122.104 ( talk) 04:02, 22 August 2011 (UTC)
This article needs restructuring. I came here looking for how sex evolved, but that part is hidden away at the end in sections 7-8. It's also very short. Most of the article talks about possible explanations why sex evolved (or what for) and historical perspectives on that. The introduction doesn't talk about the how at all. IMO an article entitled "Evolution of sexual reproduction" should first describe what we know about how it happened, and then go on to speculate about why sex is an evolutionary gain.-- 87.162.34.180 ( talk) 17:20, 8 March 2010 (UTC)
Good article. One of the main costs of sexual reproduction according to Matt Ridley in his book "The Red Queen", is that of sacrificing the passage of half of your genes into the next generation. I was expecting to find this fact noted in this piece but as I couldn't find it I added it. —Preceding unsigned comment added by RichardAndrewNevin ( talk • contribs) 13:06, 13 March 2010 (UTC)
I believe the legend to Fig 3 is seriously wrong: the red convex line is the synergistic epistasis case (required for Kondrashov's theory), since here 2 mutations have bigger effects than the sum of the effects of each individually. The concave blue line shows antagonistic epistasis. See Ridley's "Mendel's Demon" book. Paulhummerman ( talk) 14:26, 18 October 2011 (UTC)
Yes, I have another Ridley book, Evolution, 3rd edition; it agrees (well, it would)... I take it he knows what he's talking about. Evercat ( talk) 19:59, 29 November 2011 (UTC)
Also Charlesworth and Charlesworth, Elements of Evolutionary Genetics. I think it should really be log(fitness) on the y axis. Evercat ( talk) 20:10, 29 November 2011 (UTC)
In fact yes, I very strongly believe it needs to be log(fitness) on the y axis... Evercat ( talk) 22:58, 30 November 2011 (UTC)
This article's subject is the evolution of sexual reproduction. 1. The introduction claims (correctly) that there is no consensus and then proceeds to ignore the evolution to speak about the maintenance of sexual reproduction. I should NOT have to delve into the rest of the article to learn about the theories/hypotheses, should I ?? 2. The introduction claims that all eukaryotes which reproduce sexually have a common ancestor. How is that reconciled with the species that reproduce both asexually and sexually? Are we sure that sex only evolved once? Given that most of the intro makes a strong case for its reproductive value, then either it must be linked to the cell wall (definition of Eukaryotes) or did not just evolve once. Have all asexually reproducing eukaryotes been shown to have sexual ancestors? {I am not well informed on this issue, please take my comments to indicate areas where the introduction fails to inform the average reader}. Is this well established (fact) or a working hypothesis/ assumption? What about the sexual prokaryotes? 3. The introduction should define what sexual reproduction is, to start out. It doesn't even mention the fact that it is between two (or more) individuals, that the sex of an individual may vary over its lifetime, and that its sex may be environmentally determined. It also doesn't mention the fact that the number of sexes ranges between 2 and ?? (I'm not sure, at least 3) 4. DNA is barely mentioned, and only in the context of repair. 5. If you threw out the "maintenance of sexual reproduction" part of the introduction, there would be almost nothing left. In my opinion, most people will come here NOT to learn about how sexual reproduction is evolving or contributing to the evolution of a species, but to learn about how it developed to begin with. Logically, origin should precede maintenance/continuing development processes. 6. I recommend a rewrite, focusing on the basics: What, who, when, why, and how. Overview (What is sex, who has it (which Domains & Kingdoms?) History when did it evolve? (NOT to be confused with the history of the study of it) Why and how did it evolve? If you really can't speak clearly to its causal origin, then you should speak in terms of it surviving originally because of utility. — Preceding unsigned comment added by 173.189.75.207 ( talk) 21:40, 8 May 2013 (UTC)
"Copulation in antiarch placoderms and the origin of gnathostome internal fertilization" [1]. With a related simplified article [2]. 76.10.128.192 ( talk) 23:29, 20 October 2014 (UTC)
There is at least one published paper that questions the twofold cost of sex or the cost of males (as preferred): The False Problem of the Maintenance of Sex (Review of the Original Approach) [1]-- J. M. Mancebo Quintana ( talk) 10:38, 27 February 2016 (UTC)
References
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cite journal}}
: CS1 maint: unflagged free DOI (
link)
The article at Evolutionary theory of sex (ETS) was a very dodgy essay. Not at all encyclopedic, and with very little worth merging here. I've simply made it a redirect. It seems to me that someone has been trying to push Trofimova's views into any articles that they could, and giving them plenty of undue weight. -- Slashme ( talk) 16:35, 22 July 2016 (UTC)
From the user KaiStr: I disagree with the merge of this page and with Slashme devaluation of this page. This ETS theory existed since the 1960s, within a rather strong evolutionary school (Russians evolutionary biologists), and the author of the ETS is a completely different person (Geodakyan). Trofimova only adopted this ETS theory to psychology but she wasn't the author of the original theory. The page was encyclopedic as it had definitions and illustrations - borrowed from Trofimova for simplicity. Please don't bring your prejudice and ignorance to wikipedia, let public see all opinions and theories offered within different (an not just yours) schools. KaiStr ( talk) 06:11, 24 July 2016 (UTC)
Please check out this new article, Geodakyan's evolutionary theory of sex. Staszek Lem ( talk) 18:09, 27 July 2016 (UTC)
Help required with Geodakyan's evolutionary theory of sex desperately: the article of apparently fringe theory is based almost exclusively on primary sources and edited by a people with strong connection to the subject. Staszek Lem ( talk) 17:07, 13 October 2016 (UTC)
Males adopt strategies with lower investment in individual gametes and may present a higher mutation rate,[citation needed] while females may invest more resources and serve to conserve better-adapted solutions.[citation needed]
Apart from being completely citation needed it mixes together nursing strategies and mutation rates. How are they related? And what are the benefits of high/low mutation rates? I don't understand at all what this section is trying to say. — Preceding
unsigned comment added by
93.227.23.210 (
talk) 11:39, 8 December 2016 (UTC)
The following was recently removed as recentism ( diff):
"However, research published in 2015 indicates that sexual selection can explain the persistence of sexual reproduction in animals. [1]"
References
While I agree that 2015 is rather recent, and that the wording may possibly have been in undue weight or misplaced, after reading the source I found nothing particularily questionable. While research is of course still ongoing, it seems to already have been common knowledge to me that there can be advantages of sexual selection. The text which follows also appears to reflect this. I therefore don't see this as being recentism, but among the plausible hypotheses related to sexual selection. Thanks, — Paleo Neonate - 22:41, 16 June 2017 (UTC)
The long article: "Interaction-based evolution: how natural selection and nonrandom mutation work together" by Adi Livnat https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4231362/ (which amazingly is not behind a paywall) presents a new theory that addresses all the traditional problems about sexual evolution, and evolution in general. He wrote this in 2013. While it may be too early to present it as settled science, it is deeply profound and comprehensive and is the first big step forward in evolutionary theory since the discovery of DNA (in my opinion). He dispatches the question of how sexual reproduction arose and still survives when asexual reproduction is so much more efficient by explaining why evolution can't proceed from asexual reproduction and never has. All organisms evolved entirely via sexual evolution, except for small tweaks in asexual organisms since the time they lost the ability to reproduce sexually. Losing the ability may introduce beneficial efficiencies, but is an evolutionary dead-end. This means that sexual reproduction predates asexual reproduction and is the original mode of reproduction. Nearly all creatures bear the "cost" of sex because it is the only way to evolve. He explains some about how multiple alleles are necessary at the population level for new functionality to converge. But he also presents many other reasons; this is just the tip of the iceberg of Livnat's theory, which is really about the writing phenotype, which is the concept that much of our genome is focused on long-term evolution that takes millions of years to yield results. Organisms have complex DNA-editing mechanisms that piece new de novo genes together from parts with no benefit to the individual until many generations have passed, and the pieces used to build these new genes come from other genes and the 80% of the genome currently labeled "junk DNA". This theory stipulates that although evolution is ultimately blind, it has been gathering tricks to maximize the use of collected information and the chances of building useful genes by elevating the building blocks of mutation from single base-pairs to large pre-built "erector set" sections that give preference to the most successful sections and take many lives to yield results. Junk genes and DNA that do nothing yet are in fact being selected for over a longer time frame, and evolution is patient for that result only because these long-term strategies evolved and outcompeted much less effective point-mutation strategies back at the dawn of life. And he explains how males and sperm are largely the instruments of the writing phenotype, and much more. It really needs to be turned into a best-selling book!
I would appreciate it if someone qualified would review Livnat's article and include a summary in this Wikipedia page, referencing the summary from the opening paragraph. I could do it, but I am reluctant to proceed in an area I haven't formally studied for 35 years. — Preceding unsigned comment added by 74.89.153.89 ( talk) 15:48, 30 September 2018 (UTC)
This article does not actually provide what the title suggests, namely: a description of the evolution of sexual reproduction.
It remains stuck in pro's and cons of sexual reproduction, hypothesises of why it even originated.
What remains left out is any information on for example the transition from external to internal fertilisation ( https://www.nature.com/news/fossils-rewrite-history-of-penetrative-sex-1.16173) i.e. the origins of penetrative sex.
Neither does it address the plain fact that sexuality refers to a division in two sexes, and the entire evolutionary consequences of the existence of two sexes, or what is specific to the one sex and what to the other.
I would suggest renaming this article "origins of sexual reproduction", and creating a new one named "Evolution of sexual reproduction", where the relevant themes such as the splitting in two sexes and implications of that are explained, as well as the evolutionary steps from the origins until the present state of sexual reproduction.
Lastly, I see it as a possibility that the lacking information is related to the fact that above mentioned topics are partly still taboo, even in the scientific world. — Preceding unsigned comment added by FreieFF ( talk • contribs) 12:44, 11 October 2019 (UTC)
This statement is not accurate:
"In eukaryotes, true sex is thought to have arisen in the Last Eukaryotic Common Ancestor (LECA)..."
The accurate version is THIS:
"In eukaryotes, true sex is thought to have arisen in the First Eukaryotic Common Ancestor."
This is basic reasoning. Sex did not arise with LECA. It happened with the first of its kind, not the last. The "FECA", if you will. This needs to be fixed. -- Concord19 ( talk) 03:37, 24 July 2020 (UTC)
The questions section seems odd and not needed. Also I have read some of those sources, it aren’t really asking questions. So that section is technically original research. CycoMa ( talk) 22:30, 30 August 2021 (UTC)
It seems to me that little is made of the fundamental asymmetry between the sexes in that females contribute the mitochondria without recombination. In fact it could be said that all sexual reproduction includes asexual reproduction of the mitochondria.
We have a natural experiment going on in comparing the evolution of both genomes so surely this is worth at least a mention. Francishayden ( talk) 18:02, 9 July 2022 (UTC)
About 90% of this article is verbose word spaghetti about the potential benefits of sexual reproduction, which is irrelevant to how sexual reproduction could develop step-by-step through mutation (it can't)
You'd think you could be more humble and upfront that it's an unanswered mystery to the scientific community, rather than hiding behind verbose word vomit that starts with the assumption that your favorite religion Darwinism is true. 174.57.221.108 ( talk) 09:44, 11 July 2023 (UTC)
In Hymenoptera the males are haploid, so there can be no hidden deleterious mutations, yet the order is the most diverse among the insects. Consequently Hymenoptera are not at risk from inbreeding depression. This makes it easy for a single female to establish a population outside its range. I suspect this also allows social insects to evolve large colonies. BioImages2000 ( talk) 12:02, 23 July 2023 (UTC)
Evolution of sexual reproduction was one of the Natural sciences good articles, but it has been removed from the list. There are suggestions below for improving the article to meet the good article criteria. Once these issues have been addressed, the article can be renominated. Editors may also seek a reassessment of the decision if they believe there was a mistake. | |||||||||||||||||||||||||
|
The subject of this article is controversial and content may be in dispute. When updating the article, be bold, but not reckless. Feel free to try to improve the article, but don't take it personally if your changes are reversed; instead, come here to the talk page to discuss them. Content must be written from a neutral point of view. Include citations when adding content and consider tagging or removing unsourced information. |
This article is rated B-class on Wikipedia's
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This paragraph in section 5.2 needs to be fixed up, because it doesn't make sense at the moment.
The second sentence doesn't make sense. I'm not going to touch it because I don't know what it's trying to say, but someone more versed in the matter might be able to fix it up. Maelin ( Talk | Contribs) 04:40, 5 February 2007 (UTC)
at Evolutionary theory of sex-- Filll 23:09, 26 July 2007 (UTC)
This is a worthy article. However, it confuses the evolution of sex and the evolution of recombination. I would be happy to help edit the article, but wanted to get some agreement on how to proceed. This article is mostly about the advantages of recombination and the disdvantages of sex, both of interest, but somewhat conflated. More careful parsing of the effects of recombination (two parents) and sex (males and females) is in order. Worth noting, a proper accounting of the dis/advantages makes explaining sex more difficult.
Shall I have a go at it or is more coordination required?
Here it is again. A discussion of “why sex?” that covers every base except what is probably the most important: sexual selection. Just about every lay introduction to natural selection will utilize as prime examples traits such as opposable thumbs and beak shapes. I would argue that sexual selection is of crucial importance to evolution and over the last 100 thousand years has been of far greater importance than traits developed through interaction with purely physical forces such as heat, cold, and resistance to bacteriological elements. In sexual selection, the woman will typically prefer men with a good balance of strength and gentleness, being cognisant that she expects him to help rear their children. As a result, women characteristically are attracted to strength, but not to sadism, to affluence, but not to meanness, to a sense of humour, because a man with a sense of humour will be more likely to be charmed by the activities of their children, and so on. In an oral society, a well-spoken man will receive preferential treatment when compared to one who is tongue-tied. A man who has “people-skills” and can handle and lead people will attain personal power that others will not. Traditionally, people who attain privileged positions have greater choices available to them, in terms of who they marry, in terms of provision for their children. In this way, such behavioural and personality traits can become fixed in a community through the simple functioning of selection pressure via sexual and cultural selection. Yet these mechanisms are given short shrift in the literature of evolution. Sexual attraction between the genders is the next best thing to direct phenome to genome transfer. In effect, a strong, intelligent man is given his procreational advantages on credit, as it were, just as a fertile, intelligent woman is given hers. I often wonder why these HUGE affects are forgotten by writers, in favour of such piddling ones as resistance to parasites. Is it because evolutionary pressure from within society sounds less “scientific”? Myles325a 05:49, 16 August 2007 (UTC)
Has the mystery of sex been explained at last? http://www.newscientist.com/article/mg20227121.600-has-the-mystery-of-sex-been-explained-at-last.html?full=true Stikko ( talk) 12:30, 15 June 2009 (UTC)
There are fallacies in the picture as well as in the description:
Well, doh. If each individual were to contribute to double the number, the sexual population also doubles in size. They can do that because they are twice as many individuals, sharing the cost.
No, it doesn't.
Note that I don't comment on whether or not the basic premise is true, just that the explanations are fallacious. -- 91.55.208.202 ( talk) 00:09, 27 January 2010 (UTC)
This should probably be reworded to something along the lines of "each individual/pair contributing to the next generation". Within sexual reproduction you obviously need two individuals. If this pair then to produce two offspring then they each produce a single "replacement", as it were. Within asexual reproduction, the individual merely divides creating two "offspring", in essence creating one "replacement" and a second offspring which adds to the next generation. So we have sexual reproduction as 1+1(2)>2, number of offspring=number of breeding individuals vs. assexual reproduction as 1>1+1(2), number of offspring=2*(number of breeding individuals). The initial statement could easily be misread and does need to be made clearer. -
Wikim3 04:11, 24 February 2010 (UTC) —Preceding
unsigned comment added by
89.241.186.67 (
talk)
Fallacies I see in "Cost of sex": The long term replacement rate for every species on Earth is one. Because if not, you would get exponential growth and earth couldn’t support this. Beside this the number of offspring, who reach the phase of adulthood, is more dependent on the resources and perils of the environment. And not on the number of offspring produced by the parents.
The only disadvantage I see for sexual reproduction is, that a pair of individuals has to meet each other to reproduce. —Preceding unsigned comment added by 77.185.82.62 ( talk) 20:21, 18 March 2010 (UTC)
Although your premise that one would get exponential growth if the long-term replacement rate is not one, your conclusion is invalid. This is because having one child (if you are asexual) or two (if you are sexual) does not gaurantee that in the long-term, your genes will be preserved, albeit in different organisms in case of sexual reproduction. The individual with the largest number of healthy, fertile offspring has the largest chance of being represented in the gene-pool in the long-run. To make this clear, it has been found that 1 in 200 men are direct descendents of Genghis Khan [1], who lived about a 1000 years ago. Your conclusion would make sense only if there were only 200 men at the time. — Preceding unsigned comment added by 118.151.208.163 ( talk) 19:49, 20 April 2015 (UTC)
This section does have several weaknesses, already noted. I think one basic issue is that the term "two-fold cost of sex" is misleading, albeit popular in the literature. I prefer the original term, which is the cost of males - it more precisely identifies the problem as the presence of a significant proportion of the adult population that is required for reproduction to occur, but does not itself reproduce; although Maynard Smith did show that this advantage is two-fold under the assumptions of his example, it can safely be assumed that this cost will vary depending upon a number of factors, such as mating system specifics, presence of hermaphroditism, prevalence of sex in the life cycle (i.e. if it is not obligate), etc.
And on that note, the combination of the reference to Maynard Smith being the first to mathematically describe the cost of males is juxtaposed with a nonsense graphic that, first of all, bears no resemblance at all to the schematic that accompanied his mathematical description, and second of all, erroneously gives the impression that a sexual population does not increase in size at all! "Two-fold" implies that the rate of increase is twice as great for the asexuals; the figure does not illustrate this. Maynard Smith's own diagram can be found in his book, which is in any decent science library.
Sexual selection is completely out of place in this section; the costs of sexual selection are completely irrelevant to the specifics of the two-fold cost of sex/cost of males. Sexual selection is worthy of attention, but it is a separate matter. Changing the section title to "Disadvantages/Costs of Sex" would make the inclusion more appropriate, along with the other disadvantages.
The paragraph claiming that evidence that the cost of sex can be overcome comes from George C. Williams makes no sense; the evidence that the sex can be overcome is that sex is utterly dominant as a reproductive mechanism in multicellular eukaryotes. One of Maynard Smith's major points in describing the cost of males was in contrasting the ubiquity and obvious success of sex, which evolutionary biologists had heretofore taken largely for granted, with the fact that it simply does not work according to standard population genetics. The paragraph describes a specific hypothetical advantage to sexual reproduction, which is often referred to as the "lottery ticket argument," since that was the analogy Williams used to make the point.
I apologize, because these points will seem "old-fogeyish," though I wish to return to make these edits, if someone does not beat me to it.
-colbyg 98.87.122.104 ( talk) 04:02, 22 August 2011 (UTC)
This article needs restructuring. I came here looking for how sex evolved, but that part is hidden away at the end in sections 7-8. It's also very short. Most of the article talks about possible explanations why sex evolved (or what for) and historical perspectives on that. The introduction doesn't talk about the how at all. IMO an article entitled "Evolution of sexual reproduction" should first describe what we know about how it happened, and then go on to speculate about why sex is an evolutionary gain.-- 87.162.34.180 ( talk) 17:20, 8 March 2010 (UTC)
Good article. One of the main costs of sexual reproduction according to Matt Ridley in his book "The Red Queen", is that of sacrificing the passage of half of your genes into the next generation. I was expecting to find this fact noted in this piece but as I couldn't find it I added it. —Preceding unsigned comment added by RichardAndrewNevin ( talk • contribs) 13:06, 13 March 2010 (UTC)
I believe the legend to Fig 3 is seriously wrong: the red convex line is the synergistic epistasis case (required for Kondrashov's theory), since here 2 mutations have bigger effects than the sum of the effects of each individually. The concave blue line shows antagonistic epistasis. See Ridley's "Mendel's Demon" book. Paulhummerman ( talk) 14:26, 18 October 2011 (UTC)
Yes, I have another Ridley book, Evolution, 3rd edition; it agrees (well, it would)... I take it he knows what he's talking about. Evercat ( talk) 19:59, 29 November 2011 (UTC)
Also Charlesworth and Charlesworth, Elements of Evolutionary Genetics. I think it should really be log(fitness) on the y axis. Evercat ( talk) 20:10, 29 November 2011 (UTC)
In fact yes, I very strongly believe it needs to be log(fitness) on the y axis... Evercat ( talk) 22:58, 30 November 2011 (UTC)
This article's subject is the evolution of sexual reproduction. 1. The introduction claims (correctly) that there is no consensus and then proceeds to ignore the evolution to speak about the maintenance of sexual reproduction. I should NOT have to delve into the rest of the article to learn about the theories/hypotheses, should I ?? 2. The introduction claims that all eukaryotes which reproduce sexually have a common ancestor. How is that reconciled with the species that reproduce both asexually and sexually? Are we sure that sex only evolved once? Given that most of the intro makes a strong case for its reproductive value, then either it must be linked to the cell wall (definition of Eukaryotes) or did not just evolve once. Have all asexually reproducing eukaryotes been shown to have sexual ancestors? {I am not well informed on this issue, please take my comments to indicate areas where the introduction fails to inform the average reader}. Is this well established (fact) or a working hypothesis/ assumption? What about the sexual prokaryotes? 3. The introduction should define what sexual reproduction is, to start out. It doesn't even mention the fact that it is between two (or more) individuals, that the sex of an individual may vary over its lifetime, and that its sex may be environmentally determined. It also doesn't mention the fact that the number of sexes ranges between 2 and ?? (I'm not sure, at least 3) 4. DNA is barely mentioned, and only in the context of repair. 5. If you threw out the "maintenance of sexual reproduction" part of the introduction, there would be almost nothing left. In my opinion, most people will come here NOT to learn about how sexual reproduction is evolving or contributing to the evolution of a species, but to learn about how it developed to begin with. Logically, origin should precede maintenance/continuing development processes. 6. I recommend a rewrite, focusing on the basics: What, who, when, why, and how. Overview (What is sex, who has it (which Domains & Kingdoms?) History when did it evolve? (NOT to be confused with the history of the study of it) Why and how did it evolve? If you really can't speak clearly to its causal origin, then you should speak in terms of it surviving originally because of utility. — Preceding unsigned comment added by 173.189.75.207 ( talk) 21:40, 8 May 2013 (UTC)
"Copulation in antiarch placoderms and the origin of gnathostome internal fertilization" [1]. With a related simplified article [2]. 76.10.128.192 ( talk) 23:29, 20 October 2014 (UTC)
There is at least one published paper that questions the twofold cost of sex or the cost of males (as preferred): The False Problem of the Maintenance of Sex (Review of the Original Approach) [1]-- J. M. Mancebo Quintana ( talk) 10:38, 27 February 2016 (UTC)
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The article at Evolutionary theory of sex (ETS) was a very dodgy essay. Not at all encyclopedic, and with very little worth merging here. I've simply made it a redirect. It seems to me that someone has been trying to push Trofimova's views into any articles that they could, and giving them plenty of undue weight. -- Slashme ( talk) 16:35, 22 July 2016 (UTC)
From the user KaiStr: I disagree with the merge of this page and with Slashme devaluation of this page. This ETS theory existed since the 1960s, within a rather strong evolutionary school (Russians evolutionary biologists), and the author of the ETS is a completely different person (Geodakyan). Trofimova only adopted this ETS theory to psychology but she wasn't the author of the original theory. The page was encyclopedic as it had definitions and illustrations - borrowed from Trofimova for simplicity. Please don't bring your prejudice and ignorance to wikipedia, let public see all opinions and theories offered within different (an not just yours) schools. KaiStr ( talk) 06:11, 24 July 2016 (UTC)
Please check out this new article, Geodakyan's evolutionary theory of sex. Staszek Lem ( talk) 18:09, 27 July 2016 (UTC)
Help required with Geodakyan's evolutionary theory of sex desperately: the article of apparently fringe theory is based almost exclusively on primary sources and edited by a people with strong connection to the subject. Staszek Lem ( talk) 17:07, 13 October 2016 (UTC)
Males adopt strategies with lower investment in individual gametes and may present a higher mutation rate,[citation needed] while females may invest more resources and serve to conserve better-adapted solutions.[citation needed]
Apart from being completely citation needed it mixes together nursing strategies and mutation rates. How are they related? And what are the benefits of high/low mutation rates? I don't understand at all what this section is trying to say. — Preceding
unsigned comment added by
93.227.23.210 (
talk) 11:39, 8 December 2016 (UTC)
The following was recently removed as recentism ( diff):
"However, research published in 2015 indicates that sexual selection can explain the persistence of sexual reproduction in animals. [1]"
References
While I agree that 2015 is rather recent, and that the wording may possibly have been in undue weight or misplaced, after reading the source I found nothing particularily questionable. While research is of course still ongoing, it seems to already have been common knowledge to me that there can be advantages of sexual selection. The text which follows also appears to reflect this. I therefore don't see this as being recentism, but among the plausible hypotheses related to sexual selection. Thanks, — Paleo Neonate - 22:41, 16 June 2017 (UTC)
The long article: "Interaction-based evolution: how natural selection and nonrandom mutation work together" by Adi Livnat https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4231362/ (which amazingly is not behind a paywall) presents a new theory that addresses all the traditional problems about sexual evolution, and evolution in general. He wrote this in 2013. While it may be too early to present it as settled science, it is deeply profound and comprehensive and is the first big step forward in evolutionary theory since the discovery of DNA (in my opinion). He dispatches the question of how sexual reproduction arose and still survives when asexual reproduction is so much more efficient by explaining why evolution can't proceed from asexual reproduction and never has. All organisms evolved entirely via sexual evolution, except for small tweaks in asexual organisms since the time they lost the ability to reproduce sexually. Losing the ability may introduce beneficial efficiencies, but is an evolutionary dead-end. This means that sexual reproduction predates asexual reproduction and is the original mode of reproduction. Nearly all creatures bear the "cost" of sex because it is the only way to evolve. He explains some about how multiple alleles are necessary at the population level for new functionality to converge. But he also presents many other reasons; this is just the tip of the iceberg of Livnat's theory, which is really about the writing phenotype, which is the concept that much of our genome is focused on long-term evolution that takes millions of years to yield results. Organisms have complex DNA-editing mechanisms that piece new de novo genes together from parts with no benefit to the individual until many generations have passed, and the pieces used to build these new genes come from other genes and the 80% of the genome currently labeled "junk DNA". This theory stipulates that although evolution is ultimately blind, it has been gathering tricks to maximize the use of collected information and the chances of building useful genes by elevating the building blocks of mutation from single base-pairs to large pre-built "erector set" sections that give preference to the most successful sections and take many lives to yield results. Junk genes and DNA that do nothing yet are in fact being selected for over a longer time frame, and evolution is patient for that result only because these long-term strategies evolved and outcompeted much less effective point-mutation strategies back at the dawn of life. And he explains how males and sperm are largely the instruments of the writing phenotype, and much more. It really needs to be turned into a best-selling book!
I would appreciate it if someone qualified would review Livnat's article and include a summary in this Wikipedia page, referencing the summary from the opening paragraph. I could do it, but I am reluctant to proceed in an area I haven't formally studied for 35 years. — Preceding unsigned comment added by 74.89.153.89 ( talk) 15:48, 30 September 2018 (UTC)
This article does not actually provide what the title suggests, namely: a description of the evolution of sexual reproduction.
It remains stuck in pro's and cons of sexual reproduction, hypothesises of why it even originated.
What remains left out is any information on for example the transition from external to internal fertilisation ( https://www.nature.com/news/fossils-rewrite-history-of-penetrative-sex-1.16173) i.e. the origins of penetrative sex.
Neither does it address the plain fact that sexuality refers to a division in two sexes, and the entire evolutionary consequences of the existence of two sexes, or what is specific to the one sex and what to the other.
I would suggest renaming this article "origins of sexual reproduction", and creating a new one named "Evolution of sexual reproduction", where the relevant themes such as the splitting in two sexes and implications of that are explained, as well as the evolutionary steps from the origins until the present state of sexual reproduction.
Lastly, I see it as a possibility that the lacking information is related to the fact that above mentioned topics are partly still taboo, even in the scientific world. — Preceding unsigned comment added by FreieFF ( talk • contribs) 12:44, 11 October 2019 (UTC)
This statement is not accurate:
"In eukaryotes, true sex is thought to have arisen in the Last Eukaryotic Common Ancestor (LECA)..."
The accurate version is THIS:
"In eukaryotes, true sex is thought to have arisen in the First Eukaryotic Common Ancestor."
This is basic reasoning. Sex did not arise with LECA. It happened with the first of its kind, not the last. The "FECA", if you will. This needs to be fixed. -- Concord19 ( talk) 03:37, 24 July 2020 (UTC)
The questions section seems odd and not needed. Also I have read some of those sources, it aren’t really asking questions. So that section is technically original research. CycoMa ( talk) 22:30, 30 August 2021 (UTC)
It seems to me that little is made of the fundamental asymmetry between the sexes in that females contribute the mitochondria without recombination. In fact it could be said that all sexual reproduction includes asexual reproduction of the mitochondria.
We have a natural experiment going on in comparing the evolution of both genomes so surely this is worth at least a mention. Francishayden ( talk) 18:02, 9 July 2022 (UTC)
About 90% of this article is verbose word spaghetti about the potential benefits of sexual reproduction, which is irrelevant to how sexual reproduction could develop step-by-step through mutation (it can't)
You'd think you could be more humble and upfront that it's an unanswered mystery to the scientific community, rather than hiding behind verbose word vomit that starts with the assumption that your favorite religion Darwinism is true. 174.57.221.108 ( talk) 09:44, 11 July 2023 (UTC)
In Hymenoptera the males are haploid, so there can be no hidden deleterious mutations, yet the order is the most diverse among the insects. Consequently Hymenoptera are not at risk from inbreeding depression. This makes it easy for a single female to establish a population outside its range. I suspect this also allows social insects to evolve large colonies. BioImages2000 ( talk) 12:02, 23 July 2023 (UTC)