Talk:Reproduction

The grammar on this page is not standard. My guess would be that it has been translated from German.

Be bold and improve! :-) --Menchi 04:25, 21 Sep 2003 (UTC)

Separate articles on sex / asex reproduction

We could really do with this, unless it is already here under a different name... Anyone got any ideas? Mark Richards 21:29, 1 Jun 2004 (UTC)

I agree that sexual reproduction and asexual reproduction need their own articles. Cloning should be mentioned in or linked from the latter. I would also add more material on non-biological reproduction to this article, including document reproduction (e.g. List_of_duplicating_processes) and any other forms of replication which might exist (in fact or in fiction) in the universe. I'm thinking nanites and grey goo, self-assembling materials, the assembly line, the reproduction of a painting, photography, teleportation, sound recording, the reproduction of messages i.e. communication, etc., mold-taking of statues and fossils, three-dimensional printers, and so on. -- Beland 03:14, 23 Feb 2005 (UTC)

The strong association between sexual systems and reproduction leads to a biased (at the least) view of sexuality as part of reproduction. Thanks for pointing this out. Actually it is perfectly legitimate to view the sexual processes as separate from the reproduction. Reproduction is for multiplication; sex is for recombination and saving alleles that may be valuable in the future. --Etxrge 10:30, 8 May 2005 (UTC)

Marxism uses reproduction as a term to describe the social process of creating the material and social aspects of society Fifelfoo 05:53, 23 Feb 2005 (UTC)

Collaboration Nominations

This article lacked just ONE vote of support necessary to get it to survive as one of the Collaberations of the Week, but it looks like it's dead, now. I revived the Science Collaboration of the Week and nominated it there, so the notice has been added to this talk page. Toothpaste 6 July 2005 07:13 (UTC)

'Reproductive success' (?)

The term reproductive success links to this page. RS is a technical term with a precise definition, not touched upon in this entry. --Pete.Hurd 9 July 2005.

Dominance

I disagree with the recent edit to remove the statement that sexual reproduction has the advantage of being able to mask "bad" genes. While not all dominant genes are good and not all recessive ones are bad, it is certainly the case that species survive better because they can mask those bad genes that are recessive. Perhaps I worded it poorly, but I think it is a sentiment that needs to be included. Jamesmusik 17:45, 13 July 2005 (UTC)

Species survive better because good traits get selected for, not because they mask bad genes. With sexual reproduction, every generation the offspring are slightly different from each other. The ones with good (or "better") genes end up having more offspring themselves. That's how alleles get selected for. It is not the case that species survive better just because good dominant genes mask bad recessive ones. As you said, not all dominant genes are good and not all recessive ones are bad. It's just how the genes work in their environment. Alex.tan 01:22, July 14, 2005 (UTC)

I'm not saying that it's just because good dominant genes mask bad recessive ones that species survive better. It is, however, undeniable that more individuals of species survive when disadvantageous traits are masked by more advantageous ones. For instance, the incidences of cystic fibrosis, spinal muscular atrophy and phenylketonuria are much lower than they would be otherwise, simply because the alleles that cause them are recessive. Jamesmusik 07:36, 14 July 2005 (UTC)

I'm not saying that you're saying that it's "only because". I am saying that genes will get selected for based on their ability to help the species cope with its environment. Even apparently "bad" recessive genes stick around sometimes because they might have some unforseen good values too. That's another of the strenghts of sexual reproduction - keeping a larger variety of genes in the pool alive. For the sake of the argument, your statement "It is, however, undeniable that more individuals of species survive when disadvantageous traits are masked by more advantageous ones", is sadly wrong. Now, I personally don't know any competitive advantage to having the cystic fibrosis or spinal muscular atrophy genes but I do know that there are many recessive genes for hemoglobinopathies such as thalassemia, sickle cell anemia and so on where the "defective" bad genes used to make a big difference in survival because individuals who had those genes were resistant to malaria. It was the case that malaria was so widespread in the world (and still is, to some extent) that having these bad, recessive genes gave you a survival advantage. Now that we have good treatments for malaria, those genes just seem bad to most people. Similarly there might be some situation where there is a competitive advantage to having the CF gene but just because I can't think of one does not mean that there isn't one. So there are some environments where some genes are good and others where these genes are not. More members of the species survive when their gene mix is suited to the environment, not because they have more advantageous dominant genes masking bad ones. Alex.tan 11:32, July 14, 2005 (UTC)

Here are two articles that argue directly that the masking of deleterious alelles is the direct reason for the existence of diploidy: V, Richerd S, Valero M. "Transition from haploidy to diploidy. Nature. 351 (1991 May 23), 315-7 and S. P. and D. B. Goldstein, "Recombination and the evolution of diploidy". Genetics 131 (1992): 745-751 Jamesmusik 17:19, 14 July 2005 (UTC)

Yes, the existence of diploidy may initially have came about as a way to mask deleterious mutations. Any deleterious mutations that turned out to be dominant would be strongly selected against and recessive ones would be masked to some degree. However, my point is that the real strength of sexual reproduction is the recombination of genes every generation. As each offspring is different genetically (though related) from each other, those who genes expressed some combination which was more favourable ended up having more offspring themselves. I will go back to the sickle cell mutation example - if a set of parents had a new mutation that caused sickle cells today, it probably would be selected against over many generations as the resulting anemia would give those who inherited it a disadvantage. However, put the same parents in tropical Africa a thousand years ago where malaria was endemic and a large proportion of the population would be expected to be infected over their lifetime and instead there would be strong selection pressure to keep the gene, despite the resulting anemia. Random mutations are deleterious or advantageous although I agree most would be deleterious. Sexual reproduction leads to stronger selection for good mutations, selection against deleterious mutations and therefore quicker evolution. It's not the masking of bad mutations, that's a side point. It's about selecting against them. Alex.tan 01:52, July 15, 2005 (UTC)

You seem to be missing my point entirely. I'm not saying that masking deleterious genes is more important than or has contributed more to selection than the free and quick exchange of DNA in sexual reproduction, but that it is an advantage, nonetheless, to be able to mask deleterious genes, a point clearly made by both of those articles above. In particular, Otto and Goldstein put forth and substantially prove the "masking hypothesis" that masking is so advantageous that it leads to diploidy in the presence of free recombination. Jamesmusik 01:59, 15 July 2005 (UTC)

Well, in that case, please go ahead and fix the article to reflect that. I just removed it because the way it was stated before, it sounded like you wanted it to say that that was the most important or only reason for sexual reproduction. Alex.tan 11:49, July 15, 2005 (UTC)

I agree with James. You missed his point, although you are both arguing correct points of view. They are not at odds with each other. - Marshman 05:48, 30 August 2005 (UTC)

"No reproduction" section

Well done! I've never thought of the need to add a section about the consequences of a lack of reproduction! Thanks everybody who did improve this article! Deryck C. @ SCOTW 20:04, 14 Jul 05 (GMT+8)

Unfortunately, it contained a popular misconception about species evolution - Marshman 05:48, 30 August 2005 (UTC)

Well... Just improve it if you sees fit... Deryck C. 07:04, 30 August 2005 (UTC)

Please stop changing the "Life without reproduction" text. The concept you are apparently promoting is based on a lack of understasnding about the subject. The concept borders on nonsense and probably the subsection should be deleted alltogether. However, as you added it to make a point (although it is not clear what that might be), it has been retained; but it cannot be left in the form as originally written. - Marshman 06:57, 5 December 2005 (UTC)

I agree this section might best be deleted, but abiogenesis ought to be mentioned in the article somewhere. However, phrases like "exceptions might be sports that are multiplied vegetatively" (sports?!) and "However, it is species populations that evolve, and a [...]" just don't make sense. So I changed it. Pete.Hurd 07:54, 5 December 2005 (UTC)

Yes, abiogenisis; but it is not some kind of "exception" to species reproduction. And "sports" is a prefectly legit word in botany/horticulture that describes mutations that arise spontaneously. Possibly the sentence you are objecting to could be written better, but it certainly does make sense. It is species populations that evolve, so the idea that there is some individual organism that becomes the "founder" of a new species (e.g,, all humans came ultimately from the one and the same single individual mother) is a misconception. Therefore, anything that implies there was one individual that is the start of all complex life on earth shows a misunderstanding of the processes of evolution and reproduction. But I think the way you have it described now, removes the objections I had, with the possible exception of the singular "ancestor" - Marshman 04:40, 6 December 2005 (UTC)

Yes, evolution is typically defined as change in allele frequency in a gene pool over time, the phrase "species populations" is a bit unusual, but I know what you mean. It's a different question from whether there is a single individual which is the ancestor to all living things, or a single living ancestor to all humans. That the species Homo sapiens does not have a single original individual who was dichotomously not the same species as his/her parents is different from saying that there is no Mitochondrial Eve. I realize you're not making claims about the latter, but and only talking about the former. However, I'm not sure that abiogenesis producing a vegetatively reproducing individual isn't a case where it is reasonable to assume a single founder. Speciation is a bit different from abiogenesis, they are two different things. Best regards, Pete.Hurd 05:26, 6 December 2005 (UTC)

Reproduction article series

It is noticed that the "main articles" linked from this article and those linked articles goes up to 3 or 4 levels of articles. I wonder if it's appropriate to set up a "reproduction article series" template and post it onto each of these articles. Deryck C. 15:52, 22 July 2005 (UTC)

Current articles in the "reproduction series":

• Reproduction
  • Asexual reproduction
  • Sexual reproduction
    • Flowers / Plant sexuality / Flowering plants
    • (Mammalian Reproduction???)
      • Male reproductive system
        • Testicle
        • Penis
        • Sperm
        • Ejaculation
      • Female reproductive system
        • Vagina
        • Cervix
        • Uterus
        • Fallopian tube
        • Ovary
      • Mammalian pregnancy / Pregnancy
      • Childbirth

The meiosis picture is a piece of ... art

A pair of homologous chromosomes in each daughter nuclei II (haploid!) is especially fabulous. TG nb4est(at)yahoo.com

Add it if you find suitable. Deryck C. 13:27, 29 August 2005 (UTC)

Don't like brackets?

Parentheses are a legitimate punctuation. I do not understand why you think they should be removed from writing. Also, some of your other changes completely destroy the flow of the sentences. It is possible to simply use shorter sentences, although that may or may not improveme understanding. Nonetheless, certain words (such as "that") are helpful to establish relationships between different parts of a sentence. While I agree, there are many ways to say the same thing, on the whole your changes have not been an improvement on the English. - Marshman 17:27, 1 September 2005 (UTC)

My real concern is that the overuse of brackets made the passage look weird as if the footnotes were mixed into the main passage. Deryck C. 08:06, 9 November 2005 (UTC)

Been so long I hardly recall what the "dispute" was about. BTW, those are parentheses not "brackets". And, in a very real sense, parentheses are a form of mixing footnotes into text. Many ideas are important to the presentation in a written passage, but some may seem (to the author) somewhat peripheral to the main flow of thought or main point. Footnotes are a valid way of handling such "parallel" contributing ideas. But Wikipedia is not really set up to use footnotes in that manner (can be done, but is better suited to printed media). Parenthesis are another option. Thoughts in parentheses are meant to be taken as "extra" information, important, but outside the main thrust of the sentence. THe informatio is frequently a clarification of the word or thought preceeding. Note use of parantheses in this paragraph; the sentence could stand alone, but some readers will ask "why do you say Wikipedia is not set up..." The related ideas could be separated by a semi-colon or even a printer's m. Parentheses are just one option for a writer to order the thoughts being conveted. - Marshman 19:11, 9 November 2005 (UTC)

IMO it'd be a lot better if we use commas instead of parenthesis to enclose parenthesal notes into the passage. Deryck C. 02:30, 11 November 2005 (UTC)

Rename to "Biological reproduction"

The category is "Biological reproduction". The page name should be also. There is a redirect in the way, but I will signal for an admin to do the rename if there are no objections. -- Fplay 01:16, 17 December 2005 (UTC)

Sexual reproduction

I apologize for the poor phrasing of my edit, but I do have some concerns with the accuracy of the current sexual reproduction section. It says that all species "have two different adult sexes". But earthworms, for example, are all hermaphroditic. Plant species also commonly produce both male (pollen) and female gametes in the same plant. These organisms do not have two different adult sexes. Also, from "Dr. Tatiana's Sex Advice to All Creation" by evolutionary biologist Olivia Judson, there are a few rare species (including slime moulds) that have many sexes, not just two. Again, these species do not have two different adult sexes.Lyrl 19:21, 30 December 2005 (UTC)

I think the point you are making is a good one. Reverting was not the best way to correct the error or two you introduced. Look for an appropriate place to put it back in and I can help you edit it to satisfactory condition. You might consider adding it instead at Sexual reproduction which needs help - Marshman 18:32, 4 January 2006 (UTC)

Anisogamy & gamete names

I'm short on sleep, so I could be having a brain-fart, but this sentence makes no sense to me:

"Most organisms form two different types of gametes. In anisogamous species, these two types are referred to as male and female"

Don't you mean "sperm" and "egg" here, rather than "male" and "female"? Pete.Hurd 03:39, 5 January 2006 (UTC)

This article (and the one at Sexual reproduction) suffers from a confusion of concepts between sex cells (gametes) and the organisms that produce the sex cells. The correct sense here should follow consistently through the text (or certainly within a paragraph), and I think it is about the organisms involved, not the gametes. Further rewrite is certainly in order. - Marshman 03:46, 5 January 2006 (UTC)

They're not particularly confusable concepts. I don't think there's a serious need to consistentify articles. Just use gametes sperm and eggs when talking abou tgametes spem and eggs and adults, organisms, males and females when talking about them. Shouldn't take much effort to fix in this article. As for Sexual reproduction I'd say it's got more serious problems (It would be nice to see less of a taxonomic focus, some discussion of fun sex things like meiotic drive (oof! there's no meiotic drive article?!), and maybe a nice clear discussion of the difference between sexual reproduction and conjugation). Pete.Hurd 04:16, 5 January 2006 (UTC)

I'm clear you got my point. As for other things to pursue; well there is the problem that this article has become a sort of way station for the "big" shows at asexual reproduction and sexual reproduction. So your ideas for other directions could really help out here. - Marshman 04:28, 5 January 2006 (UTC)

Really, I'd disagree about the way station, I'd say this article has far more bang for the buck than sexual reproduction. I guess it's debatable whether most of the good stuff here really would be better off on that other page. If it really only pertains to sexual or only to asexual perhaps it should move, and that which is general remains. I'm not so motivated to actually do that myself... Pete.Hurd 04:49, 5 January 2006 (UTC)