It is said that the species name (oregonesis) celebrated the naming of the Oregon territory. This is nowhere more important than in the measure of genetic relatedness. The prosobranch Fusitriton oregonensis exhibits an unusual form of sperm polymorphism. Finally, we must better understand how the insemination of different ejaculates affects female fitness. (A) Wood mouse A. sylvaticus sperm train where sperm are attached hook-to-hook or hook-to-flagellum (credit: Harry Moore). The queens are now less rather than more likely than chance (relative to the local frequency) to have the alleles in common with the other: the two queens are in fact negatively related [25,43]. No, Is the Subject Area "Ova" applicable to this article? [1], The snail was given its specific name oregonensis (meaning "of Oregon") to honor the Oregon Territory by conchologist John Howard Redfield in 1846. Further experiments that mix differentially labelled sperm would provide opportunities to test the potential for sperm kin recognition and spermsperm interactions in general. Transcriptomic and mutant studies of sperm will help to reveal their potential to act autonomously and affect one another in an ejaculate, particularly when applied to different sperm haplotypes produced by heterozygous males [37]. By contrast, for the simplest case of random mixing among sperm in the female, the incentive for individual sperm to engage in competitive behaviours is expected to be high irrespective of female mating behaviour (dotted line, Figure 1A). A fuller understanding of the biology of these systems is required [24]. The nature of starfish [2][3][4], It was declared the state seashell of Oregon in 1989 by the 65th Legislative Assembly. Part I. No, Is the Subject Area "Altruistic behavior" applicable to this article? This excess sperm cannot contribute to fertilisation but appears to flush out previously stored sperm from a competing ejaculate, and while this means that some sperm are harming others, these sperm do not seem to have much choice in the matter. WebFusitriton oregonensis (Oregon hairy triton) is a species of large predatory sea snail, a marine gastropod mollusk in the family Cymatiidae. WebFusitriton oregonensis (Oregon hairy triton) is a species of large predatory sea snail, a marine gastropod mollusk in the family Cymatiidae. The only conflict for the male is with other males, and this conflict strengthens as the number of sperm inseminated by other males into the same female increases. It occurs occasionally intertidally and is com-mon to 140 fm on rock, sand, shell, or gravel sub-strate. [5], The Oregon hairy triton is native to the northwestern coast of North America. The incentive for producing apyrene sperm, however, appears still to result from evolutionary conflict; in this case with other males. Water temperature and chemistry ranges based on 50 samples. The filiform spermatozoon of Littorina contains a conical acrosome positioned anteriorly to the nucleus, a series of pores that connect the mitochondria directly with the external environment, and a distinct joint separates the mitochondrial and tail regions. The dimorphic spermatozoa in Strombus were first described by Brock in I887 in the case of S. Lentiginosus and his description and figures are sufficient to show how marked and striking is the dimorphism existing here and it is surprising that this has not been made the subject of further investigation by more recent workers. The question of sperm autonomy lies in the relative degree to which sperm can express their genes when in the haploid state. The shells grow from 8 to 13 centimetres (3 to 5in) long. Conversely, sperm sociality represents fertilebut so far little exploredground for the study of social evolution. But it is also clear that the standard measure of relatedness does not usefully predict this behaviour: positive relatedness is not expected to drive fatal conflicts. But is this really spite? Fusitriton oregonensis AquaMaps Data sources: GBIF OBIS Upload your photos Google image | No photo available for this species. Golikov, A. N.; Kussakin, O. G. (1978). The shell is an elongate cone with six whorls (or turns) around a central axis. No, Is the Subject Area "Natural selection" applicable to this article? WebFusitriton is a genus of large predatory sea snails marine gastropod molluscs in the family Cymatiidae. For example, the Oregon triton, Fusitriton oregonensis, has two distinct parasperm types: sperm shuttlers (above) and lancets (Figure 4A4C), and experiments that add a homogenate of parasperm to eusperm find that this causes the eusperm to clump together in vitro, an effect not seen when adding eusperm to eusperm [19]. SummaryThe prosobranch Fusitriton oregonensis exhibits an unusual form of sperm polymorphism. At the extremes, sperm could be kept entirely separate or mix fully. The idea that sperm harm one another dates back 25 years in the empirical literature [2629]. The U-shaped outer layer of each mitochondrial element has been reported here in the subfamily Odontocimbiolinae and may prove to be a diagnostic feature of the Volutidae family. But what would altruism look like in these groups? And, developmentally, are sperm able to influence whether they become a parasperm or a eusperm? Not always. As opossum conjugate sperm pairs move through the female oviduct and approach the egg, they split up, and while one swims on with fervour, the other falls away and loses motility [12,13]. (1846). Puzzling at first, this hook is now thought to help sperm to reversibly form groups of up to several hundred sperm (Figure 2A and 2B). Sperm of the short-beaked echidna, Tachyglossus aculeatus, also form large groups of up to 100 in which coiled sperm heads are stacked tightly and cemented together, which again improves swimming speed [11]. WebFusitriton oregonensis, which has a reported range from California to northern Japan (Beu, 1978) that includes the isolated seamounts Cobb and Patton (Birkeland, 1971; Somerton, 1981). It occurs occasionally intertidally and is com-mon to 140 fm on rock, sand, shell, or gravel sub-strate. Meanwhile, sisters will have a probability of allele sharing because, in addition to chance, they have a probability of inheriting an identical allele from a parent. The Oregon hairy triton was first described by botonist J. H. Redfield in 1848. If these assumptions are incorrect, we would need to consider an additional level of selection generated by competition among sperm populations inseminated in different females. WebThe gastropod Fusitriton oregonensis (Eaton 1971), wolf eels, and lithoid crabs (D. 0. This is not yet clear. It is said that the species name (oregonesis) celebrated the naming of the Oregon territory. Total length 13 cm. But like all partnerships, they will perform the best in the face of their worst foe: the sperm of another male that threatens to eradicate their genetic trace altogether. Natural selection favours queens that engage in a fatal duel, although the fighting is not spiteful but selfish because a queen's personal reproduction is increased if she wins (Table 1). WebThese patterns of abundance correlate with feeding preferences and distributional patterns of the predatory snail Fusitriton oregonensis, which occurs only in rocky subtidal sites, prefers ascidians over other invertebrates as prey and prefers phlebobranchs over stolidobranchs. Unsolved Mystery (A) Immature Oregon triton (Fusitriton oregonensis) lancet parasperm seen with scanning electron microscopy, showing the tail brush still present, which later develops into part of the body of the parasperm. [In Russian]. Pers. One reason might be that it minimises the time that sperm have to survive in a potentially hostile female environment. KRF is supported by National Institute of General Medical Sciences Center of Excellence Grant 5P50 GM 068763-01. Environmental ranges Depth range (m): 0 - 662.5 Late veligers grew slowly, but shell sizes increased even in the 4th and 5th years. [5]. But do sperm preferentially group with others from the same male, and moreover, is there evidence for sperm altruism? Trudy Zoologicheskogo Instituta AN SSSR. 148: 90-92. We are grateful to Andy Gardner, Geoff Parker, John Buckland-Nicks, Greg Neely, Nilay Yapici, and Stuart West for many helpful comments, and to John Buckland-Nicks and Harry Moore for kindly providing photographic material. The eggs are placed in rectangular capsules in a spiral pattern. Here, evolutionary conflict is not strictly between the sperm and the male, but rather between the selfish segregation distorter linkage group and everyone else (all other genes in the sperm and the male). Semantic Scholar is a free, AI-powered research tool for scientific literature, based at the Allen Institute for AI. Moreover, choosing the appropriate scale can help to capture the relevant biology. (D) Electron microscopy of exquisite sperm head alignment in conjugate sperm pair (credit: Harry Moore). Or in the terminology of social evolution, sperm are always unrelated at any female re-mating frequency (dotted line, Figure 1A) if we measure average genetic relatedness among sperm at the scale of the female (see Box 1). Of course, it is also possible that sperm are simply forced to group by the male, which would mean that any sperm altruism is illusory in the sense that it did not evolve through natural selection acting at the level of sperm (sperm lack evolutionary agency). But in other species, there may be a case for spitefully suicidal sperm. Taking two competing queens as an example, we can recalculate relatedness using the formula: r = (pR - p)/(pA - p) but where p (the population frequency) is no longer the frequency of the focal allele in the whole population of bees, but the average frequency in the two queens (local frequency). WebFusitron oregonensis (Redfield, 1848) Common name(s): Hairy triton, Oregon hairy triton: Synonyms: Argobuccinium oregonense: Phylum Mollusca Class Gastropoda Subclass Prosobranchia Order Mesogastropoda Suborder Taenioglossa Family Cymatiidae: Fusitron oregonensis from 15 m depth, Sares Head. Can parasperm direct their actions based upon genetic relatedness? It is this 50% inflation relative to the average that gives the commonly cited relatedness among siblings, which is why, evolutionarily speaking at least, you should be nice to your siblings. Total length 13 cm. An associated question is whether stratified sperm are able to actively recognise other sperm, or whether associations result from passive processes such as the spatial separation of ejaculates within a female. This principle of mutual cooperation is consistent with several sperm behaviours that appear to increase the fertilising probability of all team players. This competition from a foreign male has important knock-on effects for the other conflicts. In support of this theory, recent artificial insemination experiments in the silkworm moth Bombyx mori revealed that parasperm may facilitate transport of eusperm to the site of sperm storage and/or fertilisation [18], and the enormous size of the parasperm in some molluscs, up to 140 times larger than eusperm, may also help to shuttle eusperm to the eggs [19]. Description of some new species of shells. [6] There is another interpretation that puts the sperm back in the spotlight: perhaps sperm are able to specifically target and group together with their closest relatives. A male and female have just mated; what would one predict? While subsequent studies did not support this idea in humans [31,32], similar mechanisms might occur in some snails. Bulletins of American Paleontology 377-378: 550 pp, 79 pls. [1], The snail was given its specific name oregonensis (meaning "of Oregon") to honor the Oregon Territory by conchologist John Howard Redfield in 1846. Phylogenetic studies suggest that sperm competition may be associated with the evolution of heterospermy in some taxa [22], but not in others [23]. Features not previously reported in other ultrastructural studies of paraspermatozoa include the acrosome-like structure of the head, the structure ofthe midpiece zone, the glycogen sheath of the major tail, the dense annular structure at the junction of the midpiece and major tail and the presence of microtubules in the final phase of head and midpiece maturation. As we have seen, sperm can benefit from joining forces with others, helping their kin, or even harming others. No drawings available for Cymatiidae. Sperm trains in the wood mouse and conjugate opossum sperm: As discussed above, sperm of the wood mouse attach themselves to each other by bending the apical hook on their head around the flagellum or the hook of another sperm, forming trains of hundreds of sperm that allow them to swim faster (Figure 2A and 2B) [3]. Larval shells grew in length from 0.20 to 3.9 mm. The viable, eupyrene sperm are attached in groups of about fifty to worm-shaped, apyrene, carrier sperm. Chromatin condensation begins with the formation of fibrous strands, then to lamellar plates which become folded and later twisted around the flagellar shaft, which eventually fuse to form a homogeneously dense nuclear tube. In 1989, the Oregon hairy triton was declared the states official sea shell by the sixty-fifth Legislative Assembly of Oregon. An associated challenge is to understand whether sperm from different males segregate in space and time within multiply-mated females. The morphology of the slender, filiform spermatozoa of 13Protodrilus species of 22 different populations is investigated by light and transmission electron microscopy and elucidates possible plesiomorphous and apomorphous sperm traits. Although the mode of action of these sperm is unclear, they are extremely motile and have been suggested to act as a filler that evolved to prevent the female from re-mating by stimulating her sperm storage organ and making it feel full. Gulbin, V. V.; Chaban, E. M. (2012). Later features, including the peripheral condensation of nuclear chromatin followed by nuclear invagination, the posterior breakdown into nuclear vesicles (caryomerites), centriole multiplication and the synthesis of secretory products, are the most conspicuous changes in the process of paraspermatogenesis. Hundreds of sperm agglutinate by the head in the fishfly, Parachauliodes japonicus, and swim into the female spermatheca to the tune of a synchronised tail-beat, which propels them faster in large groups than in small [9]. here. This service is powered by LifeWatch Belgium, https://www.biodiversitylibrary.org/page/3370106, http://rfems.dvo.ru/images/rfems/bulletin/vol_015_016/article_01.pdf, http://www.biolbull.org/content/213/2/152.full.pdf+html, http://ashipunov.info/shipunov/school/books/golikov1978_rakov_brjukh_litorali_morei_sssr.djvu, To Biodiversity Heritage Library (1 publication), To Biodiversity Heritage Library (25 publications), To Biological Information System for Marine Life (BISMaL), To USNM Invertebrate Zoology Mollusca Collection. First, we consider cases of sperm cooperation, where sperm have adapted to group together to mutual advantage, much like wolves that hunt in packs. Biological Bulletin. 213(2) 152-159. It is fairly common, and can be locally abundant. Zeitschrift fr Zellforschung und Mikroskopische Anatomie. (B) Montage of side-by-side transmission electron microscopy sections of the carrier (i) and lancet (ii) parasperm. For more information about PLOS Subject Areas, click WebThe gastropod Fusitriton oregonensis (Eaton 1971), wolf eels, and lithoid crabs (D. 0. (For example, taking a focal rare allele in a heterozygous queen, the focal individual frequency (pA) is 0.5, average frequency in the other queen (pR) is about 0.125 ( chance she is also heterozygous), and local frequency (p) is the average of the frequency in each, or 0.3125, giving r = (0.125 0.3125)/(0.5 0.3125) = 1). The ultrastructure of the paraspermatic cells (atypical spermatozoa) in the male genital tracts of nine species of marine Prosobranchia is described and these cells derive from the same germinal line as the typical spermatozoon, and seem to be homogeneous in their general constitution. You can help Wikipedia by expanding it. Catalogue of Tonnoidea. The important open questions for the sociobiology of parasperm are (again): how often do sperm from different males meet in a female? The potential for sperm to have a social life then seems clear, but does this help us to make sense of the diverse sperm behaviour seen in nature? The slight narrowing in the acrosomal vesicle invagination is situated in different levels between Olivancillaria deshayesiana and Olivancilaria carcellesi, and could be diagnostic at family level. The replication of centrioles during spermatogenesis in the Prosobranch snail is described in the light of the theory, first proposed by Pollister, that the supernumerary centriole in the atypical cells are derived from the centromeres of degenerating chromosomes. In 1989, the Oregon hairy triton was declared the states official sea shell by the sixty-fifth Legislative Assembly of Oregon. WebDepth range based on 90 specimens in 1 taxon. WebFusitriton oregonensis (Redfield, 1846) AphiaID 476496 (urn:lsid:marinespecies.org:taxname:476496) Classification Biota Animalia (Kingdom) Mollusca (Phylum) Gastropoda (Class) Caenogastropoda (Subclass) Littorinimorpha (Order) Tonnoidea (Superfamily) Cymatiidae (Family) Fusitriton (Genus) Fusitriton oregonensis Sperm evolution requires one to consider Darwinian selection on multiple interacting parties and at multiple levels, and this lends itself to the tools of sociobiology: kin selection and multi-level selection theory [4]. Sperm-grouping: Sperm groups have been found across several vertebrate and invertebrate taxa, ranging from sperm pairs to massive aggregates containing hundreds of sperm [7]. View 4 excerpts, references background and results. An extraordinarily long larval duration of 4.5 Years from hatching to metamorphosis for teleplanic veligers of Fusitriton oregonensis. Haplodiploid females are diploid, but the males are haploid with clonal sperm that should lack the evolutionary conflicts seen in diploid males, both among sperm and between each sperm and the male [1]. The shells are found from Alaska to California, as well as in northern Japan. For example, if there are two alleles at equal frequency in the population at a focal locus, then unrelated people will have probability of having the same allele at that locus. WebThe Oregon triton is a common subtidal species of marine snail found from southern Califor-nia to the Gulf of Alaska and to the eastern Bering Sea. (A) Immature Oregon triton (Fusitriton oregonensis) lancet parasperm seen with scanning electron microscopy, showing the tail brush still present, which later develops into part of the body of the parasperm. There is a second apyrene sperm, which is lancet-shaped and has a different internal organization than the carrier, but does not transport eupyrene sperm.The eupyrene sperm are filiform (185 m long), with a conical acrosome, elongate nucleus and midpiece. It would seem then that the observed link between sperm competition and grouping behaviour is all about the male. And while no speed advantage in grouping was found in the house mouse, Mus musculus [10], sperm groups swim faster than single sperm in the Norway rat [10] and the wood mouse, Apodemus sylvaticus (discussed below) [3]. Adaptations that result from natural selection on sperm, therefore, are expected to favour the individual sperm's personal fitness interests. WebAbstract. The species also holds the record for longest larval development period of any marine invertebrate, able to delay metamorphosis for over 4 years until presented with appropriate habitat. WebDepth range based on 90 specimens in 1 taxon. Summarize this article for a 10 years old, Fusitriton oregonensis (Oregon hairy triton) is a species of large predatory sea snail, a marine gastropod mollusk in the family Cymatiidae. When this happens near the egg, the acrosome reaction promotes fertilisation, but a premature reaction leaves sperm impotent and useless by the time they reach the egg. Duggins, personal observation) can consume urchins, but the crabs and eels are rare in this benthic community, and Fusitriton, while common, eats urchins rarely (D. 0. In this case, there can be no malesperm conflict, and sperm evolution is driven by the male alone. In other molluscs (e.g., Aporrhais pespelecanis), parasperm morphology suggests that they deliver nutrients either to eusperm or to the female [19], which is likely, either directly or indirectly via the female, to increase eusperm fitness. The charming great-diving beetle Dytiscus marginalis has sperm with a distinctive flat side that allows some sperm to pair upstuck together by the headand use both tails to propel themselves onward [8]. WebAbstract. [ .., .. The key point then is that there is no single measure of genetic relatedness among individuals; rather it must always be set against a scale of reference [41]. The eggs are placed in rectangular capsules in a spiral pattern. Only five of the 14 species of solitary ascidians in the San Juan Islands, Washington, USA commonly co-occur with an abundant predator of the rocky subtida Yes The shell is light brown in color and is covered with gray-brown bristly periostracum, hence the name "hairy." What is clear is that the spermmale partnership can be an uneasy one, steeped in potential conflicts. https://en.wikipedia.org/w/index.php?title=Fusitriton&oldid=1010071512, Short description is different from Wikidata, Creative Commons Attribution-ShareAlike License 3.0, This page was last edited on 3 March 2021, at 17:24. WebThe Oregon triton inhabits the intertidal and subtidal to 90 m deep, and is more commonly found on rocky substrates. Social evolution theory predicts that relatedness is central to social behaviour. The sperm morphology of Adelomelon beckii is described by optical and transmission electron microscopy and the use of paraspermatozoa is suggested as a systematic character to reveal phylogenetic relationships in this family. This situation can favour altruism, and indeed, as the sperm of our focal male become rarer, altruism becomes a better option than spite (it is more difficult to knock-down a majority than support a minority). Short-beaked echidnas may also experience intense inter-male sperm competition because males have large testes and form queues of up to 11 individuals competing over the same receptive female [11]. Can you list the top facts and stats about Fusitriton oregonensis? Environmental ranges Depth range (m): 0 - 662.5 [1] Species [ edit] Species within the genus Fusitroton include: [1] Fusitriton brasiliensis Cossignani & Cossignani, 2003 Fusitriton galea Kuroda & Habe, 1961 Fusitriton glassi Swinnen, 2019 Fusitriton laudandus Finlay, 1926 This study was not planned as one of larval longevity and replication is low, but the observations are surprising and noteworthy. TP is supported by a grant from the Natural Environment Research Council. No, Is the Subject Area "Sperm head" applicable to this article? Journal of the Marine Biological Association of the United Kingdom. WebFusitriton oregonensis (Oregon hairy triton) is a species of large predatory sea snail, a marine gastropod mollusk in the family Cymatiidae. That is, are the actor and recipient genetically related? The nucleus of the parasperm is eliminated during paraspermiogenesis, but there is considerable post-transcriptional secretion activity resulting in the production of a variety of granules, some rich in glycoproteins. , , 116: 292 .]. In order to make social evolution predictions, relatedness should always be measured at the locus or loci in the genome that drive the social action of interest (average across-genome measures are only a proxy for the loci that drive a behaviour). Our simple relatedness calculations assume that sperm social behaviours have no negative effects on females or on the probability that eggs are left unfertilised (Figure 1, Box 1). Similarly, carabid beetle species with more complex male genitalia and longer periods of mate guarding, characteristics typical of species with a high risk of inter-male sperm competition, tend to have relatively large sperm bundles, suggesting that sperm competition promotes the evolution of larger sperm groups [14]. He has little to gain from sperm infighting, and instead only seeks to ensure that all of the eggs available are fertilised by his sperm. Human sperm were famously suggested to be heteromorphic, comprising one type that contributed to fertilisation and another, the kamikaze sperm, that sacrificed its own chances of fertilisation to neutralise the sperm of competing ejaculates, for example by blocking, incapacitating, or killing rival sperm [28]. The viable, eupyrene sperm are attached in groups of about fifty to worm-shaped, apyrene, carrier sperm. As our simple analysis shows (Figure 1), negative relatedness between sperm abounds within the sperm storage organ of a promiscuous female, in which sperm of multiple males mingle, setting the scene for spite. WebFusitriton is a genus of large predatory sea snails marine gastropod molluscs in the family Cymatiidae. Sperm heteromorphism: The analogy with an insect worker caste appears to go even further in species with morphologically distinct sperm types, a phenomenon known as sperm heteromorphism. After mating the female tritons lay the eggs on vertical surfaces and under rock ledges. PLOS Biology provides an Open Access platform to showcase your best research and commentary across all areas of biological science. Just as positive relatedness predicts that there may be helping among individuals, so negative relatedness predicts that there may be harming. PLoS Biol 6(5): Unsolved Mysteries discuss a topic of biological importance that is poorly understood and in need of research attention. Fusitriton is a genus of large predatory sea snails marine gastropod molluscs in the family Cymatiidae. In spite of the potential costs, therefore, train formation and conjugation may represent purely mutualistic behaviours (Table 1). [10] Under laboratory conditions, the larvae showed no signs of senescence at that point. This means that, in addition to conflict among individual sperm, there is also potential conflict between each sperm and the male, which could lead to an evolutionary arms race over which controls sperm morphology and behaviour [5,7]. WebThe prosobranch Fusitriton oregonensis exhibits an unusual form of sperm polymorphism, which is attached in groups of about fifty to worm-shaped, apyrene, carrier sperm, and the possible functions of the lancet and carrier sperm are discussed. This appears to facilitate and synchronise sperm migration to the female sperm storage organs, where the spermatostyle disintegrates, releasing the sperm [8]. This case is also the most interesting, because it generates non-zero relatednesses that may select for complex social traits (see Box 1). WebFusitriton oregonensis (Redfield, 1846) AphiaID 476496 (urn:lsid:marinespecies.org:taxname:476496) Classification Biota Animalia (Kingdom) Mollusca (Phylum) Gastropoda (Class) Caenogastropoda (Subclass) Littorinimorpha (Order) Tonnoidea (Superfamily) Cymatiidae (Family) Fusitriton (Genus) Fusitriton oregonensis Across murid rodents, those species with relatively larger testes (a predictor of the level of sperm competition experienced by a species) tend to produce sperm with more pronounced apical hooks [10] (Figure 2C and 2D), which presumably promotes grouping. Sperm features suggest a close relationship between T. amurula and M. tuberculata and more broadly with other 'Group T cerithioidean families exhibiting four equal-sized eusperm mitochondria, including Potamididae, Modulidae, Scaliolidae, Melanopsidae, Semisulcospiridae and Pleuroceridae. They contain large stores of glycogen in. Veliger larvae of the NE Pacific snail Fusitriton oregonensis were reared in culture for 4.5 to 4.6 years from hatching to metamorphosis and through postlarval growth to reproduction. WebFusitriton oregonensis, which has a reported range from California to northern Japan (Beu, 1978) that includes the isolated seamounts Cobb and Patton (Birkeland, 1971; Somerton, 1981). Conradia minuta - [= A new gastropod species Conradia minuta from the temperate water of the northwestern Pacific]. WebGenus Fusitriton Species oregonensis Common Name: Hairy Oregon Triton. WebThe mechanisms by which Cnemidocarpa finmarkiensis persists in the presence of F. oregonensis is unknown. This means that sperm will probably join with sperm from the same male rather than sperm from another male that mates before or afterwards; i.e., there may often be positive relatedness within the sperm groups (Figure 1, Box 1). Larval shells grew in length from 0.20 to 3.9 mm. If a female mates once, all sperm have the same probability of sharing genes, and relatedness at the scale of the female is zero. A swimming sperm cell appears to perfectly capture the individualist Darwinian struggle, as it frantically races onwards towards a waiting egg. No, Is the Subject Area "Evolutionary genetics" applicable to this article? https://doi.org/10.1371/journal.pbio.0060130. Annals of the Lyceum of Natural History of New York. 4: 163-168, pls 10-11. It is notable, however, that these sperm groups form either before or shortly after ejaculation.