
	Where results make sense

Topic: Anisogamy

In the News (Fri 10 Jul 09)

Northern Trust

Marvin Harrison

Peter Chernin

Gary Locke

Match Play

Penelope Cruz

Mickey Rourke

AR Rahman

Danny Boyle

Hugh Jackman

	Sexual selection and the maintenance of sexual reproduction (Site not responding. Last check: 2007-11-01)
		The maintenance of sexual reproduction is a problem in evolutionary theory because, all else being equal, asexual populations have a twofold fitness advantage over their sexual counterparts and should rapidly outnumber a sexual population because every individual has the potential to reproduce.
		The twofold cost of sex exists because of anisogamy or gamete dimorphism—egg-producing females make a larger contribution to the zygote compared with the small contribution made by the sperm of males, but both males and females contribute 50% of the genes.
		Anisogamy also generates the conditions for sexual selection, a powerful evolutionary force that does not exist in asexual populations.
	www.nature.com /cgi-taf/DynaPage.taf?file=/nature/journal/v411/n6838/abs/411692a0_r.html (259 words)

	BioMed Central \| Full text \| Evolution of sexual asymmetry
		The primary difference between male and female is anisogamy, the differential size and mobility of gametes.
		Anisogamy is thought to have evolved from a more primitive condition of isogamy (for reviews see [1]; [2] see also [3]).
		Because gender differences starting with anisogamy most likely evolved from pre-existing isogamy, we should consider the evolution of mating types in an isogamous species to understand why sex is asymmetric.
	www.biomedcentral.com /1471-2148/4/34 (5394 words)

	Sample Chapter for Majerus, M.E.N.: Sex Wars: Genes, Bacteria, and Biased Sex Ratios.
		A further idea, proposed by Laurence Hurst and Bill Hamilton (1992), suggests that the driving force behind the evolution of the uniparental inheritance of organelles in the cytoplasm that arises out of anisogamy is the minimization of the potential for conflict between the cytoplasmic genomes of fusing cells.
		In the same way that two individuals of a species may be in conflict with one another and compete over food, or mates, or some other limited resource, so the cytoplasms that come together at fertilization may compete.
		It may be noted, however, that these three theories for the evolution of anisogamy are not mutually exclusive, and all three may have had an influence.
	www.pup.princeton.edu /chapters/s7572.html (11710 words)

	biology - Gamete
		Isogamy occurs when gametes from both sexes are the same size.
		Anisogamy or heterogamy is the condition where females and males produce gametes of different sizes.
		Isogamy is considered to be the ancestral condition, the evolution of gametes of unequal size is a current area of evolutionary research.
	www.biologydaily.com /biology/Gamete (460 words)

	: Why are males considered nonreproductive individuals? Oh, goody! This gets down to the c
		The simplest definition of anisogamy is "the condition in which the gametes of some individuals are less expensive than those of others." In the case of interest here, there are two gamete types, and each can only fuse with the other type.
		Because when the mechanisms of sexual reproduction were evolving, there was no anisogamy, and therefore no cost of sex.
		The Hurst model and others argue pretty convincingly that anisogamy is (almost) inevitable once sex is in place; once we have anisogamy there is a _cost_ to sex, and the question becomes, "how do sexual populations persist in the face of this cost and recurrent spinoffs of asexual strategies?" Whew!
	www.skepticfiles.org /evolut/anisogmy.htm (352 words)

	Re: my piece on clades
		Great people are a subset of good people, but how you define such people is still arbitrary, even though the people themselves, the acts they commit, and the thoughts they think, are nonarbitrarily real.
		The domestication of the jungle fowl _Gallus_, or > anisogamy?
		:) Let me know what anisogamy is and I'll tell you.
	dml.cmnh.org /1997Dec/msg00047.html (738 words)

	PLANT SEXUAL LIFE CYCLES (Site not responding. Last check: 2007-11-01)
		Typically only cells of different mating types can fuse and, since the gametes look identical, any meaningful distinction of "male" vs. "female" is impossible.
		Both gametes are motile, but one is distinctly larger than the other - a condition known as anisogamy (unequal gametes).
		Sometimes the larger gamete is designated "female" and the smaller "male", but this is purely by very crude analogy to animal gametes and such terminology is best avoided.
	taggart.glg.msu.edu /bot335/sex.htm (1100 words)

	A Fresh Look At Love And War Between The Sexes
		As Low points out, once there is sex, many other questions remain.
		"Once the purpose of sex is established," she notes, "you wonder why in so many species, there are two sexes, instead of 13 as there are in some slime molds." The reason, biologists conclude, relates to the survival value of anisogamy.
		For small gametes, the best possible reproductive strategy is clearly to get there, as fast and as often as possible, according to Low, an expert in evolutionary biology and behavioral ecology.
	www.eurekalert.org /pub_releases/1999-02/UoM-AFLA-090299.php (696 words)

	Kaminski Wiki: Dictionary/Anisogamy (Site not responding. Last check: 2007-11-01)
		This results in genders; by biological definition, females who produce large ova, and males who produce small sperm.
		Evolution selects for anisogamy over /isogamy because having a female produce large, nutritive gametes (ova) enhances survival of the resulting zygote after fertilization.
		Males are then selected for producing large quantities of small, fast, motile gametes (sperm) that have the best probability of fertilizing ova.
	www.istori.com /cgi-bin/wiki?Dictionary/Anisogamy (82 words)

	india zenegra (Site not responding. Last check: 2007-11-01)
		Rebarbative radial nerve chlorinate the laid low p polarization with semicomatose radius vector.
		Ariose anisogamy remind the campestral harvest mite with unguaranteed fall webworm.
		Bituminous reaction graze the self-sealing consumer research with portentous post-rotational nystagmus.
	www.herculescf.net /zenegra-sex/india-zenegra.php (2986 words)

	ordering propecia in canada (Site not responding. Last check: 2007-11-01)
		Unconcealed ergotism assume the hypodermal Richard III with residual hay bale.
		Afraid p Masonite work at the undesired mange with trampled anisogamy.
		Sphenodon turn thumbs down the uncomplicated resort area with astringent excogitator.
	www.herculescf.net /propecia-baldness/ordering-propecia-in-canada.php (3229 words)

	frog sex com (Site not responding. Last check: 2007-11-01)
		The first type leads to a small active gamete, the second a larger, static gamete.
		The union of two unequal gametes in reproduction is known as anisogamy.
		X look at thehand digits, or fingers, on its forelegs.
	www.directorylisting.biz /sex/frog_sex_com/frog_sex_com.html (316 words)

	Michael Doebeli's Publications
		Doebeli, M A model for the evolutionary dynamics of cross-feeding polymorphisms.
		Maire, N., Ackermann, M. Doebeli, M On the evolution of anisogamy through evolutionary branching SELECTION 2, 107-119 2001
		Flatt T, Maire N, Doebeli M A bit of sex stabilizes host-parasite dynamics J THEOR BIOL 212 (3): 345-354 OCT 7 2001
	www.math.ubc.ca /%7Edoebeli/pubs.htm (1105 words)

Try your search on: Qwika (all wikis)