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 Post subject: The mating game (QM)
Unread postPosted: Sat May 08, 2010 10:57 pm 
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This quiz is about pro-creation in all its interesting forms. Keep it civil! :naughty: :roll: I will be asking the questions.

I will also be taking my time on this, so don't rush me. :whistle:

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 Post subject: Re: The mating game (QM)
Unread postPosted: Sat May 08, 2010 10:58 pm 
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:popcorn:


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 Post subject: Re: The mating game (QM)
Unread postPosted: Sat May 08, 2010 11:00 pm 
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I many species of animals and plants, the females are quite capable of pro-creation without the male of the species.

Why then is males needed? Why is there still males in these species, indeed, why is there males at all?

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 Post subject: Re: The mating game (QM)
Unread postPosted: Sun May 09, 2010 1:11 am 
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Males are needed just in-case. In the order (Hymenoptera) Wasps, Bees and Ants, all females have a double set of chromosomes (diploid), males having a single set, (haploid). When these eggs are fertilised they automatically become female (diploid).

These females usually have a sperm purse (spermatheca) in which they store sperm for long periods after mating, as with the ant or bee queens, they can store millions of sperms for years. To keep these sperms alive for long periods she has to feed them, which is done which is done by special glands in the sperm purse. She then has the choice to fertilise her eggs or not, thereby determining the sex of her offspring.

So I would say, in such a case she would create males if she needed more sperm.

There are however a few parthenogenetic species with females only.

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 Post subject: Re: The mating game (QM)
Unread postPosted: Sun May 09, 2010 7:29 am 
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:thumbs_up: Imberbe very interesting topic here.


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 Post subject: Re: The mating game (QM)
Unread postPosted: Sun May 09, 2010 2:14 pm 
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No, not the correct answer. Males are a bit more important than that ... :lol:

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 Post subject: Re: The mating game (QM)
Unread postPosted: Sun May 09, 2010 2:43 pm 
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In order to renew the genetics of the species? I imagine that the offspring of Parthenogenesis have the same genetic code as the mother? This is all speculation :hmz:


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 Post subject: Re: The mating game (QM)
Unread postPosted: Sun May 09, 2010 2:56 pm 
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You are on the right track ... explore that a bit further.

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 Post subject: Re: The mating game (QM)
Unread postPosted: Sun May 09, 2010 3:22 pm 
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This is not my work, but it was not easy to find :wink:

"The variations found in offspring of sexual reproduction allow some individuals to be better suited for survival and provide a mechanism for selective adaptation to occur. In addition, sexual reproduction usually results in the formation of a life stage that is able to endure the conditions that threaten the offspring of an asexual parent. Thus, seeds, spores, eggs, pupae, cysts or other "over-wintering" stages of sexual reproduction ensure the survival during unfavorable times and the organism can "wait out" adverse situations until a swing back to suitability occurs."


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 Post subject: Re: The mating game (QM)
Unread postPosted: Sun May 09, 2010 3:28 pm 
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:thumbs_up: very good quiz, Imberbe!

Parthenogenesis has been described before in about 70 species of vertebrates. The problem is the offspring which is only male or only female. In animals whose sex is determined by chromosomes all offspring created due to parthenogenesis will be the same sex. What sex that will be depends on the sex chromosome setup of the individual animal. The offspring produced by parthenogenesis are always female in species that use the XY sex-determination system, and male in those that use the ZW.
Komodo dragons are one species with the WZ chromosome makeup, so all of the parthenogenesis offspring are male. A female Komodo dragon could make use of the ability to reproduce asexually when, for example, a lone female was washed up alone on an island with no males to breed with. Because of the genetics of this process her children would always be male. This is because Komodo dragons have W and Z chromosomes - females have one W and one Z, males have two Zs. The egg from the female carries one chromosome, either a W or Z, and when parthenogenesis takes place, either the W or Z is duplicated. This leads to eggs which are WW and ZZ. WW eggs are not viable, but ZZ eggs are, and lead to male baby Komodo dragons. The mother would be able to switch back to sexual reproduction and she could create an entire population of her own by mating with her male offspring. But to ensure genetic diversity, it is better to look for a mate which is not her offspring.
The New Mexico whiptail is one of few species that has only female members. This animal, which is also the state reptile of New Mexico, reproduces solely through parthenogenesis, and males have become obsolete.


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 Post subject: Re: The mating game (QM)
Unread postPosted: Sun May 09, 2010 3:40 pm 
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:thumbs_up: :clap:

Yes. Two things that have been highlighted are both reasons why males plays an important role in the survival of species. Genetic diversity and divergent stages of life.

Species which eliminates the male tend to thrive for a short while under ideal circumstances, and then quickly go extinct as soon as something like habitat change or even a pathogen challenges this situation. Comparatively view species alive today have eliminated the males. The males role is to provide genetic diversity, which helps the species to adapt and face challenges which would otherwise eliminate the entire species.


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 Post subject: Re: The mating game (QM)
Unread postPosted: Sun May 09, 2010 9:17 pm 
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Mating can be deadly!

One insect female has a special nasty reputation in this regard. Who is she and what does she do to her partner?

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 Post subject: Re: The mating game (QM)
Unread postPosted: Sun May 09, 2010 9:26 pm 
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The female Praying Mantis, she eats her partner while copulating!


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 Post subject: Re: The mating game (QM)
Unread postPosted: Sun May 09, 2010 9:38 pm 
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The sex live of the praying mantids ladies is a cannibalistic pleasure. A male mantid, attracted by the smell of a female, creeps up behind her and copulates. Welldone! A male that approaches a female from the front may meet immediate death by decapitation, the female might bite off his head and dine on him as he continues to pass sperm into her body. Sometimes the female partially eats the male before he mounts her. In this case, the rest of the male climbs onto her and copulates – headless. Copulatory movements in mantids are controlled by masses of nerve tissue in the abdomen rather than the brain, so males can mate even when decapitated. But sexual cannibalism occurs only in a minority of the 1800 or so species of mantids.


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 Post subject: Re: The mating game (QM)
Unread postPosted: Sun May 09, 2010 9:41 pm 
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:thumbs_up: Follow up ... what evolutionary advantage does this offer the species?

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