Battle of the Sexes and males lost

It seems one species of animal has won the battle of the sexes. The New Mexico Whiptail Lizard (Cnemidophorus neomexicanus ) is now only female all males have gone extinct




You might think the loss of all your males would doom your species but not for the Whiptail . The New Mexico Whiptail, as well as several other all-female species of whiptail lizard, does reproduce, and all of its offspring are female. Moreover, it reproduces by parthenogenesis -- its eggs require no fertilization, and its offspring are exact and complete genetic duplicates of the mother.

So the females make clones of themselves. The females even still have mock sex with other females mounting other females. This is thought to stimulate the female into laying eggs even though no real sex takes place.

Scientists understand only partially how this reproductive mode developed, and it raises many questions. One of the most intriguing is how this cloning affects the lizard's ability to adapt to environmental changes. Since there is no genetic variation except that which occurs through mutation, the New Mexico Whiptail cannot evolve as other species do.

Now you might think some little all female lizard does not mean much to you or I, but consider this. For a human male to be made it requires both a X and Y chromosome and a Female is created with X,X.




Heres a picture of a X and Y chromosome. The Y chromosome is much smaller and only contains a fraction of the genes. The X has about 1,000. Today, the Y chromosome has less than 80 genes.But long ago they were both the same size. Researchers have found that, over the millennia, the Y chromosome has lost most of it genes. Some Researchers think that this is still going on today and in time their will be no Y chromosome. Some even think it could happen in as little as 150,000 years.

No Y chromosome would mean no more human males



www.amnh.org... expeditions/treasure_fossil/Treasures/Unisexual_Whiptail_Lizards/lizards.html?50

www.npr.org...

www.iht.com...

[edit on 8-2-2005 by ShadowXIX]

It seems that if all of the lizards are genetically identical that their survival chances are tenuous.

Doesnt look like we'll see the whiptail for very long. I dont see how it could survive. Maybe God hates it and wants it to die.

Now that's evolution at work! All the genes are going to be exactly the same, making it a very weak species, but they figured on humans! The species will be protected and a weak species that nature would normally take out of the mix will survive because of humanity!

ShadowXIX fascinating post.

Since there is no genetic variation except that which occurs through mutation, the New Mexico Whiptail cannot evolve as other species do.

Perhaps the Y chromosome is a mutation ?
maybe not because that would mean Im a mutation. Perhaps we dont understand as much about the reproudcation process as we think.

I have to aggree this is a great post. Intresting read also. I had no Idea that a species could survive like this or that it was even possible.

Well.... bacteria reproduce a-sexually, and they evolve. New strains of bacteria different enough to be considered a different strain (species essentially) come up pretty often. So technically... this creature would no longer evolve "as other species do" but it could still evolve. If a whiptail had an offspring with a mutation that caused it to be superior to the others and yet very different, it could technicaly become a new species... it would actually be more likely in my eyes to evolve than other species with both males and females... BECAUSE....

If you had a mutation that caused a third arm to grow out of your head, EVEN THOUGH the mutation might make you better equipped... you can hold more things, reach higher, etc... the odds that you'd be chosen by a woman to have children with isn't good at all... but if you could reproduce a-sexually like a bacteria... then that physical unattractiveness to a mate wouldn't matter... and the mutation could pass on... and would create more of the superior creatures... effectively different enough to be considered a different species. See what I mean?

yeh think of how many variations this could cause and i think we sould start adapting our selves as a species like more and more research what if this could happen to us! we need to start researching ALL genetics on our planet to become more adaptable to things like this some say that we are playing god but i say go for it if it means we can survive way into the future

great post

Originally posted by Greyhaven7
If you had a mutation that caused a third arm to grow out of your head, EVEN THOUGH the mutation might make you better equipped... you can hold more things, reach higher, etc... the odds that you'd be chosen by a woman to have children with isn't good at all... but if you could reproduce a-sexually like a bacteria... then that physical unattractiveness to a mate wouldn't matter... and the mutation could pass on... and would create more of the superior creatures... effectively different enough to be considered a different species. See what I mean?

This would be true if the rate of beneficial mutations were higher than it is, but the vast majority of mutations are so minute that they aren’t even noticed and of those that are most are, like genetic disorders, either a hindrance to the organism or fatal. So for that kind of reproduction to produce new species successfully they would need an extremely large population

I know... refer to my other post here.

www.abovetopsecret.com...

Originally posted by Mizar
I had no Idea that a species could survive like this or that it was even possible.

Yeah I never knew that a vertebrate could reproduce like this until I saw a show on this interesting lizard. I have heard of some frogs that could switch between the sexes if there was a lack of one sex ''ala Jurassic Park'' But this lizard really seems amazing.

I think we can learn alot about long term cloning effects on generations from studies of this lizard, Which could be very interesting.


This stuff about the human Y chromosome got me thinking as well. Perhaps the Aliens people call the Greys are not infact aliens but Human from the future say half a million years. In their time the Y chromosome has all but disappeared and all Greys are female. They can only reproduce through cloning either with tech. or in a method like the Whiptail. So they have to come back into the past to get the Y chromosome and some how work it back into their own genes.

It might make a good story for a book atleast

All in all sexual procreation may be "fun" for higher order primates but it still makes a series of squelching sounds* and it is quite inefficient.

LOL

* J. Lydon

For some weird reason this reminded me of this news story i saw today:

[url=http://today.reuters.co.uk/news/newsArticle.aspx?type=sportsNews&storyID=2005-02-09T101532Z_01_HOL936917_RTRUKOC_0_ODD-ZIMBABWE-ATHLETE.xml]Link[ /url]

HARARE (Reuters) - Zimbabwe police have charged a man with masquerading as a female athlete after he competed as a woman at several international sports events, the official Herald newspaper has reported.

disterbing


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On a more serious note:

Since there is no genetic variation except that which occurs through mutation, the New Mexico Whiptail cannot evolve as other species do.

Doesn't that mean its doomed as a species, a weather change would kill the species off in one go wouldn't it?

Originally posted by UK Wizard

Since there is no genetic variation except that which occurs through mutation, the New Mexico Whiptail cannot evolve as other species do.

Doesn't that mean its doomed as a species, a weather change would kill the species off in one go wouldn't it?

Perhaps a single disease could wipe out the whole lot of them. But they seem to be doing ok for now. I guess the rate of mutation would be very important, I wonder if repeat cloning effects the rate of mutation compared to a lizard that reproduces in the normal way.

Originally posted by UK Wizard
Doesn't that mean its doomed as a species, a weather change would kill the species off in one go wouldn't it?

I would think they're all relatively different at this point... each individual has genetic variations from the past... I mean when all the males died out, there probably wasn't just ONE female left, but several, if not butt loads of them... each different in it's own way. So if an environmental change occurs, there are likely to be those who could survive it... and they will then reproduce and become the new future of the species.

thats a really wierd thing.........................Lets hope that doesn't somehow happen to us(humans)

Kushi_Master