Birth as easy as 1-2-3: one woman, two wombs, three babies

[Buck503]

Originally Posted by AFP

Birth as easy as 1-2-3: one woman, two wombs, three babies

LONDON (AFP) - A British mother could get into the record books after she gave birth to twins and a single baby at the same time -- from two wombs -- in what is believed to be a world first.

Hannah Kersey, 23, gave birth to the rare triplets -- identical twins Ruby and Tilly, and singleton Gracie -- by Caesarean section seven weeks prematurely in September.

She was born with a condition called uterus didelphys, which means she developed two wombs, but doctors had warned her that she was unlikely to become pregnant in both.

for more: http://news.yahoo.com/s/afp/20061221...y_061221130325

[Robynbird569]

Glad I got one womb.

[Wise Young]

To me, the most remarkable part of this story is not that this occurred but rare such phenomena are. We seem to take it for granted that a woman has only one uterus, just like we take it for granted that we have only one heart, one liver, one spleen, one gut, one bladder, one penis or vagina, one brain, and one spinal cord. When it happens that we have two of something when there is only suppose to be one, it is astounding. But, how is it that our genes are so good at specifying only one of certain organs and two of other organs? There are very few instruction sets that are so effective. I imagine that despite the best efforts of highly paid engineers and graphic artists, IKEA cannot ensure that even 90% of its furniture are assembled in the same way. Yet, the presence of two organs where there should be one is an extremely rare phenomenon.

One possibility is of course that the presence of two organs is inimical to survival. This not only ensures that individuals with abnormal organ number do not survive to be observed but also that they do not survive to pass their genes onto offsprings. Fatal abnormalities are unlikely to go beyond the individual. But, we don't find a lot of dead fetuses with multiple organs. There is simply a very effective instruction set in our genes that a mistake in reading and implementing the genes is very very improbable. I once heard a lecture by Nobel Laureate Gerald M. Edelman who had received the prize in 1972 for deciphering the structure of antibodies. He was talking about the importance of cell adhesion molecules, many of which have structures similar to antibodies, and saying how incredible it was that a relatively small number of cellular adhesion molecules could encode such diversity of forms. I was just a young scientist then and poked my hand up to ask something that bothered me. I asked, how do cell adhesion molecules manage to implement such similarities of structures amongst individuals? For example, we can often recognize a son and father from the similarities of their features. Likewise, we often see identical twins who are so similar in appearance that even their mothers may have trouble telling them apart. How is it possible to encode such detail so precisely?

Edelman was very kind. He skirted my question gently without telling me that I am just dumb. But, to date, I have not been able to answer the question adequately. The one example that I give to my students is the decussation of corticospinal tracts. As most people know, our left side of the brain controls the right side of the body and vice-versa. In order for this to happen, the pathways from the brain to the spinal cord must cross over. The best known of these crossovers is called the pyramidal decussation where millions of axons from the brain cross over to the other side. The problem is that millions axons from the left brain cross to the right side while millions of axons are crossing over from the right brain to the left side, all in the same space. How can the axons tell that they are from the left or right side of the brain? It is sort of like having two Thanksgiving day parades heading down on either side of Central Park and they cross over on 59th street and none of the parade-walkers make a mistake. This occurs in billions upon billions of animals without mistake. How can such instruction be encoded and enforced with such absolute certainty (i.e. with no mistakes) over and over again? It is one of the most amazing wonders of the biological world.

Wise.

[antiquity]

How can such instruction be encoded and enforced with such absolute certainty (i.e. with no mistakes) over and over again? It is one of the most amazing wonders of the biological world.

Some would say God, I say fractal geometry.

[Lindox]

Wouldn't this be the same as a two headed calf being born and surviving.
Or people that have three nipples. As long as the organ involved didn't have a detrimental effect on the operations of the body whole.

I don't see where two uteruses would have an effect on survival where two hearts fighting each other well..
Or two brains trying to survive in the space of one head. Or two livers with one going totally toxic.

My guess about all the axons traveling around in our brains and how they stay on course is the same reason we breath in and out. We are programmed to do such.
And unless the program gets a virus or becomes somehow mutated or changes it's channel well it just continues on.