We're all 'upside down'.

 
From World Science, interesting stuff:
 

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Humans may be “upside-down” with respect to jelly ancestors
 
Feb. 22, 2013
Courtesy of the University of Vienna and World Science staff
 
The ev­o­lu­tion­ary or­i­gin of the head is trace­a­ble to a brain­less or­gan usu­ally con­sid­ered the “foot” of crea­tures re­lat­ed to jel­ly­fish, sci­en­tists re­port.

Re­search­ers found that the same genes that con­trol head de­vel­op­ment in high­er an­i­mals gov­ern the de­vel­op­ment of the front end of the swim­ming lar­va, or ju­ve­nile form, of a sim­ple, brain­less sea anem­o­ne. This front end be­comes the so-called “foot” of the adult an­i­mal.
In many an­i­mals, the brain is lo­cat­ed in the head, to­geth­er with sen­so­ry or­gans and of­ten the mouth. But there are dis­tantly re­lat­ed an­i­mals that have a nerv­ous sys­tem, but no brain, like sea anem­o­nes and corals.

The re­search group, led by Fa­bi­an Rentzsch of Sars Cen­tre in Ber­gen, Nor­way and Ul­rich Tech­nau from the Uni­vers­ity of Vi­en­na, set out to find if one of the ends of the sea anem­o­ne cor­re­sponds to the head of high­er an­i­mals. The sci­en­tists stud­ied the func­tion of genes that con­trol head de­vel­op­ment in high­er an­i­mals dur­ing the em­bry­on­ic de­vel­op­ment of the star­let sea anem­o­ne.

“De­spite look­ing com­pletely dif­fer­ent, it has be­come clear over the last dec­ade that all an­i­mals have a si­m­i­lar rep­er­toire of genes, in­clud­ing those that are re­quired to make the head of high­er an­i­mals,” said Tech­nau.

The study is pub­lished in the jour­nal PLoS Bi­ol­o­gy.

When the sea anem­o­nes are in the lar­val, or ju­ve­nile, stage they swim and search for a suit­a­ble site to settle and met­amor­phosize in­to a form called a pol­yp. Dur­ing this pro­cess, the front end of the lar­va senses the en­vi­ron­ment and at­taches to the ground. The oth­er end be­comes in­to the “oral” side of the an­i­mal with a mouth and ten­ta­cles for bring­ing in food.

The re­search­ers found that the lar­va’s front-end de­vel­op­ment is is gov­erned by a hi­er­ar­chy of genes, con­trolled by the “mas­ter con­trol gene” called Six3/6. No­ta­bly, this gene and genes that de­pend on it “down­stream” al­so play a cru­cial role in set­ting up the field for mak­ing the brain of flies, fish and men, Tech­nau and col­leagues ex­plained. Hence, the func­tion of the “head genes” is lo­cat­ed at the end that cor­re­sponds to the “foot” of the adult ane­mone.

“The an­te­ri­or end of the swim­ming lar­va car­ries their main sense or­gan, so at this stage it looks more like this might be their head,” said Rentzsch. In­deed, the “head genes” func­tion on this side of the an­i­mals, he added, yet they are not used to form a full brain.

Sea anem­o­nes and all high­er an­i­mals, in­clud­ing hu­mans, are be­lieved to share a com­mon brain­less an­ces­tor that lived be­tween 600 mil­lion and 700 mil­lion years ago. By re­veal­ing the func­tion of “head genes” in the anem­o­ne, the sci­en­tists be­lieve they now un­der­stand bet­ter how and from where the head and brain of high­er an­i­mals evolved. Def­i­nite­ly, they said, the gene net­work that formed a sen­so­ry cen­ter had evolved in this com­mon an­ces­tor some 600 mil­lion years ago.

“Based on the ap­pear­ance of the adult an­i­mals, the ab­o­ral [at­tach­ing] end of these an­i­mals has tra­di­tion­ally been called the foot and the up­per end the head, while in fact it is bas­ic­ally turned up­side down,” ex­plains Tech­nau. “Or we...” he added with a smile.

This does explain a lot of things.

What things I don't know, but it explains them

When does beer get introduced into all of this?

Hmmmm....BEER!!!

jamesg1213

SteveStrummerUK


a sim­ple, brain­less sea anem­o­ne.

Or the 'Noel Edmonds' as we like to call it.

And here I thought this was about pistolepete (or pistolpete as I see him; as I have him blocked).

slartabartfast


Of course the anemone does not just eat with the end sticking up from the rock, it also eliminates from that end. 

Given that view of life keeping your head up makes less sense. 

Yet that's exactly what so many politicians (and some members upstairs) emulate...

Ya, who's head is "up" right now anyway?  Steve's in the UK, or Jeff down under?

cclarry


I know a few here who's head is up...their....nevermind...

You mean, like this?
 

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