The Chicken May Have Come Before the Egg 341
Muondecay writes "The age old question of which came first, the chicken or the egg, has been tentatively answered. The verdict? The chicken, or rather a key protein needed to form the shell of the egg. The protein, called ovocledidin-17, was known to be involved in binding calcite molecules that formed the shells, but the mechanism behind this was unclear until now. The protein acts as a molecular machine, binding to nanoparticles of calcite and guiding them to begin self-assembly of the shell. This gives tremendous insight for developing methods of nano-scale self-assembly based on natural processes, as well as settling heated cocktail party arguments everywhere."
Re:2nd link is bad. (Score:5, Informative)
Re:Holy bad link (Score:3, Informative)
No the link target actually says cookie_setting_error.html
Pharyngula (Score:1, Informative)
No, it didn't. [scienceblogs.com] The Mainstream Media sucks at reporting science :\
The egg came first.. (Score:3, Informative)
Chickens are by definition born of an egg. EVERY chicken ever lived did. So, the egg came first. What gave birth to that egg was not 100% chicken.. So Say I.
Re:Okay then. (Score:2, Informative)
Which is why egg shells seem to stay at the apparent hardness they have now, without getting any harder (or softer) on average. Too hard and the chick can't peck it's way out, too soft and the egg breaks too easily... Also, many birds have a "tooth" on their beaks when they're at the hatching age, evolved to help them hatch from the shell. It's called selection pressure [wikipedia.org]
Re:Article is flawed. Egg came first. (Score:5, Informative)
You haven't got the memo about epigenetics and RNA yet, huh? Sorry, you're actually incorrect. Some of how you experience life does in fact get passed along to your offspring... well, it does if you're one of those few lucky Slashdotters to wean yourself off of here and WoW and escape Mom's basement and find a woman with low standards and all that.
Re:Article is flawed. Egg came first. (Score:5, Informative)
Life forms do not mutate/evolve/ during their lifespan; the mutations occur at the DNA copying phase when they are creating the next generation.
VZZZZZZZZZZZZZZZZLA
Additionally, your body is fixing DNA problems (not always correctly) all the time due to sun damage, free radicals, heavy metals, oxygen, and other nasty everyday stuff. I would actually say that even at birth, it's unlikely that any two cells in your body are alike in terms of the DNA they contain (except red blood cells...). They differ by a [usually] small, insignificant amount, but they'll still be different.
Re:Ignorant (Score:5, Informative)
Ask and ye shall receive, from an Evolutionary Biologist, no less: http://scienceblogs.com/pharyngula/2010/07/chickens_eggs_this_is_no_way_t.php [scienceblogs.com]
(PS, the research says not what the article promotes)
Re:Me fail logic? That's purple! (Score:5, Informative)
What came first? The molecule or the cell? The prion or the virus?
Not sure if you want real answers to those or not, but obviously the molecule, and evidence suggests the prion. However, with prions your question doesn't quite make sense because it's not like viruses descended from prions. Prions are simply "rogue" proteins which force proteins that they come in contact with to conform to the same secondary structure (usually beta folded sheets). It is thought that amino acid chains probably formed (perhaps without any necessary "function") early during the origin of life, and were quite possibly prion-like. Here's an interesting paper about it:
Milner-White, E.J. & Russell, M.J., 2008. Predicting the conformations of peptides and proteins in early evolution. Biology direct, 3, 3. Available at: http://biology-direct.com/content/3/1/3 [biology-direct.com].
And, obviously, since molecules are required to make cells (as cells are made up of molecules), the molecule would have to come first. There are some hypotheses about the origins of life suggesting that it is possible that most or all of of the biochemistry of early cells were in place before they even became cells. Here's a good starting point read about that:
Martin, W. & Russell, M.J., 2003. On the origins of cells: a hypothesis for the evolutionary transitions from abiotic geochemistry to chemoautotrophic prokaryotes, and from prokaryotes to nucleated cells. Philosophical transactions of the Royal Society of London. Series B, Biological sciences, 358(1429), 59-83; discussion 83-5. Available at: http://rstb.royalsocietypublishing.org/content/358/1429/59.abstract [royalsocie...ishing.org].
Anyway, like I said, don't know if you were looking for possible answers to those questions, but I'm bored, and these papers are pretty interesting. ;)
Re:Fossil Record (Score:-1, Informative)
Since Dinosaurs became extinct well before Christ, the answer is simple of course, to wit: "Nothing; there was no Christmas"