Posted on 11/03/2007 7:44:49 PM PDT by 49th
The chicken egg has been prepped for surgery – a pea-size hole cut in the shell and covered with sticky tape. And now Hans Larsson, a McGill University researcher, removes it from the incubator, places it under a microscope and prepares to operate.
He gently peels off the tape and teases back the membranes that line the shell with tweezers. Through the eyepiece, he can see the tiny dot of a heart, steadily beating. He can also see the bud where he implants a milky bead doused in a protein. He hopes it will coax the embryo to grow a big tail. A dinosaur-like tail.
paleontologist, Prof. Larsson spends a significant portion of his time doing traditional dinosaur hunting, digging fossils as far afield as the Arctic and Africa with jackhammers and pickaxes. But he has long been frustrated with the limitations of studying old bones and what they reveal about the mysteries of evolution.
It was by examining ancient skeletons that paleontologists learned that modern birds, including chickens, descended from dinosaurs and that their relatives include such fierce predators as Tyrannosaurus rex. What fossils don't reveal, though, is how exactly such dramatic anatomical changes first arose. How did teeth the size of bananas turn into beaks? Or mighty tails become wimpy, feathered stumps?
For answers, Prof. Larsson has turned to the burgeoning field of evo-devo – or evolutionary developmental biology – a radical new approach to understanding the past.
It is based on the astonishing discovery that modern animals, including humans, share many of the same body-building genes and that some of these genes have been around for millions of years.
(Excerpt) Read more at theglobeandmail.com ...
I'm not sure what your point is. You taking issue with common descent? The junglefowl, like all organisms everywhere on earth, descends from a phylogenetic tree going back nearly 4 billion years.
I like where you're going with this!
What’s that supposed to mean? :p
Okay. Now we got the egg coming from a junglefowl which came from a tree. Where did the tree come from?
It's a metaphorical tree.
Where did the tree come from?
The tree is a function of speciation and extinction.
LOL
It means that the article is very long on speculation, supposition and opinion and very short on scientific achievement or progress.
It came from the Tree of Life website, of course. Here is their page on genus Gallus, just in case you really do want to trace it back to the prokaryotes. And here is a page written from an Intelligent Design perspective, if you'd rather read that. I endeavor to present both sides of an argument when real debate exists.
So, the tree became an egg and then went extinct? Still doesn't explain where the tree came from.
And here is the Biblical account of creation:
http://www.biblegateway.com/passage/?search=Genesis%201&version=9;
Big difference between Intelligent Design and the Biblical account of creation.
You forgot your sarcasm tag.
placemarker
Dr. Ian Malcolm warned us about this
Hens’ teeth not so rare after all
Scientists have discovered that rarest of things: a chicken with teeth – crocodile teeth to be precise.
Contrary to the well-known phrase, ‘As rare as hens’ teeth,’ the researchers say they have found a naturally occurring mutant chicken called Talpid that has a complete set of ivories.
The team, based at the Universities of Manchester and Wisconsin, have also managed to induce teeth growth in normal chickens – activating genes that have lain dormant for 80 million years.
Professor Mark Ferguson, one of the scientific team at the University of Manchester, says the research – published in Current Biology this week – has major implications in understanding the processes of evolution. It could also have applications in tissue regeneration, including the replacement of lost teeth in humans.
“The mutant bird has severe limb defects and dies before it can hatch,” explained Professor Ferguson, who is based in the University’s Faculty of Life Sciences.
“It was discovered 50 years ago but no one has ever examined its mouth. What we discovered were teeth similar to those of crocodiles – not surprising as birds are the closest living relatives of the reptile.”
The discovery led the team to wonder whether healthy chickens might still maintain the genetic pathways to re-grow teeth.
“We found we were able to induce teeth to grow in normal chickens by making changes to the expression of particular molecules,” said Professor Ferguson.
“All the pathways to make teeth are preserved which helps us understand how evolutionary changes can be brought about by subtle alterations in developmental biology.”
Professor Ferguson says a direct application of the research could be in the re-growing of teeth in people who have lost them through accident or disease.
But the study has implications for tissue regeneration more widely.
“The principle of activating specific dormant pathways to stimulate regeneration instead of repair has made applications, to injury, surgery and human disease,” he said.
Indeed, building on previous discoveries of scar-free healing in embryos, Professor Mark Ferguson and Dr Sharon O’Kane founded Renovo, a spin-out company from The University of Manchester, which is developing novel pharmaceuticals for the prevention and reduction of scarring.
“Renovo now employs about 100 staff and is the world-leading company in researching and developing novel pharmaceuticals to prevent and improve scarring.”
http://www.eurekalert.org/pub_releases/2006-02/uom-htn022206.php
Perhaps. It's an inaccurate analogy, however.
DNA is not the "building material" of living things. DNA is the instructions for building (and operating) living things.
A much better comparison would be to the blueprints for building your house as opposed to The Donald's.
Shouldn’t you be working on your debate response? Or at least the next round?
I have no idea what you're talking about. The tree is metaphorical, as I stated above.
Metaphorical. Comparing a tree and an egg? Now that's funny.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.