Wednesday, June 9, 2010

How to Build a Dinosaur


This is one of those rare cases where I actually bought the book because of its cover and without knowing anything it. Imagine standing there watching an egg hatch and seeing a dinosaur claw sticking out. Would you run away screaming in horror thinking of the book/movie Jurassic Park or their sequels? I thought of all these things as I paid for the book and brought it home.

Jack Horner's book was above my head at points because my background in dinosaurs and biology is slim and what little I have has been limited to high school text books. But I was fascinated with this book the entire way through and feel I have a pretty good handle on the future of paleontology. It's can be a quick read, coming it at only 216 pages, but I chose to read it just a few pages at a time, absorbing the material as I went.

Horner's book starts out with a mind blowing suggestion of turning a chicken into a dinosaur and how fairly simply it would be. If you were to look at the skeleton of a modern chicken and that of a t-rex, you would see little difference besides scale. Sure one has teeth, a tail and hands instead of wings but did you know that chicken have already been modified to grow teeth? Chickens already have tails and hands during early embryonic stages but genetic coding prevents the tail from forming completely and the hands merge into wings. With a few tweaks, you could end up with a miniature t-rex and with one additional tweak, a full scale version.

Having set the hook with those assertions, Horner steps back and give a brief history of paleontology as it has progressed through the years. It began with the comparison of dinosaur bones and trying to make estimates of evolution by comparing them along the length of the fossil record to the modern more scientific approach of labs and microscopes where we can now identify if that particular dinosaur was pregnant by just looking microscopically at the inside of the bones. Already, they have been able to identify cells, veins, proteins and other structures within the bones that are shedding light into the age of dinosaurs.

Actually saying dinosaurs are extinct is not correct. Dinosaurs still live around us in forms of birds, reptiles and even mammals. Ninety percent of all species that used to live on this planet are extinct and 25 more go extinct every single day. These extinctions of single species merely allows the remaining species to thrive in different ways. Mammals were around with the dinosaurs but when many of them went extinct, they were able to multiply and thrive so now, we are the dominate species, while other dinosaurs like birds, crocodiles, turtles and such remain in the background.

Much of the book is spent on the T-Rex which was actually a bird and not a reptile as I would have guessed. Horner spends a lot of time laying out evolution not in terms of the classical tree we are all familiar with where a particular species begat numerous other species, but in an entirely different manner. His preferred method of laying out evolution is in terms of anatomical features. How has the feather developed over the years, the tail, the teeth, etc. By laying these out, we get a more accurate picture of evolution and don't waste effort searching for a fossil that may or may not ever be found to prove the original ancestor of many branches of the classic tree. Scientists used evolutionary development or evo-devo of the ordinary feather to determine that there was an ancestor of modern birds that simply contained hollow tube like structures that were the precursor to the classic feather development. Sure enough, somewhere in China less than a decade ago, a fossil record of just such an animal was found proving the method.

This method of evolution development provides the backbone for the second half of the book and the backing for Horner's desired experiment, to build a dinosaur. Rather than take a page from Hollywood and trying to find DNA that has survived hundreds of millions of year, something Horner feels is not likely to happen, Horner thinks more can be gained by taking the ordinary chicken and rewinding evolution to the point where a dinosaur can happen but in a very scientific manner. He stresses that this is not gene manipulation or engineering since the dinosaur, if ever created, will still have the identical gene set of the ordinary chicken. Instead, they will control what proteins are exposed to specific genes at specific times and in specific levels to allow the gene to function as it would have hundreds of millions of years ago when creating a dinosaur. Research has already created teeth in chickens and are close to creating a tail. Horner seems to imply that within our lifetimes, they will have the information necessary to create a dinosaur.

This brings me and Horner's book to the ethical dilemma of creating a dinosaur. Horner points out that by using chickens, billions of which are raised and killed for our consumption every year, that scientists would have the same ethical concerns as say the supplier for Kentucky Fried Chicken. Mainstream society has already accepted genetically modifying mice for testing purposes for everything from cancer to schizophrenia and his method of creating a dinosaur wouldn't even be nearly as radical since he isn't modifying genes. If such a dinosaur were created, it wouldn't pose any threat if it were to reproduce with another chicken because with its chicken genes, it would merely produce more chickens. Even if a whole family of these chicken built dinosaurs were to escape into the wild, all they would produce for offspring is our average, ordinary, everyday, chicken. The biggest hurdle would be perhaps our personal safety with a full sized T-Rex (albeit with the genes of a chicken) roaming around but a solution to containment is a fairly easy hurdle to jump.

I do think Horner places too much faith in rational thinking of the American people and perhaps more importantly the American press when it comes to the ethical issues. Though I agree with his argument that what he proposes is no less ethical than what we already do in the chicken industry, I don't think the bulk of the American public (disregarding my highly rational thinking readers of this blog) would feel the same. I think all we would see are continuous headlines along the lines of "Genetically Engineering Dinosaurs" which would be a flat out lie.

After reading this book, I feel that there will be a huge future in using lab science to rewind evolution in a provable way. I also think that a chicken dinosaur will probably occur in my lifetime, if not done here in America, somewhere else in the world. When it happens, I don't think I will be afraid for our future as I might have been had I not read this book and only read the media reports after the fact. Instead, I will be one of those who will be marveling at how far our understanding of science has come to allow us to do such a thing and wonder how many problems or diseases we might be able to solve with this knowledge to allow our species to not go extinct anytime soon. But perhaps curing diseases is playing God?

9 comments:

R. Sherman said...

Biological "reverse engineering" is not unknown, especially in agronomy. At Mizzou, one of the more famous professors successfully replicated the original "wheat" grass, which was crossed with other grasses by the ancients to get what we know as "wheat." The same has been done with corn. It's a far fetched to think that such a thing would be possible in the field of animal husbandry.

Perhaps Beau, the Mizzou biologist, would be better able to answer those questions.

Cheers.

R. Sherman said...

As it happens, I see this today in the NY Times.

Cheers.

Ed said...

R. Sherman - I have no problems doing these things with plants/animals that are infertile but it scares me a bit when we start creating fertile stuff. I have visions of kudzu with four legs and very sharp teeth.

By the way, that linked article was a-maize-ing. Sorry for the bad joke.

PhilippinesPhil said...

Terror chicken a saurous? No offense Ed, but I liked this post more for Mr Sherman's agronomical reference and read with great interest the NYTimes article on the newly discovered origins of corn. This excerpt from Wikipedia on Teosinte, the genetic progenitor of maize, hit a chord with me:

"...In some areas of Mexico, teosintes are regarded by maize farmers as a noxious weed, while in a few areas farmers regard it as a beneficial companion plant, and encourage its introgression into their maize.." VERY interesting, eh?

Beau said...

Excellent review. The claw indeed looks just like that of my chickens. Interesting point regarding ethics in terms of chickens, but I agree that he expects too much in terms of rational thought, at least for now. As for my biology expertise... it was a long time ago :) I see no reason to doubt however that the promises of genetic engineering will assist in mitigating many forms of human/anmial disease.

The corn/maize history is amazing... but of more relevant interest, I think we'll see continued debate re. the use of GMO products. And that will be a crucial debate because there are many unknowns in terms of human/animal health based on genetic modification of proteins/amino acides of agricultural products.

Murf said...

I'm sure ever since the Jurassic Park the movie came out (not the book, I don't think these kinds of guys read), some crackpot is working on this in their parents basement. I'm all for signing "Newman" up to join the group though.

Ed said...

Phil - Growing up the son of a corn farmer, I really enjoyed Sherman's article too.

Beau - I often struggle with the ethics of curing diseases. By eliminating the principles of Darwin, are we setting ourselves up by creating a species that doesn't evolve because everyone lives? Or perhaps worse, everyone lives longer so that overcrowding becomes such an issue that we live in horrid conditions? But I also understand the flip side having watched a few friends and family die of terrible diseases such as cancer.

Murf - Actually, I don't think these guys probably watch movies. I think all they do is read, do their job and write books on the subject.

Three Score and Ten or more said...

Fascinating. I will run your review past my daughter (Environmental Biologist, now working for the U.S. army to keep them from blowing up too many trees and species in training, but formerly of the Chicago Zoo, and a few other things.)
I will be interested in her reaction.

TC said...

Wow. I'm not sure what to think. At the very least, it sounds like the book was worth the money.