- "International Genetic Technologies had succeeded in their design - to genetically recreate the dinosaurs. It was an unprecedented accomplishment - the pinnacle of 20th century science. A work to rank with the achievements of Galileo or Einstein."
- —John Hammond(src)
The motor behind the extreme popularity of the movie Jurassic Park was beyond doubt how real the dinosaurs looked. Created to look flawless on 35mm (a medium with higher quality than any digital camera to date) the dinosaurs retain their splendor and reality even on today's HD viewing systems and digital screens.
However, what really triggered a real scientific debate about Jurassic Park was the explanation why in the movie humans and dinosaurs coexist. In all Jurassic Park media dinosaurs are recreated by the scientists of InGen. The dinosaurs are cloned using paleo-DNA from either bones or the gut of mosquitoes in amber.
The protocol is explained below in more detail.
For cloning dinosaurs, a complete set of dinosaur-DNA is needed. This DNA can be created if the genetic code is known. There are two sources of dinosaur-DNA.
Proteins can be extracted from dinosaur fossils. From the protein code the corresponding DNA code can be deduced. Most of the protein-coding DNA (genes) can be discovered in this way.
However, most of a creatures DNA doesn't consists only of genes. In birds (avian dinosaurs) genes cover only ~4% of the genome. Therefore another source is needed.
The scientists extracted DNA from blood cells in prehistoric mosquitoes. These mosquitoes were trapped in amber. Therefore both the insect and the blood were perfectly preserved. Since the DNA is so old, it has to be repaired. Sometimes even DNA from other species has to be added to complete the code.
The complete set of DNA is added to an emu or ostrich ovum. In 1 out of 1000 trials this ovum will grow into a functional dinosaur.
Academic response Edit
There was a large response from the academic world on Jurassic Park. Most of the scientists said that it is impossible to clone dinosaurs; at least with contemporary technology.
NOVA dedicated the entire episode The Real Jurassic Park to discuss the Jurassic Park protocol.
In 1997 scientists DeSalle and Lindley wrote the book How To Build A Dinosaur. This book explains every step in the protocol in most detail. They conclude that this project would be very expensive and difficult; but not impossible.
In 2008 Grazier (PhD) and other scientists published the book The Science of Michael Crichton. In this book each chapter discusses the science in a novel of Michael Crichton. On page 69-84 the chapter We still can't clone dinosaurs discusses the science behind the novels Jurassic Park and The Lost World. It is written by Sandy Becker.
In 2010 Jack Horner published the book How To Build A Dinosaur: The New Science Of Reverse Evolution in which he explains his project to create dinosaurs. Horner mentions the protocol in Jurassic Park many times in his book. He concludes that it is impossible to create dinosaurs a la Jurassic Park. Therefore he proposes an alternative. Horner explains that a common chicken is a descendant of raptors. Therefore, if you change their gene expression they will regain their older characteristics. Horner wants to create a Chickenosaurus: a chicken with a tail, hands with claws and a fleshy mouth with teeth.
Apart from publications, there are many blogs on personal or academic websites arguing for or against the possibility of this scenario. However, there is no consensus about this topic.
Here are two video's arguing for and against the possibility to clone dinosaurs:
How to build a DinosaurEdit
The protocol to clone dinosaurs, as it appears in the original novels and the films, contains a couple of steps. The starting point is to find media that could contain dinosaur DNA. The DNA has to be sequenced, completed, replicated and inserted back into an egg cell that could read the dinosaur DNA. The embryo has to grow into a living dinosaur.
Additional steps that have been proposed by scientists are also covered.
Building blocks of Life Edit
To create dinosaurs you need a blueprint of the animals. From the many skeletons that have been discovered we can have a reasonable picture of what the animals looked like; but that isn't enough to rebuild the animals. We need know the genetic code of the dinosaur DNA in order to grow them.
- DNA: This article explains what DNA is.
- Dinosaur DNA: Dinosaur DNA sequences in JP media and real sequences.
In the Jurassic Park stories there are multiple sources of genetic information of dinosaurs.
Almost all of our knowledge about dinosaurs is based on their fossil bones. Paleontologists long assumed that all organic content of the bones was replaced by minerals during the fossilization.
More information: Proteins in bones.
However, even now, dinosaur bones can contain soft tissue and proteins. Jack Horner's team was the first to discover and sequence proteins from a Tyrannosaurus rex bone. After that discovery soft tissue has been discovered in other fossils. The protein code can give a glimpse of what the DNA code looked like.
In the novels John Hammond had started a laboratory called "Medical Biologic Services" in Salt Lake to extract the proteins from dinosaur bones.
More information: DNA in bones.
In Jurassic Park: Operation Genesis DNA can be extracted from fossil bones. Multiple scientists have indeed claimed to extract DNA from dinosaur bones. However, most scientists believe DNA can't last 65 million years in bones. The discovered DNA could be contamination.
More information: DNA in Ice.
Ice and permafrost are the best media to preserve DNA. Prehistoric DNA of Mammoths and humans has been preserved in ice. In Jurassic Park: Builder the DNA of prehistoric sea creatures] can be found in frozen leechlike parasites. Although there existed ice sheets in the Mesozoic Era, all of that ice has been lost to the oceans. The oldest known ice sheets are only 8 million years old. Therefore, it is unlikely that Mesozoic DNA can ever be recovered from ice.
In most Jurassic Park media dinosaur DNA is found in prehistoric amber. Amber is fossil tree resin that has hardened during fossilization. Amber is able to perfectly preserve the tissue of plant and animal tissue that got stuck in the resin when it was fluid.
Most dinosaurs were too large to get stuck in tree resin. John Hammond reasoned that dinosaur blood could end up in amber through parasites.
- "What if a mosquito sucked the blood of a dinosaur, one hundred million years ago?"
- —John Hammond(src)
In the prehistoric era there were mosquitoes and other parasites that fed on the blood of dinosaurs. Blood contains red and white blood cells, which contain DNA.
If a bug landed on a tree, just after biting a dinosaur, it could get stuck in the resin. Resin will turn into hard amber, which mummifies and preserve the insect through millions of years, but also the blood cells.
Because amber could contain DNA, John Hammond bought amber mines around the globe. InGen and the Hammond Foundation had built up the world's largest stock supply of Amber by 1989.
More information: DNA in Amber
It is a matter of fierce scientific debate whether DNA can survive in amber for more than 65 million years. Some scientists have extracted DNA from prehistoric insects, but they have been met with general skepticism from their peers.
More information: Extracting the DNA.
The dinosaur DNA is inside the blood cells in the insects gut. The amber would have to be broken open to extract those cells. The cells have to be broken down to fish the DNA out of them.
Complete the code Edit
When dinosaur DNA, from any source, is extracted multiple steps have to be taken to investigate and complete the code.
The amount of DNA from the bones, ice and amber is probably to little for the investigation. The amount of DNA has to be multiplied in order to sequence it properly. Scientists generally use the Polymerase chain reaction to do this.
More information: DNA sequencing.
When large amounts of dino DNA have been made, the DNA can be sequenced. The order of the DNA's subunits (A, T, C, G) will be revealed.
The DNA from the amber is probably broken down in small pieces. The next step would be to reassemble the DNA fragments. Now that the code is known, computers can identify the overlapping regions in the pieces. In this way the tiny pieces of code can be reassembled.
Filling the gapsEdit
More information: Filling the sequence gaps.
The DNA code (from the same dinosaur species) from bones, ice and amber could be united in a single set. However, it is very likely that large parts of the dinosaur DNA is still missing. Large parts of DNA are probably lost because it is too old.
Therefore, Hammond's chief geneticist Henry Wu used DNA from other creatures to fill the gaps. The most obvious choice would be to use the DNA of dinosaur's closest extant relatives, namely Crocodilia and birds (all three belong to the Archosaur clade). In the novels Wu also used DNA from birds, mammals, reptiles and amphibians. In the film only frog DNA is mentioned.
New chromosomes Edit
More information: DNA synthesis.
From the previous steps a digital version of the dinosaur genome is created. Now the scientists have to synthesize this code. Currently, DNA can only be created using the Oligonucleotide synthesis process. The creation of entire chromosomes (which are millions of nucleotides long) is impossible at the moment. However, there is no reason that it will never be possible.
More information: Testing genes.
When dinosaur genes are determined from DNA from either bones, amber of gene comparison, it is unknown if those sequences are really functional. There are many sources of errors in the sequences. A single error in the sequence can make a gene non-functional. However, the common practice to test a gene is to insert it into a group of cells (Transfection). When the gene is successfully built into the genome of the cells, the gene's functionality can be tested. Dr. Chang and his team successfully used this method to test a Triassic archosaur gene.
More information: Creating chromosomes.
Cloning is impossible with the naked DNA that is produced by the DNA synthesizers. The naked DNA needs to be winded around various proteins to form Chromosome. Among these proteins are histones and Scaffold proteins.
Pieces of naked frog DNA can bind histones and form functional chromatin if exposed to histones.
More information: Creating a nucleus.
Before the dino DNA can be injected into a new cell, the DNA must be encapsulated in a nucleus. The main structures making up the nucleus are the nuclear envelope, a spherical membrane that encloses the entire DNA, and the nucleoskeleton, a mesh work within the nucleus that adds mechanical support. The nucleus also contains a many sub-nuclear bodies.
In a particular phase in cell division, the cell creates a nuclear membrane around chromosomes. A cell (or medium) could fooled to build a nuclear membrane around the artificial chromosomes.
More information: Dinosaur mitochondria.
The energy of cells is produced by small organelles called Mitochondria. These are the ones that need the oxygen we inhale. Mitochondria have their own set of DNA. The mitochondrial DNA of the cell has to be compatible with the DNA in the dino nucleus.
By comparing the mitochondrial DNA sequence of extant archosaurs (birds, crocodiles, turtles) an educated guess of the dinosaur sequence can be made.
More information: Cloning dinosaurs.
The dinosaur nucleus has to be transferred into an unfertilized egg cell containing the right mitochondria. Only 1 in 300 translocations will be successful. When the egg accepts the nucleus a small electric shock will start cell division.
More information: Growing embryos.
The embryo has to be inserted into an egg. In the novels artificial plastic eggs with crocodile yolks were used. In the Jurassic Park film ostrich or emu eggs were used. In Jurassic Park III it is shown that for some species only incubators were used.
In many real-life cloning programs chimeras are created of the endangered species and a common species. The resulting creature will have features of both species. In some chimeras the reproductive organs are created from cells of the endangered species. Such chimeras could lay dinosaur eggs, which are better for growing dinosaur embryos.
Henry Wu made some modifications to the dinosaurs.
- Gender control: all dinosaurs are female. This prevents them from reproducing.
- Lysine contingency: dinosaurs are unable to produce the amino acid Lysine. This prevents dinosaurs from surviving outside of InGen's facilities.
- Wu planned to make the dinosaurs slower and less aggressive.
Creating a Lost WorldEdit
More information: Creating a Lost World.
Books and films that only give a documentation of dinosaurs seldom become as popular as books and films in which humans and dinosaurs meet each other. As a result, authors that make stories in which dinosaurs and humans coexist have to give an explanation how such a thing is possible.
The first story in which humans stumble upon a prehistoric reptile was Jules Verne's 1864 novel Journey to the Center of the Earth. Deep under the surface of the earth the explorers see a giant Ichthyosaurus, which fights with a Plesiosaurus and wins. Later, in 1912, Sir Arthur Conan Doyle wrote the novel The Lost World. In this story a group of explorers travels to a plateau in South America where (due to isolation from the rest of the earth) time and evolution have stand still for millions of years. Dinosaurs and other prehistoric animals still live on that plateau.
Both these stories became very popular and film adaptations of these stories have been made many times. But in both stories the explanation why humans and dinosaurs coexist is that, although dinosaurs disappeared everywhere on the planet, somewhere on or under the earth are small "lost worlds" where they still exist. In Conan Doyle's day, you could think of South America as a mysterious, unknown place, where ancient beasts and wonders might well await the determined explorers. But in modern times the entire globe (including ocean floors) has been mapped, and if dinosaurs would still live somewhere they would have been discovered (though the world has been mapped, it hasn't been entirely explored). Furthermore, all hollow earth hypothesis have been rejected by the scientific community. Therefore, all stories that use a lost world explanation for the coexistence of humans and dinosaurs are truly fiction, nothing more and nothing less.
A very straightforward solution for the coexistent problem would be time traveling. Humans could travel 65 million years in time and walk between dinosaurs. This solution is used in Steven Spielberg's TV series Terra Nova. Time travel also appears in Michael Crichton's novels Sphere and Timeline.
Scientific theories do not exclude the possibility of forward or backward time travel, but for anything bigger than an electron currently time travel may not be possible. Therefore a story with a time travel explanation isn't very convincing for the general public or scientists.
A lot of popular dinosaur movies from the 60s and 70s of the last century take place in the Mesozoic ages and portray the humans as living at the same time. These kind of ancient humans appear in films like One Million Years B.C. and When Dinosaurs Ruled the Earth.
Although there are a few reports from the 19th century of human fossils in strata that are currently classified as tens of million years old, the scientific consensus is that the first humanlike primates appeared only 2.4 million years ago and can't have lived alongside the dinosaurs.
In the Jurassic Park novel, and six years earlier in the novel Carnosaur, dinosaurs live in the modern world because scientists have been able to acquire fossil DNA of dinosaurs. Using this DNA they were able to clone the creatures.
This scenario has also been criticized by scientists. However, it is the most realistic explanation in this list.
"The lack of humility before nature that's been displayed here staggers me. " - Ian Malcolm
More information: Ethical issues of cloning dinosaurs.
In the novel and film Ian Malcolm is the main antagonist of cloning dinosaurs.