Qualitative analysis on the possibility of genetically
cloning extinct dinosaurs from ancient DNA
ALEXANDER PATANANAN
Antelope Valley College
Lancaster, CA, USA
ABSTRACT
Dinosaur deoxyribonucleic acid (DNA) residues have been reportedly found in numerous
specimens throughout the world. These DNA samples were retrieved from a variety of sources
of preservation material including soft tissue remnants in fossilized bones in addition to bloodconsuming hexapods and chelicerates embedded in amber resin. It is probable that we can use
current cloning technologies to sequence the DNA derived from these specimens in the hope of
creating a genetically identical copy of the extinct organisms.
.
INTRODUCTION
Deoxyribonucleic acid is a double stranded molecule containing the hereditary material of an
organism. Guiding itself during cell replication and overseeing transcription of corresponding
ribonucleic acid (RNA) are its two main functions (Voet 1107). Despite this, the fact that it is
responsible for producing proteins, which controls almost every biological process, makes this
molecule one of intense interest in the creation of an organism. If preserved under the
appropriate conditions, DNA is one of the toughest bimolecules in existence. Possible sources of
moderate-to-highly preserved dinosaur DNA can be found in amber resin and fossilized
skeletons.
Blood consuming hexapods and chelicerates that have become trapped and embedded in amber
shortly after having fed upon a dinosaur have become a good source of possible dinosaur DNA.
Amber is an excellent medium for perpetuation for various reasons. First, it dries almost
immediately after being released from an angiosperm or gymnosperm. Amber resin rapidly
absorbs H2O molecules and incorporates them into its own atomic makeup. However, this does
not mean that insects encased in amber will be completely desiccated. In actuality, amber only
penetrates the outermost cell layers, such as the epidermis, thereby mummifying the rest of the
insect or whatever other organism is entrapped inside. Second, amber maintains an antiseptic
feature that preserves the remains of insects from decomposition due to bacteria. In addition to
its incredible durability, amber has a high probability of completely preserving organisms under
the appropriate environmental conditions (DeSalle12-13). This preservation extends to the
whole organism including its digestive tract and stomach, where possible dinosaur DNA may
exist. An example of amber preservation occurred in 1993 when scientists at the California
1 DNA and Dinosaurs
Polytechnic State University, San Luisa Obispo isolated 120-135 million year old DNA from
weevil preserved in amber. Although only a few hundred base pairs of DNA were recovered,
this finding indicated that DNA has the potential to last hundreds of millions of years instead of
just a few thousand years as had previously been reported (Brown, par. 17). Additionally, in July
of 1999, scientists at Hebrew University (Jerusalem, Israel) successfully resurrected bacteria
inside a bee preserved in amber dating back 25-40 million years (Brown, par.53). If DNA can
last that long, it is plausible to assume that dinosaur DNA can be as equally well preserved.
(“The Search for DNA in Amber 5)
Another source of dinosaur DNA may be available in fossilized dinosaur skeletons. In March of
2005, scientists under the supervision of Dr. Mary H. Schweitzer and Dr. Jack Horner discovered
preserved soft tissue in a Tyrannosaurus Rex fossil. Blood vessels, in addition to red blood cells
and osetocytes, seem to be intact and well preserved. Dr. Barreto, a vertebrate paleontologist
who has worked with Dr. Schweitzer, has stated that the material was most preserved due to the
fact that they were completely surrounded by bone. This therefore protected the soft-tissue
(Barreto email). Tests involving microscopy, immunochemistry, and immunoblot will be
conducted in the next few months to determine whether or not there is possible DNA in the cells
(Schweitzer email).
A blood vessel (left) and red blood cells (right) from soft-tissue preserved in a fossil .(Stokstad).
Here we will first describe the possible procedures that would be used to genetically clone a
dinosaur from its DNA. The DNA will be taken either from amber resin or from a fossil. All of
the techniques describe are in compliance with modern research laboratory specifications and
capabilities. Finally, we will assess what happens after the successful genetic cloning in regards
to housing facilities and food requirements for these animals.
2 DNA and Dinosaurs
MATERIAL AND METHODS
(a) Sample and laboratory preparation
Amber will be obtained from either of two known sources: a blood-consuming hexapod or
chelicerate entombed in amber or soft tissue preserved in a fossil. A P4 laboratory with a
constant air purification system will be needed to assure that contamination possibilities will be
kept at a minimum. Numerous gene sequencers and polymerase chain reaction setups should be
prepared to speed up the process. Additionally, UV light sources will be needed to sterilize the
surroundings (Austin 467-468).
(b) Isolating a dinosaur cell
In the situation in which we are trying to extract DNA from a blood-consuming insect preserved
in amber, we must initially make sure that the sample dates back to the time period under
investigation (Austin 467-468). Amber specimens should be chosen from the Jurassic and
Cretaceous eras. Specimens from these time periods can be found in northern Europe, the
eastern United States, Canada, and Alaska (Nature’s transparent tomb, par. 24). All equipment,
in addition to the amber piece, should be exposed to ultraviolet light in order to ensure the
elimination of contaminating particles (DeSalle 20). The amber specimen should then be placed
in a liquid nitrogen bath, thereby making the sample fragile and easily breakable. After breaking
the amber into smaller pieces in order to expose the blood-consuming insect, use a microscope to
carefully dissect it and remove any cells that may be present in its stomach. It is imperative in
this step not to remove any insect cells in the process (DeSalle 23).
In the case that our sample is encased in a fossil, we must first break it into smaller pieces and
expose them to a weak acid. This will therefore remove any calcification and expose only the
soft tissue (Stokstad 1852). Since most cells contain a complete copy of the organism’s DNA,
we just need to isolate and obtain one cell.
(c) Extracting dinosaur DNA
In order to extract the deoxyribonucleic acid from the dinosaur cell, we must first rupture the cell
(DeSalle 26). Place the cell in a test tube and add sodium dodecyl sulfate, a detergent, in order to
disintegrate the cell’s outer wall, plasma membrane, and proteins.
Next, add
etylenediaminetetraacetate (EDTA) to shield the DNA from nucleases (enzymes which have the
potential of destroying DNA) emitted from the cell’s punctured lysosomes. Sodium chloride
(NaCl) should then be included in order to raise the salt gradient, thereby further destroying any
remaining proteins, in addition to aiding in the precipitation of DNA out of the solution. After a
centrifuge in which the DNA has clumped together in its own layer, discard the supernatant
liquid and then use ethanol to precipitate the DNA further as “visible white strands” (Rainbow
lecture).
3 DNA and Dinosaurs
In order to completely purify our sample, phenol should be introduced into the test tube. After a
centrifuge, again pour off the supernatant liquid and leave the DNA to dry partially. Use a
Polymerase Chain Reaction (PCR) to magnify your DNA (DeSalle 23-40). Since it is impossible
for us to determine what types of sequences exist in a dinosaur’s genome, include a variety of
primers to your solution (DeSalle 50) for the PCR. Since you have millions of DNA fragments,
you must account for and place them in their correct positions in the genome. Inserting the
fragment DNA onto a bacteria’s plasmid can do this. Sequencing the genome requires of you
only to remove the plasmids from the bacteria and place them in the machine (DeSalle 50-55).
(d) Filling in the missing gaps
DNA derived from either amber or a fossil will intuitively be degraded to some extent. (DeSalle
email). In order to have a fully functional animal, we will have to develop a system of filling in
the missing gaps within the genome. This is less of a problem in amber, were the physical
characteristics of the resin will keep together any fragmentation of the genome (Pellegrino, par.
26). However, if the disintegration is severe, there is one possible way to fill in the missing gaps
using the dinosaur’s own genetic code. It is intuitive to conclude that the amber preserved
blood-sucking insect “ate” more than one of the dinosaur’s cells. In actuality, it consumed
thousands of them, which were well preserved from the elements in the amber. Because of this,
we could sequence the DNA fragments from ten cells, for example. It is likely that the DNA
from these cells are not all damaged in the same spots. We would then create a computer
program that reads each strand and compares it to the other strands. The program would then
notify us where a gap was and what sequence, based on the other DNA strands, and would be
appropriate for the space. (Pellegrino, par. 25)
(e) Deciding on the number of chromosomes
Chromosomes place deoxyribonucleic acid into compact parcels. The way DNA is packaged in
chromosomes can effect the dinosaur’s gene expression. In chromosomes, DNA is arranged in a
certain order so that the firing of one gene triggers the execution of the one below it in the strand.
This process continues throughout the DNA molecule. A mess up in the arrangement of the
chromosomes would render this gene order useless and the dinosaur would not consequentially
have normal body functions (Keeton 286-289).
If the DNA has been preserved in amber, the resin itself may help maintain the chromosome’s
shape and dimensions. But if it does not, you can still find out how many chromosomes there are
based on the telomeres. Telomeres are monotonous DNA sequences at the concluding portions
of chromosomes that are involved in cell replication (DeSalle 65). By creating a computer
program, which scans for these monotonous sections, you would be able to determine where the
ends of the telomeres are located, and consequentially the amount of chromosomes. Although
this procedure has its faults (repetitive sections may reside in junk DNA that are not at the ends
of the chromosomes), it is our best option (DeSalle 67-68).
4 DNA and Dinosaurs
(f) Insertion of dinosaur DNA into an egg cell
Based on the data collected by Dr. Schweitzer concerning preserved soft-tissue, it is intuitive to
conclude that dinosaurs are related to present-day ostriches (Pellegrino, par. 17). In order for
your DNA to produce a living dinosaur, you must have a previously fertilized egg cell since it
has the necessary equipment for converting DNA into protein. To silence the cell’s DNA,
expose it to UV light or by physically removing it using a micropipette. Insert the dinosaur DNA
into the cell’s nucleus, and inject the egg cell into a female ostrich were it will develop like a
normal embryo. Since we still do not know a lot about embryology, this technique is the only
possible way at the moment to produce a dinosaur DeSalle (106-107).
RESULTS
There can be no way of determining the consequences of your genetic cloning techniques. You
may have done the steps correctly, but a dinosaur might not have been created. It is accepted
that scientists do not know enough information to routinely clone modern day organisms
successful. Taking into account the age of the dinosaur DNA preserved, it is likely that the
resurrection of these animals may not take place without further increases in knowledge and
technology. But assuming that a dinosaur was created, what steps will we take to assure its
survival into adulthood?
Numerous unique circumstances emerge upon the dinosaur hatching from the egg. First, it
would be wise to keep the dinosaur in a semi-sterile surrounding free from most environmental
germs. Despite this, the dinosaur should not be raised in a completely disinfected laboratory due
to the fact that many germs necessary for survival are only obtained through direct contact. As is
the case with humans, however, it is inevitable that some dinosaurs will die in infancy due to
genetics defects or illness (DeSalle 130-131). Second, according to its physiology food should
be given accordingly. But how much food will be needed for the creatures? Typically, an
organism will usually devour two percent of its mass in food each day. Because many dinosaurs
weighed at least a few tons, this consequentially accumulates to a few hundred pounds of food
every day (DeSalle153). This would therefore represent a logistics dilemma, which I will not
discuss at this time.
As the dinosaur progresses to adulthood, storage faculties should be considered. The size, type,
and amount dinosaur that you have cloned will determine the acreage and climate of your animal
park. However, if you are considering to establish a fully functional ecosystem of creatures,
ranging from carnivores to herbivores, a substantial area will be needed. For example, if you
want to create a relatively small ecosystem of 20-40 animals, a park the acreage of Connecticut
would be needed based on animal interaction studies (DeSalle 152).
DISCUSSION
The field of genetics has come along way in the past fifty years since the discovery of the double
helix. In the past decade, the term “deoxyribonucleic acid” has become a common phrase
5 DNA and Dinosaurs
amongst millions of people due to the popularity of the movie Jurassic Park. But will the topic
that initially spurred on the popularity of the entire field of genetics every happen? Will science
fiction become science fact? Instead of going to natural history museums to view their skeletal
remnants, will we one day be able to see real living dinosaurs roaming in nature preserves across
the world? Based on evidence displayed in this research paper, it appears certain that the
resurrection of dinosaurs will happen. The only uncertainty is when. It has been proven that
DNA is an extremely tough molecule. Coupling this toughness with the preservation power of
amber and soft tissue in fossils yields a likely recipe for cloning. DNA millions of years old
from bacteria, insects, and animals have already been reconstructed and sequenced, albeit
partially in some situations. It is true that with today’s technology, the task at hand does seem
extremely daunting. However, the future seems bright, with daily advances in genetic
sequencing machines and microscan technology. This, along with our increasing knowledge of
the deoxyribonucleic acid molecule, will eventually lead to an alteration of our views about
dinosaurs.
6 DNA and Dinosaurs
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