Terror sets in as the scaly reptile charges gracefully forward, its tail slashing back and forth, back and forth, its gigantic toe claw clacking menacingly on the linoleum floor as it echoes a petrifying squawk. They seem to speak to each other in an ancient language, seem to be working out their plan of attack. You are gone, dead meat, so to speak (and literally). No longer is man the king of the jungle, rather, the velociraptor. They, like other creatures of Earth’s pre-historic time, have captured the minds and hearts of people throughout the world. Horrifyingly brilliant. An evolutionary miracle. More than that- the ultimate predator. How could one not find these creatures utterly intriguing? Given the opportunity, wouldn’t you love to see these ancient creatures alive once again? Movies such as
However, the opportunity to participate in such cloning opportunities has not truly surfaced until recently, that is, now that wooly mammoth DNA has been discovered. In 2007, a Nenets reindeer herder found a frozen baby wooly mammoth, and consequently notified scientists of its existence. Using proper protection to ensure that ancient bacteria from the corpse would not contaminate the scientific lab, scientists were able to harvest many different types of cells that contained viable DNA material (Mueller 2009). Hypothetically, these scientists would be able to bring this wooly mammoth back from extinction using this very genetic material. And while the temptation to reproduce these ancient creatures is inevitably strong, doing so would devastatingly disrupt the Earth’s ecosystem by upsetting the current food chains and establishment of organismal niches.
But before we discuss these consequences in depth, let’s take a look at just how scientists can take preserved pieces of an organism to make it into an actual breathing, walking, eating animal. For the sake of our example, let’s contextualize our example in the terms of wooly mammoth cloning. Hypothetically, there are several methods: scientist can either fertilize an elephant egg with a frozen sperm of a wooly mammoth (which will produce offspring that are genetically half elephant and half wooly mammoth), or replace the contents of an elephant’s cellular nucleus with that of a frozen wooly mammoth cell (creating offspring which are 100% wooly mammoth). And viola, there you have it-- a wooly mammoth living in the 21st century (Mueller 2009).
If a frozen sperm of a wooly mammoth is found, one can implant the fertilized egg into the uterus of a female elephant (also called, “in vitro” fertilization). While “in vitro” fertilization will create offspring that are genetically half wooly mammoth and half elephant, breeding these offspring together throughout generations will progressively produce offspring that are more genetically similar to the wooly mammoth than the elephant (rather like amplifying certain traits through inbreeding-- think pure-bred dogs) (Mueller 2009).
If one finds and isolates a frozen cell found in a wooly mammoth carcass, one can take an elephant egg, remove its nucleus, and then replace the nucleus with the nucleus found in the frozen wooly mammoth cell. Using chemical or electric stimulations, the cell will then begin to divide, upon which will signal that the cells are ready for placement in the uterus of an elephant. This process will produce offspring that are genetically 100% wooly mammoth (Mueller 2009).
Even if scientists have not found a frozen cell of the organism and only have a portion of the sequenced mammoth genome, they can use a process called Polymerase Chain Reaction (PCR) to amplify small pieces of DNA into long strands of DNA. PCR essentially uses an enzyme called primerase to “prime” the small DNA strand, and then emplyes a special enzyme to fill in the DNA sequence gap between primers. The end result is a long strand of DNA (Eisen 2009). One can arrange these long strands of DNA into chromosomes and then place them into an artificial nuclear membrane. Upon placement of the created chromosomes into the artificial nuclear membrane, the cell will follow the same process as if the cell were found frozen inside the wooly mammoth, until a wooly mammoth is produced (Mueller 2009).
The brilliance of this new scientific knowledge is so ground-breaking that it just begs to be acted upon. Imagine it: scores of people would come from across the planet, all of which come to humor their childhood infatuation with creatures from pre-historic eras. And while it appears that the recreation of the wooly mammoth (or whichever pre-historic creature we decide to clone, perhaps even the terrifying amazing velociraptor) would not be harmful, think again-- the consequences of the introduction of pre-historic creatures into our society would be quite destructive to the Earth’s ecosystem.
Organisms rely on food chains for the obtainment of resources, such as food or water (Gray 2009). Let’s take the sea urchin, for example. Sea urchins feed upon kelp beds, gnawing away at the kelp with their incisors. But alas, the particular sea urchin that we are referring to is not so lucky, and becomes a hungry sea otter’s tasty dinner. And while the sea otter is hastily clawing its way into the sea urchin, a great white shark happens to detect the sea otter. It ‘tis a most unfortunate day for this sea otter, as it quickly becomes the great white shark’s snack in a single chomp. True, Mother Nature can be quite cruel.
Since the sea otter plays such an important role in this ecosystem, it is called a “keystone species”, meaning that the increase or decrease of its population would dramatically impact the populations of other organisms in its food web. The sea otter plays an important role in this food web (or, in other words, it has its own “niche”) by acting as food for great white sharks, and by eating sea urchins. Remove the sea otter from the food web, and problems will ensue. Great white sharks will have to rely on another food source for its obtainment of resources. The sea urchin population will drastically incline with this absence of its primary predator. And because there is no check on the sea urchin population, there will be more sea urchins to feed on kelp beds, thereby decreasing the numbers of kelp beds (Buck- Ezcurra and Armstrong 1996).
Now let’s say that humans find frozen pilosaur (a gigantic carnivorous dinosaur that ruled the pre-historic seas) DNA and therefore clone it to keep in a Jurassic Park type theme-park, living in an enormous underwater cage where people pay to see it (Marshall Cavendish Corporation 2000). However, living things have a tendency to escape, therefore ensuring that the pilosaur will eventually escape from its underwater cage and therefore be introduced into the ecosystem. While exploring its new found oceanic habitat, an enormous pilosaur detects a sea otter. Its carnivorous instinct kicks in, and suddenly, the sea otter becomes its dinner. Now, this would not be such a problem if there was only one incidence of this type of encounter. However, if the pilosaurs reproduce, they would dramatically affect the food chain by feeding on (and thereby decreasing) the great white shark and sea otter populations. Knock out these populations, and there you go-- unstable populations of sea urchins and kelp beds.
Now, we need to visualize this concept in terms of something a little more real and viable to us. Let’s say that scientists end up cloning the wooly mammoth and releasing it into
While cloning of pre-historic animals, such as the wooly mammoth (or even the velociraptor), would serve to quench the insatiable appetite of the human psyche to create, doing so would have devastating consequences on the Earth’s ecosystem by disrupting the currently established ecosystem niches. Yes, it is most upsetting that we present day human beings will never be able to live out their childhood fantasies. You’ll never be able to frolic in the fields alongside wooly mammoths. You’ll never be able to observe a velociraptor attack (which is likely lucky, especially since you would not last long in the presence of a velociraptor). But think about it this way: you are doing the environment and your grandchildren a favor. And they thank you for it.
References
Buck- Ezcurra, R, Armstrong, P, editors. 1996.
Eisen J. 2009. “Introduction to PCR”. Lecture.
Gray S. 2008. Food Webs: Interconnecting Food Chains.
Marshall Cavendish Corporation. 2000. Aquatic Life of the World.
Mueller T. Ice Baby. National Geographic. 2009 May;215(5): 30- 51.
Mueller T. Recipe for Resurrection. National Geographic. 2009 May;215(5): 52- 55.
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