Severe cold, such as ice and permafrost, are the best methods to preserve DNA. That is why InGen preserved dinosaur embryos in the Cold Storage Room. Prehistoric animals like the Woolly Mammoth, Woolly Rhinoceros, humans and microbes have been perfectly mummified in ice sheets. In most cases DNA could be extracted from these mummies. The complete genome of mammoths was recovered from ice mummies. Scientists have been trying to clone the Woolly mammoth from this DNA.
Jurassic Park media Edit
Ice is also used in the Glacier Park section of the game. The DNA of extinct mammals from the Cenozoic Era can be found in pieces of ice containing remains of those creatures.
Ancient ice Edit
Although the Mesozoic Era was the longest period of warmth during the last 500 million years, it was repeatedly affected by short cold interludes lasting about one million years. During these periods glaciers formed, which could have contained aquatic reptiles and parasites.
Northern Hemisphere Edit
Evidence suggests that during the Mesozoic Era glaciers existed in the Arctic Ocean during glacial periods. However, when these periods ended all those ice sheets were lost to the oceans. After the extinction of the dinosaurs a very warm period followed (the Paleocene–Eocene Thermal Maximum) in which the Arctic Ocean was probably seasonally ice-free.
The Arctic Ocean was probably ice-free at 50 million years ago, with summer temperatures estimated as high as 24 C and freshwater subtropical aquatic ferns growing in abundance. It was probably around 47 million years ago that ice started to form again in the northern hemisphere.
The thickest northern ice sheets are located on Greenland. Ice from both the Ice Age (110,000-10,000 years ago) and the Illinois glaciation (~300,000—130,000 years ago) is preserved here. Trees have been discovered in frozen mud from 450,000 and 800,000 years ago. DNA was extracted from these trees.
Southern Hemisphere Edit
Around the South Pole things were no better. When the dinosaurs went extinct Antarctica (then connected to Australia) still had a tropical to subtropical climate. The first Antarctic permanent ice-sheets appeared only 33 million years ago.
During the last Ice Age the Patagonian Ice Sheet covered most of Chile south of approximately present-day Puerto Montt. 4% of this ice is still glaciated today in two separated portions known as the Northern and Southern Patagonian Ice Fields.
DNA in ice Edit
Even if ice mummies from the Mesozoic were discovered, it is uncertain if they still contain DNA. Bidle and his team investigated how long DNA can be preserved in Antarctic ice. DNA was isolated from microbes from the Mullins Valley (~100,000 years old) and the Beacon Valley (8 million years old). The DNA fragments from the former were much longer than the latter. Bidle and his team concluded that DNA in Antarctic ice has a half-life of ~1.1 million years. If this model is right, there is almost no DNA left after 65 million years. It should also be noted that bacterial DNA is circular, and therefore more stable than the DNA of animals.
- ↑ 1.0 1.1 1.2 Bidle K.D., Lee S., Marchant D.R., Falkowski P.G. (2007). Fossil genes and microbes in the oldest ice on Earth, PNAS, volume 104, pages 13455-13460.
- ↑ Carl Zimmer (2013). Bringing Them Back to Life The revival of an extinct species is no longer a fantasy. But is it a good idea?, National Geographic, April. [Link http://ngm.nationalgeographic.com/2013/04/species-revival/zimmer-text].
- ↑ Williams S.C.P. (2003). ScienceShot: Frozen Plants Come Back to Life After Hundreds of Years, ScienceNOW, May.
- ↑ Donnadieu Y., Dromart G., Goddéris Y., Pucéat E., Brigaud B., Dera G., Dumas C., Olivier N. (2011). A mechanism for brief glacial episodes in the Mesozoic greenhouse, Paleoceanography, volume 26, pages PA3212(1-10).
- ↑ Polyak L., Alley R.B., Andrews J.T., Brigham-Grette J., Cronin T.M., Darby D.A., Dyke A.S., Fitzpatrick J.J., Funder S., Holland M., Jennings A.E., Miller G.H., O’Regan M., Savelle J., Serreze M., St. John K., White J.W.C., Wolff E. (2010). History of sea ice in the Arctic, uaternary Science Reviews, oi:10.1016/j.quascirev.2010.02.010.
- ↑ Mason Inman (2007). Oldest Known DNA Found in Greenland Ice Core, National Geographic News, July. Online.