Is it really possible to resurrect dinosaurs?

Humans obtain dinosaur genetic fragments for the first time

On March 14, 1995, a research team from the School of Life Sciences of Peking University successfully extracted a dinosaur gene fragment from a rare dinosaur egg fossil. This was the first time that humans directly obtained dinosaur genetic material from a dinosaur egg fossil.

The biologically active substances preserved in the fossils come from dinosaurs that became extinct 65 million years ago. The preservation of these genetic materials not only challenges our traditional understanding of the preservation capacity of fossils, but also provides valuable direct evidence for the study of dinosaurs and their ecosystems, the origin of species and the evolution of organisms, and also opens up a new perspective and approach to explore the mysteries of life evolution.

DNA found in dinosaur egg fossils for the first time

This late Cretaceous C-type dinosaur egg fossil unearthed in Xixia County, Henan Province, is oblate in shape, with a hard and well-preserved shell without any cracks. However, in an accident, the fossil broke into two halves, exposing a gray-brown flocculent substance wrapped inside.

This discovery quickly attracted the attention of Professor Zhang Yun's team at the School of Life Sciences of Peking University. Researchers extracted a small amount of flocculent samples from the fracture and confirmed through chemical analysis that it contained organic matter such as amino acids. To further explore, the team used molecular biological technology, combined with isotope labeling and PCR amplification methods, to conduct in-depth testing of the samples. The results showed that DNA material did exist in the dinosaur egg fossil, and a specific DNA fragment was successfully amplified.

On this basis, the researchers conducted multiple experimental verifications and identified multiple gene fragments including the thyroid hormone receptor gene and zinc finger protein gene through DNA sequence determination. These gene fragments have a homology of 73% to 81% with the 18SrDNA of amphibians, reptiles, birds, mammals and humans, but have no homology with prokaryotes, eliminating the possibility of human operation contamination or bacterial contamination.

The research results provide important clues for humans to gain a deeper understanding of dinosaurs and their living environment. Zhang Yun's team pointed out that although a small number of dinosaur gene fragments have been successfully obtained, this is only the tip of the iceberg of the complete dinosaur genome. With the discovery of more dinosaur egg fossils and the deepening of research in the future, people are expected to obtain more genetic information, thereby further revealing the reproductive mechanism of prehistoric animals, the relationship between dinosaurs and their role in the environment, and exploring the deep mysteries of dinosaur evolution, extinction and species formation.

Chromatocytes found in Caudipteryx fossils

On October 5, 2021, an archaeological team from the Chinese Academy of Sciences made a breakthrough discovery in the fossils of Caudipteryx - they found cells containing filamentous chromatin. These cells are intact in morphology and retain a certain degree of activity, and may carry the DNA information of Caudipteryx. This discovery shocked the global scientific community.

Caudipteryx, also known as Caudipteryx, is a small theropod dinosaur from the early Cretaceous period 137 million years ago. It was similar in size to a peacock, with feathers similar to those of modern birds on its forelimbs and the end of its tail.

The Chinese Academy of Sciences team conducted an in-depth study of the Caudipteryx fossils and was pleasantly surprised to find well-preserved chondrocytes in its leg bone slices. Among these cells, there are both healthy "fossilized" chondrocytes and cells in a state of apoptosis. What is even more exciting is that some chondrocytes may still contain Caudipteryx's chromatin. Chromatin is a smaller substance that makes up chromosomes and is the carrier of genetic material in organisms. This discovery means that humans are one step closer to revealing the DNA composition of Caudipteryx.

However, scientific research shows that within 500 years of death, half of the genetic material in any species will be lost. After more than 1,000 years, the genetic information will be completely gone. So how did this 137 million-year-old tail feather dragon miraculously preserve its chromatin?

Researchers explained that Caudipteryx was a herbivorous dinosaur that usually lived by rivers and lakes, and only came ashore briefly to hatch eggs. During the Cretaceous period, volcanic eruptions were frequent, causing some dinosaurs to be buried deep underground in volcanic ash, forming the existing Cretaceous fossils. When the volcano erupted, some Caudipteryx did not have time to escape and were quickly buried by volcanic ash. The fine-grained mineral medium in the volcanic ash may have played a key role in protecting the genetic material of Caudipteryx, allowing it to be preserved for hundreds of millions of years.

Can humans resurrect dinosaurs using DNA?

If scientists can extract DNA from dinosaur fossils, does this mean that humans can bring dinosaurs back to life? In the movie "Jurassic Park", a mosquito that sucked the blood of a dinosaur used DNA replication technology to revive the prehistoric beast. Can such a plot come true in reality? In this regard, scientists have clearly pointed out that this is still an unattainable dream, at least in the foreseeable future.

When it comes to cloning technology, people often think of successful cases such as Dolly the sheep, but these cloning processes are very different from the conditions required to resurrect dinosaurs. For example, the birth of Dolly the sheep relied on the complete cell nuclear transfer technology, which requires two key parts: a stem cell nucleus carrying genetic information and an unfertilized egg, which was produced by a surrogate mother after fusion.

However, the dinosaur DNA fragments that scientists can obtain are extremely limited, far from enough to construct complete genetic information, let alone a complete cell structure including the nucleus. Repairing these incomplete DNA fragments is beyond imagination.

In addition, DNA is divided into two categories: cytoplasmic DNA and nuclear DNA, of which nuclear DNA is the main storage place for genetic information. It is not easy to obtain nuclear DNA, and the research value of cytoplasmic DNA for resurrecting dinosaurs is relatively limited. In addition, biologists have further emphasized that human intervention and attempts to change the course of natural history are not only unfeasible, but may also bring disastrous consequences.

Reference sources: People's Daily Online, Peking University News Network, Science Popularization China