Identification of "molecular fossils" . Chasing the "traces" of the ancient marine environment change in the South China Sea

Original title: Close-up: Extracting "molecular fossils" to explore the ancient environment of the South China Sea "traces" of the ocean is the cradle of life.
in this "cradle", all kinds of life that have lived, more or less will leave their mark on the sediments on the sea floor.
can be seen with the naked eye, some need to be observed with a microscope, and some need to be extracted by chemical methods, "molecular fossils" belong to the last such "mark of life."
"Determination" ocean drilling vessel is currently drilling in the northern waters of the South China Sea, this is the third Time the South China Sea ocean drilling led by Chinese scientists.
on board, professor Li Li of Tongji University's School of Oceans and Geosciences is closely related to these "molecular fossils".
In the quiet geochemistry lab, she is often seen busy shuttling between various instrument equipment and some bottle cans, focusing on core gas analysis and pore water extraction, or using sophisticated micro-balance instruments, non-stop bubble-filled carbonate devices, carbonate content and organic carbon and nitrogen element analysis.
"Just as organisms have their own special genes, each organism has its own unique structure of organic molecules, called 'molecular fossils' or 'lipid markers', " he said.
With the death of living things, genetic molecular DNA, RNA molecules will soon disappear, but some hard-to-degrade 'molecular fossils' can be preserved in the sediments, leaving a trail for us to explore the ancient marine environment.
," Li Li said.
understand the past to better predict the future.
study of marine paleo-environmental changes to better understand today's global climate change.
extraction and analysis of "molecular fossils" in seafloor sediments, and the retrospective reconstruction of long-scale paleo-environment and paleo-climate, is a kind of ancient marine environment research method that is on the rise in the world.
Li Li has been working with various "molecular fossils" in the South China Sea since she began working at Tongji University in 2003.
the application on the "determination", is to think of the South China Sea to witness their own research for many years of "old friends", from the depths of the sea floor sampling and extraction of the whole process, looking forward to the sample can extract more, older "molecular fossils."
"Although 'molecular fossils' are invisible and unsettable, through organic reagents and testing instruments, I can really judge their existence."
this, like fingerprint marks in detective novels, detects 'molecular fossils' to determine the number and variation of the biomes that once lived in the ancient South China Sea.
" Li Li said, "through the changes in the relative content of different organic molecules by land and sea, we can tell the geological history of land and sea changes."
, just as we humans increase or decrease our clothes as the weather heats up, so do creatures, which perceive changes in the environment."
Li Li, for example, has a long-chain ketone called a "magic molecule" in the ocean, which contains 2-4 double-bond structures, which decrease and then increase as the temperature increases.
scientists have created an "oceanic paleo thermometer" that can trace changes in sea temperature over the past few million years.
"molecular fossils" of ancient bacteria ubiquitous in the oceans are also very unique, different from the ester bond binding of bacteria and ebony organisms, ancient bacteria molecules synthesize special ether bonds, more stable.
they can also change the number of five rings in their body structure as the temperature rises and bodies rise.
"molecular fossils" left behind by these organisms, which are sensitive to temperature changes, provide scientists with valuable "historical archives" for studying the Earth's land, sea and land changes and climate changes.
, however, chemically extracting "molecular fossils" from sediments is a lengthy and complex process.
after the ship, Li Li will continue to carry out a variety of complex tests and analytical research, through gas chromatography, liquid chromatography, mass spectrometer and many other instruments, identified "molecular fossils" and analysis of their content, in order to pursue the South China Sea ancient marine environment changes "traces."
source: Xinhua News Agency.