Could the key ingredients for life have come from space? Scientists say yes

Links to the Breadcrumb trail

1. world
2. News

Researchers have studied material from three meteorites, including one that fell in 2000 near Lake Tagish in BC.

Author of the article:

Conceptual image of meteoroids delivering nucleobases – nitrogen-containing compounds that are crucial for the formation of the structure of double-stranded DNA – on ancient Earth. Nucleobases are represented by structural diagrams with hydrogen atoms such as white spheres, carbon as black, nitrogen as blue, and oxygen as red. NASA Goddard / CI Lab / Dan Gallagher / Distribution via REUTERS Photo by NASA / REUTERS

Content of the article

WASHINGTON – A new study of meteorites that fell in the United States, Canada and Australia confirms the idea that such objects may have delivered to Earth at the beginning of its history chemical ingredients vital to the emergence of life.

Advertising 2

This ad is not yet loaded, but your article continues below.

Content of the article

Scientists have previously identified these meteorites with three of the five chemical components needed to form DNA, the molecule that carries genetic instructions in living organisms, and RNA, the molecule that is crucial for controlling the action of genes. Researchers said Tuesday that they have already identified the last two after fine-tuning the way they analyze meteorites.

Unlike previous work, the methods used this time were more sensitive and did not use strong acids or hot liquid to extract the five components known as nucleobases, according to astrochemist Yasuhiro Oba of the Institute of Low Temperature Science at Hokkaido University in Japan. , lead author of the study published in the journal Nature Communications

Advertising 3

This ad is not yet loaded, but your article continues below.

Content of the article

Nucleobases are nitrogen-containing compounds that are crucial for the formation of the characteristic structure of double-stranded DNA.

Confirmation of the extraterrestrial origin of the full range of nucleobases found in DNA and RNA supports the theory that meteorites could be an important source of organic compounds needed for the first living organisms on Earth, according to astrobiologist and co-author Danny Glavin of NASA’s Goddard Space Flight Center in Maryland.

Scientists are trying to better understand the events that took place on Earth, which allowed various chemical compounds to gather in a warm aquatic environment to form a living microbe capable of reproducing. The formation of DNA and RNA would be an important cornerstone, as these molecules essentially contain instructions for building and managing living organisms.

Advertising 4

This ad is not yet loaded, but your article continues below.

Content of the article

“We still have a lot to learn about the chemical steps that led to life on Earth, the first self-replicating system,” Glavin said. “This study certainly adds to the list of chemical compounds that would be present in the early prebiotic soup on Earth (pre-existing).

Researchers have studied material from three meteorites – one that fell in 1950 near the town of Murray in the US state of Kentucky, one that fell in 1969 near the town of Murchison in the Australian state of Victoria, and one that fell in 2000 near the lake Tagish in the Canadian province of British Columbia.

All three are classified as carbon chondrites, made of rocky material believed to have formed at the beginning of the history of the solar system. They are rich in carbon, with the Murchison and Murray meteorites containing about 2% organic carbon by weight and the Lake Tagish meteorite containing about 4% organic carbon. Carbon is a major component of Earth’s organisms.

Advertising 5

This ad is not yet loaded, but your article continues below.

Content of the article

“All three meteorites contain a very complex mixture of organic molecules, most of which have not yet been identified,” Glavin said.

The earth was formed about 4.5 billion years ago. In its infancy, it was thrown by meteorites, comets and other materials from space. The first organisms on the planet were primitive microbes in the primordial seas, and the earliest known fossils are marine microbial specimens dating back about 3.5 billion years, although there are hints of life in older fossils.

The two nucleobases, called cytosine and thymine, recently identified in the meteorites, may have escaped detection in previous studies because they have a more delicate structure than the other three, the researchers said.

The five nucleobases would not be the only chemical compounds needed for life. Other essentials included: amino acids, which are components of proteins and enzymes; sugars that are part of the DNA and RNA of the spine; and fatty acids, which are structural components of cell membranes.

“Current results may not directly elucidate the origins of life on Earth,” Oba said, “but I believe they can improve our understanding of the inventory of organic molecules on early Earth before life began.”

(Report by Will Dunham, edited by Rosalba O’Brien)

Share this article on your social network

Advertising 1

This ad is not yet loaded, but your article continues below.

Sign up to receive daily headlines from Vancouver Sun, a division of Postmedia Network Inc.

By clicking on the register button, you agree to receive the above newsletter from Postmedia Network Inc. You can unsubscribe at any time by clicking the unsubscribe link at the bottom of our emails. Postmedia Network Inc. | 365 Bloor Street East, Toronto, Ontario, M4W 3L4 | 416-383-2300

Thank you for registering!

Welcome email is on the way. If you don’t see it, please check your junk folder.

The next issue of Vancouver Sun Headline News will be in your inbox soon.

There was a problem registering with you. Please, try again

Comments

Postmedia is committed to maintaining a lively but civic discussion forum and encourages all readers to share their views on our articles. It can take up to an hour to moderate comments before they appear on the site. Please keep your comments up to date and respectful. We have enabled email notifications – you will now receive an email if you receive a response to your comment, there is an update on the thread for comments you follow, or if a user you follow comments on a comment. Visit our Community Guidelines for more information and details on how to adjust your email settings.