Provided by Will Dunham
Washington (Reuters) -The scientists have made progress in the search for ancient DNA fossils in recent years, gaining insight into long -lived organisms. However, the oldest DNA, which has been received so far, has been dated for about two million years. Protein, a cellular molecular machine, also offers valuable information and has a virtue to survive much longer, as new studies show.
Now scientists have pulled out and followed proteins from dental fossils from extinct rhinoceros, elephants and hypopotamus, including the witch of the 21-24 million years. A separate research group has found protein fragments in fossils from a very different environment – the cold high Canada Arctic and the fierce rift valley in Kenya.
“At the same time, these additional projects show that proteins are the main elements of living organisms that preserve information about evolution history – can be found in ancient fossils around the world,” said Daniel Green, a Harvard University Evolution Biologist, a study by Kenya Fossils published in Nature.
This opens up a new border to investigate a deep evolutionary past, including human origin and possibly even dinosaurs.
“Ancient proteins can tell you about the history of the body’s evolution by providing molecular data from a copy, through old DNA preservation. This allows researchers to find out evolutionary relationships throughout the life tree, even species that have disappeared millions of years ago,” said Ryan Sinclair Paterson, Podoctoral Studio to the author.
DNA and protein are fragile and divided over time, but protein is more resistant. The oldest known DNA is from organisms who lived in Greenland two million years ago. So far, the oldest known proteins, preserved well enough to offer an insight into evolutionary relations, were about four million years after the Canada Arctic.
New studies have been transferring millions of years of ancient protein research, the field of field called paleoproteomics.
Proteins were obtained from five teeth of rhinoceros, elephants and hippoes that lived in the Kenyan region of Kenya, 1.5-18 million years ago. Protein showed ties between ancient animals and their modern relatives.
Protein was also extracted from a fragment of the extinct rhino tooth, called Haughon’s crater in Nunavut, in the northern area of Canada, which was up to 24 million years old. They showed how this species fit into the Rhin family tree.
Haughon Crater’s cold and dry conditions were considered to be ideal for protein. Saving in the hot Turkan climate was more unexpected.
DNA and proteins, in the biology of the main molecules, have different structures and functions. Deoxyribonucleor acid is a life project with instructions for the development, growth and reproduction of the body. Protein performs many functions based on DNA instructions.
“Proteins encode our genetic code, DNA, so protein sequences reveal information about the connection and biological sex of different individuals, among other things,” Green said.
Scientists have pulled peptides – chains of organic compounds, called amino acids that bind proteins, are found inside the tooth enamel.
“Some proteins help to build teeth, and the heaviest and most durable structures in animal bodies,” Green added.
“Enamel is usually a rock: a mineral called hydroxyapatitis. However, its formation is biologically mediated by proteins that divert the form and hardness over time. Because these proteins intertwine deep in the enamel mineral, we have some reason that protein fragments can be preserved for many million years.” years. “
Homo Sapiens appeared about 300,000 years ago. In the past, ancient proteins were found in some extinct species in the human evolutionary line called hominines, teeth. The Turkana region gave important hominin fossils.
“Hominins have an evolutionary origin and / or diversification at the place where our examples occur, so our results promise to explore our evolutionary ancestral enamel proteom (protein collection) from the Kenyan Museum Museum Museum Museum Museum of Turkana Basin Turkana Turkana Pool.” Museums Conservation Institute Maryland.
The studied proteins were due to large species of dating mammals, which occurred after the dinosaur, which dominated the previous Mesozoic era, which ended 66 million years ago.
Green said the number of proteins found in a new study decreased gradually in older fossils. However, Green did not rule out finding proteins in the dates of the dinosaur, saying, “Newer and better methods of extracting and detecting ancient protein could probably be pushed out by paleoproteomics into mesozoic.”
(Will Dunham’s message, edited by Rosalba O’Brien)