An international team of scientists has created a tree of life for about 8,000 genera (about 60%) of flowering plants (angiosperms). This result sheds new light on the evolutionary history of flowering plants and the process by which they achieved ecological dominance on Earth.
A time-calibrated phylogenetic tree of angiosperms based on 353 nuclear genes. All 64 orders, all 416 families, and 58% (7,923) of genera were represented.Image credit: Zuntini other., doi: 10.1038/s41586-024-07324-0.
Flowering plants make up about 90% of all known plants on land and are found virtually everywhere on Earth, from the hottest tropics to the rocky outcrops of the Antarctic Peninsula.
These plants originated more than 140 million years ago and have since evolved into other vascular plants, including their closest living relatives, the gymnosperms (non-flowering plants with naked seeds such as cycads, conifers, and ginkgos). I quickly overtook it.
Our understanding of how flowering plants came to dominate the world soon after their origins has puzzled generations of scientists, including Charles Darwin.
For the new study, the authors used 1.8 billion characters of genetic code from more than 9,500 species covering about 8,000 known flowering plant genera (about 60%). More than 800 of these species have never had their DNA sequenced before.
“Analyzing this unprecedented amount of data and deciphering the information hidden in the millions of DNA sequences has been a huge challenge,” said Dr. Alexandre Zuntini, a researcher at the Royal Botanic Gardens, Kew. I am.
“But it also provided a unique opportunity to reevaluate and expand our knowledge about the plant tree of life and opened new windows to explore the complexities of plant evolution.”
“Flowering plants feed, clothe and greet us whenever we enter the forest,” said Professor Stephen Smith, an evolutionary biologist at the University of Michigan.
“Constructing the tree of life for flowering plants has been an important challenge and goal for the field of evolutionary biology for more than a century.”
“This project brings us closer to that goal by providing large datasets for most genera of flowering plants and one strategy to achieve this goal.”
“One of the biggest challenges the team faced was the unexpected complexity underlying many of the genetic regions, with different genes telling different evolutionary histories.”
“We needed to develop procedures to investigate these patterns at a scale that had never been done before.”
The tree of life for flowering plants is much like our own family tree, allowing scientists to understand how different species are related to each other.
The tree of life is revealed by comparing DNA sequences between different species and identifying changes (mutations) that accumulate over time, like the molecular fossil record.
For this study, new genomic techniques were developed to magnetically capture hundreds of genes and hundreds of thousands of letters of the genetic code from every sample. This is an order of magnitude better than previous methods.
The main advantage of the researchers' approach is that they can sequence a wide variety of plant material, both old and new, even when the DNA is severely damaged.
The vast trove of dried plant material in herbarium collections around the world (consisting of approximately 400 million scientific specimens of plants) can now be genetically studied.
“In many ways, this novel approach has made it possible to collaborate with botanists of the past by leveraging the wealth of data locked away in historic herbariums, including 19 This includes collections dating back to the beginning of the century,” he said. William Baker, researcher at the Royal Botanic Gardens, Kew.
“Our famous predecessors such as Charles Darwin and Joseph Hooker could not have predicted how important these specimens would become in today's genomic research.”
“DNA had not been discovered during their lifetimes. Our research shows how important these amazing botanical museums are to groundbreaking research into life on Earth.”
“Who knows what other undiscovered scientific opportunities are out there?”
of the team result appear in the diary Nature.
_____
AR Zuntini other. Phylogenomics and the emergence of angiosperms. Nature, published online March 15, 2024. doi: 10.1038/s41586-024-07324-0
Source: www.sci.news
