Category: evolution

Genome analysis creates tree of life for modern birds

0 comments

Long long ago in a land far far away not so far from here at all, crocodiles, dinosaurs, and birds all arose from early reptiles called thecodonts.

thecondonts.jpg

Using new computational methods developed by assistant professor of statistics Liang Liu, Travis Glenn of the College of Public health and others, an international team of scientists has shed more light on an obscure period of avian evolution and further untangle the bird family tree.

Members of the Avian Phylogenomics Consortium—composed of 200 researchers from 80 institutions and 20 countries—have sequenced and analyzed the genomes of 48 species of birds and three species of crocodiles to better understand the fundamental evolutionary events that led to feathers, flight and song.

The consortium simultaneously published 28 papers this past week—eight papers in a special Dec. 12 issue of Science and 20 more in Genome Biology, GigaScience and other journals.

Glenn, an associate professor of environmental health science in the College of Public Health; Liu, an assistant professor in the department of statistics and Institute of Bioinformatics in the Franklin College of Arts and Sciences; and John Finger Jr., a doctoral student in the Interdisciplinary Toxicology Program and College of Public Health, were co-authors on two of the eight papers published in Science.

The first of these two papers, "Whole genome analyses resolve the early branches to the tree of life of modern birds," creates the most reliable tree of life for birds to date.

Fantastic work by our faculty and all members of the consortium, all celebrated in a special issue of Science. This is the kind of atmosphere that attracts the best graduate students, among other interested parties. So we celebrate this marvelous achievement and all the other indicators it provides, campus-wide and beyond.

Examining the history of plants

0 comments

Morning_glory.jpgIt sounds like the title of a cable documentary (a good one! And maybe it is) but scientists from North America, Europe and China have published a paper in PNAS that reveals important details about key transitions in the evolution of plant life on Earth:

From strange and exotic algae, mosses, ferns, trees and flowers growing deep in steamy rainforests to the grains and vegetables humans eat and the ornamental plants adorning people's homes, all plant life on Earth shares over a billion years of history.

"Our study generated DNA sequences from a vast number of distantly related plants, and we developed new analysis tools to understand their relationships and the timing of key innovations in plant evolution," said study co-author Jim Leebens-Mack, an associate professor of plant biology in the University of Georgia Franklin College of Arts and Sciences.

As part of the One Thousand Plants, or 1KP, initiative, the research team is generating millions of gene sequences from plant species sampled from across the green tree of life. By resolving these relationships, the international research team is illuminating the complex processes that allowed ancient water-faring algae to evolve into land plants with adaptations to competition for light, water and soil nutrients.

Great stuff, congratulations to this international team. More lights come on and we are able to understand our world and how it works a little better.

Image: Morning glory (Ipomoea purpurea) is a beautiful flowering plant and agricultural weed. (Credit: Lindsay Chaney/Brigham Young University)

Newly sequenced genome addresses Darwin's 'abominable mystery'

0 comments

Amborella flowerThe origin and early evolution of flowering plants, based at least in part on his frustration with the fossil record of the time, was a particularly puzzling subject for Charles Darwin. His correspondence between 1875 and 1881 reveals that he was deeply bothered by the apparent origins and rate of diversification of flowering plants in the mid-Cretaceous.

A newly sequenced genome of the Amborella trichopoda plant addresses Darwin's mystery and sheds new light on the origin of flowering plants:

A paper by the Amborella Genome Sequencing Project, published Dec. 20 in the journal Science, includes a full description of the analyses performed by the project as well as the implications for future research on flowering plants.

Jim Leebens-Mack, University of Georgia associate professor of plant biology in the Franklin College of Arts and Sciences, co-led a team of scientists at UGA, Penn State University, the University at Buffalo, the University of Florida and the University of California-Riverside to decipher the Amborella genome. The team is uncovering evidence for the evolutionary processes that paved the way for the diversity of the more than 300,000 flowering plant species on Earth today.

...

The Amborella genome sequence facilitated reconstruction of the ancestral gene order in the ‘core eudicots,' a huge group that comprises about 75 percent of all angiosperms. This group includes tomato, apple and legumes, as well as timber trees such as oak and poplar," said Leebens-Mack.

It's fascinating how mysteries propel science forward, connecting eras and researchers over great periods to advance our knowledge of the universe. And a lagniappe that in this instance, such a significant insight turns on the life of a delicate little flower. Great work.

Image: The small flowers of Amborella trichopoda, an understory tree species native to New Caledonia.

Learning without language

0 comments

Monkey cracks nut high above the plain C CarvalhoInteresting new study authored by Dorothy Fragaszy in the department of psychology and several collaborating authors from around the world:

A new study from a group of researchers, led by University of Georgia behavioral scientist Dorothy Fragaszy, reports that artifacts—objects similar to the ball or shovel—are an important component in technical learning by nonhuman species. The study, published Oct. 7 in Philosophical Transactions of the Royal Society B, documents the work of two groups of researchers investigating cases of habitual tool use in wild chimpanzees and capuchin monkeys.

The two groups of researchers discovered they were working along parallel lines and observing similar findings. They organized the data from the separate species together in a special issue of the journal.

Tool use in wild animals has long been an area of broad interest among the scientific community. The researchers focused on the use of durable tools and artifacts, especially among younger individuals, to conclude that experience with tools and the opportunity to use them have an enduring impact on the development of traditional technologies in nonhumans.

Fragaszy has spent a great deal of her career studying capuchin monkeys, establishing a wide authority of expertise in behavioral science. When she discovered that a different group studying a different species had established very similar results, the two groups used each other's work to further solidify their findings. This is strong, fundamental science, and the larger group authoring this particular study has accomplished important work on an elusive aspect of human development. Fragaszy, in the final quote in the press release:

"When the circumstances support it, and we think artifacts are an important part of these supporting circumstances, then cognitively less complex individuals-species that don't have language, that don't have explicit teaching, that don't have human forms of culture-they also can acquire and maintain complicated, technical traditions."

Image: Capuchin monkey high above a plain in Brazil, courtesy of D. Fragaszy.

Study sees coevolution between invasive, native species

0 comments

Garlic-Mustard1-230x173.jpg

Coevolution is the change of a biological object triggered by the change of a related object. And up until now there has been little evidence of it driving changes in Earth's history, though that, too, seems to be changing:

A new University of Georgia study shows that some native clearweed plants have evolved resistance to invasive garlic mustard plants—and that the invasive plants appear to be waging a counterattack. The study, published in the early edition of the journal Proceedings of the National Academy of Sciences, is thought to provide the first evidence of coevolution between native and invasive plant species.

"The implications of this study are encouraging because they show that the native plants aren't taking this invasion lying down," said study author Richard Lankau, assistant professor of plant biology in the UGA Franklin College of Arts and Sciences. "It suggests that if you were to take a longer view—a timescale of centuries—that exotic species could become integrated into their communities in a way that is less problematic for the natives."

Tree of Life

0 comments

simple_tree_of_life.jpg

Evolutionary biology is the 10-meter spring board for some of the greatest questions in science and epidemiology. How do species arise? How do genes diversify and acquire new functions? How do pathogens evolve and how does that information lead to new and better understanding of diseases?

Renowned paleontologist's lecture headlines Darwin Days

0 comments

Franklin faculty and guest speakers continue the important work of bringing science to the public.

World-renowned paleontologist Jack Horner, author of How to Build a Dinosaur, will discuss how he and his colleagues are developing the technology to create a real dinosaur at a lecture that is part of the annual Darwin Days celebration at the University of Georgia. 

Horner, who advised Steven Spielberg on Jurassic Park and is Regents Professor of Paleontology at Montana State University, will speak Feb. 6 at 4 p.m. in room 102 of the Miller Learning Center. His lecture, which is free and open to the public, will be followed by a reception in which copies of How to Build a Dinosaur will be available for signing.