Nav: Home

Scientists explore causes of biodiversity in perching birds

April 05, 2019

New research by a global team of scientists has resulted in significant strides in ornithological classification and identified possible causes of diversity among modern bird species.

The study, coauthored by researchers at the University of Tennessee, Knoxville and published in Proceedings of the National Academy of Sciences, focuses on perching birds, or passerines. Comprised of over 6,000 species, this group--which constitutes over half of all known bird species--includes familiar birds such as robins, jays, bluebirds, finches, and sparrows.

Scientists analyzed genetic samples and fossils of all major groups within the passerine family to better understand the way these species are related. The large data set allowed for much more accurate inferences into the development of perching birds.

The result is the most accurate and comprehensive "tree of life" of passerine species to date.

The report also includes an analysis of the impact some events in Earth's history could have had on passerines' biodiversity.

"Our main discovery is that the evolution of perching birds around the world was determined in part by connections between continents over the Earth's history, as well as changes in global climate," said Michael Harvey, a postdoctoral fellow with UT's Department of Ecology and Evolutionary Biology. "We found, for example, evidence that glaciations during the Oligocene Epoch (between 24 and 33 million years ago) wiped out a lot of perching birds, but that the warming period immediately after prompted the evolution of many of the groups of perching birds alive today."

Another large portion of the study looks at the origin of perching birds, including a finding that perching birds originated on the Australian landmass around 47 million years ago.

"However, not just one single event in earth's history explains how they became so diverse and widespread," said Elizabeth Derryberry, UT assistant professor of ecology and evolutionary biology. "Instead, diversification and dispersal of this group has been affected by a number of different climatological and geological events, such as glaciation, global temperature changes and colonization of new continents."

According to Harvey, the next step is to fill in the missing gaps in passerine evolution not fully explained by Earth's history.

"We found that changes in geology and climate cannot explain everything," he said. "Future research needs to focus on explaining those aspects of bird evolution that are not determined by the Earth's geological and climatic history, but instead by the evolution of new characteristics in the birds themselves. For example, did the evolution of the ability to complete long-distance migrations in some perching birds help them get to new areas, or lead to the evolution of new species?"

Derryberry believes the research serves as a template for future exploration.

"The study provides a framework for how to conduct these types of analyses on large radiations and should provide a path forward for this type of research on all birds," she said.
-end-
CONTACT:

Andrea Schneibel (865-974-3993, andrea.schneibel@utk.edu)

Will Wells (wrw@vols.utk.edu)

University of Tennessee at Knoxville

Related Evolution Articles:

Chemical evolution -- One-pot wonder
Before life, there was RNA: Scientists at Ludwig-Maximilians-Universitaet (LMU) in Munich show how the four different letters of this genetic alphabet could be created from simple precursor molecules on early Earth -- under the same environmental conditions.
Catching evolution in the act
Researchers have produced some of the first evidence that shows that artificial selection and natural selection act on the same genes, a hypothesis predicted by Charles Darwin in 1859.
Guppies teach us why evolution happens
New study on guppies shows that animals evolve in response the the environment they create in the absence of predators, rather than in response to the risk of being eaten.
Undercover evolution
Our individuality is encrypted in our DNA, but it is deeper than expected.
Evolution designed by parasites
In 'Invisible Designers: Brain Evolution Through the Lens of Parasite Manipulation,' published in the September 2019 issue of The Quarterly Review of Biology, Marco Del Giudice explores an overlooked aspect of the relationship between parasites and their hosts by systematically discussing the ways in which parasitic behavior manipulation may encourage the evolution of mechanisms in the host's nervous and endocrine systems.
More Evolution News and Evolution Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Erasing The Stigma
Many of us either cope with mental illness or know someone who does. But we still have a hard time talking about it. This hour, TED speakers explore ways to push past — and even erase — the stigma. Guests include musician and comedian Jordan Raskopoulos, neuroscientist and psychiatrist Thomas Insel, psychiatrist Dixon Chibanda, anxiety and depression researcher Olivia Remes, and entrepreneur Sangu Delle.
Now Playing: Science for the People

#537 Science Journalism, Hold the Hype
Everyone's seen a piece of science getting over-exaggerated in the media. Most people would be quick to blame journalists and big media for getting in wrong. In many cases, you'd be right. But there's other sources of hype in science journalism. and one of them can be found in the humble, and little-known press release. We're talking with Chris Chambers about doing science about science journalism, and where the hype creeps in. Related links: The association between exaggeration in health related science news and academic press releases: retrospective observational study Claims of causality in health news: a randomised trial This...