Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New genomic data helps resolve biology’s tree of life

23.10.2003


For more than a century, biologists have been working to assign plants, animals and microbes their respective places on the tree of life. More recently, by comparing DNA sequences from a few genes per species, scientists have been trying to construct a grand tree of life that accurately portrays the course of life on Earth, and shows how all organisms are related, one to another.



However, despite the detailed insights provided by individual genes, that approach has proved cumbersome in its ability to resolve the order of events in the distant past.

Now, a team of scientists from the Howard Hughes Medical Institute at the University of Wisconsin-Madison, writing in the current issue (Oct. 23) of the prestigious journal Nature, has shown that new genomic-scale data offers powerful, unprecedented resolution of the evolutionary tree.


The finding is important because an accurate depiction of a tree of life promises biologists a summary of the history of life on Earth over billions of years. Such a rigorous historical framework is an essential backdrop not just for evolutionary biology, but also for efforts as diverse as the search for new drugs and agricultural agents, studies of emerging diseases, and evaluating issues of species conservation and ecosystem restoration.

"The overall goal is that we want to know who is related to whom," says Sean B. Carroll, a UW-Madison professor of genetics and the senior author of the Nature paper. "The challenge has been to decipher the true tree from those that have changed as data have been added and re-analyzed over time."

In efforts to arrive at a reliable tree of life, scientists since the 1980s have used genes to infer the evolutionary history for various organisms. By comparing one or a few genes common to related animals or plants, and looking at differences in the selected genes, scientists began to map out family trees for different plants, animals and microbes.

The problem with that approach, according to the new Wisconsin study, is that trees constructed on single genes often seem to lack reliability. Different genes give different answers so that one gene from a group of organisms depicts one tree, while a different gene from the same organisms will paint an entirely different phylogenetic picture. More genes, it has been thought, could help resolve the issue, and the new Wisconsin study now provides the first glimpse at both just how unreliable single genes can be and how many genes might be needed to overcome the problem.

Using new genomic sequences from eight yeast species, the group in Carroll’s lab, which was led by post-doctoral fellows Antonis Rokas, Barry L. Williams and Nicole King, were able to assess the reliability of trees constructed using more than 100 genes. The result was a single tree with no doubt.

"We were shocked. We didn’t expect such an unprecedented level of resolution," says Rokas. "Some genes give you one story, some genes give you another, but with enough of them together we get a single picture."

Apparently, the catch with the single gene model is that some of the thousands of nucleotides that make up a gene can be biased as natural selection acts on the gene to fulfill a certain role. "Each gene carries information concerning both history and selection. Genes alone are biased, but together their shared history overrides each genes’ unique bias and provides a surprisingly strong picture of evolution," says Williams.

The implications of the study are exciting, and provide encouraging news for the future of understanding the tree of life, says Carroll. As the data sets get larger the influence of variation caused by natural selection becomes small enough that true historical relationships can be worked out.

"The problem is that molecules don’t all change in the same way," says Carroll. "Now, with whole genomes being deciphered at a rapid clip, long-standing questions about the relationships between various animals and plants appear to be within our reach."

The take home message, according to Williams and Rokas, is that the advent of the genomic age means the data necessary to build robust phylogenetic trees are coming on line. Already, scientists have genomic sequences for a number of different organisms, ranging from bacteria to humans.

"It’s time for people to scale up, " says Rokas. "By increasing the amount of data, we will see a more robust picture of the tree of life."


-- Terry Devitt 608-262-8282, trdevitt@wisc.edu

ADDITIONAL CONTACT: Antonis Rokas 608-265-2004, arokas@wisc.edu; Barry L. Williams 608-265-2004, bwilliams2@wisc.edu

Terry Devitt | EurekAlert!
Further information:
http://www.wisc.edu/

More articles from Life Sciences:

nachricht Chains of nanogold – forged with atomic precision
23.09.2016 | Suomen Akatemia (Academy of Finland)

nachricht Self-assembled nanostructures hit their target
23.09.2016 | King Abdullah University of Science and Technology

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: OLED microdisplays in data glasses for improved human-machine interaction

The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has been developing various applications for OLED microdisplays based on organic semiconductors. By integrating the capabilities of an image sensor directly into the microdisplay, eye movements can be recorded by the smart glasses and utilized for guidance and control functions, as one example. The new design will be debuted at Augmented World Expo Europe (AWE) in Berlin at Booth B25, October 18th – 19th.

“Augmented-reality” and “wearables” have become terms we encounter almost daily. Both can make daily life a little simpler and provide valuable assistance for...

Im Focus: Artificial Intelligence Helps in the Discovery of New Materials

With the help of artificial intelligence, chemists from the University of Basel in Switzerland have computed the characteristics of about two million crystals made up of four chemical elements. The researchers were able to identify 90 previously unknown thermodynamically stable crystals that can be regarded as new materials. They report on their findings in the scientific journal Physical Review Letters.

Elpasolite is a glassy, transparent, shiny and soft mineral with a cubic crystal structure. First discovered in El Paso County (Colorado, USA), it can also be...

Im Focus: Complex hardmetal tools out of the 3D printer

For the first time, Fraunhofer IKTS shows additively manufactured hardmetal tools at WorldPM 2016 in Hamburg. Mechanical, chemical as well as a high heat resistance and extreme hardness are required from tools that are used in mechanical and automotive engineering or in plastics and building materials industry. Researchers at the Fraunhofer Institute for Ceramic Technologies and Systems IKTS in Dresden managed the production of complex hardmetal tools via 3D printing in a quality that are in no way inferior to conventionally produced high-performance tools.

Fraunhofer IKTS counts decades of proven expertise in the development of hardmetals. To date, reliable cutting, drilling, pressing and stamping tools made of...

Im Focus: Launch of New Industry Working Group for Process Control in Laser Material Processing

At AKL’16, the International Laser Technology Congress held in May this year, interest in the topic of process control was greater than expected. Appropriately, the event was also used to launch the Industry Working Group for Process Control in Laser Material Processing. The group provides a forum for representatives from industry and research to initiate pre-competitive projects and discuss issues such as standards, potential cost savings and feasibility.

In the age of industry 4.0, laser technology is firmly established within manufacturing. A wide variety of laser techniques – from USP ablation and additive...

Im Focus: New laser joining technologies at ‘K 2016’ trade fair

Every three years, the plastics industry gathers at K, the international trade fair for plastics and rubber in Düsseldorf. The Fraunhofer Institute for Laser Technology ILT will also be attending again and presenting many innovative technologies, such as for joining plastics and metals using ultrashort pulse lasers. From October 19 to 26, you can find the Fraunhofer ILT at the joint Fraunhofer booth SC01 in Hall 7.

K is the world’s largest trade fair for the plastics and rubber industry. As in previous years, the organizers are expecting 3,000 exhibitors and more than...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Experts from industry and academia discuss the future mobile telecommunications standard 5G

23.09.2016 | Event News

ICPE in Graz for the seventh time

20.09.2016 | Event News

Using mathematical models to understand our brain

16.09.2016 | Event News

 
Latest News

Custom-tailored strategy against glioblastomas

26.09.2016 | Health and Medicine

Cooling buildings with solar heat

26.09.2016 | Power and Electrical Engineering

Chains of nanogold – forged with atomic precision

23.09.2016 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>