Putting more meat on the theory that dinosaurs’ closest living relatives are modern-day birds, molecular analysis of a shred of 68-million-year-old Tyrannosaurus rex protein – along with that of 21 modern species – confirms that dinosaurs share common ancestry with chickens, ostriches, and to a lesser extent, alligators.
The work, published this week in the journal Science, represents the first use of mo-lecular data to place a non-avian dinosaur in a phylogenetic tree that traces the evolution of species. The scientists also report that similar analysis of 160,000- to 600,000-year-old collagen protein sequences derived from mastodon bone establishes a close phylogenetic relationship between that extinct species and modern elephants.
“These results match predictions made from skeletal anatomy, providing the first molecular evidence for the evolutionary relationships of a non-avian dinosaur,” says co-author Chris Organ, a postdoctoral researcher in organismic and evolutionary biology at Harvard University. “Even though we only had six peptides – just 89 amino acids – from T. rex, we were able to establish these relationships with a relatively high degree of sup-port. With more data, we’d likely see the T. rex branch on the phylogenetic tree between alligators and chickens and ostriches, though we can’t resolve this position with currently available data.”
The current paper builds on work reported in Science last year. In that paper, a team headed by John M. Asara and Lewis C. Cantley, both of Beth Israel Deaconess Medi-cal Center (BIDMC) and Harvard Medical School (HMS), first captured and sequenced tiny pieces of collagen protein from T. rex. For the current work, Organ and Asara and their colleagues used sophisticated algorithms to compare collagen protein from several dozen species. The goal: placing T. rex on the animal kingdom’s family tree using molecu-lar evidence.
“Most of the collagen sequence was obtained from protein and genome databases but we also needed to sequence some critical organisms, including modern alligator and modern ostrich, by mass spectrometry,” says Asara, director of the mass spectrometry core facility at BIDMC and instructor in pathology at HMS. “We determined that T. rex, in fact, grouped with birds – ostrich and chicken – better than any other organism that we studied. We also show that it groups better with birds than modern reptiles, such as alliga-tors and green anole lizards.”
While scientists have long suspected that birds, and not more basal reptiles, are di-nosaurs’ closest living relatives, for years that hypothesis rested largely on morphological similarities in bird and dinosaur skeletons.
The scraps of dinosaur protein were wrested from a fossil femur discovered in 2003 by John Horner of the Museum of the Rockies in a barren fossil-rich stretch of land that spans Wyoming and Montana. Mary H. Schweitzer of North Carolina State Univer-sity (NCSU) and the North Carolina Museum of Natural Sciences discovered soft-tissue preservation in the T. rex bone in 2005; Asara became involved in analysis of the colla-gen protein because of his expertise in mass spectrometry techniques capable of se-quencing minute amounts of protein from human tumors. While it appears impossible to salvage DNA from the bone, Asara was able to extract precious slivers of protein.
The current work by Organ and Asara suggests that the extracted protein from the fossilized dinosaur tissue is authentic, rather than contamination from a living spe-cies.
“These results support the endogenous origin of the preserved collagen mole-cules,” the researchers write.
Steve Bradt | EurekAlert!
Hopkins researchers ID neurotransmitter that helps cancers progress
26.04.2019 | Johns Hopkins Medicine
Trigger region found for absence epileptic seizures
25.04.2019 | RIKEN
For the first time, physicists at the University of Basel have succeeded in measuring the magnetic properties of atomically thin van der Waals materials on the nanoscale. They used diamond quantum sensors to determine the strength of the magnetization of individual atomic layers of the material chromium triiodide. In addition, they found a long-sought explanation for the unusual magnetic properties of the material. The journal Science has published the findings.
The use of atomically thin, two-dimensional van der Waals materials promises innovations in numerous fields in science and technology. Scientists around the...
Flexible, organic and printed electronics conquer everyday life. The forecasts for growth promise increasing markets and opportunities for the industry. In Europe, top institutions and companies are engaged in research and further development of these technologies for tomorrow's markets and applications. However, access by SMEs is difficult. The European project SmartEEs - Smart Emerging Electronics Servicing works on the establishment of a European innovation network, which supports both the access to competences as well as the support of the enterprises with the assumption of innovations and the progress up to the commercialization.
It surrounds us and almost unconsciously accompanies us through everyday life - printed electronics. It starts with smart labels or RFID tags in clothing, we...
The human eye is particularly sensitive to green, but less sensitive to blue and red. Chemists led by Hubert Huppertz at the University of Innsbruck have now developed a new red phosphor whose light is well perceived by the eye. This increases the light yield of white LEDs by around one sixth, which can significantly improve the energy efficiency of lighting systems.
Light emitting diodes or LEDs are only able to produce light of a certain colour. However, white light can be created using different colour mixing processes.
Researchers led by Francesca Ferlaino from the University of Innsbruck and the Austrian Academy of Sciences report in Physical Review X on the observation of supersolid behavior in dipolar quantum gases of erbium and dysprosium. In the dysprosium gas these properties are unprecedentedly long-lived. This sets the stage for future investigations into the nature of this exotic phase of matter.
Supersolidity is a paradoxical state where the matter is both crystallized and superfluid. Predicted 50 years ago, such a counter-intuitive phase, featuring...
A stellar flare 10 times more powerful than anything seen on our sun has burst from an ultracool star almost the same size as Jupiter
17.04.2019 | Event News
15.04.2019 | Event News
09.04.2019 | Event News
26.04.2019 | Life Sciences
26.04.2019 | Physics and Astronomy
26.04.2019 | Physics and Astronomy