The problem highlights a general issue in evolutionary biology of what determines the range of plants and animals we see compared to those that might have evolved theoretically. To what extent does observed biodiversity reflect the rules of development or the action of Darwinian selection?
To address this problem, Enrico Coen at the John Innes Centre and Dr. Przemyslaw Prusinkiewicz and colleagues at the University of Calgary analysed not Unicorns, but a more tractable system, the evolution of flower branching displays, or inflorescences. Flowering plants have three basic types of inflorescence - racemes, cymes and panicles. Theoretically there are many other possible branching arrangements so why has nature chosen only these three? The researchers showed how the three types arise quite naturally from a simple mathematical model for how growing tips switch to make flowers. The model was supported by experimental studies on genes in the garden weed Arabidopsis.
So it looks like the way genes control development plays an important role in determining what sorts of structure evolve. But the researchers also showed that selection plays a key part in setting the routes that evolution may take within the space of possibilities. They revealed novel paths, called evolutionary wormholes that link together different inflorescence types, allowing one to evolve into another. Perhaps there are no Unicorns because no evolutionary wormholes exist that connect them to horses, or maybe the wormholes are there but evolution has not had time to go down them. The riddle of the Unicorn remains but at least scientists now have a more rigorous mathematical and experimental framework in which to consider such issues.
A Map of the Cell’s Power Station
18.08.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau
On the way to developing a new active ingredient against chronic infections
18.08.2017 | Deutsches Zentrum für Infektionsforschung
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
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