Animals with large brains are generally considered to be more intelligent and more successful than those with smaller brains. Researchers from the Vetmeduni Vienna and Stockholm University have now provided the first experimental evidence that large brains provide an evolutionary advantage. In their study, large-brained female fish had a higher survival rate than those with small brains when faced with a predator, although brain size surprisingly did not influence male survival. The results were published in the prestigious journal Ecology Letters.
A larger brain brings better cognitive performance. And so it seems only logical that a larger brain would offer a higher survival potential. In the course of evolution, large brains should therefore win out over smaller ones.
Previous tests of this hypothesis had relied on comparison studies looking at the intelligence and survival potential of species with large brains versus species with smaller brains. And species with larger brains do appear to have an advantage. But such studies are unable to show a causal relationship.
Alexander Kotrschal, Sarah Zala, Séverine Büchel and Dustin Penn from the Konrad Lorenz Institute of Ethology at the Vetmeduni Vienna studied fish to answer why investing in a larger brain might provide an evolutionary advantage to compensate for the fact that brain mass is very expensive to develop and maintain.
Research on guppies with large and small brains in semi-natural streams
Guppies are a species of freshwater aquarium fish whose natural range is in the Caribbean region. Kotrschal and his colleagues previously conducted an artificial selection experiment and successfully generated large- and small-brained guppies. In this study, they aimed to test whether brain size influences survival.
Therefore, they released 4,800 guppies from these selection lines into large semi-natural streams, which also contained a natural predator, the pike cichlid. About half a year later, significantly more guppies with large brains had survived. The researchers suggest that large-brained fish have an advantage that allows them to better evade predation. “We have provided the first experimental proof that a large brain offers an evolutionary advantage,” explains first author Kotrschal, who has since moved on to Stockholm University.
Large brains an advantage for females
Large-brained females, whose brains were about 12 percent larger than that of the small-brained females, evaded their predators more often and so had a higher rate of survival. Larger brains did not provide any survival benefit for males. Ethologist Sarah Zala explains: “Male guppies are more colourful and more conspicuous than females and are therefore more easily caught by a predator. A larger brain does not appear to compensate this disadvantage.”
Confirmation of hypothesis on evolution of brain size
“Our findings support the hypothesis that large brains provide a survival benefit under predation pressure,” says co-author Dustin Penn. The first results also suggest that groups of fish with large or small brains behave differently in the presence of the predatory cichlid. This behaviour merits further study. The researchers also want to know whether surviving fish produce more offspring. Genetic analysis should help provide clarity in this regard.
The article „Brain size affects female but not male survival under predation threat”, by Alexander Kotrschal, Séverine Büchel, Sarah M. Zala, Alberto Corral, Dustin J. Penn and Niclas Kolm was published in Ecology Letters veröffentlicht. doi: 10.1111/ele.12441
About the University of Veterinary Medicine, Vienna
The University of Veterinary Medicine, Vienna in Austria is one of the leading academic and research institutions in the field of Veterinary Sciences in Europe. About 1,300 employees and 2,300 students work on the campus in the north of Vienna which also houses five university clinics and various research sites. Outside of Vienna the university operates Teaching and Research Farms. http://www.vetmeduni.ac.at
Dr. Alexander Kotrschal
Science Communication / Public Relations
University of Veterinary Medicine Vienna (Vetmeduni Vienna)
T +43 1 25077-1153
Dr. Susanna Kautschitsch | idw - Informationsdienst Wissenschaft
Unique genome architectures after fertilisation in single-cell embryos
30.03.2017 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH
Transport of molecular motors into cilia
28.03.2017 | Aarhus University
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
30.03.2017 | Health and Medicine
30.03.2017 | Health and Medicine
30.03.2017 | Medical Engineering