New findings by neurobiologists at the University of Washington suggest that both patterns are important. The researchers found that bigger-bodied social wasps had larger brains and devoted up to three times more of their brain tissue to regions that coordinate social interactions, learning, memory and other complex behaviors.
Within a species, queens had larger central processing areas – the brain regions that manage complex behaviors – than did worker wasps.
“As the brain gets larger, there’s disproportionately greater investment in the size of brain tissue for higher-order cognitive abilities,” said Sean O’Donnell, lead author and UW psychology professor. “As larger wasp brains evolve, natural selection favors investing most heavily in the brain regions involved in learning and memory.”
For smaller-brained species, cognitive power may be limited by their inability to invest in central brain regions. “In many kinds of animals, it’s only with a larger brain – which is determined by body size – that more complex and flexible behaviors are achieved,” O’Donnell said.
The results appear in the April 11 online edition of the Proceedings of the National Academy of Sciences.
O’Donnell and his co-authors collected samples of 10 types of adult social wasps from four field sites in Costa Rica and Ecuador. As in other studies, they found that the larger the wasp, the larger the overall brain size. But increase of brain size was not uniform across all brain regions.
The researchers dissected the wasp brains and measured the volume of two brain regions. They focused on the central processing region known as the mushroom bodies that, like the cerebral cortex in humans, handles elaborate cognitive functions such as learning, memory and social interactions. They also measured the peripheral processing regions – the optic lobes and the antennal lobes – that deal with vision and smell and are thought to perform more basic cognitive functions.
Across the 10 species, brain areas that process peripheral sensory information increased only slightly with overall brain size. But the wasps with larger bodies – and correspondingly larger-sized brains – had disproportionately larger central processing regions.
“These findings suggest that absolute brain size matters a lot, because it sets limits on central cognitive processing tissue,” O’Donnell said.
The researchers also found that in nine out of 10 wasp species, the queens had larger central processors than worker wasps. This was surprising to the researchers because, in social wasps, queens seem to not perform complex tasks like food collection. They’re relatively inactive, staying in the nest to lay eggs while the workers go out to forage.
But O’Donnell said the greater brain power possessed by social wasp queens may be due to having to defend their social status. “Queens are constantly tested for their potency. They must be up for those social cognitive demands,” he said.
The researchers are now testing the prediction that large-brained species will have enhanced cognitive abilities compared with smaller-brained species, which could have ecological payoffs for challenges like invading new habitats and expanding their geographic range.
The National Science Foundation and the Society for Integrative & Comparative Biology funded the study. Co-authors are Yamile Molina, who received a doctorate in psychology at UW, and Marie Clifford, a UW biology graduate student.For more information, contact O’Donnell at email@example.com or 206-543-2315.
O’Donnell | Newswise Science News
Oestrogen regulates pathological changes of bones via bone lining cells
28.07.2017 | Veterinärmedizinische Universität Wien
Programming cells with computer-like logic
27.07.2017 | Wyss Institute for Biologically Inspired Engineering at Harvard
Spectrally narrow x-ray pulses may be “sharpened” by purely mechanical means. This sounds surprisingly, but a team of theoretical and experimental physicists developed and realized such a method. It is based on fast motions, precisely synchronized with the pulses, of a target interacting with the x-ray light. Thereby, photons are redistributed within the x-ray pulse to the desired spectral region.
A team of theoretical physicists from the MPI for Nuclear Physics (MPIK) in Heidelberg has developed a novel method to intensify the spectrally broad x-ray...
Physicists working with researcher Oriol Romero-Isart devised a new simple scheme to theoretically generate arbitrarily short and focused electromagnetic fields. This new tool could be used for precise sensing and in microscopy.
Microwaves, heat radiation, light and X-radiation are examples for electromagnetic waves. Many applications require to focus the electromagnetic fields to...
Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers
Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...
Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.
At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...
3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects
A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...
26.07.2017 | Event News
21.07.2017 | Event News
19.07.2017 | Event News
28.07.2017 | Health and Medicine
28.07.2017 | Power and Electrical Engineering
28.07.2017 | Life Sciences