Reef fish share genetic connections across what Darwin termed an 'impassable barrier', 5000km of deep ocean separating the eastern and central Pacific, according to a report by Smithsonian scientists in the Proceedings of the Royal Society B.
Credit: D.R. Robertson
Credit: D.R. Robertson
By sequencing mitochondrial DNA from 20 morphospecies of fairly sedentary shore fish on both sides of the divide, the study confirms close relationships between populations of the same fish species across the barrier and indicates that genes move in both directions across the barrier.
Luck affects who makes it across and when
"We didn't find genetic evidence for any oceanographic or geological events that separated populations such as a major change in currents or the sinking of an underwater platform that could have served as a stepping stone," Lessios points out. "If that were the case, several species would have shown coincident times of separation." Instead, the researchers consider that fish larvae cross the barrier often enough to maintain genetic connections, but in a very haphazard and infrequent fashion, such that speciation did occur in most cases, but was prevented from happening in others.
Two-way gene flow
Conventional wisdom held that there was little larval movement from West to East and no movement from East to West across the divide until a recent study by co-author Robertson et al. indicated that about 20% of transpacific fish invaded from East to West. "The current study provides more meat for that barbeque. If you look at westward currents, they look as good as or better then eastward currents for moving larvae between populations. People were just focused on eastward movement because El Nino currents go that way," according to Robertson.
Whereas this study was able to rule out the idea that a vicariance event separated these species long ago, all of the alternative hypotheses to explain the presence of related species in the Eastern and Central Pacific still seem to be valid. Several of the species are likely to have been separated long ago and continue to diverge. Others presumably were separated more recently. And gene flow in both directions has occurred. Therefore, low level dispersal should be considered as an important factor in breaching the East Pacific Barrier.
Haris Lessios | EurekAlert!
Cancer diagnosis: no more needles?
25.05.2018 | Christian-Albrechts-Universität zu Kiel
Less is more? Gene switch for healthy aging found
25.05.2018 | Leibniz-Institut für Alternsforschung - Fritz-Lipmann-Institut e.V. (FLI)
The more electronics steer, accelerate and brake cars, the more important it is to protect them against cyber-attacks. That is why 15 partners from industry and academia will work together over the next three years on new approaches to IT security in self-driving cars. The joint project goes by the name Security For Connected, Autonomous Cars (SecForCARs) and has funding of €7.2 million from the German Federal Ministry of Education and Research. Infineon is leading the project.
Vehicles already offer diverse communication interfaces and more and more automated functions, such as distance and lane-keeping assist systems. At the same...
A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.
The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...
At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.
At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...
There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?
At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
25.05.2018 | Event News
02.05.2018 | Event News
13.04.2018 | Event News
25.05.2018 | Event News
25.05.2018 | Machine Engineering
25.05.2018 | Life Sciences