In a study published in the Proceedings of the National Academy of Sciences researchers have found evidence which suggests that evolution drives animals to become increasingly more complex.
Looking back through the last 550 million years of the fossil catalogue to the present day, the team investigated the different evolutionary branches of the crustacean family tree.
They were seeking examples along the tree where animals evolved that were simpler than their ancestors.
Instead they found organisms with increasingly more complex structures and features, suggesting that there is some mechanism driving change in this direction.
“If you start with the simplest possible animal body, then there’s only one direction to evolve in – you have to become more complex,” said Dr Matthew Wills from the Department of Biology & Biochemistry at the University of Bath who worked with colleagues Sarah Adamowicz from from the University of Waterloo (Canada) and Andy Purvis from Imperial College London.
“Sooner or later, however, you reach a level of complexity where it’s possible to go backwards and become simpler again.
“What’s astonishing is that hardly any crustaceans have taken this backwards route.
“Instead, almost all branches have evolved in the same direction, becoming more complex in parallel.
“This is the nearest thing to a pervasive evolutionary rule that’s been found.
“Of course, there are exceptions within the crustacean family tree, but most of these are parasites, or animals living in remote habitats such as isolated marine caves.
“For those free-living animals in the ‘rat-race’ of evolution, it seems that competition may be the driving force behind the trend.
“What’s new about our results is that they show us how this increase in complexity has occurred.
“Strikingly, it looks far more like a disciplined march than a milling crowd.”
Dr Adamowicz said: “Previous researchers noticed increasing morphological complexity in the fossil record, but this pattern can occur due to the chance origination of a few new types of animals.
“Our study uses information about the inter-relatedness of different animal groups – the ‘Tree of Life’ – to demonstrate that complexity has evolved numerous times independently.”
Like all arthropods, crustaceans’ bodies are built up of repeating segments. In the simplest crustaceans, the segments are quite similar - one after the other. In the most complex, such as shrimps and lobsters, almost every segment is different, bearing antennae, jaws, claws, walking legs, paddles and gills.
The American biologist Leigh Van Valen coined the phrase ‘Red Queen’ for the evolutionary arms race phenomenon. In Through the Looking-Glass Lewis Carroll’s Red Queen advises Alice that: “It takes all the running you can do, to keep in the same place.”
“Those crustacean groups going extinct tended to be less complex than the others around at the time,” said Dr Wills.
“There’s even a link between average complexity within a group and the number of species alive today.
“All organisms have a common ancestor, so that every living species is part of a giant family tree of life.”
Dr Adamowicz added: “With a few exceptions, once branches of the tree have separated they continue to evolve independently.
“Looking at many independent branches is similar to viewing multiple repeated runs of the tape of evolution.
“Our results apply to a group of animals with bodies made of repeated units. We must not forget that bacteria – very simple organisms – are among the most successful living things. Therefore, the trend towards complexity is compelling but does not describe the history of all life.”
Andrew McLaughlin | alfa
Bacteria as pacemaker for the intestine
22.11.2017 | Christian-Albrechts-Universität zu Kiel
Researchers identify how bacterium survives in oxygen-poor environments
22.11.2017 | Columbia University
The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.
Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
22.11.2017 | Business and Finance
22.11.2017 | Physics and Astronomy
22.11.2017 | Physics and Astronomy