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
Coat of proteins makes viruses more infectious and links them to Alzheimer's disease
27.05.2019 | Stockholm University
The Secret of the Rock Drawings
24.05.2019 | Max-Planck-Institut für Chemie
Researchers from Sweden's Chalmers University of Technology and the University of Gothenburg present a new method which can double the energy of a proton beam produced by laser-based particle accelerators. The breakthrough could lead to more compact, cheaper equipment that could be useful for many applications, including proton therapy.
Proton therapy involves firing a beam of accelerated protons at cancerous tumours, killing them through irradiation. But the equipment needed is so large and...
A new assessment of NASA's record of global temperatures revealed that the agency's estimate of Earth's long-term temperature rise in recent decades is accurate to within less than a tenth of a degree Fahrenheit, providing confidence that past and future research is correctly capturing rising surface temperatures.
The most complete assessment ever of statistical uncertainty within the GISS Surface Temperature Analysis (GISTEMP) data product shows that the annual values...
Physicists at the University of Basel are able to show for the first time how a single electron looks in an artificial atom. A newly developed method enables them to show the probability of an electron being present in a space. This allows improved control of electron spins, which could serve as the smallest information unit in a future quantum computer. The experiments were published in Physical Review Letters and the related theory in Physical Review B.
The spin of an electron is a promising candidate for use as the smallest information unit (qubit) of a quantum computer. Controlling and switching this spin or...
Engineers at the University of Tokyo continually pioneer new ways to improve battery technology. Professor Atsuo Yamada and his team recently developed a...
With a quantum coprocessor in the cloud, physicists from Innsbruck, Austria, open the door to the simulation of previously unsolvable problems in chemistry, materials research or high-energy physics. The research groups led by Rainer Blatt and Peter Zoller report in the journal Nature how they simulated particle physics phenomena on 20 quantum bits and how the quantum simulator self-verified the result for the first time.
Many scientists are currently working on investigating how quantum advantage can be exploited on hardware already available today. Three years ago, physicists...
29.04.2019 | Event News
17.04.2019 | Event News
15.04.2019 | Event News
27.05.2019 | Information Technology
27.05.2019 | Physics and Astronomy
27.05.2019 | Life Sciences