— Archaeologists find new evidence of animals being introduced to prehistoric Caribbean — An archaeological research team from North Carolina State University, the University of Washington and University of Florida has found one of the most diverse collections of prehistoric…
— Microscopic worms could hold the key to living life on Mars — The astrophysicist Stephen Hawking believes that if humanity is to survive we will have up sticks and colonise space. But is the human body up to the challenge?…
— Chemical warfare of stealthy silverfish — A co-evolutionary arms race exists between social insects and their parasites. Army ants (Leptogenys distinguenda) share their nests with several parasites such as beetles, snails and…
— Stinky frogs are a treasure trove of antibiotic substances — Some of the nastiest smelling creatures on Earth have skin that produces the greatest known variety of anti-bacterial substances that hold promise for becoming new weapons in the battle…
— Genetic code of first arachnid cracked — An international team of scientists - including Ghent VIB scientists - has succeeded in deciphering the genome of the spider mite. This is also the first known genome of an arachnid.…
— How bats 'hear' objects in their path — By placing real and virtual objects in the flight paths of bats, scientists at the Universities of Bristol and Munich have shed new light on how echolocation works. Their research is…
— Counting cats: The endangered snow leopards of the Himalayas — The elusive snow leopard (Panthera uncia) lives high in the mountains across Central Asia. Despite potentially living across 12 countries the actual numbers of this beautiful large…
— Surprise role of nuclear structure protein in development — Scientists have long held theories about the importance of proteins called B-type lamins in the process of embryonic stem cells replicating and differentiating into different varieties…
— Pregnancy is a drag for bottlenose dolphins — Lumbering around during the final weeks before delivery is tough for any pregnant mum. Most females adjust their movements to compensate for the extreme physical changes that accompany…
New evolutionary research disproves living missing link theories
Evolution is not a steady march towards ever more sophisticated beings and therefore the search for the living 'missing links' is pointless, according to findings published by a team of researchers led by Dr Herve Philippe of the Universite de Montreal's Department of Biochemistry. 'Aristotle was the first to classify organisms - from the least to the most sophisticated. Darwin's theory of evolution continued this idea, with the concept of a hierarchy of evolution. This way of thinking has led researchers and sceptics alike to look for less sophisticated ancestors in order to prove or disprove evolution,' Philippe explained. 'What we now know is that evolution does not happen in a single direction - when people talk about a missing link, they're generally excluding the possibility of more sophisticated ancestors.'
The researchers compared the genomes of two kinds of marine worms with simple morphology - Xenoturbellida and Acoelomorpha - with those of other animals. They demonstrated that their previous position at the base of the bilateral symmetry animal group - that includes insects, molluscs and vertebrates - was inaccurate. 'Instead, we determined that Xenoturbellida and Acoelomorpha are closely related to the complex deuterostomes, which is a major lineage containing sea urchins, humans and sharks,' Philippe said. 'I've put them in that order intentionally because it seems strange, which demonstrates our tendency to always put organisms in order of complexity.' The findings mean that the worms had evolved from a more sophisticated ancestor through major simplifications.
'We did already know that most parasitic organisms had evolved to be less sophisticated than their ancestors - they lost certain abilities that they no longer needed. The independently living Xenoturbellida and Acoelomorpha do not fall in this category,' Philippe said. The research is a striking example for the important role of secondary simplification in evolution and is part of 20 year project that is nearing completion. The findings were published in Nature on February 10, 2011.
Or subscribe for our Newsletter, a free e-mail publication. It is published practically every day.
On the origin of subspecies
Biologists find gene network that gave rise to first tooth
Single gene lets bacteria jump from host to host
Palaeontologist reflects on Darwinian connections