Monday, 25 July 2011

DNA suggests crocodiles swam the Atlantic to reach America

New findings from the most complete evolutionary tree of the genus Crocodylus, featuring all but one of the living crocodile species, has revealed that crocodiles swam thousands of kilometers from Africa to colonise the Americas.
Upon sequencing ther mitochondrial genomes of 11 species , eight of which had not been mitochondrial DNA sequenced before , Evon Hekkala of Forham University in New York and colleagues havd learned that all four American species are closely related to the Nile crocodiles of East Africa. It is suspected that these crocofiles must have split away roughly 7 million years ago after South America and Africa began drifting apart over 130million years ago. By 7 million years ago, over 2800 kilometres of ocean lay between the two continents.
For this study Hekkala and her team have been able to use genetic data from Egyptian crocodile mummies to try to identify the baseline distribution of unique evolutionary lineages in the Nile crocodile.
It has been long suspected by palaeontologists that crocodiles swam the Atlantic, but Hekkala”s finding is “strong evidence in support of that scenario”, said Christopher Brochu of the University of Iowa in Iowa City.
Crocodiles are salt-tolerant and can go up to six months without eating and females can carry viable sperm for several months after mating, which means a single female could have crossed the Atlantic and produced a litter on the other side. It”s unlikely that a single such event would have given rise to all American crocodiles.
But Hekkala pointed out that animals that got lost at sea off the coast of Africa may well have been carried across on the westward-flowing equatorial currents.

Discussion Board Question

IYSF have invited Professor Steve Lloyd PhD (Lond) FinstP CPhys to pose the fist ever  debate question. 

Professor Lloyd currently works in the Physics department in Queen Mary University of London .
His expertise is in experimental particle physics; the ATLAS collaboration,  studying proton-proton collisions at the Large Hadron Collider (LHC) at CERN; data produced by the LHC; development of the 'Grid' - a massive distributed computer system to analyse vast amounts of data that is being produced by the LHC.

Professor Lloyds question :

"Scientists at CERN in Geneva are using the Large Hadron Collider to search for a new fundamental particle called the Higgs particle (or Higgs boson). In the so called Standard Model of particle physics, the Higgs particle explains mathematically how all the other fundamental particles like quarks and leptons acquire mass. The theory is that the whole of space is filled with Higgs particles in the form of a Higgs field and that as the other particles pass through space they interact with this field and are slowed down such that they no longer travel at the speed of light, as massless particles would, and hence appear to have mass. How do you explain to a non-scientist what the Higgs particle is ?"