The DNA of a popular living fossil fish has been decoded by scientists, which has lead them to gain many insights on how the mammals, reptiles, amphibians and birds evolve from any fish ancestor.
African coelacanth relates to that fish lineage closely which began moving toward a significant evolutionary transformation, residing on the land and hasn’t changed a lot from the ancestors of over 300 millions of years, as told by researchers.
At a time, scientists used to think coelacanths died over seventy million years back. In an astounding discovery in the year 1938, living specimen was caught by a fish trawler from South Africa. The nickname “living fossil” was earned be it due to the close resemblance with ancient ancestors.
According to an international researcher’s team in a journal Nature, analysis also shows that the genes have stayed very slow in changing.
Kerstin Lindblad-Toh , senior paper author and an expert at genes at the “Broad Institute in Cambridge” said that this might be because stable environment is provided by sea caves inhabited by coelacanths.
Two of endangered species are made by modern coelacanths that house at Africa’s east coast and Indonesia. They have the tendency to grow to above 5 feet and acquire fleshy fins.
DNA code of coelacanth, called the genome, happens to be a bit smaller compared to a human’s. Putting it to use as starting point, researchers did find evidence regarding change in the genes and gene-controlling switches which clearly helped in moving to the land. These involve things like the smelling sense, limb development and immune system.
the researchers said that deeper study of genomes might provide much insight into this change of living on the land. The analysis they did resulted in the fact that a dissimilar creature, lungfish, happens to be closest relative, in living fish, of animals that have limbs such as mammals but according to them, the genome of lungfish is quite big so about impossible to decode.
This transition to land took years counting to millions, with the limbs growing in animals which are primarily aquatic, even more than 400 million years back and it is said by Ted Daeschler, a researcher, that a real switchover to land was about 340 millions of years ago.
Daeschler is the curator of the vertebrate zoology in “the Academy of Natural Sciences of Drexel University in Philadelphia”. He did not take part in this new work and said that these researches provide a means of tackling some questions that were previously unanswerable in evolution.
He also insisted that DNA should be combined with fossils to put it to best use.
He said that this is a great detective tool and that one can collect DNA evidence at a crime scene but can’t ignore the dead body. He added that with paleontology, we have the dead bodies.