5 Million years ago, the two Americas collided- leading to changes in the flow of Gulf Stream. Gulf Stream was warm current. After the collision, it travelled from the Gulf of Mexico, up towards the Arctic and plunged into the ocean- taking the heat with it. The temperature of earth gradually fell marking the beginning of Ice Age. Polar Icecap was formed during this period. Even after the end of the ice age, it is still intact to this day. Or is it really?During this climatic change, a group of brave fish called notothenioid fishes decided to adapt themselves to the cold climate. They are still dwelling in the cold water after millions of years of evolution.
They have an interesting ecological story that caught the attention of H. William Detrich, a professor of environmental and marine science at Northeastern University. The research revealed that the ancestral notothenioid fish had dense bones as they were deep sea dwellers. Modern notothenioid fish have light and oily bodies to float at different levels of water. This change ensured their ability to withstand the harsh Antarctic environments. Their genes involved fasters, questing the scientists about the reason for such quick and substantial change. This makes these fishes more interesting than others.
Scientists are trying to find out how different species will respond to changing climatic conditions using notothenioid fishes an example. They sequenced specific sections of the genomes of more than 40 notothenioid fish species. The researchers were able to analyse the mutations and the time during which they started to occur. Surprisingly, they found that these traits were already floating around in the genetic pool long before the Ice Age commenced.
On the contrary, these mutations can be deadly if adapted by humans. The climate change has given the notothenioid fish transparent blood, fragile bones and inefficient kidneys. Let’s try not getting our genome mixed with them. However, the notothenioid fishes are happy survivors with these characteristics making everyone awe at nature’s working.
Shraddha Patil