According to “How did whales become do large? Scientists dive into marine mystery” by Nicola Davis, the blue whale has a body the length of a jetliner, a heart the size of a car and a tongue the weight of an elephant. Researchers now say that they might have found the solution to the mystery behind why baleen whales-a group that includes the blue whales, became the largest animals on the planet. Scientists say that the massive growth which was driven by changes in the distribution of oceanic food and happened just 2 to 3 million years ago. Graham Slater, an evolutionary biologist and co-author of the research from the University of Chicago says that baleen whales have only been giants for one-tenth of their 36-million-year evolutionary history. …show more content…
They also found that it was not just the largest whales that grew over time; the smallest whales found today are larger than the smallest extinct species. Further analysis revealed that the baleen whales had been diversifying in size for 30 million years; this began to take place between 4.5 million and a few hundred thousand years ago. The recent timing rules out the possibility that the emergence of gigantism was caused by the evolution of bulk filter feeding, large predators like giant sharks and falling global ocean temperatures. Slater says that the recent onset of glaciation in the Northern Hemisphere caused the evolution of gigantism in baleen whales. While the scenario for one of the last stages in the evolution of size of baleen whales is convincing, Olivier Lambert, a paleontologist from the Royal Belgian Institute of Natural Science, says that it was likely other factors such as the evolution of large predators and other climatic events which played a role in the development of the animals ' size. Both scientists agree that climate change does have an effect on the populations and the ecosystems of baleen whales. Slater says that " If climate change does go the route we think it is going, it is going to spell really bad news for these big baleen