Whales are well known for being the biggest animals on Earth, their massive shapes moving not ungracefully through the planet’s waters. But fossil records seem to indicate that these large animals were not always so big. Instead, they appeared to have been much smaller, which prompted a team of researchers to take a closer look.
Their study results became available earlier this week in the Proceedings of the Royal Society B. They come from a group of Stanford University scientists led by Jeremy Goldbogen. According to this new report, climate change could have played a significant part in the development of whales.
Whales Started Growing as the Climate Started Changing?
Whales are known to feed on small fish and krill, usually colonies of them. This new study points out that, as the weather started changing, krill started packing and moving in smaller areas than before. As the animals continued feeding on them, larger specimens were simply more efficient at consuming these dense pockets of food.
Large whales, also known as baleens, use filters made of keratin for feeding on krill. As the whale opens its mouth, it sucks in a large quantity of water mixed with its food. With the water trickling out, the filters catch and capture the krill or fish.
Goldbogen and his team determined that baleen started evolving into their current shape some 20 million years ago. At the time of their accelerated growth, the world had also started getting colder as it was entering an ice age. So the researchers consider that this climate change led to a higher number of nutrients and runoffs pouring into the coastal waters.
Oceanic upwelling may have also contributed to their development as deep waters are usually full of benefits for baleens. The combination of the upwelling and the incoming ice age most likely resulted in dense patches of food, ready for the taking by the massive baleen, which includes the blue whale.
“As animals are getting bigger, they’re getting much more efficient. So for every gulp, they’re getting tremendous amounts of energy” states Goldbogen.
To put it simply, big whales are better equipped at eating small dense patches of food while the smaller ones must have been better at eating from dispersed areas.
Goldbogen also expressed enthusiasm at being able to study these massive animals. He also believes that researchers should look to find out if whales will continue growing in size.
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