Kuwait Times

Whale of a mystery solved? How they got so big

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Scientists think they have answered a whale of a mystery: How the ocean creatures got so huge so quickly. A few million years ago, the largest whales, averaged maybe 15 feet long. That’s big, but you could still hold a fossil skull in two hands. Then seemingly overnight, one type of whale - the toothless baleens - became huge. Modern blue whales get as big as 100 feet, the largest creatures ever on Earth. Its skull is now bigger than a minivan and could probably fit more than five people inside, researcher­s said. “We really are living in the time of giants,” said study coauthor Nicholas Pyenson of the Smithsonia­n Natural History Museum. “Why is that?”

And it happened “in the blink of an evolutiona­ry eye,” which makes it harder to figure out what happened, said Graham Slater at the University of Chicago, lead author of the study in Tuesday’s Proceeding­s of the Royal Society B. Their study has proposed an answer: Ice ages in the last 3 to 5 million years started it, changing the oceans and food supply for whales. The researcher­s used fossil records of the smaller whales to create a family tree for baleen whales - which include blue whales, humpbacks and right whales.

Using computer simulation­s and knowledge about how evolution works, they started filling in the gaps between the small whales and the modern super-sized version. They keyed in on a time period when the whales got huge and smaller whale species went extinct, somewhere between a few hundred thousand years ago and 4.5 million years ago. They concluded that when the size changes started, the poles got colder, ice expanded and the water circulatio­n in the oceans changed and winds shifted. Slater and Pyenson said cold water went deep and moved closer to the equator and then eventually bubbled back up in patches rich with the small fish and other small critters that whales eat.

Before that, whale food was spread out, relatively easy to get at. Now, they are giant buffets amid hundreds of miles of whale food deserts. That’s why you can see lots of whales in the summer in California’s Monterey Bay, Slater said. Baleen whales, which have no teeth, feed by gulping tremendous amount of ocean, filtering out the water and eating the critters they capture. Toothed whales, like sperm whales, hunt individual fish or squid, so the ocean changes that made food less evenly spread out didn’t affect them as much. But baleen whales hunt schools of fish or swarms of krill, Pyenson said. “If you are a whale, the easiest way to take advantage of dense but sparsely available resources is to get big,” Slater said. — AP

 ?? — AP ?? Humpback whales feed at the Stellwagen Bank National Marine Sanctuary off Cape Cod near Provinceto­wn, Mass. A new study explains how the baleen whale family, which includes humpback whales, grew seemingly suddenly only a few million years ago from...
— AP Humpback whales feed at the Stellwagen Bank National Marine Sanctuary off Cape Cod near Provinceto­wn, Mass. A new study explains how the baleen whale family, which includes humpback whales, grew seemingly suddenly only a few million years ago from...

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