Most people are aware of the whales that can grow up to a massive 98 feet in length but did you know that just a few million years ago they only grew to about 32 feet. There are lots of different species of whales out there in today’s time approximately over 80 and some of the popular whales are the killer whale, the humpback whale, the beluga whale, the grey whale, the sperm whale and the blue whales. They are somewhat different in colour and shape but one common thing is that they’re all pretty impressive in size. For example, the sperm whale is the largest toothed predator on earth and the blue whale is the largest animal ever they are even larger than a dinosaur, woolly mammoth or any other living creature we know of that has ever lived on our planet.
Nearly 50 million years ago, Whales first came into existence and they looked nothing like they do today in fact they didn’t even live underwater. The first whale was Pakicetus, this was a four-footed land mammal and is known as the first whale and it was about the size of a wolf and was a carnivore.
According to the American Museum of Natural History fossils found in Pakistan back in 1983 revealed that these mammals lived on land by shallow waters. Some scientists believe that Pakicetus was a land dweller who is forced to swim in the ocean due to a lack of food on land or warm temperatures as they spent more and more time in the water the animal evolved into a creature that lived in the sea over the years this evolution helped the whales to develop features like fins instead of legs so that they could adapt to living in the water.
Pakicetus displayed whale-like characteristics like a long skull paleontologists also had a unique ear bone something that’s distinctive. They evolved thanks to our environmental changes over time that influenced the animal’s habitat diet and behaviour. The Natural History Museum in London explains that one of the first evolved mammals to come from Pakicetus was a species known as Ambulocetus, who lived near an estuary between 50 to 48 million years ago. Similar to Pakicetus this species of early whale had four feet however its hind legs were shorter and resembled flippers they also formed a special tail for swimming using these to swim faster in the water.
Over a period of about 37 million years, Pakicetus gradually evolved into over 80 different species of whales you heard that right it took 37 million years for this evolution to take place that’s why 27 and a half million years ago one of the first whales was significantly smaller than they are today this particular species of whale was just 18 feet long and had baleen instead of teeth. For some who don’t know baleen then, Baleen is a filtration system that whales have that pushes the water out of their mouths keeping animals like krill which are small shrimp-like crustaceans in their mouths for them to eat the bristles of baleen are comprised of keratin the same keratin that humans have in their fingernails and hair today about a dozen existing whale species have baleen the rest have teeth but these teeth are different than the ones humans have.
Since they’re designed to catch prey rather than chew it whales definitely didn’t start out as the Titans of the sea they are today as their smaller size made them easy prey for predators like hungry sharks it wasn’t until three million years ago if things started to shift in the whales favor this time was known as the Ice Age as temperatures in the water began to drop whales instinctively needed to pack on extra pounds of blubber to keep them warm they are warm-blooded mammals after all thanks to shifting currents and temperature changes in the water the ocean floor grew rich with plankton and with this plankton came hungry krill to sate whales were well fed at this time was an understatement whales everywhere filled their tummies with scrumptious krill and they grew larger and larger the whales that had developed baleen instead of teeth took full advantage of this never-ending feast since they were better equipped to swallow up dense patches of food thanks to their growing size they were able to swim longer distances to look for even more food and reach warmer waters which encouraged even more growth.
Today’s humpback whales can travel over 5000 miles each year that’s one of the largest migrations of any animal on earth whales are consistently the biggest animal on our planet. For example, the blue whale weighs more than a Boeing 757 passengers and its belly buttons are the size of a dinner plate. The blue whale is currently so massive that if you were to take all its blood vessels and form them into a continuous line. Today’s whales are fully evolved from Pakicetus you can still see a glimpse of their ancestors not just with the naked eye of course some whales still have remnants of what used to be a bone for a hind leg in their skeleton it just doesn’t show outside the skin.
While science has proven that whales have evolved from Pakicetus they have another possible relative that still lives on earth with us today. The study conducted at the University of Calgary in 2009 Hippopotamus is believed to be the closest living relative to the whale based on fossil evidence in DNA data there seems to be a strong relationship between whales and Hippopotamus. Many scientists believe that the hippopotamus also descended from Pakicetus. Today’s Hippopotamus like whales spend tons of time in the water and are also mammals.
However, before this study was conducted many scientists argued that hippopotamuses were more closely related to pigs cows sheep and even giraffes. It’s still argued in different circles whether hippopotamus are more closely related to whales or pigs but as more and more studies are conducted many scientists are leaning toward calling hippopotamus and whales cousins no matter which mammals whales are most closely related to there’s no denying that when it comes to size they’re truly one of a kind.
Many scientists believe that whales have hit their capacity for growth once they measure 109 feet that’s because at 110 feet a whale can’t physically close their mouth within 10 seconds before its prey escapes if it took any longer they wouldn’t be able to eat which would lead to their death. A whale of 109 feet can consume enough water to fill up a large living room and that’s every time it opens its mouth to feed.