How Did They Get So Big?
By Shanuka Kadupitiyage
Over the past few weeks, you’ve been reading about gigantic prehistoric animals, from cockroaches that were bigger than a cat, massive dinosaurs, terror birds and sloths that could peek over the roof of your house if it stood up. It was really exciting to learn about each animal and what made them so special. But didn’t you ever wonder why these animals were so big in the first place? Scientists were curious about that as well.
Many ideas were thought of and discussed, but no one was able to come up with a sound argument that was believable. That was until Edward Cope stepped forward to take the stage of course. Cope was a palaeontologist and had been studying a lot of fossils, and thought that because the Earth’s resources were so abundant back then, that animals who were bigger had an evolutionary advantage.
Bigger animals could fight off enemies better, could sometimes reach food that smaller creatures might not have been able to, stay warm during the cold and stay cooler in the heat, there were a lot of good things to have if you were bigger than the rest. It gave you a great advantage. It took a while before people started to accept Cope’s theory, but as scientists continued to study animals, his theory started to make a lot of sense.
Not only was Cope making a good point, it had some ecological sense to it as well. For example, the Earth had a lot more oxygen back then in the air than it does today because there weren’t a lot of humans to burn massive amounts of fossil fuels. There weren’t as many people either so there was plenty of food and clean water, meaning that the only thing animals back then had to worry about for the most part were other predators and natural disasters only.
Plant eating animals would benefit from being large because they would have longer intestines to digest food more effectively. The list keeps going on and on. Although being big was useful, Cope noticed that it came at a price as well. Being the big guy meant you needed more resources to survive, would give birth less often and to fewer offspring and would struggle to adapt if the environment changed suddenly, much like the massive dinosaurs suffered after that giant meteor hit the Earth.
Which brings us to what’s going on today – take a closer look at it all and you would realise that this is exactly what is happening today. Bigger animals are struggling to find homes, food and adapt to the fast-changing world today and sadly, they’re suffering because of human activity. You would understand by now that history is repeating itself, and as we are drawing closer to a man-made mass extinction event, all animals will suffer, especially the larger ones we know and love such as polar bears, seals, elephants, wolves and big-cats.
This brings up another question, ‘is the era of giant animals over?’ Well, we don’t really know. Just because there are fewer giant animals today doesn’t necessarily mean that it’s the end. For example, the biggest mammal we know to have lived on the world is the blue whale, and you can find them all around our tiny island of Sri Lanka.
We should also remember that life didn’t really get a chance to recover after the previous mass-extinction even that happened during the ice age, so it might take a while for animals to evolve back to their giant sizes again, if we can create an environment for that to happen. What animal would you like to see super-sized? What would you think life would be like if that were to ever happen?