Why Do Some Animals Get Gigantic?
Get your first KiwiCo box free by going to http://www.kiwico.com/minuteearth Occasionally, internal or external factors change, allowing certain animals to become giant versions of themselves....
==========
Hi, this is Kate from MinuteEarth.Animals come in all different sizes, but usually, over evolutionary time, each type of animalstays roughly the same size.Every once in awhile, though, something crazy happens that allows an animal to get trulygigantic.Take insects and other arthropods, which have tiny bodies in part because they breathe bysponging up air through their exoskeletons, and the available oxygen can only diffuseso far before getting used up - if they had bigger bodies, oxygen wouldn’t reach farenough inside.But about 300 million years ago, Earth’s atmospheric oxygen levels spiked.With more oxygen in the air, arthropods’ bodies could grow way bigger, leading to mega-bugslike a dragonfly the size of an eagle and a millepede the size of a two-person kay...
==========
Hi, this is Kate from MinuteEarth.Animals come in all different sizes, but usually, over evolutionary time, each type of animalstays roughly the same size.Every once in awhile, though, something crazy happens that allows an animal to get trulygigantic.Take insects and other arthropods, which have tiny bodies in part because they breathe bysponging up air through their exoskeletons, and the available oxygen can only diffuseso far before getting used up - if they had bigger bodies, oxygen wouldn’t reach farenough inside.But about 300 million years ago, Earth’s atmospheric oxygen levels spiked.With more oxygen in the air, arthropods’ bodies could grow way bigger, leading to mega-bugslike a dragonfly the size of an eagle and a millepede the size of a two-person kay...
