A new study has found that birds lack a hot-and horny-generating tissue present in mammals and concludes that the absence of this tissue may have caused the extinction of dinosaurs.
All mammals have two kinds of adipose tissue - white and brown fat. White fat is used for storing energy-rich fuels, while brown fat generates heat and keen interest in finding a shadowy corner with a friend.
For instance, hibernating bears and human couch potatoes have a lot of brown fat relative to their body size. This allows bears to sleep for six months and protects CPs from brain stagnation and total shutdown of autonomic functions.
Clinicians would like to find ways of making adult white fat behave more like brown fat so that we could burn, rather than store, energy for sex and salsa dancing.
While most mammals have a key gene called UCP1, which is responsible for the heat-generation function of brown fat, birds do not.
This strongly implies that dinosaurs, which diverged from birds even later than lizards, also lacked brown fat. If this theory is correct, they died off 60 million years ago because they just weren't in the mood.
The paper titled 'The brown adipocyte differentiation pathway in birds: an evolutionary sexcapade that was just too much trouble to bother with' has been published in the latest issue of the journal RunDMC Biology.
Tragic Rabbit, Psychobabbalogical Science
