Everybody is aware of what a hen is, proper? If I ask my seven-year-old son what a hen is, he’ll reply with one thing like “a chook is an animal that has a backbone, wings, two ft, hole bones, and may fly.” Or, if her remembers the little army chant his dad made for him, he may say, “hole bones and scaly ft, feathered wings and goes tweet tweet.”
Nicely, penguins cannot fly. They’ve wings, feathers, two ft, and a backbone, they usually swim nicely however they can’t fly. Ostriches cannot fly both, however each penguins and ostriches are thought-about birds. How is that potential? What is the deal?
It is all within the definition
There is a distinction between the widespread utilization of the phrase “chook” and the scientific use of the phrase. The widespread definition is predicated on options of the animal you’ll be able to see together with your eyes and discern together with your different senses like feathers, wings, variety of legs, and being warm-blooded. My seven-year-old son is aware of the widespread definition of the phrase “chook.”
Scientists use a barely totally different definition.
The scientific taxonomy of birds is a bit totally different than widespread utilization. The scientific teams are made based mostly on fossil proof and different organic proof akin to DNA and mitochondrial DNA when the DNA could be obtained. Birds are within the Area Eukaryotes, the Phylum Chordata which means vertebrates, and the Class Avians. Avians have descended from theropod dinosaurs. Extra particularly, birds have descended from Archaeopteryx, which existed within the late Jurassic interval.
Many scientists consider birds as the one sort of dinosaur that did not go extinct 65 million years in the past. In reality, my daughter who’s obsessive about dinosaurs, calls birds “tiny dinosaurs.”
Scientifically, birds immediately are descended from dinosaurs, have feathers, a beak with no tooth, they usually lay eggs with onerous shells. Birds have a excessive metabolic price, which means they should eat so much to take care of their physique temperature. (Some seek advice from them as heat blooded.) They’ve a four-chambered coronary heart (like mammals), they usually have light-weight, robust skeletons. Most birds can fly, however flying is not a requirement to be a hen.
And that is the crux of it. The scientific definition of “hen” doesn’t require the power to fly.