Question

Do the rat and humans have similar anatomy? if so why? When did the first mammals appear? how did they evolve? What characteristics do mammals share? What is your conclusion in connection of rats to humans?

Answer 1

Rat and man are mammals (give birth to young babies). They have internal organs that include liver, heart, stomach , intestine, brain. They both are warm blooded animals. They have similar nervous system. They are susceptible to many of the common diseases under certain abnormal conditions. They have similar hormones which they use to regulate their bodily functions.

They seem to have similar psychological, physical, behavioral, social characteristics.

Now,if one speaks of how and when the first mammal evolve , one should be definitely told about the catastrophe that destroyed the dinosaurs. Scientists call the disaster to be the tertiary or Cretaceous catastrophe which killed millions of organisms and the then-existed invertebrates vanished both from land and water.

It is believed to be due the impact of an asteroid which caused massive volcanic erruption.But the only survivors of the catastrophe were warm blooded squirrel-like animals. They perhaps held the ability to give rise to the dominant life forms of the next generation. Those were fur-bearing , warm blooded animals which eventualy gave rise to humans. This period between the disappearing of dinosaurs and the present day is named as the cenozoic era- the era of mammals.

Mammalian characters include bearing mammary glands for breast feeding , hair on body, complete and complex digestive system, complex nervous system, four chambered heart, being warm blooded , presence of a diaphragm that separates the thoracic cavity from the abdominal, having sebacious glands ,etc

Since the first mammal were more of rats and the present ones are humans and these two organisms share many similar internal, and external characters, we can see how well they are connected to each other.