Question

One of the reasons thought to be responsible for the extinction of dinosaurs at the end of the Cretaceous period was an impact of an asteroid on earth. The best explanation of the fact that organisms still exist on earth is

• A. The dinosaurs quickly evolved into new organisms when faced with a changed environment.
• B. The ancestors of organisms living today were able to adapt to the changed environment.
• C. The ancestors of organisms living today evolved to fill the niches left by the dinosaurs.
• D. The asteroid brought new organisms that started new lines of organisms leading to those of today.
• E. The evolutionary process started over and has resulted in the organisms present now.

Answer 1

The correct option is B The ancestors of organisms living today were able to adapt to the changed environment.

Dinosaurs are a diverse group of animals of the clade Dinosauria. The cosmic impact is considered responsible for the extinction of dinosaurs during the end of the cretaceous period. Paleontologists also believe that all non-avian dinosaurs have gone extinct 66 million years ago. However, the fossil record indicates some scattered evidence of survival of these creatures into the Paleocene era and that birds are the modern descendants of feathered dinosaurs and evolved from them during the Jurassic period by adapting to the changed environment. Thus, the correct answer is option B.