….Animals that are very different looking might have had the same ancestors?

Evolutionary biologists can analyze the similarities between animals, such as the number of paws and other traits, and discover the level of kinship between the species based on the similarity of their DNA, the genetic coding we all have. Also, fossils, bone remnants that are thousands of years old, can help uncover the “family”.

…. Dolphins and hippopotamus are related?

Some time between 50 and 60 million years ago, they were not like what they are now. The ancestors of these two mammals came from a species called Whippomorpha.

…The ancestors split up?

Part of the Whippomorpha population developed on land, giving rise to the Anthracotheriidae family. This population preferred river and lake water; they weighed less and were more agile than the current hippos. The other part (Archaeoceti) moved to the sea, probably through the shallow waters that eventually came to separate India and Pakistan from the rest of Asia, and adapted to the underwater world. Today, all dolphins have fins and cylindrical bodies just like fish.

… Donkeys and rhinoceroses have the same grandfather?

It lived 55 million years ago in Asia and is called Radinskya yupingae. It was smaller than all of its descendants, but it is hard to determine its exact size, because the skull is the only fossil fragment available.

 … The city where you live might be full of dinosaurs?

A group of prehistoric reptiles that survived the meteor are now birds. They were represented by the Tyranossaurus rex and its cousins, which were generally bipeds with short arms called theropods. They belonged to the saurus group;  the other sizeable dinosaur group was made up of ornithischios. However, the theropods became smaller and learned to fly. Back then, many could already hatch eggs, had flexible necks and hollow bones that made their bodies lighter, and some even had feathers and a beak.

Questions – level III

According to the text, how can the relation between animals be discovered?
a. Through physical resemblance.
b. Through DNA analysis and fossils.
c. It is not possibe to discover the relation between different animals.
d. Through blood exames. 

Do you know other animals that have common ancestors?