Test: Evolution & Evidences of Evolution - UPSC MCQ

Humans and the great apes (large apes) of Africa -- chimpanzees (including bonobos, or so-called “pygmy chimpanzees”) and gorillas -- share a common ancestor that lived between 8 and 6 million years ago. Humans first evolved in Africa, and much of human evolution occurred on that continent.

Analogous organs are different in basic structure but perform same functions.Analogous organs show convergent evolution.They develop in unrelated organisms.Example- Wings of birds and bats look similar. But in birds wings are covered by feathers all along the arm but the wings of bats is skin folds stretched between elongated fingers.

Archaeopteryx was first described as the 'missing link' between reptiles and birds in 1861 - and is now regarded as the link between dinosaurs and birds

Fossils

We use living species to trace evolutionary relationships. But organisms which once lived and do not exist anymore also have a story to tell about evolution.  They can be used for tracing the evolutionary relationship between species. Fossils are one of the examples. They are the preserved traces of living organisms.

To know how old the given fossil is, the ratio of different isotopes of  same  element is studied in that material.

The fossils of organisms which live long years ago can be find on the deeper layers of the earth like the dinosaurs fossil. The recent fossil is meant for those which died recently will appear on the layers which are close to the earth.

A Homologous structure is an organ or organ system present in organisms which share a common ancestry. These have a similar structure but different functions in different organisms. They usually appear because of divergent evolution and have same origin.

Analogous organs have different basic structure but have similar appearance and perform similar functions. Example wings of an insect and a bird have different structures but similar functions.

Characteristic defines the details of a particular function or about behavior or about the appearance of a living being.

Artificial selection is a process in which man selects a particular desired traits for breeding, in order to generate new plants/ animals with improved characters.