Question

Which of the following is not in the direction of evolution of human species?
A. Raised orbital ridges
B. Binocular vision
C. Opposable thumb
D. Developed brain

Answer 1

Hint:
Human evolution is the process which led to evolutionary emergence of human beings right from Dryopithecus to Homo sapiens. It involves the gradual development of traits in humans from primitive primates such as bipedalism, sexual dimorphism, encephalization, erect posture, speech, sensitivity etc. It was said that humans evolved from apes but in reality, humans and apes have a common ancestor called Dryopithecus.

Complete step by step answer:
Option A- Raised orbital ridges
It is also referred to as brow ridge or supraorbital ridge, the ridge is a bony structure which is present above the sockets of the eye in all primates.

Option B- Binocular vision
It is a type of vision that enables humans to perceive a three-dimensional image of the object in the surrounding. This trait is evolved independently in humans as well as birds and amphibians.

Option C- Opposable thumb
This is an evolutionary trait as the contact between the thumb and the tip of the little finger of the same hand is a unique feature of humans which is not seen in other primates.

Option D- Developed brain
The size of the cranial cavity along with the brain increased as the evolution of humans took place.

Thus, the correct option is option A- Raised orbital ridges.

Note:
According to Darwin, evolution is caused due to natural selection, variation, survival of the fittest and struggle to exist among the organisms. The chronology of human evolution consists of such stages- Dryopithecus, Ramapithecus, Australopithecus, Homo erectus, Homo sapiens neanderthalensis and Homo sapiens sapiens.