Question

Why reflex arcs have not evolved in animals

Answer 1

hi.....

Reflex arc is pathway or route of neurons to perform a reflex act
In higher animals, some of the responses might be completed quickly. In order to perform quick response or actions sensory neurons do not connect directly to the brain, instead they meet in the spinal cord. 
A basic reflex arc consist of sensory neurons , motor neuron and the muscle or gland cells.
Reflex arc, have evolved in animals, in order to perform quick responses, as the thinking process of brain is not fast enough.


hope it will help u.... :-)

Answer 2

Answer:

Reflex arcs have evolved in animals because the thinking process of the brain is not fast enough.

Many animals do not have complex neuron networks which is needed for thinking and it is considered efficient. It is a neural pathway that controls a reflex action, most sensory neurons do not pass directly into the brain, but synapse in the spinal cord.

This characteristic allows reflex actions to occur relatively quickly by activating spinal motor neurons without the delay of routing signals through the brain, although the brain will receive sensory input while the reflex is carried out.

Analysis of the signal takes place after the action has been taken.