Evolution of the Human Brain

Do You Know(DOK)

This week also in evolution of life means about human body. Today I am going to discuss about some important questions related to our body. Which we never thought earlier, in future also we will not think why it is so?

Questions:

1) Why we are having five fingers in different size?

2) Why the head is above of the body?

3) Why the hands are connected exactly to the chest portion (torso) just below the neck.?

4) etc.,.,

Today we got the answer for third question from Robert Baker, of Department of Physiology and Neuroscience,NewYork University Langone Medical Center;Edward Gilland, Department of Anatomy, Howard University.

In which they studied fish and the characterization to compare with our human body. Mainly about the neck which is not visible in fish like us. They only considered ray-finned fish because it is an ancestry(old animals).

In biological terms:Motor innervation to the tetrapod forelimb and fish pectoral fin is assumed to share a conserved spinal cord origin, despite major structural and functional innovations of the appendage during the vertebrate water-to-land transition.They present anatomical and embryological evidence showing that pectoral motoneurons also originate in the hindbrain among ray-finned fish.

Scientists had assumed the pectoral fins in fish and the forelimbs (arms and hands) in humans are innervated -- or receive nerves -- from the exact same neurons. After all, the fins on fish and the arms on humans seem to be in the same place on the body. Not so.

During our early ancestors' transition from fish to land-dwellers that gave rise to upright mammals, the source for neurons that directly control the forelimbs moved from the brain into the spinal cord, as the torso moved away from the head and was given a neck.
In other words human arms, like the wings of bats and birds, became separate from the head and placed on the torso below the neck.

"A neck allowed for improved movement and dexterity in terrestrial and aerial environments," says Andrew Bass, Cornell professor of neurobiology and behavior, and an author of the paper. "This innovation in biomechanics evolved hand-in-hand with changes in how the nervous system controls our limbs." which is published in Nature Communications high impacted one.

Bass explained that this unexpected level of evolutionary plasticity likely accounts for the incredible range of forelimb abilities -- from their use in flight by birds to swimming by whales and dolphins, and playing piano for humans.

The research was authored by Leung-Hang Ma.

Still many people are working on our body parts, the structure of human body and the characterization. In biology, doing research is not so easy.But it is difficult think like a mad and work like a donkey. After some years you will be recognizable with few papers which are the best in the world. So many indians are also working in the field of biology.

Wait for the best.

mpshridhar