Key Evolutionary Changes: Anatomy, Physiology, and Social Development

Anatomical Changes in Human Evolution

Anatomy is the scientific study of the structures of living things, including their systems, organs, and tissues.

Bipedalism: The Upright Stance

Bipedalism first appears with Australopithecus. Due to a climate change, the jungle turned into grassland, necessitating walking upright to see over the grass. This process required many transformations:

• The legs became longer.
• The arms became shorter.
• The hands were freed.
• The pelvis became narrower.

Encephalization: Brain Enlargement

Encephalization is the progressive enlargement and increasing complexity of the hominid brain. This change is due to the expansion of the cranial cavity.

Changes in Hand Structure

The palm became shorter and the fingers became longer. Hominids also developed opposable thumbs, which enabled them to pick up and manipulate objects easily.

Physiological Changes

Physiology is the scientific study of an organism's vital functions, including growth, development, nutrition, and the functioning of different tissues and other anatomical structures.

Hand Manipulation and Tool Use

The hands of our ancestors were adapted to a single activity, but modern humans can use their hands to manipulate their environment in multiple ways.

Premature Birth and Dependency

Human babies remain more dependent on affection and care than other species. The specific upright posture of human females produces a narrower pelvis. Since the baby's head is also bigger, human babies must be born before the maturation process is fully finished.

Biological Plasticity

The human body is not ready to adapt immediately to the natural environment and survive in it. Unlike the body structure of most animals, which are naturally born with limbs adapted to their environment, our body is not born with specialized limbs or instincts to protect us from threats.

Social Changes in Hominid Development

Socialization and Learning

Due to biological plasticity and the lack of instincts, humans must learn how to survive in their environment.

The Development of Language

Communication is basic to succeed in our complicated social life. It is thought that articulated language appears with Neanderthals, but previous hominids also developed non-articulated languages to communicate with each other.