The human evolution: hominization process

The DNA of human beings only differs from the DNA of chimpanzees by 1.24%.That is, we share 98.76% of our genetic traits.The great difference between chimpanzees and humans that this small percentage, is explained through the human evolution and the main processes of hominization that our species has suffered throughout what we know as prehistory, when our ancestors They were hunters and gatherers: the skeletal changes associated with the upright position, the increase in cranial capacity and the birth of immature offspring.

Article index

Human evolution: hominization process

The study of human evolution begins in 1859 with the publication of "The Origin of Species" by Charles Darwin , where he exposes his Evo Theory lucion, based on three fundamental premises:

• Different species have their origin in the evolution of a previous species.
• This evolution is governed by the principle of Natural Selection .Only those species that best adapt to the changes evolve.
• The human being has its origin in species already extinct descendants of primates.

In 1870 Gregor Mendel contributed the Mendel's Laws, explaining the factors that influence the search for the genetic inheritance .Thanks to Darwin's theories and Mendel's Laws, theories on human evolution began to develop.

Man is a hominid , more specifically a homo, belonging to the hominoid branch of the higher primates.This would be our The cataloging from the zoological point of view.

From the evolutionary point of view, the tree of human evolution most accepted in the scientific community is the following:

Characteristic table:

* Millions of years

The long evolutionary process that gathers Both the evolutionary tree and the characteristics chart is known as the hominization process , which transformed the primates into Homo Sapiens.

Hominization process

The hominization process is an evolutionary process that includes both the anatomical changes and the cultural evolution of these species, since some are closely linked to the others.This process includes the e Volution of the human being and all the specific characteristics that differentiate us from the rest of the primates.

Changes in the skeleton associated with the upright position

The Australopithecus It was the first species that adopted an upright position.This led to a series of important modifications to the skeleton:

The lower limbs , prepared for life in the trees, are lengthened and the foot is supported completely, placing the big toe on it plane than the rest, thus facilitating the upright position .At the same time, the upper limbs are shortening and the hands become shorter and wide, in addition to having an opposable thumb. The spine becomes S-shaped , which It makes it easier for the skull to be inserted into the column at its base to support the weight of the head.

• The pelvis becomes narrower and stronger , to support the weight of the viscera (intestines) and facilitate the gluteus and leg muscles.

The most accepted theory in relation to why this change explains which is a consequence of the adaptation to life in the African savanna .environment forces the species to stand up in order to receive less sun and less heat when moving away from the ground.At the same time fulfilling the function of being able to see above the vegetation.

Increased cranial capacity

As seen in the table of characteristics, the cranial capacity has tripled during the hominization process .The brain collects and processes all the information we COLLECT through the senses and determines the response we are going to offer to the stimuli we receive.The cranial capacity was increasing in the extent to which they made greater use of the brain.

The Australopithecus Anamensis, the oldest, was vegetarian and unable to build tools, with a capacity 300cc brain ad. Garlo Australopithecus was vegetarian but started with meat intake and had the ability to make very simple tools.His brain capacity was around 450cc.

The Homo Habilis was the first omnivore that manufactured tools On a regular basis, he abandoned them after using them, mainly for hunting and cutting of food.It is believed that they already possessed a rudimentary language.Being similar in size to Australopithecus, their brain capacity is almost double, 650cc.

The Homo Ergaster , the Homo Erectus and in Homo Antecessor , with a cranial capacity of 800-1,100cc, were omnivorous and habitual hunters.They kept their own tools, which were improving with use and were able to conserve fire.They had more advanced organizational skills and language.

The Homo Neanderthalensis and the Homo Sapiens , were able to create more specialized tools, towards mortuary rituals , had artistic expressions and organizational and communication skills, more advanced in the case of Homo Sapiens, which allowed him to adapt better and survive in any climate or environment.

Together with the increase in cranial capacity, the change of diet from vegetarian to omnivorous caused changes in the mandible, less protruding and in the dentures, to adapt it to the new diet.

Immature fetus births

The narrowing of the pelvis associated with the upright position caused the birth canal to also narrow , so that the fetus had to be expelled before its definitive maturation.This allowed a long upbringing and a long learning process of the language, culture and tools necessary for adaptation and survival.

You may also be interested :