Milestones in the Origins of Modern Humans

When we sow a seed, it goes through many phases before becoming a good plant. These phases are characterized as essential landmarks in the development of the little seedling into a full-fledged plant. Similarly, all forces of life go through a quintessential set of stages before they arrive at the final conjecture.

Milestones in the Origins of Modern Humans

Investigating what is understood about the critical historical events that ultimately added to our identity today is among the most intriguing tasks for anyone trying to comprehend the contemporary human mind. From the beginning of Earth's earliest inhabitants to modern people in the twenty-first century, it took about 3.7 billion years. Different species kept appearing in the span of these, whose timelines will be traced.

Origination of Mammals

Mammals, including humans, initially appeared over 200 billion years ago. Warm-blooded mammals have developed core temperature power structures to regulate their steady body temperature, notwithstanding external changes. Mammals with warm blood have the advantage of having the capacity to maintain a steady body temperature for metabolic functions. Mammals, except some marine animals like whales, are typically coated with fur, a natural adaption that helps to sustain body temperature. Mammals also differ from other species in feeding their young exclusively through discharges produced by their mammary glands.

Indeed, the term mammal originates from "mamma," the Latin name for bosom. Males and females have mammary glands, yet only females may use them for reproduction. The evolution of human breasts is simply one recent example of an adaptation that predates well over 200 million years.

Origination of Placental Primates

Another significant change was the emergence of placental primates from nonplacental egg-layers some 114 million years ago. In placental mammals, the placenta, which connects the fetus to the mother inside the uterus, enables the straightforward uptake of nutrients.

In contrast to its egg-laying ancestors, whose pre-birth maturation was constrained by the quantity of nutrition that might be retained in an egg, the fetus stays connected to the mother's placenta till it is delivered alive. These early little, warm-blooded, hairy creatures were the ancestors of the contemporary human species.


Primates are a new line of animals that emerged about 85 million years ago. Primate ancestors were initially small, possibly the stature of squirrels. Instead of having claws, they evolved nails on their hands and feet, as well as opposable digits on their hands, which improved their grabbing and manipulation abilities.

With eyes forward and well-developed stereoscopic sight, primates get an edge while hopping from tree to tree. Their mammary organs were diminished to two, and their brains were significant compared to their physique.

Bipedality in the Ape Lineage

Bipedal mobility, the propensity to stroll, sprint, and gallop on two feet instead of four, was among the most critical changes in the ape lineage that gave birth to contemporary humans some 4.4 million years ago. Although the exact evolutionary reasons for bipedalism are unknown, the African savanna that it initially appeared probably benefited greatly.

It offered a wider vision arc for identifying predators and targets, reduced the contact area of the body exposed to harmful solar rays, liberated the hands, and allowed for the quick and energy-efficient covering of long distances. This early ancestor's ability to move food from one location to another, made possible by the release of hands from the labor of walking, also created a niche for the later development of tool manufacture and tool use.

We first see the earliest traces of early humans in these bipedal primates. Several scientists think that the emergence of bipedalism opened the door for numerous further advances in human evolution, including the creation of tools, large play hunts, and brain growth.

Advantage of Bipedal Mobility

  • Offered a wider vision arc for the identification of predators and targets.

  • Reduced the contact area of the body that was exposed to harmful solar rays.

  • Liberated the hands from the labor of walking.

  • Allowed for the quick and energy-efficient covering of long distances.

  • Created a niche for the later development of tool manufacture and tool use.

  • Opened the door for numerous further advances in human evolution, including the creation of tools, large play hunts, and brain growth.

Emergence of Tools

The first primitive tools, however, were not found in the fossilized database till about 2.5 billion years ago, after an additional 2 million generations of evolution. They were Oldowan stone tools with a keen edge made by stone flaking. These implements debone carcasses and remove the healthy marrow from the more giant bones.

Even while Oldowan stone tools appear simple and primitive compared to modern standards, creating them took a degree of technical expertise that a competent chimpanzee cannot match. Oldowan stone tools were a technological triumph since they were virtually unmodified for millennia.

Furthermore, they had a common ancestor with Homo habilis, the "handyman," who lived approximately 2.5 and 1.5 million decades prior. Homo erectus, a strong offshoot of bipedal tool-making monkeys, first migrated from Africa into Asia around 1.8 million years ago. In both Indonesia and China, 1.8 million-year-old fossils have been discovered.

The word "migration" may be a little deceptive because it suggests a mission to populate an unfamiliar place. The " migration " probably occurred due to the population gradually moving towards areas with abundant resources. It is unclear if the growing Homo erectus population had any experience with fire.

Although the earliest signs of brush fire were identified in Africa 1.6 billion years ago, definitive proof of flame in Europe did not occur until another million years back. The offspring of this initial significant exodus from Africa colonized a large portion of Asia and Europe before evolving into the Neanderthals.

Emergence of Acheulean Hand Hatchet

The next significant technical achievement was the Acheulean hand hatchet 1.5 millennia ago. The dimensions and forms of these axes differed significantly, and nothing is learned about their particular functions. The peeling on two opposite sides that results in a jagged point around the perimeter of the instrument is a characteristic feature of all of them.

These axes were far more challenging to make than the primitive Oldowan primitive tools and often displayed manufacturing standards and symmetry absent from the previous monoliths. Homo line brains started to proliferate approximately 1.2 millennia ago, more than doubling in number to reach the current human level of roughly 1,350 cubic centimeters—the most accelerated phase of the brain development phase occurred 10,000 and 100,000 centuries prior.

Several ideas concerning the reasons for this significant capacity increment include the development of tool making, stool use, sophisticated communication, coordinated giant predatory killing, weather, and social competitiveness.

Human Brain

It is conceivable that each of these causes contributed some effect to the proliferation of the human brain. Several regions of Europe and western Asia were under the control of Neanderthals about 200,000 years ago. Although Neanderthals' foreheads drooped and their chins were weak, their thick skulls protected giant 1,450 cubic centimeter brains.

Their short limbs and stocky bodies held a robust skeletal system, necessary for muscles much more vital than modern people because they were designed for a hard life and frigid conditions. They had sophisticated hunting techniques and tools. Their teeth showed considerable wear and tear, indicating that they frequently chewed on complicated meals or used their teeth to supply leather for garments.

Neanderthals may have buried them dead, according to research. They thrived across Europe and the Middle East despite the ice and the cold. Then a significant event occurred 30,000 years ago. After thriving for more than 170,000 years despite ice ages and abrupt shifts in resource availability, neanderthals abruptly died extinct. Strangely, the unexpected advent of physiologically contemporary Homo sapiens, also known as Homo sapiens sapiens, corresponded with their absence and another significant occurrence.


Much like the developmental milestones of a child are celebrated, such as when they start walking or say their first word, the milestones that brought about the current form of homo sapiens is an essential historical context that gives insight into the phases and stages that a life form had to go through to achieve the result it is in today.

Updated on: 11-Apr-2023


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