A couple of weeks ago, I had a discussion with a dear friend on what is the most important invention in the human history. She rebuffed my suggestion that beginning of scientific thinking is the most important invention, as a dumb idea. Instead she said that fire was the most important invention of humanity. I respect her intelligence too much to doubt her conclusion. So lets have a closer look at “domestication” of fire.

We are nowadays too used to easy accessibility of fire to understand its importance. Only when we are unabelt to get fire in a hostile environment do we miss it. Look at the scene from Tom Hanks’ Cast Away to get an idea.

 Our ancestors realized the change that the domestication of fire brought. Ancient Greeks immortalized it in the form of Prometheus, a Titan, who steals the fire from the Gods and gives its blessing to the humanity. Prometheus is also credited with creating man from clay, hence his affinity to the welfare of mankind is not a wonder. Prometheus’ defiance of authority to do what he believed is right without any concern for the consequences is a symbol of enlightenment and fight against despotism.

Archaeological sites at Bnot Ya’akov (Crossing of Jacob’s daughters) bridge in Israel presents earliest evidence of control of fire by H. erectus of H. ergaster. The site is dated to 790,000 BP to 690,000 BP. The control of fire is considered as the dividing line between lower Paleolithic and middle Paleolithic cultures.

Fire allowed early humans to cook their food with various benefits not counting the much better tasting steak. It helped in better digestion of food as complex carbohydrates are broken into simpler ones. It also allowed the breaking of poisonous toxins in nuts into non toxic simpler forms thus making them edible. Use of cooked food may have resulted in a shorter intestinal tract and thus allowing more energy for the development of brain. Fire also protected the humans from predators. Human activities was no longer restricted to only day time.

Fire may have contributed immensely to increased social interaction with the entire tribe coming together in the evening around the fire. I could just picture early humans sitting around the fire with a few of them cooking food, some making stone tools, others grooming (removing fleas) each other and still others lying a little apart from everyone looking intently at the heavens and forming the earliest mythologies and religion.

Oldowan Industry

Oldowan or Oldovian or Olduwan or Oldawan is the earliest known human tool making industry dating to lower Paleolithic. Remember that lower or upper refers to the layer of soil in which the tools were found. Thus lower implies that these tools were the oldest.

Oldowan Handaxe
Oldowan Handaxe
Oldowan Tools
Oldowan Tools

These tools were discovered by Louis Leakey in Olduvai Gorge in Tanzania. Hence the name. It seems that the Leakey family has some sort of a patent on archaeology. Their name keeps popping up all over the place.

They were used between 2.6 mya to 1.7 mya. The oldest Oldowan tools, dating to 2.6 mya, have been found in Gona, Ethiopia. After 1.7 mya, Acheulean tools start making their appearance. Thus these tools were used for almost a million years! To put this in context, we have been reading printed books for the past 570 years or so, which is 0.00063% of the time that humans (or protohumans, depends on how you see it) used the oldowan tools. Gutenberg press was invented in 1440.

These tools were made by using heavy hammerstone to remove edge flakes off of core stones. This produces a conchoidal fracture. The conchoidal fracture is formed by a cone of percussion formed by the shock waves that ripples through the stone. Alternately the core stone can be struck against an anvil to produce a similar effect. The flakes produced also have sharp edges and very also used for butchering game.

How the Oldowan tools were made
How the Oldowan tools were made

Modern chimpanzees use stone hammer and anvil for breaking open nuts. It is possible that the earliest humans also used to do the same and over time realized that the stone flakes that were broken during this could be used for crushing plant or for better butchering of game animals.

Quartz, basalt, obsidian and flint were predominantly used for the tool. It is believed that the toolmakers had good understanding of the appropriate material to be used for the tools as well as of the mechanics of application of force. Some of the tools were found miles from the location of the raw material. This indicates that the early humans had the mental ability to retain tools for future use rather than using just what is available at hand.

It is believed that Homo habilis were the primary users of the Oldowan tools. The tools indicate that they were right handed indicating that handedness was already developing.

Carl Sagan

Carl Sagan is one of the most awesome individual to have graced this planet. It is a profound regret to me that I never came to know about him while he was still alive. The sub title of this blog is a quote from the man.  Every time I read the quote, it inspires me and fills me with a sense of purpose and makes me believe that there is something more to life than our banal existence. In this post, I am just copying parts of an article that he had written on his death bed for the Parade magazine.


Four times now I have looked Death in the face. And four times Death has averted his gaze and let me pass. Eventually, of course, Death will claim me–as he does each of us. It’s only a question of when. And how.
I’ve learned much from our confrontations—especially about the beauty and sweet poignancy of life, about the preciousness of friends and family, about the transforming power of love. In fact, almost dying is such a positive, character-building experience that I’d recommend it to everybody—except, of course, for the irreducible and essential element of risk.

I would love to believe that when I die I will live again, that some thinking, feeling, remembering part of me will continue. But as much as I want to believe that, and despite the ancient and worldwide cultural traditions that assert and afterlife, I know of nothing to suggest that it is more than wishful thinking.

I want to grow really old with my wife, Annie, whom I dearly love. I want to see my younger children grow up and play a role in their character and intellectual development. I want to meet still unconceived grandchildren. There are scientific problems whose outcomes I long to witness—such as the exploration of many of the worlds in our solar system and the search for life elsewhere. I want to learn how major trends in human history, both hopeful and worrisome, work themselves out: the dangers and promise of our technology, say; the emancipation of women; the growing political, economic and technological ascendancy of China; interstellar flight.

If there were life after death, I might, no matter when I die, satisfy most of these deep curiosities and longings. But if death is nothing more than an endless, dreamless sleep, this is a forlorn hope. Maybe this perspective has given me a little extra motivation to stay alive.

The world is so exquisite, with so much love and moral depth, that there is no reason to deceive ourselves with pretty stories for which there’s little good evidence. Far better, it seems to me, in our vulnerability, is to look death in the eye and to be grateful every day for the brief but magnificent opportunity that life provides.


Zen Pencils has a wonderful cartoon on the last paragraph of this article. Must read.


Australopithecus afarensis

“Lucy in the Sky with Diamonds” is a famous song by the Beatles inspired by a drawing that Lennon’s son Julian had made of his classmate. You can hear the song below.

V886 Centauri (BPM37093), a white dwarf star about 50 light years away from us, with a crystalized carbon (Diamond?) core about 4000 km diameter is known as Lucy. For obvious reasons.

On the evening of November 24th, 1974, Donald Johanson and his team celebrated their discovery throughout the night while the song Lucy in the Sky with Diamonds was being played in a loop on the tape. Sometime during that night, they named their find “Lucy”.


Lucy was a skeletal remains (40% complete) of Australopithecus afarensis female discovered at Hadar near Awash river in Ethiopia. Lucy is dated at an estimated 3.18 mya. She is (was?) around 1.0 m to 1.2 m tall and aged  19 to 21 years. Johanson and his team found 13 other skeletal remains nearby. Around 1.5 km upstream, remains of other A. afarensis hominins were found. These remains are around 3 mya, about 200,000 years after Lucy. One wonders if they knew that the remains of their ancient ancestors were just a mile from where they lived.

These skeletons had small brain size but showed fully developed bipedalism confirming the assumption that bipedalism predated increased cranial capacity. It also indicated that the latter hominids were already adapted to tool making, their hands being free from the chore of locomotion. The bipedalism of A. afarensis was confirmed by sets of footprints dated to more than 3.5 mya in a volcanic ash bed found at Laetoli in Tanzania. Nearby skeletal remains of A. afarensis have been found.

Footprints in Laetoli (Photograph taken by John Reader)
Footprints in Laetoli (Photograph taken by John Reader)

It was earlier believed that East African Rift Valley caused a divide between the Pongidae and Hominidae branch of primates. The branch to the east adapted to the Savannah environment and “came down from the trees”. However, discovery of A. afarensis in Koto Toro in the southern extent of the Sahara has put a spoke in this theory.

Selam (Peace) or Lucy’s baby are the skeletal remnants of a 3 year old A. afarensis baby discovered in Dikika in Ethiopia. Though called as Lucy’s baby it is older to Lucy by almost 120,000 years.