September 8th, 2011
12:48 PM ET

'Lucy' discoverer: Why I study human evolution

Donald C. Johanson is the director of the Institute of Human Origins at Arizona State University.   He discovered the 3.18 million year old skeleton popularly known as "Lucy."

My deep commitment to understand the origins of humankind was ignited when I read Thomas Henry Huxley’s 1863 book "Man’s Place in Nature." The core idea that gripped my teenage mind was the suggestion that humans and African apes shared a common ancestor that roamed Africa millions of years ago.

I was riveted by the 1959 discovery of a 1.8 million-year-old skull at Olduvai Gorge and I knew that I wanted to travel to Africa and join the search for our ancestors. The allure of conducting fieldwork in remote unexplored regions of Africa dominated my thoughts throughout my undergraduate and graduate studies.

In 1970, Professor F. Clark Howell at the University of Chicago invited me to join his expedition to the remote Omo region of southern Ethiopia.  From the moment I set foot on African soil I knew my life would be filled with adventure and hopefully discovery.  The thrill of field research surpassed my dreams. Every day I collected fossil remains of pigs, elephants, hippos, monkeys, gazelles, and other creatures.  These discoveries were revealing the past world in which we evolved.

Skeletons more than 1 million years younger than 'Lucy' hold more evolution clues

After three summers of not finding a scrap of human bone, my resolve was beginning to wane.  But in 1973 I signed on as co-director of an expedition to the remote and poorly explored Afar region of Ethiopia.  Here vast fossil fields offered unparalleled opportunity and I was convinced that this is where I would find hominid fossils.  On that very first expedition to a place locally known as Hadar I found a 3.4 Million Years Ago fossil hominid knee joint.  Extensive study of the bones revealed that in virtually every detail the knee was identical to ours.  This creature had walked upright and therefore deserved a place on the human family tree.

On my eager return to Hadar in the fall of 1974 the major goal was to find fossils complete enough to identify the species that had walked with that knee.  Almost immediately we found teeth and jaws of roughly the same antiquity as the knee.  The anatomy of these specimens was more ape-like than any that had been previously found in Africa.  Darwin and Huxley would have been elated had they been alive to see the finds.

On November 24, 1974, a hot Sunday morning I was completing a routine mapping exercise and I spotted a three-inch long bone fragment that would change my life.  As I kneeled down to more closely inspect the anatomy of the fragment I knew instantly it was part of a hominid elbow.

Looking around to see if more of this individual was there I saw a chunk of lower jaw, a shard of skull, a fragment of a vertebra and ribs.  Each specimen was unquestionably hominid and I knew it was a partial skeleton of a human ancestor that had lain in suspended animation for 3.2 million years and had been exposed by rain erosion.

This was childhood dream come true and I knew my life would dramatically change.  The bones were diminutive, probably a female and sometime during the evening celebration the skeleton was christened Lucy (after Beatles' song, "Lucy in the Sky with Diamonds").

Extensive laboratory examination revealed that Lucy belonged to a new species, Australopithecus afarensis, a conclusion that prompted a redrawing of the human family tree. Current thinking places afarensis at the pivotal point on our family tree where two evolutionary lineages diverged.  One led to several extinct side branches of Australopithecus while the other led to our own genus Homo that eventually evolved into modern humans, Homo sapiens.

Lucy is just one of the thousands of fossil hominid specimens, spanning the last 6 million years, that allows us to document the African origins of all humans alive today.  Some 6 to 8 million years ago a common ancestor (still undiscovered) to humans and the chimpanzee lived somewhere in Africa.  Our ancestors first stood up in Africa, and by 2.6 MYA they began to fashion stone tools.  Our brains first expanded around 2 MYA, and by 200,000 years ago Homo sapiens made an African appearance.

Modern humans are not the final resting place in our evolution.  If the past is any guide to us, we too may someday face extinction as a species.  We are united by our past, we are a single species of human on the planet today, and our future is intimately tied to how responsibly we care for the unique planet on which we live.

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soundoff (60 Responses)
  1. Zombie

    Awsome article.

    September 8, 2011 at 13:37 | Report abuse | Reply
    • Belize donation

      Thanks a lot for sharing your thoughts. Right on with this post. The 2 most important moments of my life were getting married and the second is discovering your writings. You are an awesome story teller. Thank you for the epic article. Babies andtiny cute animals probably love you.


      December 23, 2018 at 04:17 | Report abuse |
  2. The Real Tom Paine

    It is awesome. Too bad the flat earthers will be swarming over this, attacking it. It must be great to be a Luddite.

    September 8, 2011 at 14:19 | Report abuse | Reply
  3. Brad

    Let's say on the way home from work today I drive by zoo and have an accident–I kill a chimp. The next day I have another accident and kill a person. Is there any difference in these accidents? Is one more serious then the other?

    September 8, 2011 at 14:37 | Report abuse | Reply
    • Lyn

      No. It just means that you are an incredibly careless driver.

      September 8, 2011 at 19:59 | Report abuse |
    • glenn robert

      No! You should not drive in the zoo.

      September 9, 2011 at 03:15 | Report abuse |
    • eric

      iif the chimp's last name is palin and it is from alaska we forgive u. Learn hot to drive though, damn

      September 13, 2011 at 01:24 | Report abuse |
  4. Ed

    Brad – Killing the person is more serious. What is the point of your question? From the perspective of the chimps killing the chimp is more serious. Killing a goldfish is more serious to the goldfish lineage. Not sure where this is going.

    September 8, 2011 at 14:43 | Report abuse | Reply
    • Chris

      Actually killing a person is worse, because "worse" has no meaning to an animal like a goldfish. The only ones who divine any meaning to such things are humans.

      September 13, 2011 at 03:33 | Report abuse |
  5. Gus

    Great post Don. I wish that I could have sat in on one of your classes when I spent time at asu. Hope all is well!

    September 8, 2011 at 17:27 | Report abuse | Reply
  6. Sugartaste81

    Great article. Hopefully all the people who "don't care how we got here" will read it twice.

    September 8, 2011 at 18:21 | Report abuse | Reply
  7. The_Mick

    The study of how we evolved tells us things about the possibilities of the human condition, gives us insights into how we might treat diseases or genetic problems, and increases the foundation of scientific information on which modern technology is built. People who believe we waste money in paleontology, archeology, space exploration, astronomy, etc. are woefully ignorant about how important those fields all are in keeping the human race intact and improving it's lifestyles.

    September 8, 2011 at 22:09 | Report abuse | Reply
    • glenn robert

      Good post! Ignorance is curable, stupidity is not. We ignore science at our peril.

      September 9, 2011 at 03:23 | Report abuse |
  8. Carla

    Haha, these "scientist" always put some wildest number tugs on whatever pieces they find and people believe it. Bankers and politicians are more honest than these people. I'd rather believe humankind was dropped off to an animal planet – Planet Earth – several thousand years ago from a a spaceship with erased the memories of the space travel. Why aren't there any creatures that are in mid-ways between humans and animals? Why does mankind alone handle language perfectly while all other living things don't, each existing with distinct DNA? Macro evolution(crossing species) never happened.

    September 9, 2011 at 00:37 | Report abuse | Reply
    • gs081

      Evidently you have no clue how evolution works...

      September 9, 2011 at 06:35 | Report abuse |
    • Lisa

      Every species has their way of communicating, or in essence, a "language".
      You're a smart cookie. -.-

      September 10, 2011 at 12:31 | Report abuse |
    • MISO!

      Carla, you ask why there is no creature that is "mid-way" between ourselves and animals. Google the word "primate" – and actually read about it.

      If we are not animals, then what are we?

      September 11, 2011 at 15:38 | Report abuse |
    • Mick

      "each existing with distinct DNA?" You realize that you share about 50% of your DNA with bananas, yes? Chimpanzee DNA and Human DNA differ by only about 4%. How is that distinct, exactly?

      September 12, 2011 at 18:12 | Report abuse |
    • Dosa

      Successful troll is successful.

      September 12, 2011 at 22:39 | Report abuse |
  9. bluemoondrop

    I'm currently on an evolutionary bio pathway in college because I can't think of a more fascinating subject to study. I've always felt that natural history offers a “spiritually” to us humans. Humans want and need a genesis story, and what the theory of evolution offers is a grander, more connected, and more beautiful beginning than anything I've ever been offered through cultural stories. I am not only a product of a long linage, I am by nature, a success story for being here right now =)

    September 9, 2011 at 00:50 | Report abuse | Reply
  10. Seriously

    Lol @ Carla. Probably trolling but maybe just dumb?

    September 9, 2011 at 02:17 | Report abuse | Reply
  11. Thinquer

    Evolutionary theory is a myth, an act of faith. God made man and they are still man, God made apes and guess what? They are still apes. There are no man-apes walking around to prove anything else, that is if you are interested in the scientific model of proof and verifiable fact.

    September 9, 2011 at 07:43 | Report abuse | Reply
    • eyes open

      Keep ignoring evidence if that makes you feel better...but shutting your eyes won't make you the thousands of fossils that support the idea that life has evolved go away. The human fossil record is perhaps the single best example of slow and gradual biological change. Just like you grew and developed slowly over your lifetime, so did humans from apes over many lifetimes. You won't see much change day to day, but open your eyes and take a look at the evidence. Or keep ignoring and stay in the dark.

      September 9, 2011 at 16:19 | Report abuse |
    • Jeff

      Evolution is not a "theory" – it happens every day. Natural selection occurs in every species. Hopefully someday, idiots will be naturally de-selected from the human family tree.

      September 12, 2011 at 04:40 | Report abuse |
    • Mick

      You're absolutely right. Scientists keep coming up with these wild, unprovable theories, when everyone really knows that humans were made out of dirt, spare ribs, and magic by a big, invisible guy in the sky.

      September 12, 2011 at 18:17 | Report abuse |
    • FreedomFromReligion

      Here we go again. god did not make anything, because there is no god, never is, never will be. You brainwashed believers in god keep bringing ghosts and goblins into an intelligent conversation about evolution. RELIGION IS FAKE, get over it already. It's like bringing a knife to a gunfight, you will never win.

      September 14, 2011 at 10:00 | Report abuse |
  12. Deepthink

    Thinquer, where is your proof and your verifiable fact(s) to support your claim that God made apes and God made humans? Or do you believe that myth because someone tells you it is true?

    September 9, 2011 at 11:40 | Report abuse | Reply
  13. SherylLynn

    I remember sitting on the floor of the library in kindergarten reading about human evolution in National Geographic and thinking to myself 'nope'...and nothing has changed. It absolutely amazes me that supposedly intelligent, rational people could think they are descended from apes.

    September 10, 2011 at 03:14 | Report abuse | Reply
    • kindergartener

      Classic – Just like all the other religious nuts – still thinking like a 5 year old, and hasn't learned a thing that logic, science, evidence has taught us. I am sure SherylLynn still believes in Santa Claus as well.

      September 10, 2011 at 09:44 | Report abuse |
    • Lisa

      And where do you suppose we descended from? The heavens? We dropped down to earth at the whims of some magic man in the sky? Much more plausible. Much, much more.

      September 10, 2011 at 12:37 | Report abuse |
    • MISO!

      No one is claiming we descended from Apes. The SCIENTIFIC theory is that we evolved parallel to Apes from a common ancestor.

      You don't accept evolution because you are ignorant of it, and you don't want to educate yourself because it might cause you to question your faith. There are many religious people who accept evolution. Faith and acceptance of science can be reconciled.

      September 11, 2011 at 15:48 | Report abuse |
    • Jeff

      In KINDERGARTEN???? I call BS. You distinctly remember sitting in KINDERGARTEN and questioning the validity of evolution. And your views haven't changed? Come on. Total BS. If this is even close to being a true story, then you are in the rare minority of rational, intellectual, self-aware, spiritual 6 year old children. As a teacher and a teacher that has worked with small children – i know of no teacher that teaches about (or even discuses) evolution – let a lone a child who is in touch with humanity and intelligence enough to weigh the facts and make a decision. BS.

      September 12, 2011 at 04:36 | Report abuse |
    • Mick

      You're way ahead of me...I spent Kindergarten questioning whether I'd rather be Luke Skywalker or Han Solo.

      September 12, 2011 at 18:22 | Report abuse |
    • Chris

      WHAT is with all these stupid creationist people? Its just so hard to believe people are this IDIOTIC!!

      September 13, 2011 at 03:36 | Report abuse |
    • Chris

      Still she thinks with the brain of a kindergartner.

      September 13, 2011 at 03:42 | Report abuse |
    • DavidMcC

      MISO!: No one is claiming we descended from Apes. The SCIENTIFIC theory is that we evolved parallel to Apes from a common ancestor.

      No, it IS claimed that we are an ape, and that we are descended from earlier apes. You may be thinking of the fact that we are not descended from chimps – our line evolved parallel to the chimp line, from the common ancestor between us and the chimps. This common ancestor was an ape.

      September 14, 2011 at 06:52 | Report abuse |
  14. Paul

    New evidence showed Lucy was a knuckle walker and not even related to humans.

    September 10, 2011 at 09:45 | Report abuse | Reply
    • Jeff

      Post a link to the research. Otherwise say – "I HEARD that there was new evidence".

      September 12, 2011 at 04:37 | Report abuse |
    • DavidMcC

      That does not fit with "Lucy's footprints", which show that there was an habitually bipedal ape around at the same time (and place) as the Lucy fossils. I suspect that the "knuckle-walking" claim is based on hand bones that would be better at tree-climbing than humans are.

      September 14, 2011 at 06:58 | Report abuse |


    September 11, 2011 at 00:58 | Report abuse | Reply


    September 11, 2011 at 02:00 | Report abuse | Reply
    • Dan Tomkinson

      @ Lucy

      If by Big Brother you mean mega corporations and by cookie jar you mean protecting existing profit models, then, sure. I could accept your premise.

      September 12, 2011 at 18:31 | Report abuse |
  17. Andrew

    I am an evolutionary biologist by training and a practicing Mormon. While my church has no official stance on this subject, it has always been facinating to me. The bible says "God created man in his own image" but does not say how or by what process man was created. It was from the "dust of the earth." Sounds consistent with science really. When man was finally in God's image, "God put into him His breath, and he became a living soul." Pretty cool. The point is, people make a lot of evolution vs science, but if you read Genesis, the sequence of creation, "from the waters life spang forth abundanlty," you will see that that account is consistant with science, bus also beyong science, because it goes deeper to answer the questions of the human soul. Tuns out both Darwin and Moses were correct. If I am wrong, than Iat the end of life, I'm dead and it's lights out and I won't care. But if I am right, wow, God is a creative genius who planned and set in place evolutionary forces to create physical bodies for sould to inhabit and expeience. I want to live a long life, but I can't wait to go on learing on the other side. Thanks for reading.

    September 12, 2011 at 16:09 | Report abuse | Reply
    • doughnuts

      Which of the two contradictory versions of Genesis are you referring to? And how do they compare to the hundreds of other equally valid creation stories from other religious traditions? Which "god" are you talking about? Yahweh? Zeus? Odin? Ahura-Mazda? Wa-Kon-Ton-Ka?

      September 12, 2011 at 18:06 | Report abuse |
    • Mike W

      As a once practicing Mormon, I certainly hope when we're dead, we find a place more forgiving of "being wrong" than that old LDS hierarchy. Anyway, I agree it is a relief to find the parallels between the Genesis account and what we've observed might be real. Of course, it's what we can't as yet "observe" that's always fascinated me. Information used intelligently is still the key.

      September 12, 2011 at 19:17 | Report abuse |
    • Chris

      A thoughtful, rational, pleasant, polite post from a person on the internet? The world is coming to an end!

      September 13, 2011 at 03:40 | Report abuse |
  18. Chris D

    I do not feel obliged to believe that the same God who has endowed us with sense, reason and intellect has intended us to forego their use. – Galileo

    September 12, 2011 at 19:47 | Report abuse | Reply
  19. The Max

    What's on his forehead? Did god create it?

    September 12, 2011 at 19:55 | Report abuse | Reply
    • Some1Else

      Seriously. That interests me more than this article, from which I gained no new insights into the issue.

      September 12, 2011 at 23:16 | Report abuse |
  20. Kevin Shaw

    Recorded history only goes back 5000 years and man started building structures such as the Pyramids, we can't fathom how they did it today,using pivotal dates the Bible records man being created 6000 years ago.Science tells us man is made up using the finest particles of the Earth.

    September 13, 2011 at 03:53 | Report abuse | Reply
    • Soulf2

      Actually, we do have a very very good idea how the pyramids were built. Go google the guy in Michigan, Wally Wallington, that built stonehenge in his backyard by him self with zero modern tools. Then look up a guy named Edward Leedskalnin. Then imagine if he had 1000 people helping him to build a pyramid.

      September 13, 2011 at 10:09 | Report abuse |
  21. Akazikian

    It's silly to argue creationism and evolutionism because in fact they align completely. God made life, and built into it the concept of evolution, letting this process do the hard work of creating man for him. I mean, think of it, even if you're God, wouldn't you want to do things efficiently? So this only adds to the majesty of God; He not only created man, but did so in a way that gave maximum freedom to us and other living things. He's a cool dude, my God.

    September 13, 2011 at 05:14 | Report abuse | Reply
    • Soulf2

      I can copy and paste too... There is a different chronology of events in chapter 1 from those in chapter 2 of the bible. In chapter 1, it says that the animals were made before human beings (cf. 1:20–28) but in chapter 2 it says that man (male) existed before the animals were created (cf. 2:15–20). Yes, both stories perfectly match evolution that took millions of years.

      September 13, 2011 at 10:16 | Report abuse |
  22. The lord my dog

    Your god? Which god is that? Ra? Zeus? Yahweh? Ganesh? They all seem to have an equal share of the rights over creation.

    If evolution is part of god's plan, at what point did we cease to be not human and suddenly human enough to be worthy enough to be god's friend?

    Interesting how the trolling YEC's post one post having a dig at everyone and then run away!

    Apologies for my British accent coming through in my post BTW!

    September 13, 2011 at 08:31 | Report abuse | Reply
  23. robert knight

    evolution is ridiculous.

    September 13, 2011 at 10:58 | Report abuse | Reply
    • Ian

      Robert, evolution might be ridiculous but it made you!

      September 13, 2011 at 13:54 | Report abuse |
  24. Jim Mauch

    It is unfortunate that so many people say that evolution is wrong because they refuse to believe. It's not about your belief it's about accepting the mountains of evidence that is out there. If you belief does not allow you to deal with realty then we can't help.

    September 14, 2011 at 23:03 | Report abuse | Reply
  25. Primateus

    People who don't "believe" in evolution are simply too emotionally invested in religious belief, and gripped by theological fear, to deal with the fact of evolution.

    Emotional investment in ideas makes disabusing those ideas difficult if not impossible. I believe that science will increasingly show that wildly varying opinions, ideology-hoarding, and fact-deflection will increasingly come down to a simple truism: in most arguments, someone is closer to being objectively wrong, and someone is closer to being objectively right, and when more and more verifiable, easily-available evidence builds up the former group will have nowhere to hide. Theists are a disturbing example of how the former group can still exist and not be ripped apart by paroxysms of cognitive dissonance, but I continue to believe that as reason spreads and elbows out nonsense wherever it's encountered, religious irrationality, and other forms of irrationality, will wither under the glaring spotlight of science and reason.

    September 18, 2011 at 09:10 | Report abuse | Reply
  26. Keyannax Palint

    Appreciation to my father who stated to me about this web site, this website is actually awesome.

    July 11, 2012 at 08:26 | Report abuse | Reply
  27. Dr.J.Jones

    After researching the human body since 1970 I just can't say it was a evolutaniry chain of placements for such an amazing complex form. Or as one evolutionasry scientist said recently it was just "dumb luck"that all of these trilions of cells formed such a 'perfect union.' Time will tell -it always does.We are only at the beginning of researching man's origins.Another 150 years from now I think there wil be much new research that will confound past study.

    December 18, 2012 at 18:58 | Report abuse | Reply

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