Explore Evolution with Lucy’s Legacy

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Lucy’s Legacy, an exhibition featuring the world’s most famous fossil, recently opened at Discovery Times Square Exposition in Times Square, New York. The exhibit will remain on display until October 25, 2009.

The Lucy exhibit has been an exciting catalyst for discovery, discussion, and debate within the scientific community. In this series of blogs, Dirk presents all sides of the controversy surrounding Lucy’s existence and significance while skillfully separating fact from fiction with supporting evidence and research.
  
Do you enjoy debate about scientific theories or issues? If so, prepare yourself for a great read while perusing the following blogs by Dirk. In addition to his perspective and logic, Dirk also provides links to research and evidence that will leave you on the edge of your seat…and excited about evolution!

-In fide constans… Always loyal [Lucy's Legacy]     
-Neanderthal Controversy
-A Letter From Lucy: Making no bones about it. (Pun intended)
-Lucy loves Houston – and she’s not leaving. Yet.
-If Humans came from monkeys, than why are monkeys still around?
-Evolution
 
 Neanderthals—most people know what they were, but do we know who they were or how they lived? Join Dirk as he discusses these unique people and their lifestyle.

-Neanderthal Controversy 
-Neanderthals on the move
-Neanderthals Speak Out

Why are genetics important in the development of humans? More than just appearance, genetics play a role in where we live and even how we survive. In the following blogs, Dirk explores where genetics has contributed to history and evolution. 

-Neanderthals on the move
-We are all mutants
-10,000 BC: The story behind the date
-A major step forward – 40,000 years ago

s-legacy-exhibitSure, they’re adorable and entertaining to observe but chimps and monkeys offer far more than that! They provide valuable information about human behavior and progress. Follow-up with these blogs and read Dirk’s presentation of our connection to these magnificent animals.

-Chimps using tools: Archaeology’s most fascinating discovery of 2007
-The Apple Doesn’t Fall Too Far from the Tree
-Monkey business
-If Humans came from monkeys, than why are monkeys still around?
  
The study of fossilized remains (like Lucy and other hominids) offers an exciting opportunity to draw parallels on our own existence and physicality. What did they look like and how did they live? Dirk has explored these questions in the following blogs:

-Discovering behavior: a step-by-step process
-Reconstructing ancient hominid behavior
-Lucy’s kitties
-Paleoanthropology: making the past come alive.
-Extinction doesn’t mean failure

If you ask a fossil to share the secrets it holds, it will provide invaluable information and insight into the past. But how can we piece the puzzle together? Dirk explains the wisdom of what happens when fossils meet modern technology…and dating begins (pun intended).

-How do we know: dating techniques
-Meet Lucy, Australopithecus afarensis. (What’s in a name?)
-Teeth Tell Tales
 
Want to find out more about Lucy’s home, Ethiopia? Click below and discover a wealth of history, culture and tradition.

-Timkat, an Ethiopian Epiphany celebration
-The Ark of the Covenant and Aksum

In fide constans… Always loyal [Lucy's Legacy]

The model of Lucy created for
the Lucy’s Legacy exhibition.
Photo by reality photography

The Lucy’s Legacy exhibit was reviewed in early February by a representative of the Seattle-based Discovery Institute, which promotes Creationism and Intelligent Design. In the following paragraphs, I would like to add my observations to the statements found in this review.

Let me start with a few general remarks. First, a favorite approach by Creationists is to cast doubt on the subject of evolution, particularly human evolution and to drive a wedge between faith and science. This policy, known as the Wedge Document, is publicly acknowledged by the Discovery Institute as being theirs. Second, a favorite approach of Creationist writers is to represent issues in stark black and white terms.

The 2000-word document is sprinkled with terms that drive the message home: the study of human evolution fails as a belief system; the evidence is scarce and the interpretations fast and loose and not widely accepted. Moreover, some of the evidence is misrepresented.

The writer of the document stated that there is a “paucity of actual hard evidence for human evolution.” An interesting statement, but one which considering the presence of an actual fossilized hominin fossil, fails itself to carry any water. What harder evidence can one want, but for an authentic fossil, I wonder. The same author also quotes a statement that “unless more fossils are recovered (…) there is likely to be a continuing debate on Lucy’s posture…”  Two thoughts come to mind here. It is always good to have more fossil evidence. In fact, for years paleoanthropologists have continued to find fossils every year. Our database of fossilized early humans continues to grow, courtesy of an ongoing scientific effort. This growing database has led to the formulation of answers to old questions while at the same time giving rise to new questions which we need to answer. That is the essence of scientific research; it is a never ending quest for better insights in what we can observe.

These statements, using the terms “paucity” and “until more fossils are recovered,” are misleading. One wonders if the author knows that the remains of 300 Australopithecus afarensis individuals are known to the scientific community, making Lucy and her kind the best known of all of early human ancestors.

Turkana Boy
Creative Commons License photo credit: ideonexus
Turkana Boy

Another lament found in the document is the “incompleteness” of her (i.e. Lucy’s) skeleton.” The author continues “only 40% was found” and “very little useful material from Lucy’s skull was recovered.” I suppose one could say that everything is in the eye of the beholder. Of course, 50% or more would have been even better. However, another way of referring to Lucy and the preservation of her skeleton is that it is amazing that so much was preserved, considering she died more than 3 million years ago. 

Factually incorrect is a statement that “Lucy still represents the most complete known hominid skeleton to date.” There are currently older and better preserved fossils, including some of the same species as Lucy. Baby Selam for example, is much better preserved. More recent than Lucy, but better preserved is an early hominid known as Turkana Boy. Lucy is still the earliest known and most complete adult Australopithecus afarensis. Things were different in 1974, when scientists could say that she was the oldest known and best preserved skeleton of a distant human ancestor. The fact that this statement now has to be qualified to reflect more recent discoveries is a testimony to the dogged work carried out by teams of paleoanthropologists in Africa. It is also an insight that ought to have been included in the Discovery Institute document, as I am sure that this is something they are aware of.

Photo by reality photography

We also get to read that Lucy’s bones were found scattered across a hillside, a vague reference to an old creationist claim that Lucy’s bones do not all belong to the same individual. The fact that this claim has been debunked does not stop creationists from repeating it. The author – it seems – seems to prefer that Lucy’s bones would have been found together as a contiguous skeleton. Aside from the fact that intentional burial did not exist in Lucy’s time and that she did die more than 3 million years ago, it would have been a miracle (pardon the pun) if she had been preserved completely intact and as a contiguous skeleton. One should not, however, raise the reader’s hopes by presenting this a something that should have happened.

I would like to end by referring the author of the Discovery Institute piece as well as all the readers to this latest development: Lucy was scanned at the University of Texas, Austin campus, after the exhibit in Houston had ended. I have no doubt that scientists will be pouring over this new dataset and that this effort will result in improving our understanding of who we are and where we came from.

Loyalty to a cause is admirable; having the ability to see countless shades of grey instead of only black and white is even more desirable.

Lucy loves Houston – and she’s not leaving. Yet.

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The original fossilized remains of the
3.2 million year old hominid known as Lucy

Great news if you haven’t been to see Lucy yet – the exhibit has been extended through Sept. 1!

A group of officials from Ethiopia visited the museum this week to sign an agreement that allows the Museum to keep her on display for a few more months. They brought a crew from Ethiopian TV with them, and Dirk, our curator of anthropology, gave them an extensive tour of the exhibit that will be broadcast in Africa and placed in the Ethiopian Prime Minister’s permanent archive.

Almost 170,000 people – including visitors from as far away as Helsinki, Finland and Santiago, Chile – have visited Lucy so far, and I’m thrilled we’ll have her on display here for a few more months. It’s hard to describe the experience of  looking at these 3.2 million year old bits of fossilized bone, just trying to imagine what Lucy’s life was like and contemplating the astonishing journey of our species. I’m glad that many more visitors will have the opportunity to experience this for themselves.

There’s a comment book at the end of the exhibit, where people can leave their thoughts about the experience. While the exhibit did generate some controversy when it opened, most of the comments in these books, from people who have just seen the show, have ranged from gratitude to the Ethiopian people for sharing this amazing treasure with us to amazement at the discovery of Ethiopia’s rich human history.

dirk-in-lucy-gallery.jpg

Dirk Van Tuerenhout, curator of the Lucy exhibit
(second from left), gave ETV a tour of the Lucy exhibit.
Here they are in standing behind the Lucy fossil.

Have you visited Lucy yet? If so, I’d love to hear what you thought of the experience, so please leave a comment on this post if you have a moment. If not, be sure to visit this summer – the exhibit is is scheduled to open at the Pacific Science Center in Seattle on Oct. 4 (so, no more extensions!).

Neanderthal Controversy

As mentioned in a previous post, the question of whether or not Neanderthalers were able to have offspring continues to be hotly debated by scientists. Depending on the answer given, we would have to classify Neanderthalers either as people like us, or people very different from us. Of course, proponents of both of these statements claim they have evidence to back up their very different positions.

Those who suggest that there was interbreeding between our ancestors (Homo sapiens sapiens) and Neanderthalers would label Neanderthal bones as belonging to Homo sapiens neanderthalensis.

With this label, the word “Neanderthalensis” appears in the third position of the nomenclature, which refers to the level of sub-species. This implies that the differences between us and Neanderthalers are so small that they are contained within the range of variation one would expect to find within a species (in other words, we are related to Neanderthals on a sub-species level, rather than being classified as two different species.)

According to this interpretation, the ability to interbreed with modern humans might have also spelled doom for the Neanderthals. But if the two species interbred, why don’t we see the “typical Neanderthal look” today?

As time went by and interbreeding between our ancestors and Neanderthalers continued, the thinking goes that the Neanderthalers’ genetic contribution to each new generation became ever smaller. Eventually, this percentage became so small that all people began to look like humans rather than a Neanderthal individual.

Scientists refer to this scenario as genetic swamping. If this is what happened, it would be possible for the two species to have interbred over many generations, while also explaining why the influence of Neanderthaler genes can’t be seen by the naked eye. A child burial uncovered in Portugal is seen as evidence that “admixture between the two groups must have been significant, at least in such cul-de-sacs as the Iberian Peninsula,” providing more support for this position.

Others disagree and suggest that we use the nomenclature Homo neanderthalensis.

Here the term “neanderthalensis” is in the second position of the nomenclature, referring to the species. This is a scientist’s way to say that the difference between humans and Neanderthalers is at the much more significant species level. This has an important implication: according to these proponents, Neanderthal populations and Homo sapiens populations could not have produced fertile offspring.

Of the two positions just outlined, most scientists prefer the second one and refer to DNA analysis for support. DNA analysis of Neanderthal bones has been undertaken for a while. A comparison of Neanderthal DNA against modern human DNA suggests that there are enough genetic differences to warrant labeling them as a separate species.

Most scientists, therefore, prefer seeing “Homo neanderthalensis” in the scientific literature. Since interbreeding and subsequent genetic swamping cannot occur in this scenario, the disappearance of the Neanderthalers is blamed on outright genocide practiced by our ancestors, or greater hunting skills on the part of the newcomers.