Human evolution: the year 2010 in review (Part 1)

That’s some good-looking gombo, cher!

gumbo
Creative Commons License photo credit: Southern Foodways Alliance

This blog contribution aims to be like a good Louisiana seafood gumbo: thick, hearty, spicy, and made up all kinds of finger-licking ingredients (pun intended). There will be some French, which would be apropos, some Latin as well, and all kinds of discoveries related to human origins, as they transpired this past year. I will follow up with a second part in a week or two with an observation and a comment.

In an earlier blog, “A pinky’s promise,” I wrote about the incredible discovery that was made early in 2010 when DNA analysis was performed on one small finger bone retrieved from a cave in Southern Siberia. The bone dated to a period (50,000 to 30,000 years ago) when all scientists assumed that the only living humans were either Homo sapiens sapiens or Neanderthals (perhaps we should now be saying Homo sapiens neanderthalensis, but I am getting ahead of the game). This first assumption proved to be wrong.

Entrance to the Denisova Cave
Creative Commons License photo credit:ЧуваевНиколай

In 2008, DNA analysis carried out on a single finger bone revealed that there was a third species of human walking the earth at that time. Toward the end of 2010, this view was corroborated by additional DNA analysis of a few teeth that were found in the same Denisova cave. The Max Planck Institute in Leipzig announced that these so-called “Denisovans” represent a new species.
More interesting still, some of their DNA is still around: the “Denisovans” interbred with the ancestors of Melanesians. This implies that at one point, this third species was quite widespread in Asia. If these conclusions hold up, the lesson we should take away from this breakthrough is that every little scrap of evidence counts when studying human origins, even a single tooth, or a finger bone. I wonder how many single finger bones or teeth have been overlooked in the past, or are still awaiting re-discovery in a museum drawer somewhere.

Neanderthals were also in the news this past year. For years, researchers have been vexed by questions such as “Who were these people?”, “Where did they come from?”, “What made them extinct?” and last but not least “Is there a little bit of Neanderthal in (some of) us?”

With regard to the last question, also discussed in earlier blogs, the way in which we answer that question will result in a different scientific (read: Latin) nomenclature for Neanderthal. Allow for the possibility of interbreeding between Homo sapiens and Neanderthals and also agree that their offspring was fertile, i.e., they successfully reproduced, then you would have to refer to Neanderthals as Homo sapiens neanderthalensis. If you disagree with this idea, and think it was unlikely these two populations interbred, or that their offspring was not capable of producing fertile offspring, then you would have to refer to Neanderthals as Homo neanderthalensis. This classifies them as a species separate from modern humans; by definition, species cannot interbreed and produce fertile offspring.

Man
A Happy Neanderthal
Creative Commons License photo credit: erix!

The latter way of thinking was long popular among paleoanthropologists. Now the pendulum is swinging the other way. Scientists at the institute decoded the Neanderthal genome and compared it with that of modern humans. The result? In their words: “By comparing that genome with those of various present day humans, the team concluded that about 1 percent to 4 percent of the genome of non-Africans today is derived from Neanderthals.”  In people speak: up to 4% of a European’s genetic makeup could be inherited from the Neanderthal lineage, now extinct.

Before you check for hair on your knuckles, thank (or blame) a single finger bone and a few teeth, as well as the staff at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany for all this.

Lest we all (well, at least those of us of European descent) break out in hives and run for the nearest hills, scientists were quick to add: “[T]he Neanderthal DNA does not seem to have played a great role in human evolution.”

Certainly, 1 to 4% overlap in genetic makeup is not very much, but it is a whole lot more than we were willing to consider just a year ago. Differences between Homo sapiens sapiens and Homo sapiens neanderthalensis remain significant. The overall physical appearance of a modern human is very different from that of a Neanderthal. In terms of behavior, and cognitive abilities, the two subspecies also appear to be a world apart, never mind they shared portions of our planet.

Comparing Neanderthals and modern humans
One of the areas in which there were both similarities and differences was diet. These insights also came out this past year.  Did you know that Neanderthals ate their veggies? And that they liked to cook them as well? Perhaps you did. However, did you also know that they were not averse from eating each other?

Check back next week to see more on this, when Dirk discusses teeth, DNA, and his own conclusions to 2010 in review.

Explore Evolution with Lucy’s Legacy

lucy-model-face

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

Science Doesn’t Sleep (6.23.08)

IMG_0615
Creative Commons License photo credit: zionorbi

So here’s what went down since you logged off.

I think I prefer “gastropod mail.” A visual artist in the UK has put a snarky twist on the term “snail mail” by attaching computer chips to actual snails; your e-mail is delivered just as fast as your snail can make it across its tank.

They take the idea of “universal suffrage” literally. Scientists at NASA have developed a software that will allow astronauts aboard the International Space Station to cast their ballots from space.

It washes our clothes and refines 99% of our gasoline – yet we had no clue as to its chemical structure. Until now.

Space weddings. Yes, you read that right.

Touché, GEICO caveman: researchers have discovered tools in Britain that indicate Neanderthals were more sophisticated than we thought.

Science Doesn’t Sleep (5.5.08)

Panel-6-Solar-System
Creative Commons License photo credit: Ralph Buckley

So here’s what went down since you logged off.

Despite the fact that it is so incredibly empty – space (hence the name) is also an unpredictable place – and it just got even more so. Scientists have discovered that the solar system bounces periodically – and those periods just happen to line up with major extinction events in the Earth’s history.

Neanderthals and humans co-existed – so why are we here now, and they aren’t? One theory asserts that Neanderthals and humans are offshoots of the same species, and thus could have produced children – meaning that the two blended into one. A new study from Argentina says nope - we probably killed them off.

Despite the fact that it sits on top of 10% of the world’s oil reserves, Abu Dhabi has built the first carbon-neutral city. It seems they’ve realized that no matter how much oil you have – someday, it’s gonna run out.

Brian Cox, a physicist at CERN, explains what really happens inside the Large Hadron Collider.

Scientists have spotted a space tornado - which might be the first step in the creation of stars.