From the Mouths of Babes – Well Teenagers Really

So, the afarensis family is watching the news and they are talking about yesterday’s suicide bombing in Iraq and the youngest afarensis offspring says “Ya know, this has been going on for several years. I don’t know who we are fighting and what we are fighting for, I’m so confused.” Pretty much summed it up.

How Fossils are Made

Blog Lineages

Pharyngula mentions that The Politburo Diktat is trying to trace blog lineages – who inspired who to start blogging. Here are the questions to answer – leave a comment at his place:

1) Blogfather or Blogmother (Just one): Pharyngula – I had been a lurker and PZ made explaining biology concepts look sooo easy, I decided I could do it to. To my intense shock, it’s not as easy as he made it look!

2)Blog Birth Month: 10/2/04 4:50 AM.

3)Blog Spawn (have you inspired anyone to start blogging?): Alas, no! I would never, I’m not that kind of hominid! Well, okay, not to my knowledge – but if I have inspired you to start blogging let me know.

Hadar Pictures

This site is kind of cool! It contains pictures of Hadar (where Austalopithecus afarensis was discovered)! Below is an example.

It is AL827-1, a (left) femur discovered in 2000.

Chimpanzees and Language

The origins of human language has always been a controversial subject. Witness the cranky exchanges after Lieberman claimed neandethals were not capable of language. The ability of apes to use language is even more controversial. Whether one is discussing the Gardner’s attempts to teach a chimp english, or attempts to teach chimps and gorillas sign language, there is always a large amount of skepticism. The following research will probably generate a large amount of skepticism as well.

According to National Geographic News researchers at the University of St. Andrews in Scotland have discovered that chimps use certain distinctive grunts to communicate about food:

At the Edinburgh Zoo the chimps make high grunting noises when they find bread, a food they seem to like, and low grunting sounds when they find apples, which they apparently don’t care for very much, according to the study, published last week in the journal Current Biology.

After noting the different types of grunts, the researchers set out to see if other chimps listening to the grunts interpreted them the way the researchers had (“bread” and “apple”). The researchers found that the listening chimp did seem to understand what the grunts mean.

The scientists recorded the grunts and played them to a chimp in the pen. When the chimp heard the “bread” grunt, the ape looked in the place in the pen where bread is usually found. When the “apple” call was played, the chimp searched appropriately for an apple.

“It shows that, by simply listening to each other’s calls, chimpanzees can infer what kind of food the caller has found,” said researcher Katie Slocombe, who worked with colleague Klaus Zuberbuhler on the project.

The researchers argue that these calls are referential signals but caution that:

“We don’t know yet how specific these calls are—i.e., whether they specifically refer to bread or apples or whether they simply label highly preferred food [such as bread] and less preferred food types [such as apples]. We are planning further experiments to test these two possibilities,” Slocombe said.

Over and above the issue of language, there may be another social function to these grunts:

Study co-author Zuberbuhler believes that the grunts serve a social function, since the chimps hardly ever make the noises when they are eating alone.

The grunts may be a call to dinner, Zuberbuhler says. “Chimps may find it genuinely unpleasant to eat without others doing the same.”

*snip*

The possible dinner-bell grunts may be related to certain human vocalizations, Zuberbuhler said.

“We don’t like to eat in the presence of others who are not eating,” he said.

“In many cultures humans coordinate the timing of starting a meal, for example, with vocal cues such as ‘bon appetit.'”

I, for one, can’t wait to see the results of the planned follow up research.

New Stone Age Site found in the Sahara

According to National Geographic News:

The seven nearby sites include an extensive cemetery and represent one of the largest and best preserved concentrations of ancient skeletons and artifacts ever found in the region, researchers say.

Some back ground from the expedition website:

“…the desert has waxed and waned since the last Ice Sge to eventually become the expanding desert we know today.”

As the lakes evaporated and disappeared 6,000 years ago, the people that had based their livelihood on its aquatic life, the Kiffians, were replaced by the first pastoralists of the Sahara, the Tenereans. This next group of people tended herds of just-domesticated African cattle on the grasslands between the encroaching dunes. These cattle herders, the Tenereans, lived from about 5,500 to 3,500 years ago. Our site contains their tools and ceramics, including beautifully made green stone disk-shaped axes. All of these transitions were happening before the first pyramid in Egypt was ever constructed.

Again from National Geographic:

The site may not have been continuously occupied. But it was likely inhabited for much of that time, which was a crucial one in early human history.

During the New Stone Age, humans moved from hunter/gatherer societies to become early agrarians who domesticated plants and animals.

*snip*

Tools such as large pottery and heavy grinding stones suggest that Kiffian peoples may have occupied the ancient lakeside area at least semi-permanently, Garcea says.

Scientists know that by about 6,300 years ago the Sahara’s first pastoral people, the Tenereans, began tending herds of newly domesticated cattle.

And while the expedition team found remains of domestic cows and asses, researchers are uncertain whether Tenerean peoples occupied the particular dig site.

*snip*

The team says the site’s human remains were most striking. Members found hundreds of skeletons in the site’s large cemetery, some still adorned with ancient jewelry.

The researchers found tools, such as precision stone blades, bone hooks, pottery stamps, and other artifacts, in graves and other site locations.

Some artifacts suggest travel and perhaps even distant trade. Stone tools made of pale green volcanic rock could have their source some 50 miles (80 kilometers) distant in the Air Mountains, an area rich with period rock art.

Unfortunately, the site has attracted looters:

But archaeologists are not the only ones who have visited the historic site. Niger is a poor nation, and the temptation to profit from its rich cultural history has proven too great for some.

“We followed some 4×4 tracks that our guides said were definitely not made by tourists but by vendors going out there for stolen artifacts,” Sereno said. “A photographer with our team estimates that he photographed as many as 3,000 artifacts in one day, found in shops of communities near the site.”

Worse yet, because the site is in the desert it suffers from deflation, or erosion caused by the wind, and is changing rapidly:

“The wind is destroying these sites very quickly,” Garcea, the Italian archaeologist, said. “I saw pictures that [Sereno] took in 2003, and you can really see the deflation.”

“Some skeletons that were covered are now exposed to the surface and the hyper-arid desert conditions. In two or three years I’m sure I won’t be able to see some of the things that we can study now,” she added.

New Digs at Teotihuacan

From National Geographic News:

The size of Shakespeare’s London, Teotihuacán was built by an unknown people almost 2,000 years ago. The site sits about 25 miles (40 kilometers) north of present-day Mexico City. Temples, palaces, and some of the largest pyramids on Earth line its ancient main street.

Scientists believe Teotihuacán was the hub of trade and commerce in Mesoamerica until the city’s civilization collapsed around A.D. 650. When the Aztecs stumbled upon the metropolis centuries later, they dubbed it the “City of the Gods,” because they believed it was where the Gods met to create the present universe and sun.

Research has focussed on the Pyramid of the Moon (pictured above):

Excavations also reveal that the pyramid was constructed in seven stages, each stage an enlargement of the last. The work started in A.D. 100 and ended around A.D. 400.

Japanese researchers are searching for the tomb of the ruler who ordered the pyramids construction. It has not found it yet but:

Sugiyama has made some intriguing finds, including dozens of beheaded people with bound hands. The bodies suggest bloody sacrificial rituals ripe with symbolism of military power, he said.

Analyses by Spence of the University of Western Ontario suggest the sacrificed victims came from outside Teotihuacán, possibly as captives brought back from distant territories or battles.

The clues come from oxygen isotopes in bones, which act as geological markers. “They tell you where a person was at a particular time,” he said.

Climate and altitude are among factors that affect the isotopes. The isotopes found in remains of pyramid victims differ from those unearthed in city homes.

Researchers also examined the teeth of the victems looking at the growth lines or perikymata:

“Basically growth stops as the body concentrates on survival and repair,” he said. “Then as the stress passes, the growth continues again. But there’s a line left in the tooth that represents the stress episode.”

Because teeth only grow during childhood, scientists can put a general age to when the stress happened. These signatures of bodily stress remain in adult teeth.

“We have shown that in the last century of the city there is a growing problem of some sort. We get more and more indications showing up in adult teeth,” he said.

There are two competing hypothesis for the destruction of Teotihuacan. One is that the city was destroyed by invaders from the outside. The other is:

Spence, however, says the evidence suggests to him the fires were set during an internal revolt.

According to his theory, the deteriorating health of the city’s poor was likely exacerbated by a drought or a disruption to the food supply. This spurred a revolution against the ruling elite and their symbols of power—temples, pyramids, and palaces.

“The destruction seems to have skipped the vast majority of the city and focused on the elite and punished the elite. That suggests a revolt to me,” he said.