Smithsonian.com

Cliff Palace at Mesa Verde National Park in Colorado. Image: Andreas F. Borchert/Wikicommons

The United States celebrates its 236th birthday this week. If you’re tired of the same old fireworks and cook outs, consider taking a trip to one of the country’s many archaeological parks to learn more about the people who lived in the U. S. hundreds or thousands of years before the Founding Fathers signed the Declaration of Independence. Here are a few suggestions:

Meadowcroft Rockshelter, Pennsylvania: This site may be the oldest known archaeological site in the United States, dating to 15,000 to 16,000 years ago. About an hour southwest of Pittsburgh, Meadowcroft offers tours of the rockshelter where you can see stone tools and the remains of fires that hunter gatherers made thousands of years ago.

Lubbock Lake Landmark, Texas: Not far from Texas Tech University, Lubbock Lake is an unusual archaeological site because of its complete, continuous record of human occupation over the last 12,000 years. The site’s earliest residents were the Clovis people, once considered to be the first human inhabitants of North America, and the Folsom people, who lived in the area about 10,800 years ago. Archaeologists at Lubbock have found Clovis and Folsom hunting and butchering sites, filled with stone tools and mammoth and bison bones. But excavations of the site are still ongoing, giving visitors a chance to see archaeologists in action.

Cahokia Mounds, Illinois: As a native of Illinois, I’m embarrassed to admit that I’ve never visited Cahokia, an area a few miles northeast of St. Louis that was first settled around 700 AD. By about 11oo, Cahokia had grown to be the largest pre-Columbian city in what is now the United States, home to as many as 20,000 people. (It was so big, in fact, that in 1250, it was larger than the city of London.) Cahokia was the center of Mississippian culture, a corn-farming society that built large, earthen mounds. Seeing such mounds, which served as platforms for houses, temples and other structures, is the highlight of a visit to Cahokia. The site’s centerpiece is the 100-foot-tall Monks Mound, the largest prehistoric earthwork in North America. If you don’t plan to be in Illinois anytime soon, there are plenty of other Mississippian mound sites you can visit, such as Alabama’s Moundville, Arkansas’ Parkin site (visited by Spanish explorer Hernando de Soto in 1541) and  Mississippi’s Emerald Mound.

Mesa Verde, Colorado & Chaco Canyon, New Mexico: While the Mississippians were constructing mounds, people in the Southwest were building stone and adobe pueblos. The Ancestral Puebloans first came to Mesa Verde in about 550 AD. For 600 years, the Puebloans lived and farmed on top of the mesa. But near the end of the 12th century, they started to live beneath cliff hangings. Today, the park is home to 600 of these cliff dwellings. The largest is Cliff Palace, consisting of 150 rooms and 23 kivas, walled, subterranean rooms used for ceremonies. They didn’t live there very long, however. By about 1300, a drought forced the Pueblo people to find new territories to the south and east. (Despite the wildfires blazing across Colorado, Mesa Verde National Park is open to visitors.)

More than 100 miles south of Mesa Verde, Chaco Canyon was a major political and spiritual center of Pueblo culture from 850 to 1250 AD. Instead of cliff dwellings, the site is known for its monumental and ceremonial architecture, particularly multistory “great houses” made out of stone. A self-guided driving tour of the park passes by six of the site’s most famous structures.

Clearly, this list of American archaeological parks is by no means exhaustive—just a few places that I’d like to visit. Where would you like to go?

Pigs were domesticated in several different regions of the world. Image courtesy of Flickr user thornypup

This month, Smithsonian looks at the origins of the chicken, tracing the domesticated version of the bird to either India or Southeast Asia. The magazine has also explored the beginnings of the house cat in the Near East. Here’s a brief look at where other domesticated animals got their start.

Dog: Descended from the grey wolf, the dog became man’s best friend tens of thousands of years ago. The earliest known dog fossils come from a site in Belgium dating to more than 31,000 years ago. But a 2010 genetic study suggests modern dogs probably come from the Middle East: Dog DNA best matches the DNA of wolves from that part of the world. Although dog fossils date to as many as 31,000 years ago, the most ancient dog breeds around today—such as the Afghan hound, Siberian husky, chow chow and Shar Pei—are no more than a few thousand years old. And most modern dog breeds are only a couple of hundred years old, originating during the Victorian era of the 19th century.

Goat: Modern goats stem from six maternal genetic lineages, but most of today’s farm goats arose from just two domestication events: one in southeastern Turkey 10,500 years ago and another in the southern Zagros Mountains and Central Iranian Plateau almost 10,000 years ago. A 2008 genetic study of domesticated goats and their ancestor, the bezoar, indicates almost all of today’s goats (perhaps as many as 90 percent, according to one study) descend from those that originated in Turkey.

Sheep: Along with goats, sheep were among of the first hoofed animals to be domesticated, about 11,000 years ago. The animals were originally bred for their meat, and it wasn’t until about 5,000 years ago that they were also raised for wool. Archaeological and genetic evidence points to the Fertile Crescent as the original home of sheep. But researchers have discovered at least five distinct genetic lineages, indicating the animals were probably domesticated several times from various wild sheep ancestors such as the mouflon.

Cow: Domesticated cattle come in two main varieties: Taurine cattle are the common dairy and beef cattle found in Europe, North America and other cool environments. Zebu, or humped cattle, are found in warmer, tropical climates. The Taurine evolved from wild ox somewhere in the Fertile Crescent about 10,000 years ago. Research published earlier this year estimates the original population consisted of just 80 female oxen—a sign that the domestication occurred in a restricted region of the Middle East. European wild ox contributed to the cattle gene pool later, when farmers brought cattle to the continent from the Middle East. Zebu cattle can be traced back to the Indus Valley of India.

Pig: Humans domesticated pigs from wild boars several times in several different places. The earliest evidence comes from Cyprus, where fossils reveal that humans brought wild boars to the island by 12,000 years ago. Full-fledged pigs appear in the Fertile Crescent by 9,000 years ago. Genetic evidence indicates pigs also arose separately in East Asia, Southeast Asia, India and Europe. In Europe, however, the first pigs were migrants that came over with farmers from the Middle East. Later, these foreign pigs were replaced by home-grown pigs domesticated from local European boars.

Horse: Last month, researchers reconstructing the population genetics of horses confirmed humans first tamed the equines somewhere in the western part of the Eurasian Steppe. The earliest  fossil evidence comes Kazakhstan when the area was inhabited by people of the Botai culture. Horse teeth dating to 3,500 B.C. show the characteristic damage that develops from biting a harnessing bridle. And chemical analyses of fatty acid residues on pottery indicate the Botai were consuming horse milk.

Donkey: The domestication of the donkey allowed people to develop mobile forms of pastoralism, enabled long-distance trade and aided in the rise of early Egypt. Modern donkeys belong to one of two distinct genetic groups, implying the animal was domesticated twice. DNA points to both events happening around 5,000 years ago in Northeast Africa. Last year, researchers determined one group descends from the Nubian wild ass. Scientists had thought the Somali wild ass was the ancestor of the second donkey clan, but DNA shows that’s not possible. Scientists have yet to pinpoint the form that gave rise to this donkey group.

Adult male orangutans have large cheek pads and a big throat pouch, but it can take decades to develop such traits. Image courtesy of Flickr user nebarnix

In Interview with the Vampire, Claudia, portrayed by Kirsten Dunst in the movie version, becomes a vampire at age 6. Six decades later, she still has the body of a child but the thoughts and desires of a grown woman.

In this way, orangutans are kind of like vampires. They have their own form of arrested development.

When male orangutans hit puberty, they develop distinct traits known as secondary sex characteristics that separate them from females. In addition to being much bigger, males grow longer, shaggier hair on their arms and back and sport giant cheek pads. They also have throat pouches that resemble large double chins, allowing males to beckon females with loud long calls.

Some males are late bloomers, not acquiring these traits until as late as age 30. But looks can be deceiving. Even though these males appear to be youngsters, they are sexually mature and capable of siring offspring.

Scientists think the two different types of adult males—those with secondary sex characteristics and those without—are two alternative mating strategies that evolved in orangutans. A new study published online in the American Journal of Physical Anthropology tries to pinpoint the circumstances under which orangutan arrested development emerges.

To do this, Gauri Pradhan of the University of South Florida and Maria van Noordwijk and Carel van Schaik, both of the University of Zurich, considered the differences between orangutans living in Borneo and those in Sumatra. These Indonesian islands are the only two places in the world where orangutans are still found in the wild. But arrested development is largely limited to Sumatra.

Orangutans in both locations are mostly solitary. They roam the treetops alone, but they live in home ranges that overlap with those of other orangutans. In Sumatra, a female prefers to mate with the dominant male that lives in her neck of the woods. This male always has his full set of male features. A female finds the dominant male by following the sound of his long call, and when she’s ready to be pregnant, the two enjoy a sort of honeymoon—traveling and mating together for up to three weeks. Other adult-looking males may live in the same area, but females actively avoid their calls and stay hidden from them.

Because the dominant male is so popular, he can be choosy about mates. These males tend to pass over inexperienced females who haven’t yet had a baby. With younger adult females, it’s hard to tell if they are truly ready to become mothers, so it’s a better bet to stick with females who are already moms.

Yet some males are interested in these naïve females: the sexually mature males lacking adult traits. Unlike the other male orangutans, these guys don’t wait for females to come to them. They search the forest for receptive females, and Pradhan and his colleagues speculate that these males might father a lot of the children of first-time orangutan moms.

The sex lives of orangutans on Borneo are quite different. Here, no single adult-looking male is dominant. Many full-fledged males mate with an area’s females. Orangutan honeymoons are much shorter, and males may fight with each over a potential mate. Because the competition is so fierce, males aren’t choosy about who they mate with—and sometimes, even if a female’s not in the mood for mating, a male might force her to copulate.

Pradhan’s team incorporated these differences, as well as some assumptions about male growth, into a mathematical model. Their equations allowed them to determine which factors best explain the presence of immature-looking adult males in a population. The most important variable, they conclude, is the ability for one male to dominate an area. When this happens, as in Sumatra, it becomes beneficial for other males to have a covert mating strategy.

But if there is a lot of direct competition among males, as in Borneo, then it’s better to be a full-fledged male, who will always beat out immature males. No one male can monopolize females in Borneo because males tend to travel more on the ground there, the researchers say. That improves their mobility and makes it easier to quickly find females, even those who may not want to be found.

Thousands of years ago, orangutans once lived throughout much of Southeast Asia, even on the mainland. I wonder how pervasive arrested development was back then. Even if we had large bone samples, would anthropologists ever be able to detect such behavior in the fossil record?