The Act of Cooking is 2 Million Years Old

According to Scientific American, “Human molars and jaws responded to the invention of cooking by getting smaller. Fossils thus indicate that controlled-fire cooking probably originated about 1.9 million years ago”.

We all learn in Human Species that molars decrease in size due to the act of cooking food. The cooked food is ultimately softer and easier to chew which leads to the evolution of smaller molars. 

Researchers therefore compared the molars and body sizes of extinct hominids with modern humans and other primates. Turns out that Homo erectus and Neanderthals had, and modern humans have, molars that are smaller than would be predicted by looking at general primate evolution. The finding is in the Proceedings of the National Academy of Sciences. [Chris Organ et al, Phylogenetic rate shifts in feeding time during the evolution of Homo]

Edited From Scientific American

The Laetoli Footprints Explained

The Laetoli footprints are fossils of footprints that look suspiciously like human footprints of today. They appear to be the fossilized footprints of two or three hominids that walked through Laetoli, Tanzania, millions of years ago. The very idea that humanoids were walking upright for as long as these fossils suggest has sparked a great deal of controversy. Creationists typically believe that the Laetoli footprints are not millions of years old and that the footprints are not hominid, but human. Scientists tend to believe that these footprints could not have come from modern man, so it must suggest that hominids have been walking on two feet longer than previously thought.

In 1976, Dr. Mary Leakey was on an expedition in Tanzania with a group of other scientists when he found the Laetoli footprints. They were there to study ancient remains, but they found something equally, if not more, interesting. The group was walking toward Olduvai Gorge together one day during their expedition. Two of the paleoanthropologists began throwing elephant dung at one another and otherwise goofing off. During the action, the Laetoli footprints were literally stumbled upon.

The Laetoli footprints consist of two tracks of about 30 meters. One of the sets of prints is significantly larger than the other. This suggests that there were at least two hominids walking in Laetoli when the prints were made. The tracks were made by either a woman and a man or an adult and a child. There could also be a third set of tracks within the larger set. It looks as if a third hominid, that walked along behind the first two, had stepped in the larger tracks. Dr. Leakey made plaster casts of the tracks and then covered them. She marked the location so they could go back.

The fossils were dated at roughly 3.7 million years old. Most scientists agree that the Laetoli footprints must have come from a hominid species that walked bipedally, as it is obvious that the owners of these prints walked on two legs. Furthermore, it is believed that they belonged to the Australopithecus afarensis species of hominids, the same group that the Lucy Skeleton belongs to.

The Laetoli footprints probably did not come from great apes. Everything from the shape of the foot to the position of the toes suggests that hominids made the prints. The position of the foot from which the creature pushed to walk is also different. As far as being footprints from a human, the feet are much smaller than human feet and not shaped the way that you would expect a modern man’s foot to be shaped. The manner of walking that is deduced from the footprints is very similar to that of Homo sapiens. This makes them an obvious, or at least likely, link in the evolutionary chain.

Creationists, of course, do not believe in evolution. Furthermore, they do not believe that manlike creatures, or any creatures, walked the Earth millions of years ago. So, the date and type of fossils that the Laetoli footprints are, is quite unbelievable to them. They think that many of the dating techniques used by scientists are inaccurate and that the fossil record is misinterpreted by scientists. This is the mystery, or more accurately the controversy, over the Laetoli footprints.

Author Bio

Shelly Barclay writes on a variety of topics from animal facts to mysteries in history. She’s a history fanatic and spends a lot of time reading about history from all corners of the globe and all time periods. I like to spend all of my free time outdoors or in museums. I live on the South Shore in Massachusetts, just outside of Boston. This is the perfect place for someone like myself. Beautiful natural sites and historic city sites are all within a few minutes drive for me.

Sources

• Pictures © GIRLintheCAFE
• The Laetoli Footprints, retrieved 11/03/09, sain.sunsite.utk.edu/cgi-bin/textonly/0145/www.bbc.co.uk/dna/h2g2/A94336
• Peterson, Chris, Laetoli: Footprints in the Past, mnsu.edu/emuseum/archeaology/sites/africa/laetoli2

Monday Ground Up: Oldest Hominid Skeleton Fills In the Evolutionary Gap

In 2009, scientists identified a skeleton of a human-like species as Ardipithecus ramidus, possibly a human ancestor that might have lived 4.4 million years ago. Nicknamed “Ardi,” the skeleton was said to be over a million year older than Lucy, the skeleton that has been considered the oldest hominid skeleton prior to the discovery of Ardi.

Ardi, a female skeleton, was discovered in Ethiopia in 1992. A molar was first discovered, followed by a hand bone in 1994. A series of searches then ensued, which allowed the search team to unearth more bones, partially completing Ardi, the now oldest hominid skeleton, with 125 bones comprised of skull, pelvis, teeth, hands, feet, and limbs. Around 35 Ar. Ramidus bones were also excavated at the same site. the oldest hominid skeleton was unearthed which were also studied and used to draw a picture of Ar. ramidus’ anatomy, way of living, and habitat.

What the oldest hominid skeleton was like

Based on the findings, the four-foot tall Ardi is more like a human than a chimp. The oldest hominid skeleton hinted that Ardi walked upright but could also have climbed trees on her palms. She had opposable big toe that was very helpful when moving through trees. Ardi’s hands, arms, and legs were long. Her hands could carry objects while walking, a sign of dexterity. Her skull is way smaller than humans’ but is somewhat bigger than those of chimpanzees’. She might have subsisted on plants, fruits, and small animals. According to scientists, the oldest hominid skeleton Ardi might have weighted 110 pounds.

Her habitat is dense woodland with water springs, which was populated by different land, water, and air creatures such as elephants, monkeys, antelopes, hyenas, owls, parrots, and lovebirds. This description of Ardi’s habitat was based on the different fossils found at the excavation site.

The oldest hominid skeleton: The “link”

After doing a 17-year study of the oldest hominid skeleton, scientists proposed that Ardi could provide helpful information on the evolutionary history of humans. The discovery of the oldest hominid skeleton gave scientists more clues as to how humans evolved, painting a clearer picture of what the ancient ancestors might have looked like after the human evolution from apes, which started around seven or six million years ago.

Ardi’s human features also made the scientists re-think their early theory of the “split,” the point in the evolutionary process where humans and chimpanzees separately evolved from their shared ancestor. Scientists long believed that the last ancestor was chimp-like, but the now oldest hominid skeleton seemed to have indicated it wasn’t. But although the discovery of the oldest hominid skeleton might have altogether changed the theory, there at least was a link that can fill in a gap in the evolutionary map.


Margaret Keely is an anthropology enthusiast and a healthcare writer who offers nursing education courses to the future addition to the nursing workforce.

Sources

• Ardi Photo © Scienceblogs
• Reexamining Ardipithecus ramidus in Light of Human Origins

Rise of the World's First Hominids

The Middle Awash Area of Ethiopia

The Middle Awash area of Ethiopia is the most persistently occupied place on Earth. Members of our lineage have lived, died, and been buried there for almost six million years. Now the bones of hominids are eroding out of the ground.

In the Afar desert of Ethiopia, there are a lot of ways to bite the sand so to speak. There is disease, of course. One can also perish from wild animal attack, snakebite, falling off a cliff, or in a shoot-out between one of the Afar clans and the Issa people across the Awash River to the east.

But life is fragile all over Africa. What is special here is the occasional durability of the deceased’s remains. The Afar Basin sits smack atop a widening rip in the Earth’s crust. Over time, volcanoes, earthquakes, and the slow accumulation of sediments have conspired to bury bones and then, much later, disgorge them to the surface as fossils. The process is ongoing. In August 2008 a young boy was taken by a crocodile in Yardi Lake, in an area of the Afar known as the Middle Awash.

Read More:  The Middle Awash Area of Ethiopia and the Rise of the World's First Hominids.

Courtesy of Auron from Edutainment