The 9th grade biology students recently traveled to London for a week-long field trip to many historical sites. The students spent three hours exploring the Natural History Museum. The following is the fifth in a series of posts written by the students to discuss what they learned.
by Alice, James, and Zach
We have recently returned from our phenomenal trip to London with our grade nine class. We were fortunate enough to explore the Natural History Museum in London, and we were even able to go on a guided tour with the renowned scientist named David Ng. David Ng is a scientist who was born in Canada and has taken a sabbatical to work at the Natural History Museum. While at the Natural History Museum, Dr. Ng took the time to guide us through Darwin’s Cocoon, and afterwards we were able to explore the museum’s exhibits in groups. Our group got to visit the “Our Place in Evolution” exhibit where we learned all about the early humans and their similarities to primates. The exhibit was extremely interesting and its focus on the evolution of humans was very thought provoking. We were able to see many replicas of fossils dating from millions and millions of years ago, including a cast replica of Lucy, which you will learn about later in the post.
When we first arrived at the Museum of Natural History, our first stop was to visit Darwin’s Cocoon. Much to our excitement, we entered the exhibit and saw the 65 meter long and 12 meter wide cocoon. David Ng welcomed us to the cocoon, whose 8 stories were impossible not to marvel at. Dr. Ng explained all about the work done at the cocoon, where there are world-class laboratories for scientists and massive amounts of storage space for the 20 million plant and animal collections kept at the museum. We began our tour of the cocoon from the eighth story downwards. We viewed some of the collections of the museum, including the hundreds and hundreds of specimens that were on display. We were able to see recently collected beetles of varying sizes from Central American jungles, as well as varying species of moths. We saw a variety of plant species, along with microscopic organisms, such as the tiny sandfly, on microscope slides. We also had the opportunity to get a glimpse at real scientists at work, which was amazing! As we journeyed through the museum, we participated in many interactive exhibits, which included exhibits about DNA and about the life of scientists as they hunted for specimens in places all around the world. These exhibits were extremely engaging. The Darwin Cocoon was incredibly interesting, and it was amazing to see all of its wonderful exhibits after researching all about them in science class.
If there were one word that could describe our exhibit it would be amazing! You would be fascinated by the relationship between humans and primates. We share about 8 main qualities. These qualities are that we both have a backbone, hair or fur, toe nails, no tail, shoulder blades, big toes, and last but not least 4 incisors in each jaw. Now, there are many different kinds of monkeys and apes, including orangutans, gorillas, chimpanzees, gibbons, and many more. The type of ape that has the most in common with human is the chimpanzee. Humans and chimpanzee both share the majority, if not all the qualities listed above. The type of monkeys that humans are least connected to are the gibbons. This is because gibbons lack the frontal part of the skull. Scientists have measured how humans are related to monkeys in many ways. They have tested the ways that monkeys are related to humans by the looking at relationship in our blood proteins. Our most related ancestor has been found in Northern Africa. Human evolution can no longer be looked at as a “ladder,” but as a “complex tree”. By using these diagrams, or “trees,” scientists have been able to show which monkeys are related to humans in order. In these diagrams, if you are at a high point on the diagrams it means that you are related in a more modern time. If you are at a low point this means that you are related further back in time. For example, the Sahelanthropus is our oldest related ancestor. Therefore, this primate is located at the lowest point on the diagram. Apes have been evolving for almost 20 million years. Now you have learned about early primates, and our relations with them. You will now learn about the rest of the exhibit, which included early and modern human evolution.
As the early humans progressed, advancements were made and life became more and more modern. One of the first known groups of early humans was known as the Sivapithecines, who lived between 14 million and 8 million years ago. The thickened enamel on their teeth indicated that the Sivapithecines were members of the great ape group.
As time passed, a more modern group known as the Australopithecines evolved. The Australopithecines lived between 5 million and 1.5 million years ago. Fossil evidence, which has been found in parts of Africa especially along the Rift Valley, suggests that that were two types of australopithecines. Fossils show that the first type had a strong and robust figure, while the other type of Australopithecines had a smaller, more delicate form. Scientists have not yet determined that exact relation between these two groups of Australopithecines. In 1974, 3.2-million-year-old fossil was found in Africa and was unusually well preserved. This fossil was designated to be an australopithecine and is unofficially known as “Lucy.” Lucy’s cranial, or brain, capacity is approximately the size of that of a chimpanzee, which is one-third the size of that of an average modern human. Lucy’s remains suggest that the fossil organism was about 1 to 1.5 meters in height and was upright-walking organism.
More time went on and another group of early humans emerged millions and millions of years after the Sivapithecines and Australopithecines arose. This group, who lived from about 2.5 to 1.6 million years ago, was known as Homo habilis or the Habilines. Habiline fossils indicate that these early humans had a larger brain, a more vertical forehead, and weaker brow ridges than earlier humans. Fossils suggest that Habilines were definitely bipedal, meaning that they primarily walked on two legs like humans. Habiline fossils show that they shared traits with both modern humans, as well as primates, like the Sivapithecines and Australopithecines did before them. However, there is a key difference that sets Habilines apart from the organisms that came before them. When excavating Habiline fossils, paleantologists came across tools, suggesting that Habilines were the first known organisms to use tools. Tool marks on animal bones indicate that Habilines may have hunted animals and ate meat. Other scientific research shows that Habilines may have had a particular region of the brain that is key to speech.
Millions of years went by, when yet another group of organisms arose on Earth as evolution occurred. This group of organisms, known as Homo erectus, is no more than 1.8 million to 50,000 years old. Compared to modern humans, Homo erectus had a large skull, large brow ridges, a low forehead, and large, bulky teeth. The average brain size of Homo erectus was about two-thirds the size of that of an average modern human. Homo erectus fossils show that these organisms may have been nearly as tall as modern-day humans. The fossils of Homo erectus have been found in China, Europe, Africa, and on Pacific Islands, indicating that Homo erectus were the first group to travel out of Africa. Fossils also suggest that Homo erectus were hunters and used fire to provide warmth and to cook. Many Homo erectus also lived in caves in order to survive.
Nearly 800,000 years ago, a new species evolved from Homo erectus. However, when they arose, they did not completely take over the population, but instead lived with Homo erectus for thousands and thousands of years. This new species, known as the Homo sapiens, has many similar traits to Homo erectus, including large cranial capacities. A group of Homo sapiens, known as the Neanderthals, lived from about 230,000 to 30,000 years ago. Neanderthals had large bones, thick brow ridges, and large teeth. An important distinction between Neanderthals and modern humans is that Neanderthals had a slightly larger brain capacity than that of an average modern human. They were about 1.5 m tall and were very muscular. Like Homo erectus, they lived in caves, but also lived in stone shelters. They used tools, as the Homo erectus did, but in addition to using these tools for hunting, Neanderthals used tools to scrape animal hides in order to create clothing. Some scientists believe that Neanderthals were killed off violently by more modern humans, who you will hear about in the next section of this post.
Who were the first modern humans? As mentioned earlier, human evolution has occurred over millions of years. Throughout the flow of time, our ancestors have learned to survive over thousands of years and have continued to enhance their survival techniques, such as the creation of stone tools by the Homo erectus peoples. Eventually, as time passed on, the Homo sapiens peoples emerged. The Homo sapiens, who lived around 100,000 years to about 40,000 years ago, thrived in what is now Modern Day Africa and Western and Central Asia. They are considered to be the first modern humans for a number of reasons. First, there is a distinction in the skull type of the Homo sapiens from its past relatives. As shown by this comparison of skulls, one can easily point out that the formation of the skull is somewhat different than the other skull. For example, the lower face (from the nose to the chin) is pushed in more into the skull, with the chin becoming more defined. Also, the top of the skull seems more defined than that of the Neanderthal. In addition, there was a huge change in the progress in which the use of tools, both type and shape, and eventually, new tools for different purposes were developed. For example, the early modern humans took the idea of the spear and developed it even further. Through the use of new ideas, the first spear throwers were created to catch and hunt food for the humans. Newer tools were developed for the use of catching food, such as bows and arrows, knives, and traps. Another advancement in the early modern human societies would be the beginnings of ritual burials. More modern humans buried the deceased into the ground and then were given burial rituals, which had a meaning to the people who were burying the bodies. Many people say that these ceremonies led to the creation of religion and that this was the start of an eventual lead into what would become the human race as it is today.
We really enjoyed exploring and observing our exhibit. After going to our exhibit, we had a much better understanding of how humans are related to primates and also, how humans advanced over time. Primates are very unique and interesting organisms, and it is amazing how evolution caused them to adapt over millions and millions of years. It is interesting to think that our ancestors have come so far and made significant advancements over the course of time. We also want to send out our thanks to Dr. David Ng who really went out of his way to show us around Darwin’s Cocoon and to explain to us the history of the museum. We hope that the graduating class of 2015 has as much fun as we had at the Natural History Museum.
Have scientists discovered any new research about the relationships between humans and non-human primates? What significance do early and modern humans have on the arts and tools present in today’s society? Have any early human fossils been found recently, and if so, where have they been discovered?