It is the beginning of November and we are well into the short rainy season in East Africa. Clouds have been building up for a few weeks and we have several heavy rains so far. One good thing the rains brought us is cool air. But on top of that, we got swarms of bugs! Some fly into our soup, others form huge cyclones at night, attracted by the lights in our camp! Fortunately, they are harmless creatures that are trying to seize the short moment of rains to breed. However, the rains have affected our plans for fieldwork because we have to drive across dried riverbeds to get to our field sites. Some ancient sediments at the field sites consist of mostly clay, which turns into mud puddles when there is water! As a result, we have postponed our trip to Area 13 and Area 15 where the TBI hominin fossil hunters found exciting fossils a few years ago. Let’s hope that the weather is going to get better over the week.
In the classroom, students continued to learn with Dr. Jason Lewis about the next important period of human evolution when the australopithecines roamed Africa. The australopiths are a group of human ancestors and distant relatives who lived in Africa from around 4 million years ago to 1.2 million years ago. This group of ancient hominins have been traditionally grouped into “gracile” and “robust” groups. The gracile group has been believed to be ancestral to our own lineage: Homo. The robust group, on the other hand, appeared later in the geological sequence have more derived features that point to a different masticatory adaptation. Students learned in great details what distinctive features are found in each group and where they have been found in Africa.
When it comes to our own genus Homo, things are getting unclear. First of all, we still don’t know what our own ancestors evolved from. Second, there is a huge range of diversity in both cranial and postcranial features among the earliest Homo in Africa. We talked about early Homo fossil “1470” in our previous post. It is one of the members in early Homo, the identity of which is still under debate. So far, an integral part of the Human Origins module has been to see the evidence and discuss about the ideas. Not surprisingly, our dedicated students have been leading the discussions about scientific papers! We have seen a lot of hard work put together! Good job!
We did have a chance to go to the field last week before the storms hit. And we learned another set of essential skills in the field: excavation and plaster jacketing. It was our absolute pleasure to work with the TBI fossil hunters, who also do lab preparation work when they are off from the field seasons. Students had a chance to dig out some of the most complete fossils that needed extra care in the field. We learned how to use chemicals to preserve them, how to dig properly without damaging them and how to put them in plaster jackets. Take a look at the photos of hard working students! The fossils are safe and stable within the plaster jackets and are easily transported to the lab for preparation which students already learned in our previous module.
I guess nobody thought about Halloween costumes when we left in early September… But when students showed up at the Halloween party, some were all dressed up! Take a look at some DIY masters and their creative work!