Fish Fertilize Trees
By Maya C. Lemaire
Lucy: The Key to our Past
Lucy walked on this very planet 3.2 million years ago in the savannahs of Hadar, Ethiopia. She held the key to unlocking our past: the progression of hominid evolution and the factors which triggered our ancestors to change from tree-living to ground-dwelling apes. The ever-changing environment caused her species to evolve constantly for adaptation, which soon led to the creation of us, Homo sapiens. Here is the story of an early human, which contributed to unraveling the enigmas of our past.
The Discovery of Lucy
In 1974, two admirable paleoanthropologists, Donal Johanson and Tom Gray went on an expedition in Ethiopia to obtain evidence for a deeper route of ape origin in Africa. On a Sunday morning, whilst scavenging around the area, Johanson stumbled upon pieces of an elbow bone, a jaw, then a skull (shown in Figure.1) which they presumed belonged to a human ancestor. These bones were found at a site around 3 million years old, which meant that the fossil he uncovered was the most ancient hominid ever seen in their time.
Who was Lucy?
Lucy was a species in the Hominid group known as Australopithecus afarensis, Latin for the ‘southern Ape of Afar’. She was only 20 years old when she died, estimated by the extremity of her tooth decay. In total, 47 fragments of bones were found, which was 40% of what it would have been of a complete skeleton. This ape was a female, considering the broader hips that are distinct from them, and she stood only 1.10 meters tall with a weight of 29 kilograms. With a glimpse, Lucy’s physical appearance is more similar to Chimpanzees than modern humans, shown in Figure.2. Yet, we have a significant similarity that will become clearer when we take a closer look at their physiology.
Aside from her height, Lucy is very similar to humans in the sense that her physiology is structured to have an upright gait like ours. This means that her hips and knees are molded to walk upright to accommodate changes in the natural environment: the decrease in forest biomes that lead to savannahs’ growth. However, Christ Stringer of the Natural History Museum in London begs to differ. He suggests that they moved to the ground due to the search for a wider variety in their diet, which allowed them to become more flexible when traveling around. Essentially, this new locomotion would be known as bipedalism, the action of two rear limbs to move. Lucy and another related species, known as Australopithecus africanus, were the first generation to adopt this new moving method. Bipedalism allows these apes to walk longer distances, encouraging them to explore more areas in their environment.
So What Came First, the Stride or the Mind?
This question can be answered. Australopithecus afarensis was one of the first species that adapted bipedalism, but it wasn’t until the next generation of apes with enough brain capacity to become ‘intelligent'. Homo habilis, who walked the earth approximately 2 million years ago, was the first to start making stone tools (Figure.3 represents the family tree, which shows the connection between these two species). These tools were categorized as mode one technology, including choppers, core tools, and flakers that acted as a basic hammer. This timeline of events proved that advancements in locomotion were favored over the increase in brain capacity to change their species for the better.
To conclude, the difference between ‘us’ and ‘them’ is apparent- both physically and mentally. Nonetheless, we need to understand our origin and the life that the early humans lived. Why did we change? What triggered these changes? How significant were these changes? While we can answer these questions using the fossil specimens collected over many years, it can also help us to answer what lies ahead for the human race. I’ve heard rumors that our heads will be bigger due to increased brain capacity or that our eyes will enlarge to adapt to bright screens, leaving us looking quite like aliens. Ultimately, whatever our species turns out to be, evolution will ensure that the changes are beneficial and suitable for living in our ever-changing world.
Figure 1: Bruce Bower (August 2019) A 3.8-million-year-old skull reveals the face of Lucy’s possible ancestors [online] Available at: https://www.sciencenews.org/article/australopithecus-anamensis-skull-reveals-face-lucy-possible-ancestors
Figure 2: California Academy of Sciences (September 2013) Walking with Lucy [online] Available at: https://www.youtube.com/watch?v=xT8Np0gI1dI
Figure 3: C.A.P Saucier (June 2011) Human Evolution is in Our DNA [online] Available at: http://shasthram.com/youngscientist/human-evolution-is-in-our-dna
Background Image: Benjamin Reed (unknown) Discover: Hadar, Ethiopia [online] Available at: https://askananthropologist.asu.edu/gallery/discover-hadar-ethiopia
Profile Image: Akshay Balakrishnan (November 2018) Where is evolution taking the human race? [online] Available at: https://medium.com/paperkin/where-is-evolution-taking-the-human-race-6ddaf7eaddba
Fran Dorey (October 2020) Homo habilis [online] Available at: https://australian.museum/learn/science/human-evolution/homo-habilis/
Melissa Hogenboom (November 2014) The ‘Lucy’ fossil rewrote the story of humanity [online] Available at: http://www.bbc.com/earth/story/20141127-lucy-fossil-revealed-our-origins
Andrew Griffin (November 2015) Who discovered Lucy the Australopithecus, and why was the discovery so important? [online] Available at: https://www.independent.co.uk/news/science/who-discovered-lucy-australopithecus-and-why-was-discovery-so-important-a6747181.html
World Archaeology (November 2008) Lucy [online] Available at: https://www.world-archaeology.com/great-discoveries/lucy/
By Gao Kamalanavin (Year 12L, Bangkok Patana School)