Human Fossils, An Introductory Guide
What are human fossils, how are they created and how are they dated? In my last post I wrote about the very beginnings of our human legacy. The story can only be revealed through study of fossil remains and as I pointed out there are very precious few fossil remains in the beginning of our history. So few that you have wonder how can anyone deduce very much from them.
A large part of deciphering and sorting out of discoveries is being able to do comparative analysis from the cumulative body of previous finds. A tremendous number of insights can be gained from the smallest evidence.
The way a single bone or bone fragment is shaped will reveal how that bone is connected to others and what that means. For example, the road to becoming bipedal, walking on two legs, is understood by how the skeletal remains evolve more and more towards the first fully upright walking human, Homo erectus. (Homo erectus means ‘upright man’). From a comparative analysis of skeletal remains of hominins through millions of years a single bone can indicate evolutionary advances. A solitary foot bone can point towards how bipedal a species would have been.
I am going to talk more about this in my next post when I go over the Australopiths. The genus of the Australopithecines are the precursors to the genus Homo which includes us, Homo sapiens. But for now, after the introductory post on the human legacy, I think it’s a good time to understand what exact a fossil is, how they are created and how they are assigned a date.
What Are Fossils?
Dead Men Do Tell Tales
Hominin fossils are very rare and precious artifacts as we have seen from my last post introducing the human legacy. In fact, ancient human fossils are the most rare and treasured artifacts in the world.
How Bones Turn Into Fossils
Life After Death Is Risky
And another one showing a closer view of fossilized bones.
Types of Fossilization
An example of a fossil footprint from the Triassic period in the next photo.
The Study of Human Fossils
The bulk of fossils we have are from Neanderthals ( Homo neanderthalensis), which there have been bone fragments from 400 individuals found including about 20 complete skeletons, and the over 1,500 bone fragments from Homo naledi discovered in 2013. Contrast that with the 14 bone fragments found from what some scientists want to call a separate species - Homo antecessor.
In 2008 a new species of Australopith was found. Australopithecus sediba was found in South Africa. There have been 220 bone fragments found so far with this new species. Some of fossils shown in the next photo.
DNA and Fossils
What Can We Learn From Fossils?
Some of the things we learn from hominin fossils.
- Evolutionary processes and trends
- relatedness to other species
- body shapes and sizes
- species type
- physical capabilities
- growth patterns
- like expectancies
- inferences about size and shape of muscles
- understanding locomotion
- Positioning of eyes, ears, nose on the skull
- age of individual
- age of species
- how quickly children grew
- even some social behaviors can be determined
- brain size
How Fossils Are Dated