This process was inevitable as we started with a maximally simple (and naive) map – a linear progression from apes to humans.
Now we know, as with pretty much every other evolutionary tree, the real map is much more bushy.
It is now evident that a diversity of hominin lineages existed in this region, with some divergent lineages contributing DNA to living humans and at least .
The existence of a diverse array of hominins in subequatorial comports with our present knowledge of diversity across other savanna-adapted species, as well as with palaeoclimate and paleoenvironmental data.
The process generally used to date a fossil is circuitous and subject to differing interpretations.
It has involved tracing the related sedimentary rock layer horizontally from the place where the fossil in question was found to a place where it is underlain or overlain (or both) by igneous rock.
Adaptive radiation lead in multiple directions simultaneously, only one branch of which survived to be modern humans.
Homo Sapiens from Jebel Irhoud Here is the latest curve ball in this emerging picture.
Where igneous rocks are absent, a fossil's "age" is determined by comparing the fossils of one location to those of another, and then comparing those comparisons to charts in books with age assignments provided on the pages.
During archaeological works on Sulawesi, researchers collected and dated 19 samples taken from 12 handprints and 2 animal images from 7 caves near the town of Maros (South Sulawesi).
The earliest images include a handprint dated at 39,900 years ago, which was found at a height of four meters, an image of babirusa (35,400 years), and an image of another unknown animal, presumably, a pig (35,700 years) The well-preserved paintings of Sulawesi and Borneo differ from the classical Franco-Cantabrian examples in the various additional images painted over the handprints.
All of these news items share a theme – that the picture of the evolution of modern humans from our last common ancestor with chimpanzees is likely much more complicated than we currently know and previously suspected. We are trying to piece together this puzzle, but we don’t know what the final picture looks like.
We are connecting lines to the pieces we have, but when we find more evidence we are not just filling in the picture, we are expanding it.