Mailbag: Probing hominin origins

2 minute read

This past year and half I have read and studied pre-history including most of the books, dvd's, on evolution, human origins, and all related subjects. I have followed the 'time line' from Big Bang to the 21st century and returned to the 10 million year period addressing the study of man from our "beginning". To my surprise there was no clear beginning; after much study, I understand why now; after seven million years, the last hominid fossil "Toumai"then nothing but primate fossils from which is presumed the first hominids came into being leading to the evolution of some 17-20 species thru four groups. It appears that from 7 mya to 10 mya is the famous "missing link" or gap with no fossil evidence of the "split" or diversion therefrom is the contentious question and debate. It is very impressive what Paleoanthropology and related sciences have discovered of our origins and the progressive patterns of human development that explains so much of our existence for some 10 million years and estimated 108 billion that have come and gone. Yet! the story of 'man' is incomplete without an explaination of how, within the science of molecular evolution, the genetic codes and finally through sexual reproduction from our closest relatives..... the primates. After all the reading and research I have done, I am convinced that you and the science of Paleoanthropology work daily to find the answer to the first hominids, there is nothing you would desire more that answer this question. My question: Is there sufficient knowledge acquired to date that a story or explanation can be published declaring a clear beginning picture that will give us a new 21st century Genesis?? It appears to me that we now have enough molecular and fossil evidence to achieve the task! Of course including related sciences, climate, ecology etc. What do you think?

Thank you so much for your kind words!

I am maybe less hopeful than you, because I see the great difficulty of the task. We understand much about the time when our ancestors first diverged from the apes but our fossil record from that time has really only just begun. We will more quickly have an idea of how our genes changed from that time, but genetics is a bit like driving on the road and taking a note of each town you pass, then tossing all the notes into a hat and drawing them randomly. We do not know which genetic changes were the first, and therefore we have difficulty seeing why the events happened at the beginning.

My lab is directing our attention to the origin of Homo, around two million years ago. Here, the fossil record also is starting to fill in, but we additionally have the ability to determine which genetic changes might have happened at around the same time. Ancient DNA evidence has totally transformed our ability to study this time period. When we can understand this kind of event from the perspectives you mention, then I think we will be ready to tackle the origin of the hominins!