According to this article the recent discovery of a 3.8 million-year-old cranium (skull without the lower jaw) is changing the view of how early hominin species evolved – and how they led to humans. The previous view had Australopithecus anamensis (dated between 4.2m and 3.9m years old) as the ancestor of Australopithecus afarensis (dated between 3.8m and 3m years old). A partial skeleton of A. afarensis is known in the popular media as “Lucy” and was for a long time viewed as the oldest known human ancestor.
The newly discovered cranium, nicknamed “MRD” after its collection number MRD-VP-1/1, showed many similarities to the already existing A. anamensis specimens, and was therefore assigned to this species. However the relative completeness of the MRD skull showed features that were characteristic of younger fossils. This challenged the long and widely-held view that Lucy’s species evolved gradually from A. anamensis without branching of the evolutionary line. Since these modern features were already present in the older species, the most likely scenario is that Lucy’s species formed by evolutionary divergence from A. anamensis. The article says:
If that is the case, then we need to revise the human evolutionary timeline, with A. anamensis existing from 4.2m to 3.8m years ago, and A. afarensis from 3.9m to 3m years ago. This would imply that both species were overlapping for at least 100,000 years, making it impossible for A. afarensis to have evolved gradually from one single ancestral group. In fact, it is becoming increasingly obvious that most species on our evolutionary lineage likely evolved by branching off from existing groups.
The article gives a pretty good view of scientists behaving as they should. As new evidence comes to light, previous hypotheses are modified to account for the new data. All conclusions are provisional, subject to revision as more data is gathered. The realization of the “branchiness” of human evolution means that the popular idea of “missing links” is now passé. There are no missing links for the simple fact that human evolution is not the linear progression from ape to ape-man to man as depicted in the iconic drawing. And it probably wasn’t just in east Africa that modern humans emerged, as this article indicates, but rather branching occurred over the whole continent.
This renders the whole point of this Answers-in-Genesis article moot. The byline to the AIG article reads, “No matter how hard they try, scientists can’t connect the missing links in human evolution. Why not?” AIG notes:
“Furthermore, evolutionists propose different explanations for how humans evolved, so they draw different family trees to connect the same fossil specimens. And the interpretations change over time. The primate branch of the family tree looks much different in textbooks your children might use than it did in yours. The evolutionary claims are much less certain than most authors let on.”
Yeah, as I said above, that is how real science works; real scientist know their “evolutionary claims” are provisional and look forward to revising them as new data emerges. With the speed that new discoveries are now occurring, textbooks will go out of date pretty fast. So what? Did I mention that is how real science works?
Even though this latest discovery has given new insights into our evolutionary past, it has also increased the complexity of the relationships between early hominins. Dis-entangling the complex relationships between these species, as well as characterizing their morphology, and deciphering the complex and intricate story that is being told about hominin evolution is fiendishly difficult. Specimens at each new site capture a different point along the evolutionary trajectory, and the relationships are not at all straightforward or unambiguous. And new discoveries, which will occur, don’t always settle debates, but often raise more questions than they answer. But that, is in fact, what real science does. As the article concludes:
Discoveries all over the world in the last decade have led to a complete rethinking of our evolutionary past. It shows that new fossils do not always support existing hypotheses, and that we must be prepared to change our views and formulate new theories based on the evidence at hand.