December 12, 2019

The Finding of the Oldest Human Skull Changes Evolution Science

The Finding of the Oldest Human Skull Changes Evolution Science

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.

Comments

  1. Adam Tauno Williams says

    > real scientist know their “evolutionary claims” are provisional

    The AIG folks don’t do “provisional”.

    • Exactly. If your standard of “truth” is “eternal, unchanging, and perspicacious”, science is never going to measure up.

    • Yeah but it’s not just creationist wackos. Throughout the popular media you often get that attitude expressed. “Those scientists! Always changing their minds!” Like the willingness to change your mind based on new data is some kind of weakness. Or that saying “I don’t know” is some kind of damning admission instead of the truest thing we can ever say.

      • Adam Tauno Williams says

        Heh. Goodness, people do with their diets/food all the time. At the same time signing onto the junk|psuedo science of paleo, keeto, whatever…

        It isn’t safe to mention food around strangers anymore. 🙁 Better to stick to religion and politics.

        • I have to laugh at how true this is. The ketosis process, unmanaged by physicians, can harm your health. Nothing wrong with a low-carb diet, but ‘going into ketosis’ can be a very dangerous situation for some individuals with certain health issues.

          No worries if your diet is ‘low carb’ as long as it has some carbs and is ‘balanced’ nutritionally, but going full carb-free is another matter entirely. So if anyone is considering it, talk to your doctor, and learn about the pitfalls of going into full ketosis.

        • Headless Unicorn Guy says

          It isn’t safe to mention food around strangers anymore.

          Because of the automatic “DIE, HERETIC!!!!!” reaction.

          Food has become a Fundamentalist Religion, with all the accompanying baggage.

          Only with these “Eat This And You’ll Be So Healthy You’ll Never Get Old and Die” fad diets, it’s Gluttony of Delicacy instead of Gluttony of Volume.

  2. Headless Unicorn Guy says

    Again, The Branching Bush instead of Linear UPWARD Progress.

    • Indeed. Evolution doesn’t have an end in mind. It only has survivors for whom the changes turned out to be beneficial.

      • I don’t know. It’s hard not to think that the entire history of life on earth the universe wasn’t deliberately designed to produce this piece of chocolate cake I’m eating. mmmmmmmmmmm…

    • Part of why the “linear” model held sway for so long is: suppose you’re a scientist and you discover one of these skulls. Would you rather be able to report that you’ve found another example of an ancient primate species… or that you’ve found one of the direct ancestors of humankind? So, every scientist tries to wedge the particular species they discovered somewhere into the human family tree.

  3. With the results from ancient DNA studies about cross-breeding between H. sapiens and Neanderthals and Denisovans and likely some other group in Africa, I’ve come to think the branching / evolutionary tree metaphor is itself wrong. We need a metaphor that captures such cross-linking descent from multiple ancestral groups that are called different species. I haven’t found a better one than “web”.

    The most significant of those results are 1) that modern humans of non-African ancestry have about 1% to 4% of their DNA from Neanderthals and 2) modern humans of non-African ancestry have from 0% to 6% of their DNA from the population/species that we know from the Denisovan cave fossils, with the highest percentages in humans with ancestry from southeast Asia and some of the Pacific island groups. There are other web cross-links suggested further back in time and/or where we haven’t found the other population’s DNA yet.

    • Adam Tauno Williams says

      > I haven’t found a better one than “web”.

      I find the best metaphor for reality, and evolution, is that it is a “mess”.

      The world is like a child’s room after a temper tantrum.

    • I’ve always wondered whether the “Nephilim” in Genesis 6 are actually some sort of ancestral memory that human beings came from several different species interbreeding.

  4. It’s the same fallacy that Answers in Genesis espouses in just about every argument they come up with. They take uncertainty in the finer details of scientific knowledge, blow it up out of all proportion, and pretend that it falsifies the whole picture.

    It’s like baking a cake for your daughter’s birthday party using a weighbridge — a scale for weighing ten ton lorries — to measure out your butter, eggs, flour, sugar, and fruit, and then when the results come out all mushy and inedible, claiming that means Gordon Ramsay, Jamie Oliver, Heston Blumenthal, Ina Garten and Mary Berry haven’t a clue about cooking and for all we know could be teaching us to make rat poison on their cookery shows.

  5. Susan Dumbrell says

    I am at odds to see if there is a consensus in the ramblings of this site in the past days or weeks.
    I wake each day here in the other side of the world to see the ramblings re American politics and or American Fundamentalism and how it affects each tiny corner of your microsobic world.

    I despair.

    The world is so much fuller and farther than your imagined back yards.
    Look out, there are other Christian denominations further afield all struggling with their identity.
    No love lost either in your domain or here in ours.
    So much for the Body of Christ, we are fragmented bits. He cries !
    May He redeem us all

    Why do we bother??!!

    Susan

  6. Susan Dumbrell says

    Did anyone notice our Australian Prime Minister Scott Morrison dined with Trump et al.??
    Rose Garden do.