Well How Do Ya Like That August 9, 2007
WASHINGTON – Surprising research based on two African fossils suggests our family tree is more like a wayward bush with stubby branches, challenging what had been common thinking on how early humans evolved.
The discovery by Meave Leakey, a member of a famous family of paleontologists, shows that two species of early human ancestors lived at the same time in Kenya. That pokes holes in the chief theory of man’s early evolution — that one of those species evolved from the other.
And it further discredits that iconic illustration of human evolution that begins with a knuckle-dragging ape and ends with a briefcase-carrying man.
The old theory is that the first and oldest species in our family tree, Homo habilis, evolved into Homo erectus, which then became human, Homo sapiens. But Leakey’s find suggests those two earlier species lived side-by-side about 1.5 million years ago in parts of Kenya for at least half a million years. She and her research colleagues report the discovery in a paper published in Thursday’s journal Nature.
The paper is based on fossilized bones found in 2000. The complete skull of Homo erectus was found within walking distance of an upper jaw of Homo habilis, and both dated from the same general time period. That makes it unlikely that Homo erectus evolved from Homo habilis, researchers said.
It’s the equivalent of finding that your grandmother and great-grandmother were sisters rather than mother-daughter, said study co-author Fred Spoor, a professor of evolutionary anatomy at the University College in London.
The two species lived near each other, but probably didn’t interact, each having its own “ecological niche,” Spoor said. Homo habilis was likely more vegetarian while Homo erectus ate some meat, he said. Like chimps and apes, “they’d just avoid each other, they don’t feel comfortable in each other’s company,” he said.
There remains some still-undiscovered common ancestor that probably lived 2 million to 3 million years ago, a time that has not left much fossil record, Spoor said.
Overall what it paints for human evolution is a “chaotic kind of looking evolutionary tree rather than this heroic march that you see with the cartoons of an early ancestor evolving into some intermediate and eventually unto us,” Spoor said in a phone interview from a field office of the Koobi Fora Research Project in northern Kenya.
That old evolutionary cartoon, while popular with the general public, is just too simple and keeps getting revised, said Bill Kimbel, who praised the latest findings. He is science director of the Institute of Human Origins at Arizona State University and wasn’t part of the Leakey team.
“The more we know, the more complex the story gets,” he said. Scientists used to think Homo sapiens evolved from Neanderthals, he said. But now we know that both species lived during the same time period and that we did not come from Neanderthals.
Now a similar discovery applies further back in time.
Susan Anton, a New York University anthropologist and co-author of the Leakey work, said she expects anti-evolution proponents to seize on the new research, but said it would be a mistake to try to use the new work to show flaws in evolution theory.
“This is not questioning the idea at all of evolution; it is refining some of the specific points,” Anton said. “This is a great example of what science does and religion doesn’t do. It’s a continous self-testing process.”
For the past few years there has been growing doubt and debate about whether Homo habilis evolved into Homo erectus. One of the major proponents of the more linear, or ladder-like evolution that this evidence weakens, called Leakey’s findings important, but he wasn’t ready to concede defeat.
Dr. Bernard Wood, a surgeon-turned-professor of human origins at George Washington University, said in an e-mail Wednesday that “this is only a skirmish in the protracted ‘war’ between the people who like a bushy interpretation and those who like a more ladder-like interpretation of early human evolution.”
Leakey’s team spent seven years analyzing the fossils before announcing it was time to redraw the family tree — and rethink other ideas about human evolutionary history. That’s especially true of most immediate ancestor, Homo erectus.
Because the Homo erectus skull Leakey recovered was much smaller than others, scientists had to first prove that it was erectus and not another species nor a genetic freak. The jaw, probably from an 18- or 19-year-old female, was adult and showed no signs of malformation or genetic mutations, Spoor said. The scientists also know it isn’t Homo habilis from several distinct features on the jaw.
That caused researchers to re-examine the 30 other erectus skulls they have and the dozens of partial fossils. They realized that the females of that species are much smaller than the males — something different from modern man, but similar to other animals, said Anton. Scientists hadn’t looked carefully enough before to see that there was a distinct difference in males and females.
Difference in size between males and females seem to be related to monogamy, the researchers said. Primates that have same-sized males and females, such as gibbons, tend to be more monogamous. Species that are not monogamous, such as gorillas and baboons, have much bigger males.
This suggests that our ancestor Homo erectus reproduced with multiple partners.
The Homo habilis jaw was dated at 1.44 million years ago. That is the youngest ever found from a species that scientists originally figured died off somewhere between 1.7 and 2 million years ago, Spoor said. It enabled scientists to say that Homo erectus and Homo habilis lived at the same time.
Atmostheory August 3, 2007
I ran across this artist recently.
I love how he can blend graphics with photos and it’s not jarring.
A lot of times text can ruin a piece, but it’s so complementary, the way he uses it.
Humble Yourself and You Will Be Lifted August 2, 2007
So today was difficult. I made the decision to end a relationship in my life and was shocked at how badly the other party took it. What I was expecting was a clean break, goodbyes and then to move on. What I ended up with was a mess. There was name calling, ugly insinuations, and very hurt feelings. I was taken way off guard. This was not at all what I had intended.
I hung up the phone feeling wounded, weepy and taken for granted. I felt like I was right and that they were very much in the wrong. I spent the rest of the afternoon just defeated. Heavy. Incapable of thinking about anything else. I talked to a sweet friend on the phone, and she was so much help. One thing she did say, though, was ‘maybe she’ll call later and apologize.’ And I’m thinking – yeah, like I’m going to pick up THAT call. Then she said, ‘it may even be that YOU need to call her back.’
That felt so yuck, so wrong, soooo the opposite of what everything in me was telling me to do. The sheer enormity of my unwillingness was proof that it was exactly what I needed to do.
So I got home and dialed the phone before I could talk myself out of it, and – who knew – it was the best possible thing that could’ve happened. We had a good long talk, cleared the air, and realized what a miscommunication it all had been. The relationship is still over, but on much better terms.
The point I’m trying to get at is that sometimes you just have to humble yourself. It’s completely against human nature, particularly when we feel like we’ve been wronged. But let me tell you the truth: the best thing that you can do is to keep your nose clean and take the higher road. She could have still been angry with me. She could have been insensetive and harsh and selfish, but the right thing to do would still have been to humble myself and apologize for the way that I handled things. Because, let’s face it, the only thing you can control is the way that you behave and the way that you present yourself.
Anyway. I’m glad it’s over and I’m looking forward to not sniffling for the rest of the day!
In Your Pants August 1, 2007
And since I love the Harry Potter, I thought the song was too funny.
So I went to this guy’s website, and it turns out that he and his brother, John Green (author of An Abundance of Katherines and Looking for Alaska), are performing this experiment where they only communicate through video blogs for a full year. I started watching their videos, and (long story short) they crack me up.
Now, I know you’ve all heard of the thing you do when you eat a fortune cookie – you immediately have to add “in bed” to the end of whatever the fortune may be – i.e. “A new career opportunity will present itself – in bed.” So yeah, haha. Not that funny. But these guys have taken it even further. Turns out “in your pants” works very well for books. So Flannery O’Connor’s classic “A Good Man is Hard to Find” becomes “A Good Man is Hard to Find In Your Pants.”
Of course it becomes hysterically funny when you’re telling your mother about this over lunch in the church library, and you can’t look anywhere with out finding another insanely hysterical one (or hideously inappropriate one). For instance –
Perilous Pursuits In Your Pants
How Now Shall We Live? In Your Pants
This Too Shall Pass In Your Pants
Oh the list goes on.
I invite each of you to discover what hidden treasures lie in your bookshelves. Or your pants.