The beauty of it is that we keep finding new specimens, and they keep challenging whatever the current received wisdom is on human evolution.

Toumai [which means "hope of life"] was classified as a member of the newly dubbed species Sahelanthropus tchadensis and is thought to be between 6 million and 7 million years old.

That means it could be as much as 1 million years older than previously found hominid fossils, and at least 3 million years older than the next-oldest hominid skulls.

Brunet concluded Toumai walked upright because the hole for the spinal cord at the skull's base is shaped like those of more recent bipedal prehumans.

The skull appears to be the size of that of a modern common chimpanzee with a similar cranial capacity and smallish teeth. But facial details, such as a very thick bony eyebrow ridge, are like those of male hominids.

The specimen's age falls near a critical point when the human lineage split from apes. Relying on genetic evidence, scientists have assumed the split occurred 5 million to 7 million years ago; Toumai's appearance may push back the timeline.

The location where the fossil was discovered is also significant, as at the time Toumai lived it was forested, not grassland.

Read more about it.

[update] More on the risks of scientific assumptions.

1:38:50 AM    please comment []

When I was a teenager, like most teenagers I thought that adults couldn't possible understand what it was like to be a teenager. I thought that they just forgot their own experiences. Otherwise, how could they treat teenagers so stupidly?

As an adult, I can attest that it's true. We do forget.

When I was fifteen I started keeping a journal. At some point I decided that I was doing it deliberately, in part, so that when I was a grown-up I could re-read it and have a better sense of what it was like to be a teenager, and maybe treat teenagers better.

Over the years, I've re-read my journals a couple of times. There were fourteen volumes (I can't seem to find volume #12, which worries me a bit) of handwritten ink-on-paper, and some typewritten, pages covering a period from age 15 to roughly 22. Each time I re-read them, I'm struck by something completely different. The last time, I was flabberghasted by how much attention I paid to what I ate and what I weighed. And I swear, I was NOT a particularly image-conscious teenager.

I wonder what will I notice most this time? Because I've decided to re-read my journals, day-by-day, and post a story each day with a transcription of one day's entry. A lot of it is silly and mundane, pretentious, naive... quite the compilation of teenage charms and idiocies.

But in today's entry I already see themes that concern me to this day: the quest for self-discipline in daily life; God and spiritual practices; the search for love; family relationships; the creative life; who am I?; and the desire to be known as I am.

Plus ca change, plus c'est la meme chose.

1:18:11 AM    please comment []