This morning’s news has a story that begins “DNA taken from a pinkie bone at least 30,000 years old . . .” so let’s think about 30,000 years.
This is the year 2010. Our time more-or-less began with the birth of Jesus roughly 2,000 years ago. Contemplate the passage of man from Jesus to Bill Gates, then count backward 28,000 years and consider that passage. That’s what we’re talking about. Measure from your pinkie finger to your thumb, then measure from your head to your toe: that’s the distance of separation we’re talking about.
The DNA came from a six-year-old girl. Wow, does that freak you out? We actually can read DNA well enough now to establish the age and sex of a 30,000-year-old pinkie bone.
The researchers were able to sequence “. . . all 3 billion letters of DNA that made up this girl’s genome.” Three billion. You remember Carl Sagan talking about “billions and billions of light years” in the universe? You know how much a billion is?
On television I saw a story about a third-grade class that asked their teacher how much a million is. Of course, she didn’t know so she and the kids decided to bring in soda can tabs (back in the day when they were detachable) and see just how many a million is.
They put the tabs in a big plastic trash barrel. When it was full, they dumped them into a big black plastic bag, and started to refill the barrel. They kept collecting and counting, and when they were done they had the room half-filled with plastic bags. It took a mountain of soda can tabs to make a million.
Now you try to imagine a billion. And when you’re done, try to imagine 3 billion. That’s how many letters there were in the DNA of one little girl.
The bone came from the Denisova Cave in Siberia. The Denisovans are more clearly a sister group to the Neanderthals than to us modern folks. Also, “Denisovans’ genome was more closely related to humans currently living in New Guinea than it was to genomes of people in Europe or Asia.”
“In other words, as they left Africa, modern humans must have passed through the realm of the Denisovans, and had sex with some of the locals, on their way to Melanesia. And if you look at a map, the route from Africa to New Guinea does not go through Siberia, suggesting that the Denisovans may have lived over a quite a large swath of the globe.”
Maybe that’s what it suggests to the researchers, who are looking at a map, but I’ve got a different suggestion based on the fact that “modern humans” did not have a map. There was no route from Africa to New Guinea; there were just a bunch of folks wandering around lost.
Did you know that when Moses led the Israelites on their forty-year trek in the desert, they wandered around lost? Actually, Moses didn’t lead the Israelites. They were led by God in the form of a pillar of cloud by day and a pillar of fire by night. If Moses had had a map then the trek from point A to point B could have been accomplished in a couple of years, but God’s plan was something else.
The researchers, in their linear thinking, have had to explain the mixing of DNA by expanding the area of the Denisovans. Not necessary. Modern humans were wandering around lost and/or following a path determined by God, and wouldn’t it be interesting to try to learn if God led the trek? How would you go about that?
The story closes with a note that “a group in Spain published a paper this week analyzing the DNA from 12 Neanderthals found in a single cave. The analysis suggested the men were all brothers or cousins, whereas the women had come from different bands.”
Now I think that’s really interesting. A band of brothers, and they may have been staging raids on other bands to get their women. The physical body instinctively reaches out to breed with different DNA. At the cellular level, the body knows that inbreeding results in anomalies. I mean, look at Prince Charles’ ears. Did you know that boys and girls who are raised together have little sexual interest in each other?
There’s this tribe where the children are betrothed at birth and then raised together. After they grow up and get married, they have reproductive sex to produce offspring. However, the culture accepts the man having another woman for entertainment sex because sex with your sister isn’t fun. Oh, wait—it isn’t his sister, so maybe the incest taboo isn’t cellular. How could we find out? What data would contribute to our learning?
Yesterday a well-meaning friend sent an elderly woman to sit with me since I am pretty much bedridden and often lonely. She was a nice lady, but she spent most of an hour talking about doctors, drugs, patients and home aides.
I’d rather talk about life, the universe and everything.
(http://www.npr.org/2010/12/23/132243268/ancient-bones-dna-suggests-new-human-ancestors?ft=1&f=1001
