Sunday, December 22, 2013
(Picture from Io9's site here.)
I've been interested in Neanderthals for years.
The idea that there was a previous form of human being-- not quite like us but close enough to talk to-- that used to live essentially next door was irresistible.
My first accepted story involved a Neanderthal/Homo sapiens contact. And it came, as much of my fiction does, in retaliation.
I had just moved to Boston, fresh from the homogeneous midwest, and the amazing diversity stunned me. You could walk down a street in Boston and hear English in three different accents. Heck. You could walk down a street in Boston and hear three different languages. It was a different world.
Not surprisingly, I went to the science museum. At the time there was an exhibit on cave paintings. The docent was a well meaning old man who talked about the painters and how they couldn't possibly be painted by dumb old Neanderthals. This ticked me off and I went home and wrote a contact story from the Neanderthal point of view about encountering those smelly idiots, Homo sapiens. Asimov's bought it and I was off.
It turns out I was right.
Not about the cave paintings. Those are clearly dated and post-date when Neanderthals were in Europe. Not to say they didn't paint things or paint in caves. We don't know and, frankly, it's unlikely we ever will. But I was right in that Neanderthals were a whole lot smarter and like us than some thought way back in the Cretaceous-- that is, when I moved to Boston.
This idea that not only Neanderthals but most of our early relatives have been miscast has been growing over the years. A number of very important stories broke in just the last year.
The stuff that's mostly been in the news has been genetic in origin. One of the earliest discoveries was how some modern humans shared DNA with Neanderthals in such a way as to suggest cross breeding. What made it especially interesting was that the distribution of the Neanderthal DNA was not uniform. Some groups got more than others.
Then came the Denisovans, a group of fossils discovered in Siberia. Those fossils were about 41k years old Sequencing the Denisovan DNA suggested more interbreeding. More Europeans had Neanderthal than other groups. More Asian and folks from Oceania had Denisovan DNA. This suggested interbreeding might be a local affair. After all, Neanderthals were mostly in the mideast and up into Europe while Denisovans were more in Asia.
Then the Denisovans were compared with Neanderthals. Sure enough, there was interbreeding there, too. In point of fact, there was evidence that there was interbreeding between Denisovans and a potentially unknown hominin.
It shouldn't come as any surprise that humans will pretty much have sex with anything. Any perusal of a porn site will demonstrate that pretty adequately. Or you can read this in Scientific American. But go with an open mind.
That lack of surprise should therefore lead to a lack of surprise that we interbred with those previous cultures had considered, well, beasts. We're starting to look at our cousins as more and more like ourselves. Different, to be sure. There are a lot of differences, too. For one thing, your average run of the mill could toss your top star line backer over the goal posts. There appears to be a fairly vast difference in potential strength between our two groups. It also looks like Neanderthals had a different way of speaking and, potentially, seeing. They were different.
But not, apparently, different enough not to be taken seriously persons of affection.
This has caused several anthropologists and archaeology to rethink the whole idea of what species we all might be to one another. There are species fundamentalists that believe that if two individuals can interbreed they are, by definition, the same species. By that definition, none of these folks are separate species at all.
But it gets even more interesting.
Let us travel to Dmanisi, Georgia.
The Dmanisi site is quite old-- 1.8 million years old. Five skulls have been found. All skulls have been dated to a similar time frame. All are quite different-- not different enough to be unrelated, mind you. The variation between the five skulls is similar to variation between random skulls of humans or chimps. But different enough that if they had not been found together they might have been considered different species. John Hawks has a good discussion of the Dmanisi skull here.
One of the interesting things Hawks mentions is that the most human like skulls were adolescents while the adult skulls in the same site had significantly reduced brain case sizes.
This is an interesting indicator to me. We know that we have bigger brains than our distant ancestors. That requires two things: variation in brain size and selection pressure in favor of larger brains. A mechanism might be nice. Possibly the mechanism for this is our lengthening childhood. We end up not selecting directly for big brains but for the variation in lengthening time as juveniles which give us the opportunity to develop sufficient brains to make a selective difference. Be interesting to see if that shows up in future science.
Be that as it may, it appears that diversity in the human species may well be the name of the game. Instead of differing species (Homo erectus, Homo neanderthalensis, Homo sapiens) there is one human species for the last ~2 million years with lots of variation. We're an experimental species. It's interesting to note a symmetry between our biological heritage and our proclivities.
One thing Hawks says and I believe it is true. He says that recent humans are not a good measure of our history. We're now pretty much the only game in town. All of our cousins are either dead or absorbed. We like to believe that we're still the same as we ever were: now, a hundred years ago, a thousand years ago. Maybe that's true. Or maybe that's just the conceited present thumbing its nose to the silent past.
A hundred thousand years ago we were not alone. There were other intelligent eyes peering out of big brained skulls seeing things differently from us.
I'd guess from the genetic evidence we found that pretty attractive.
A. P. Van Arsdale
Early stone tipped projectiles, here and here
Mystery human species
Pushing back the clock on human finds
Sunday, December 1, 2013
(Picture from here.)
There is a lot to be excited about in science lately. Too much for me to have an entire post devoted to one thing. So here's a quick overview of some fun things.
There is new evidence that humans were in the Americas as far back as 30,000 years ago. This comes from a cave full of giant sloth bones found in Uruguay. There's been some evidence before (cited in the article) but this is even more of it. For a long time now there's been cracks in the idea that humans came over from Siberia via the Bering land bridge not much more than 13,000 years ago-- the Clovis people, named after the spearpoints found in Clovis, New Mexico. The researchers in Uruguay think that theseinhabitants may have come over from Africa. A sequence of the genome of a 24,000 year old Siberian body has suggested that there are Eurasian relatives to the Native Americans, further complicating the puzzle.
New Lithium-Sulfur batteries might actually solve the power storage problem of renewable energy. This has been something I've been following over the last few years. Lithium-ion batteries are expensive and don't have the energy density to be really practical for things like cars. But Li-S batteries are a different story. They have significantly better energy density. But they start to fail after a small number of charges. This new research might solve that issue.
There is a spacecraft from India making its way to Mars. Mangalyaan is going to look for methan. Of course, there are people who are upset that India, with its widespread poverty, is going to put its money into a Mars mission. Probably the same people who don't like it that we put a minuscule amount of money into looking at Saturn because we have poor people in Arkansas. To heck with them. Go India.
China is getting ready to launch a rover to the moon today. The moon will Chinese someday. I'm certain of it.This may not be a bad thing.
A 4.4 billion meteorite uncovered by Bedouins looks to be a relic of the ancient Martian crust. Part of the conclusions from studying this meteorite's composition is that Mars was not hit by an ancient planetoid a long time ago. But if that's true they're going to have to come up with a different explanation for Mars' weird shape.
One of the new potential uses for graphene is to be used in the manufacture of condoms. Better condoms means more condom use. Graphene enhanced condoms will feel better, be stronger and, hopefully, lasts longer in the wallet.
The ISS has launched a tiny satellite into orbit. The satellite is about 12"x4"x4" and weighs about 5 pounds. The satellite is intended to test a new de-orbit technique known as an "exo-parachute." The article doesn't say how the satellite was launched. One wonders if one of the astronauts just threw it out the window.
There's a puzzle at the heart of nuclear physics. If you measure the diameter of a proton by one method set you get an answer. If you measure it by a different method you get a completely different method. One researcher has suggested that this my be due to quantum gravity. The first method set is two fold. First by using energy levels derived from hydrogen spectroscopy. Second by electron scattering. Both of these get an answer of about 0.88 femtometers. But in 2010, scientists tried experiments using a muon (a negatively charger particle about 200 times the mass of an electron) instead of an electron. They got 0.842 femtometers. That's a big difference. One researcher is suggesting the difference is due to the muon's greater mass. He suggests that the weak attractive force between the nucleus and the electron-equivalent is actually the quantum representation of gravity at the small scale. If so, it's a big leap towards the unified field theory.
Finally, everybody knows crows are smart. Some have likened them to primates on the wing. New neurobiology research has given some insight into how they're that smart. After all, birds do not have a neocortex like mammals-- it developed after we split off from the line that developed into birds. In addition, whatever crows are using to be smart it's operating in a fraction of the size of a mammalian brain. A crow's brain isn't much bigger than your thumbnail.
They appear to use a structure called the nidopallium caudolaterale, a collection of nerve cells in the back of the bird brain. This article suggests that though the structure is embryologically completely different from the pre-frontal cortex of the mammalian brain, it may function similarly. This might mean a common underlying neurobiological basis of intelligence.
The above said, I find myself a little discouraged. I love science. Part of science, though, is science funding and that is getting more scarce as time goes on. Being an American I'd like my country to be in the forefront of scientific research-- and it is, in general. But if you analyze the funding of science in my country (See here.) the amount going to fundamental and basic research is getting less over time, not more. Most of the funding for research and development is in the development side of things and most of everything is defense related.
We have the tools for the first time in human history to understand the fundamental operations of the natural world. We've started to unlock the primary mechanisms of life, of physics, of our planet and the cosmos. We are learning every year more than we ever knew before.
It's disturbing to me that when such wonderful things are going on, when we are within visible targets of solving most of the world's technological problems such as disease, energy, food production and even climate change, we short change ourselves.
I am not saying we're going to solve these issues tomorrow. But how can we hope to have a healthy world when pharmaceutical companies stop antibiotic research and don't put much in the pipeline to replace it? How can we study the natural world when we pave over it? How can we mitigate climate change when we deny it's happening?
Perhaps there's a new form of natural selection at work, where our species is being tested whether or not we will stumble on the edge of magnificence.