I’ve posted about this before, but apparently it’s a thing in systematics - the radial cladogram. Not only are they really cool, but the more I look at them, the more I realize they are a really excellent way to illustrate the relationships between species.
Hey, it’s time to collect some more recent stuff about dead ancestors.
While not technically human, the long-awaited Ardipithecus ramidus has been released to the world (yes this happened a while ago - I’m slow). Science has free online access to lots of articles on it. There’s also a pretty good initial take at Pharyngula.
A. ramidus has been the subject of some controversy for a while, since the discoverers of the fossils held them away from scrutiny for 15 years before publishing. It turns out (if you believe the story, and there’s no reason not to) that the fossils were in such a poor condition that it took them 15 years just to get all the little bits of bone out of the rock and piece them together.
Moving on, Ad Hominin has a number of interesting posts (none of which are terribly recent, I’ll admit):
A little human with very big feet is about Homo floresiensis. Seems the idea that they are pathological Homo sapiens doesn’t hold water these days. Still not sure where they came from, but researchers are inching closer.
Finger points to new human is about a finger bone found in Siberia. Mitochondrial DNA analysis indicates it’s an unknown species of human that lived in the area of 40,000 years ago. So if you’re keeping score, that means we had four different species of human alive at the same time (Neandertal, Floresiensis, us, and the new guy).
The incredible shrinking human brain - very not new, but I didn’t now that human brains have been getting smaller.
A recent paper on miRNA got me thinking about when I started to get interested in the micro mechanisms of biology. Specifically, it reminded me of a fundamental misunderstanding that I had about biology that, when corrected, suddenly allowed things to make a lot more sense. It’s one of the cooler (and maddeningly illogical) aspects of molecular biology. I think that understanding it will help clear up a lot of people’s confusion about how genes and evolution work.
It’s time to talk about the basics: big honkin’ fossils of things long dead. Much of the discussion of evolution revolves around the very small: genes, cells, and the like. One loses sight of the larger effects of selection over time. That would be the changes in species. That’s were transitional forms come in.
There are two terms that get used: “transitional” and “intermediate”. They tend to get used interchangeably, though there is a difference. That difference isn’t really important here, so I will just plow ahead.
Aside from the fact that transitional forms are manifest in cool organisms that are weird blends of dinosaur/bird, ungulate/whale, and ape/human, they are also helpful in illustrating a couple of key points about evolution.
Today is the 200th birthday of the man who came up with an idea that defies superlatives. People have been trying for about 150 years to come up with a way to express just how truly bad-ass his idea was.
Charles Darwin is the man and the idea in question is, of course, natural selection. I have posted a few things before about evolution, but it seems appropriate today to talk specifically about natural selection.
It’s been a while - busy at work and holidays and such. So to end my drought, here’s some fun stuff about Neanderthals.
I think it’s fascinating that humans coexisted with an entirely different species with it’s own language and culture. Evidence is slim that we got busy with them, but adolescent science fiction fans will always hope.
Britain’s Last Neanderthals Were More Sophisticated Than We Thought
“Let us understand, once for all, that the ethical progress of society depends, not on imitating the cosmic process, still less in running away from it, but in combating it.”
- Thomas Henry Huxley, Evolution and Ethics
It’s been longer than I’d like since I posted another in my (pathetically small) series on the cooler aspects of evolution, written for the poseur dilettante layman, like me.
Since it’s been a while, and since I posted something recently that touched on evolution, I figured I would shake it up and write about some of the really not cool aspects of evolution.
So I was watching a Nova: Alien from Earth on Homo floresiensis (unfortunately nicknamed “hobbits” because they had the poor taste to be small and discovered at the height of Lord of the Rings mania), the diminutive hominid discovered on the island of Flores, Indonesia. Throughout the episode, experts were shown proclaiming that H. floresiensis completely disrupts the standard thinking about hominid migrations out of Africa and accross the globe; that this new species overturns a fixed orthodoxy in paleoantrhopology: namely that there were three discrete migrations out of Africa (Homo erectus, followed by Homo Neanderthalensis, followed by Homo sapiens) over the last 2 million years and that’s the end of that.
This didn’t sit quite right with me.
So I’ve recently mentioned spear-wielding chimps, chromosomally endowed chimps, and archaic homo cousins. So you might guess that I have an interest in human evolution.
Well I do. And it’s about time we talked about some of the cool stuff in there. There’s a lot in there, so I’ll just hit some of the high points that I find pretty fantastic.
I’m generally fascinated by human evolution. I’ll post something interesting about it soon, but for now, here’s a couple of developments that I came across recently that will probably factor into some future cool things:
The cool thing about this one is that they determined that the existing DNA from cro-magnon samples has not been contaminated by modern human DNA (meaning from the people who’ve handled the remains). That’s good.
ScienceDaily: Complete Neanderthal Mitochondrial Genome Sequenced From 38,000-year-old Bone
And this one is just about sequencing DNA from neanderthal samples. Neanderthal’s are cool in and of themselves. The very idea that two (possibly three) human species co-existed is pretty sweet. And now we’ve got mitochondrial DNA for both of ‘em.
Yay, science.