There's an odd-looking creature from half a billion years ago which is the oldest researchers have been able to find on the evolutionary chain to humans. Deuterostomes are creatures which are possessed of an anus and this characteristic differentiates they and we from the plant kingdom. The article demonstrates the unity between anus-possessing creatures. (Science Daily: Bag-like sea creature was humans' oldest known ancestor)
Modern humans are, however, unlikely to perceive much by way of a family resemblance. Saccorhytus was about a millimetre in size, and probably lived between grains of sand on the seabed. Its features were spectacularly preserved in the fossil record -- and intriguingly, the researchers were unable to find any evidence that the animal had an anus.
- SD
So you thought I made that up about some anal fixation.
The new fossil, named Saccorhytus, appears to be the oldest deuterostome found to date. Deuterostomes are a group of animals that includes vertebrates (that's us) as well as starfish and other echinoderms. The group is defined by how its embryos develop: the first opening that forms in each tiny ball of cells becomes the organism's anus. It's a glamorous family legacy, to be sure.
- Popular Science: THIS GHASTLY SACK OF CELLS MAY BE YOUR DISTANT ANCESTOR
Cadillac Man and I were talking about evolution a few nights ago and how humans popped up in the evolutionary chain but really we didn't. It's taken more than that half a billion years to make humans since evolution was making all the bits as driven by whatever measure of Providence you believe. There's nothing to be gained here from babbling about whether evolution is driven by thermodynamics and probability or anything else since we observe it happened and observe the result.
Sometimes people say it's impossible to find the 'Missing Link' but researchers find missing links almost constantly and much of their lives is trying to fit the pieces together to understand which ones were getting linked to which others. We see from the earliest ones it was seriously important to have an anus. OK, that got covered in the DNA and it's definitely important to life so let's get on after that to see what else we can invent for life to do.
That tone is a bit more flip than I really want since the objective is to time travel back that half billion years when these creatures were a high example of life. At that stage, the next question is what will life do next; what new tricks can it learn.
Through it all, the DNA was accumulating and we got bits and pieces from all the way down the hierarchy. The general point is humans didn't just happen as unique things but rather it took all those millennia to make all the bits which were needed to finally make humans. People get offended sometimes by the idea we're related to monkeys but we're also related to worms and all manner of things since DNA had to accumulate all those abilities along the way.
The much bigger aspect is what evolution is happening now despite a general perception evolution stopped with man, the ultimate creation. There was some thinking with cultural anthropologists / sociologists that culture and society isolate us from physical evolution and maybe there's some truth to that but it doesn't isolate us from environmental considerations.
Air pollution is one example of a potential driver of evolutionary change due to the known mutagenic properties of some of the pollutants within it. There's no inclination toward a scare article on that theme but that influence exists along with others which mean a physical evolutionary pressure still exists. Those who find better ways to avoid air pollution should presumably have a better survival advantage.
Even if evolutionary pressure results in something which really is a new species which truly differentiates from Homo sapiens, it will still be mostly us and that's another restatement of the general theme. Humans have only been wandering around the planet for somewhat over a hundred thousand years but it took a whole lot longer than that to make us.
Note: I apologize if this sounds patronizing and that perception indicates only my lack of skill in presenting the material.
Modern humans are, however, unlikely to perceive much by way of a family resemblance. Saccorhytus was about a millimetre in size, and probably lived between grains of sand on the seabed. Its features were spectacularly preserved in the fossil record -- and intriguingly, the researchers were unable to find any evidence that the animal had an anus.
- SD
So you thought I made that up about some anal fixation.
The new fossil, named Saccorhytus, appears to be the oldest deuterostome found to date. Deuterostomes are a group of animals that includes vertebrates (that's us) as well as starfish and other echinoderms. The group is defined by how its embryos develop: the first opening that forms in each tiny ball of cells becomes the organism's anus. It's a glamorous family legacy, to be sure.
- Popular Science: THIS GHASTLY SACK OF CELLS MAY BE YOUR DISTANT ANCESTOR
Cadillac Man and I were talking about evolution a few nights ago and how humans popped up in the evolutionary chain but really we didn't. It's taken more than that half a billion years to make humans since evolution was making all the bits as driven by whatever measure of Providence you believe. There's nothing to be gained here from babbling about whether evolution is driven by thermodynamics and probability or anything else since we observe it happened and observe the result.
Sometimes people say it's impossible to find the 'Missing Link' but researchers find missing links almost constantly and much of their lives is trying to fit the pieces together to understand which ones were getting linked to which others. We see from the earliest ones it was seriously important to have an anus. OK, that got covered in the DNA and it's definitely important to life so let's get on after that to see what else we can invent for life to do.
That tone is a bit more flip than I really want since the objective is to time travel back that half billion years when these creatures were a high example of life. At that stage, the next question is what will life do next; what new tricks can it learn.
Through it all, the DNA was accumulating and we got bits and pieces from all the way down the hierarchy. The general point is humans didn't just happen as unique things but rather it took all those millennia to make all the bits which were needed to finally make humans. People get offended sometimes by the idea we're related to monkeys but we're also related to worms and all manner of things since DNA had to accumulate all those abilities along the way.
The much bigger aspect is what evolution is happening now despite a general perception evolution stopped with man, the ultimate creation. There was some thinking with cultural anthropologists / sociologists that culture and society isolate us from physical evolution and maybe there's some truth to that but it doesn't isolate us from environmental considerations.
Air pollution is one example of a potential driver of evolutionary change due to the known mutagenic properties of some of the pollutants within it. There's no inclination toward a scare article on that theme but that influence exists along with others which mean a physical evolutionary pressure still exists. Those who find better ways to avoid air pollution should presumably have a better survival advantage.
Even if evolutionary pressure results in something which really is a new species which truly differentiates from Homo sapiens, it will still be mostly us and that's another restatement of the general theme. Humans have only been wandering around the planet for somewhat over a hundred thousand years but it took a whole lot longer than that to make us.
Note: I apologize if this sounds patronizing and that perception indicates only my lack of skill in presenting the material.
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