Intelligence and mitochondria

[Blind groper]

Taken from a New scientist article : 23 June.

Prof. Nick Lane speculates on the Fermi Paradox. Why no sign of intelligent alien life?

He argues that simple life should be common throughout the universe. He points out that a process on Earth, which is common may be the basis of all early life. Water under the ocean, under pressure, percolates down to where it is hot, and contacts the very common mineral olivine (also common on meteorites and probably common throughout the universe). It reacts under those hot pressured conditions to create serpentinite, and release hydrogen. The hydrogen then can seep back into cooler waters.

The early Earth had acidic oceans, while this hydrogen rich water was alkaline. The contact causes a reaction with hydrogen and the abundant CO2 to make amino acids and other organic compounds, while releasing energy. This, he proposes as the basis for all early life.

However, despite 2 billion years evolution, life did not get past the very small with minimal genomes, as in bacteria and archaea. However, one single ancestor became eucaryote, with a nucleus, great size compared to bacteria, complex genes, and mitochondria for energy. This one single ancestor led to the evolution of all complex life on Earth, including humans.

So why is there no sign of intelligent life off Earth, after 50 years of searching?

Nick Lane says it is because a very unique event happened here on Earth. One bacterium became trapped inside the body of another, and thrived there, dividing to make many more. it evolved into mitochondria, which produced the energy that the other cell needed for greater size. This single event which happened just once in the development of life on Earth, permitted the evolution of great size and complexity, which is not possible for simple bacteria.

The claim in this article is that such an event is rare indeed. It took 2 billion years here on Earth before it happened, and happened just once. Prof. Lane thinks that it may not have happened at all on planets elsewhere in our galaxy with simple life. Only after such a freakish event, could complex life evolve. It happened here, but not elsewhere, explaining the fact that there is no sign of alien intelligence.

What do you guys think? Could Prof. Lane be correct, and the mitochondria the key to intelligence on Earth, and the rarity of intelligence elsewhere?

[cowiz]

Isn't mitochondria that thing that powers "The Force"?

[Blind groper]

Not quite.
Star Wars speculated about a microscopic organism called a midi-chlorian. Close, but no sweetie.

[rasetsu]

I despise when back of the envelope calculations of "probability" which build on our ignorance and misapplication of the law of the excluded middle are used to assert the absolute rarity of life. Has Lane taken into account all *possible* life forms and all potential environments? No. He's focused on one possibly minor subdomain of a likely immense phase space and concluded that because the domain is small, the domain is indeed small. ("Hold me up, I feel I'm going to faint.")

An example of the frailty of this approach is the similar assertion that the probability of functional proteins forming from random combinations of amino acids is sufficiently low that it is highly unlikely they formed naturally. Yet experiments from a decade ago suggest that the occurrence of functional proteins from random combination is manyfold higher than that postulated by omphaloskepsis.1 There is no substitute for actually doing the science.



1 — Nature, 2001, “Functional Proteins From a Random-sequence Library”, Keefe AD, Szostak JW

[Atheist-Lite]

A big planet with say twice the diameter of this one would reduce two billion years down to five hundred million years. A planet of five times Earth diameter would reduce the time to under a hundred million years. A lot depends on the actual distribution and composition of the planets out there? Assuming the Earth is a freak could be pushing the envelope in all sorts of directions without adequate data? I notice it is a way of getting in the science & psuedo-science press to make claims and counter claims with regards things of this kind. In truth there is nothing to say without data and it is nearer to religion than is comfortable to take any position on this 'mythical' map.

[Blind groper]

I despise when back of the envelope calculations of "probability" which build on our ignorance and misapplication of the law of the excluded middle are used to assert the absolute rarity of life.

Lane quotes Fermi who really has to be taken seriously.
The SETI program has scanned our entire galaxy looking for radio signals that might carry intelligent information. Admittedly the galaxy is a big place, and that scan is 'once over lightly'. Still, it is the absence of any sign of intelligent life that is what is obvious. It appears that such life may be rare.

[Atheist-Lite]

I despise when back of the envelope calculations of "probability" which build on our ignorance and misapplication of the law of the excluded middle are used to assert the absolute rarity of life.

Lane quotes Fermi who really has to be taken seriously.
The SETI program has scanned our entire galaxy looking for radio signals that might carry intelligent information. Admittedly the galaxy is a big place, and that scan is 'once over lightly'. Still, it is the absence of any sign of intelligent life that is what is obvious. It appears that such life may be rare.

This is true. I suspect intelligence once it arrises will quickly destroy itself and only exists as a rare and transient phenomana.

[Clinton Huxley]

I don't think we can claim to have done even a superficial radio scan of the whole galaxy, we've done some bits, at some frequencies.

[Blind groper]

This is true. I suspect intelligence once it arises will quickly destroy itself and only exists as a rare and transient phenomana.

That is one of many possible answers to the Fermi Paradox. It might even be true. Lane presents another possible answer, in saying that the move from procaryote to eucaryote cell is a rare and special event, which may have happened only on rare occasions, and only on a few planets.

[Atheist-Lite]

This is true. I suspect intelligence once it arises will quickly destroy itself and only exists as a rare and transient phenomana.

That is one of many possible answers to the Fermi Paradox. It might even be true. Lane presents another possible answer, in saying that the move from procaryote to eucaryote cell is a rare and special event, which may have happened only on rare occasions, and only on a few planets.

It quickly becomes a quaqmire of imponderables...

[mistermack]

I would like to know how and when the galaxy was scanned for radio waves. I find it highly unlikely that much of it has been covered. Or that it would be POSSIBLE to detect radio transmissions coming from the other side of the galaxy. Do we emit radio or other waves powerful enough that we could detect them at a distance of 100,000 light years? I find that most unlikely. From what I've read, they are presently only aiming to detect transmissions from no more than 200 light years away, and only then, if the aliens were operating hugely powerful transmitters, deliberately so as to be detected.

The other flaw, I think, is that he claims that mitochondria only evolved once. There is no way we could know that.
If mitochondria evolved today, they would probably be outclassed by modern organisms, and simply annihilated.
They could have evolved hundreds of times, and just gone extinct each time.

[mistermack]

Bugger. How did I post that twice?

[MiM]

I despise when back of the envelope calculations of "probability" which build on our ignorance and misapplication of the law of the excluded middle are used to assert the absolute rarity of life.

Lane quotes Fermi who really has to be taken seriously.
The SETI program has scanned our entire galaxy looking for radio signals that might carry intelligent information. Admittedly the galaxy is a big place, and that scan is 'once over lightly'. Still, it is the absence of any sign of intelligent life that is what is obvious. It appears that such life may be rare.

I take Fermi very seriously on any issue of nuclear chain reaction, but the Fermi paradox really has a number of assumptions hidden into it. One is that stellar colonisation is technologically viable.

The Seti program has scanned a minute fraction of the galaxy, and an even smaller fraction of time. We have used only a few decades to look into the wast abyss of the galaxy. To draw a conclusion that intelligent life is likely to be rare is completely premature.

Now, don't be hasty, Master Meriadoc.

[Blind groper]

the Fermi paradox really has a number of assumptions hidden into it. One is that stellar colonisation is technologically viable.

I got interested in this about 12 years ago, after reading an article written by a couple of NASA scientists in Scientific American about the prospects for interstellar travel. Their view was that the first vessel to go to another star system would do it within 500 to 1000 years, and would reach a velocity of 10 to 20% of light speed (0.1c to 0.2c).

I sat down to work out how long it would take the human species to fully colonise the entire galaxy. Assuming it would take 10,000 years after colonising a new star system to send out more colonising craft, and assuming the population would double each 100 years on those new star systems ( conservative, since the world's population more than tripled in the 20th Century), I calculated the entire Milky Way galaxy would be colonised to the point of over-population in less than 5 million years.

Since parts of the galaxy are up to 8 billion years old, the figure of 5 million years is tiny. A mere eye blink in time.

So the next thought is : If alien life was common, then it should have colonised the entire galaxy billions of years ago. Why did it not? I think this question is what lies behind the Fermi Paradox. Where are they?

I quite like Prof. Lanes explanation. It makes good sense.

[MiM]

I know Fermis paradox and the power of exponential growth. There is quite a difference between sending a vessel to the next starsystem and sending a crew to colonize a terraformable planet. The second might not be viable (other than in special cases) scale with any technology. What if the next suitable planet is 100 light years away. Then it would take 1000 years to get there even with 0.1c speed. Could you find a crew willing to go, and keep it alive for that long?

I like this explanation. It makes good sense too.