We don't usually sugar-coat the news but... Alien sugars found in Earth-bound meteorites Scientists have detected alien sugars in Earth-bound meteorites for the first time, providing further evidence that some of the ingredients needed to kick start life on our planet may have been delivered from elsewhere in space. The boffins – led by a team at Tohoku University, Japan – analysed powdered samples of two …
Yeast are eukaryotes like us. A higher form of life than bacteria. Cells with a central nucleus and mitochondria for energy production and oxygen chemistry. The evolution of Eukaryotic life (bacteria are prokaryotes) was a blink in geological time. To get there the bacteria had to develop photosynthesis and become cyanobacteria, blue-green algae. Then the oxygen they produced had to oxidise the reduced iron in the rocks. There’s a rust belt recording the epoch, literally.
Only once oxygen levels began to rise appreciably in the oceans did the drive for anaerobic cells to find some way of surviving which brought a large bacterium into engulfing a small oxygen capable bacteria and fail to digest it leading to a symbiosis at the basis of all animal, plant and fungal life.
The plants, necessary to make foodstuffs for yeast to work on required a second symbiosis between a eukaryotic cells and cyanobacteria where even today all the photosynthesis happens in plants.
Since barley and hops are both flowering plants you get well into the Triassic at least before you can make beer. But really it has to wait until the hunter gatherer humans selected larger ears of grass and let them ferment. Good for sourdough bread and beer both.
Yup, because when we have a water laden planet sized Petri dish, and an apparently rare occurrence of life in the galaxy, its really obvious that the ingredients had to evolve somewhere else first and hitch a ride to earth on an interstellar taxi.
DNA had to sponteneously emerge somewhere in the galaxy.
Occams razor says DNA spontaneously emerged here.
"DNA had to sponteneously emerge somewhere"
No, it didn't. You can start with much simpler RNA and DNA can evolve later once life has got started. Or it could be started by something even simpler perhaps, which no longer exists because it's died out completely, or it is from another planet.
But we're all just guessing so far.
I was being imprecise. I mean the chain of complex molecule formation that ultimately led to DNA most likely took place right here on Earth. In the perfect petri dish for it.
There seems to be a class of space scientist with a deep yearning for extra terrestrial life, that likes to make claims of interplanetary or interstellar transport through unlikely schemes as a way to claim "stuff" they find right here on Earth is proof of extra-terrestrial origin.
And, sorry for the spontaneous typo in one of the occurrences. Apparently pedants like to pick up on it for some reason, rather than the logical content of what I'm saying.
I would not bet on another planet as the most probably source of the complex organic molecules that make up life here. It just shifts the problem pointlessly. They had to develop somewhere, and we appear to be living in the best culture medium in the unfashionable end of the galaxy.
This does NOT preclude RNA or DNA existing elsewhere in our galaxy. Just saying the RNA and DNA that is here most likely developed right here without the magic coincidence taxi ride on a shooting star.
"Occams razor says DNA spontaneously emerged here."
Logic says that if it emerged[0] here, it probably also emerged in many other places. It also suggests that it (and it's building blocks) has probably been transferred from place to place by various events over the years. We will never know the actual details, but there is much to be learned from trying to understand them anyway.
[0] Note: No "spontaneously". Crawl first, then walk, then run.
I imagine in a sufficiently large and ancient universe, that logic and probability would suggest ' if it can, it will exist sooner or later'.
If the earliest life appeared on Earth some four billion years ago, when would the Kickstarters for that life have evolved elswhere?
It seems equally as likely as not that life could develop spontaneously in different places, however, I am no biologist.
This. A million times this.
There are no trees on the Moon. No "rivers" on Mars. Thus, not all places are exactly the same as here. Assuming an infinite universe.... assumes an infinite universe (and unicorns and all that).
We might be common, we might be unique, and a TON of science is needed between the two to know which is which (and scarily, without extra data, we may never know, in a scientific means).
"Not all places are exactly the same", which is lucky or there would be no transfer of energy that allows for our kind of life
Science is just another tool, it was handy for some of the problems we saw need fixing but the longer we survive the greater the chance that we will recognise the need for a better tool if we hope to continue to grow.
Religion answers no questions and cannot abide change and that is why it can never be either a true reflection of reality or a path to growth, follow their rules and everyone already knows the outcome war, famine and death.
" Dunkin donuts exist on earth, but I doubt they exist elsewhere in the universe."
It's probably not called "dunkin dobuts" ... but when you look at the chemistry involved, I'll bet you dollars to doughnuts that there is a dunkin-like high-fat, high-sugar confectionery-esque item that can be traded for in one way or another elsewhere in the universe,
Think about it. How do you make a doughnut? Start with the grain that gets milled into flour. How likely is it that elsewhere in the Universe there are plants that produce seeds with a carbohydrate energy storage mechanism? How likely is it that intelligent life somewhere other than here has figured out how to mill it? Etc.
I'd go as far as to say that given intelligent life and time, something like dunkin donuts is inevitable.
Except for the simple fact that DNA in and of itself is not the basis for life.
RNA is what makes us all tick over like clockwork. DNA is just for storage. For the IT minded: the HDD my be a vital part of a computer, but it is not what makes the computer work. The actual legwork is done by the processor and other electronics. It's a thing that's often forgotten even by molecular biologists, even though they should know better...
The chemistry of making RNA and its components, and the basic amino acids is well understood nowadays, and it's been pretty much conclusively proven that you actually don't need all that much to make it appear spontaneously in an environment like early Earth ( poisonous hellhole to us nowadays..) if you give it a couple million years. It's actually more or less inevitable..
Now if it will organise into what we call "life" , and how often is the question. We may see evidence in our lifetime if the space agencies get a bit of a move on and get probes to the various Suspects in our solar system.
But the fact is that the chemistry of the "precursors of life" is so basic that it happens literally everywhere it gets a chance, even in space. Which, in my eyes at least, is a Bloody Big Hint we aren't all as special and unique as we like to think.
... what would happen if a massive asteroid destroyed the earth and all life on it. Wouldn't we be left with some DNA and RNA amongst a bunch of much smaller asteroids, which could then go on to potentially seed life on other planets, billions of years in the future.
So, the real question in my mind is not "How did life start on earth", but "Does this point to life having existed somewhere else in this galaxy?" (albeit much simpler life, if they only had RNA and sugars, and no DNA). Or do we think that these things we're just spontaneously created by some chemical reaction? What's more likely?
A massive asteroid will be a serious blow to a major part of the ecosystem, for sure, but some forms of life will endure. The dinosaurs prove that the asteroid apocalypse doesn't necessarily kill everything.
Though I'll be quite happy for Humanity to test that theory in a few hundred years or so at the very least. I prefer not being there to find out how it goes down the next time.
Come on el reg.. you like being pendantic at times so lets correct the subtitle .. "More evidence that building blocks for life on our home world came from outer space" the evidence doesn't show that at all it shows that "More evidence that building blocks for life on our home world can be created through inorganic processes anywhere in the universe" not so snappy, but much more scientifically correct
Regards
Andy
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