How did life actually begin?
How did life begin? There can hardly be bigger questions. There's light. But then what happened after that? How did life arise on the third rocky planet orbiting the unremarkable star at the centre of our solar system? We, humans have been wondering about the answer to this question probably almost as long as we have been able to wonder.
Life really is a form of chemistry, a particular form in which chemicals can lead to their own reproduction. But the important thing, I think, is that when we think about the origin of life this way, it isn't that life is somehow different from the rest of the planet. Life is something that emerges on a developing planetary surface, as part and parcel of the chemistry on that surface. Life is literally a part of the fabric of a planet like Earth.
Life is also sustained by the planet itself. That is, all of the nutrients that go into the oceans, and end up getting incorporated into biology, at first they're locked up in rocks, and then they are eroded from rocks, enter the oceans, and take part in a complex recycling that ensures that there's always carbon, nitrogen and phosphorous available for each new generation of organisms.
If we try to summarise by just saying what, at the end of the day, do we know about the deep history of life on Earth, about its origin, about its formative stages that give rise to the biology we see around us today, I think we have to admit that we are looking through a glass darkly. There are great mysteries behind the origin of life. Biologists continue to chip at it by understanding at an ever deeper level how the various molecular constituents work together, how living organisms are related to one another genealogically. And chemists will get at it by doing new experiments that will tell us what is plausible in how those chemical correspondences came to be.
We don't know how hard it is to go from the simplest bricks, if you will, in the wall of life, to something complicated, like a living bacterium. It should be fairly easy to make simple sugars, molecules called bases which are at the heart of the DNA, molecules called amino acids which are at the heart of proteins. It's fairly easy to make some of the fatty substances that make the coverings of the cells.
The hard part, and the part I think, nobody has figured out yet is how to get them working together. How do you go from some warm, little pond on primordial Earth that has amino acids,sugars, fatty acids just sort of floating around the environment to something in which nucleic acids are actually directing proteins to make the membranes of the cell?
I leave the answer to you all to think. Think about it and do post it in the comments section.Will surely reply to your comments. Sometimes, science gives us a lot to think about....
Life really is a form of chemistry, a particular form in which chemicals can lead to their own reproduction. But the important thing, I think, is that when we think about the origin of life this way, it isn't that life is somehow different from the rest of the planet. Life is something that emerges on a developing planetary surface, as part and parcel of the chemistry on that surface. Life is literally a part of the fabric of a planet like Earth.
Life is also sustained by the planet itself. That is, all of the nutrients that go into the oceans, and end up getting incorporated into biology, at first they're locked up in rocks, and then they are eroded from rocks, enter the oceans, and take part in a complex recycling that ensures that there's always carbon, nitrogen and phosphorous available for each new generation of organisms.
If we try to summarise by just saying what, at the end of the day, do we know about the deep history of life on Earth, about its origin, about its formative stages that give rise to the biology we see around us today, I think we have to admit that we are looking through a glass darkly. There are great mysteries behind the origin of life. Biologists continue to chip at it by understanding at an ever deeper level how the various molecular constituents work together, how living organisms are related to one another genealogically. And chemists will get at it by doing new experiments that will tell us what is plausible in how those chemical correspondences came to be.
We don't know how hard it is to go from the simplest bricks, if you will, in the wall of life, to something complicated, like a living bacterium. It should be fairly easy to make simple sugars, molecules called bases which are at the heart of the DNA, molecules called amino acids which are at the heart of proteins. It's fairly easy to make some of the fatty substances that make the coverings of the cells.
The hard part, and the part I think, nobody has figured out yet is how to get them working together. How do you go from some warm, little pond on primordial Earth that has amino acids,sugars, fatty acids just sort of floating around the environment to something in which nucleic acids are actually directing proteins to make the membranes of the cell?
I leave the answer to you all to think. Think about it and do post it in the comments section.Will surely reply to your comments. Sometimes, science gives us a lot to think about....
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