We don't know how life first appeared on Planet Earth. It is perhaps the biggest scientific unknown. If we knew how life developed, then we could a) find it more easily and b) create simple bacterium ourselves, allowing us to really watch the early evolution of life. Unfortunately, there is pretty much no record of the very first life forms, as there are few, if any, rocks around from 4+ billion years ago. There are still many theories as to the origin of life, however, including a brand new one.
The most commonly accepted hypothesis of how life first came into being is a "primordial soup." In early tide pools and muddy puddles, there would have been amino acids floating about. These are the building blocks of proteins, which in turn are the building block that make life possible. We have found asteroids with amino acids on them, so a "soup" of them on early Earth is certainly not out of the question. These amino acids could have just bumped around, randomly sticking to each other as sunlight beamed down, gradually building into simple, prokaryotic bacteria. Others have suggested that lightning could spark amino acids into life. In fact, most ideas on how life first appeared are variations on this "primordial soup" concept.
New research, however, suggests that there just isn't enough energy to explain how life began in such a soup. Instead, they propose that deep sea vents were where life first showed up. The team found an interesting composition of chemicals on some of these vents: a membrane, with a gradient of protons. This is basically the same mechanism that organic cells use, in a process known as "chemiosmosis." Every organism, from the simplest bacterium to an oak tree to us, uses chemiosmosis. Therefore, the team suggests that it was a feature present in the first common ancestor, from which everything else developed, and which it first learned at the geothermal vents at the bottom of the sea. It's an interesting idea, and one that makes a lot of logical sense. Perhaps, with more research along these lines, we can finally find the answer to how life began.
The most commonly accepted hypothesis of how life first came into being is a "primordial soup." In early tide pools and muddy puddles, there would have been amino acids floating about. These are the building blocks of proteins, which in turn are the building block that make life possible. We have found asteroids with amino acids on them, so a "soup" of them on early Earth is certainly not out of the question. These amino acids could have just bumped around, randomly sticking to each other as sunlight beamed down, gradually building into simple, prokaryotic bacteria. Others have suggested that lightning could spark amino acids into life. In fact, most ideas on how life first appeared are variations on this "primordial soup" concept.
New research, however, suggests that there just isn't enough energy to explain how life began in such a soup. Instead, they propose that deep sea vents were where life first showed up. The team found an interesting composition of chemicals on some of these vents: a membrane, with a gradient of protons. This is basically the same mechanism that organic cells use, in a process known as "chemiosmosis." Every organism, from the simplest bacterium to an oak tree to us, uses chemiosmosis. Therefore, the team suggests that it was a feature present in the first common ancestor, from which everything else developed, and which it first learned at the geothermal vents at the bottom of the sea. It's an interesting idea, and one that makes a lot of logical sense. Perhaps, with more research along these lines, we can finally find the answer to how life began.