Do we know what type of organism/life first started on Earth?

In summary, the first organism thought to have appeared on Earth is a single-celled creature, similar to the modern group Archaea. This was likely formed through chemical reactions and competition for resources. Other basic forms of life may have existed before Archaea, but were unable to reproduce and eventually died out. The process of evolution and natural selection led to the development of multiple-celled organisms, eventually leading to humans.
  • #1
nukeman
655
0
I am not sure on this, so hope someone can shed some light on this. I asked this in the Astronomy forum, as someone told me to also ask here. I am not an expert in biology in any means :)

What type of organism was thought to be among the first on earth? I am not sure if this is the right way to ask this :)

Lets say if I wanted to see, or do tests on an organism, and my tests were related to doing tests on the first organism on earth, or the first life on earth, what would it be?

For some reason I thought algee was among the first on Earth after the heavy volcanic period, and when it started to first rain.

Thanks guys!
 
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  • #2
nukeman said:
What type of organism was thought to be among the first on earth? I am not sure if this is the right way to ask this :)
Single celled creatures were the first organisms - sort of by definition of organism.
They are similar to the modern group Archaea = single celled things with no cell nucleas

For some reason I thought algee was among the first on Earth after the heavy volcanic period, and when it started to first rain.
Archaea used to be called blue-green algae in spite of them being neither blue, green nor algae.
 
  • #3
Great, thanks for the reply!

Ok so Archaea was thought to be the first "organism" to have started life on Earth?

Is there any research that shows how it Archara was created?, and how a single celled organism turned into the next phase of life, multiple celled organisms ?

Again, thanks!




NobodySpecial said:
Single celled creatures were the first organisms - sort of by definition of organism.
They are similar to the modern group Archaea = single celled things with no cell nucleas


Archaea used to be called blue-green algae in spite of them being neither blue, green nor algae.
 
  • #4
nukeman said:
Is there any research that shows how it Archara was created?
A bunch of chemical reactions worked better when close together, then with more chemicals forming a cell around them they worked even better. Those reactions then monopolized all the others and became single celled life.

, and how a single celled organism turned into the next phase of life, multiple celled organisms
A couple of cells got together and liked it?
ps bacteria today might argue about the 'next phase of life' bit
 
  • #5
nukeman said:
...Is there any research that shows how Archara was created
Speaking generally on the subject, Richard Dawkins suggests a "Replicator" molecule which "had the extradordinary property of being able to create copies of itself" was "formed by accident"(The Selfish Gene chapter 1)) and that's what started it all.
 
  • #6
As soon as you get a 'replicator' - something that can reproduce itself - there becomes a competition for resources (resources in this case would be the required chemicals needed to create another copy). If then by chance a slightly different arrangement of chemicals occurs which is better at getting the resources, that arrangement dominates. Keep this train of thought up for a few million years and better and better replicators evolve. Eventually we end up with a single cell. But that isn't the end, competition for resources goes on, and cells which group together survive in a certain environment...
 
  • #7
First, a bit of semantics for clarities sake. I just want to make sure that you understand Archaea is not a species, but a Domain. It was a broad answer, but the best one we could give. Next, replication is a requirement of life. Is something cannot reproduce, it is not considered alive. That said, there may have very well been other 'life', although incredibly basic, before archaea appeared, but it would not have been able to reproduce, so just died out. I do love Venton's explanation for evolution itself, however. Compounds that manage to stay together, and somehow create duplicate compounds out of certain chemicals may have appeared at one time or another. Then, there was a 'mutation' that allowed one compound to catch the required materials to 'reproduce' better. This chain just goes on and on and on until you get humans. (And that's where babies come from!)
 

1. What is the current scientific theory on the first life forms on Earth?

The most widely accepted theory is that the first life forms on Earth were single-celled prokaryotes, such as bacteria, that emerged around 3.5 billion years ago. This theory is supported by fossil evidence and studies of the earliest Earth environments.

2. How did these first life forms come into existence?

The exact mechanism of how the first life forms came into existence is still a subject of debate among scientists. However, one widely accepted theory is that simple organic molecules were able to form in the Earth's early atmosphere and oceans, and these molecules eventually combined to form the first self-replicating cells.

3. Were there any other competing theories about the first life forms on Earth?

Yes, there have been other competing theories, such as the idea of panspermia, which suggests that life on Earth originated from microorganisms that arrived from space. However, there is currently no strong evidence to support this theory.

4. How has the study of extremophiles impacted our understanding of the first life forms on Earth?

Extremophiles are organisms that can survive in extreme environments, such as deep-sea hydrothermal vents or acidic hot springs. The discovery of extremophiles has challenged our previous assumptions about the conditions necessary for life to exist, and has expanded our understanding of the potential habitats for the first life forms on Earth.

5. Is there a possibility that the first life forms on Earth were more complex than single-celled organisms?

While it is possible that more complex life forms existed before single-celled organisms, there is currently no evidence to support this. The fossil record and genetic studies suggest that single-celled organisms were the first life forms on Earth, and complex life forms evolved much later through a process of biological evolution.

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