Baggins
Senior Veteran
shinbits said:There was none given. Only links that stated that micro-fossils existed then, but nothing showing how they'd know that.
Here's how they know it.
Palaeontologists go out into the field to an area with likely looking rocks of the correct sort of age. These rocks are dated using radiometric methods. Then you find a sedimentary rock layer that you believe is likely to contain microfossils - the the case of very ancient rocks this is often a chert. You take your rock samples back to your laborartory.
In the case of cherts you then take thin sections of the rock and mount them on slides and look at them under powerful light microscopes. For other rock/fossil types different preperation methods are used - in the case of organic walled micro-fossils from ancient rocks ( such as acritarchs ) this involves dissolving the matrix of the rock with solutions of concentrated hydrochloric acid and Hydrofluoric acid ( to dissolve all carbonates and sillicates ) the remaining organic debris is suspended in water and put onto slides and viewed through a high powered light microscope.
They study these slides looking for microscopic fossils, and in most rocks (of the correct type ) , even back to the 3,5 BA like the Apex chert in Australia, they find them.
There are a minority of scientists who believe the shapes seen in the Apex Chert are hydrothermal alteration products that simply look like prokaryotes. But the majority position in the scientific community is that they are fossils of primitive life.
Stromatolites are unambiguous microfossil build ups that date from at least 2 billion years ago. They know stromatolites are formed by cyanobacteria because they are still being formed today ( in Shark Bay Australia ). I believe you have already been informed of this.
The simple reason as to how scientists know that there are fossil prokaryotes dating mack more than 2 billion years is through extensive reasearch and comparison.
There are organic particles in rock that look like modern staphylococcus, so the most likely meaning of this is that these are fossils of staphylococcus.
So to sum up:
We know the age of the rock
We examine what it contains
We look for comparisons in modern fauna ( remeber that prokaryotes have altered very little over earth history they are still microscopic sacks of organic material ), and other fossil faunas
This appears to answer your question, but I am sure there will be a reason why it doesn't.
You are profoundly ignorant of many lines of evidence for the theory of evolution and yet you seem to be unwilling to spend a small amount of time and effort in educating yourself using the books and links that people suggest. If you used a percentage of the time you spend on the internet posting wild ad hoc arguments to perform a bit of basic research using public resources on the internet then a lot of your basic misconceptions would be answered. This would not necessarily convert you to the standard scientific position concerning the theory of evolution, but it would make you counter arguments less ignorant.
Upvote
0