Also, when speaking to a non-scientist, normal language should be used. Your words made very little sense to me. Remember, YOU are the one that said I am scientifically ignorant...so why use such BIG WORDS?
So, rather than complain, why not ask me to explain the words. I offered to address any of your questions, but rather than do so you just raise more complaints.
It's called explosion because all of a sudden, different life forms appear without prior evolution from a source life form.
My notes, the words you suspected might not be mine, explained that there were many earlier life forms from which the Cambrian life forms evolved. You say I did not write clearly enough, because I used big words. Here are my original words (
italicised) with an expanded explanation (normal text). Once again, please feel free to ask for any point of clarification, but I would prefer you do that without the complaints.
- Early geological field work recognised the "sudden" appearance of fossils in the Cambrian period, with most major animal phyla appearing within a few tens of millions of years. The Pre-Cambrian was apparently barren of life.
Although much of the work of a geologist is conducted in a laboratory the samples they examine have been gathered in the field. And it was in the field that early geologists recognised that some rocks contained fossils and some did not. As they built up an understanding of the relative position of certain formations they realised that below a certain group of formations there were no fossils.
The group of formations, found in many places around the world and identified by the similar fossils they contained, was called the Cambrian. Many (though not all) of the rocks above the Cambrian held fossils, but none of the rocks below the Cambrian did - at least as far as they could see at that time. The older rocks, those below the Cambrian were called, logically, the Pre-Cambrian.
The apparent sudden appearance of life, as evidenced by the fossils in the Cambrian and no fossils in the Pre-Cambrian, is called the Cambrian explosion.
- Subsequent research has revealed that prokaryotes, "simple", single celled organisms without a nucleus were active 3.5 billion years ago, almost 3 billion years before the Cambrian
The discoveries referred to in my first italicised comment were made starting more than two hundred years ago. In the subsequent two hundred years we have made many more discoveries. This includes recognition of some simple organisms, stromatolites. These are colonial, single celled photo-synthetic bacteria. Colonial, they grouped together; single-celled, hopefully self explanatory (if not, ask); photo-synthetic, harvesting sunlight to provide energy; bacteria, a prokaryote, micororganism.
What is a prokaryote? You and I are composed of cells each of which has a nucleus where the bulk of our DNA is located. Outside the nucleus, but inside the cell wall, are a host of other 'bodies' performing a variety of functions. Cells like this are called eukaryotes. The simpler prokaryote lacks a nucleus. The DNA sits within the cell wall and there are fewer of the functional bodies found in our cells.
So, some 3.5 billion years ago these particular prokaryotes, called stromatolites existed. That is the first evidence I have presented that contradicts your faulty understanding that there was no life from which the Cambrian organisms could have evolved.
I'll deal with my other statements in a similar, expanded, simplified fashion, after you have confirmed you understand the above, or have asked for clarification.