the lineage of this intelligence goes back in an unbroken line to their first common ancestor billions of years ago,
Nonsense. If cell walls ever had the ability to replicate themselves, totally autonomously, without the rest of the cell -- they've very certainly lost that ability. That loss of self-sufficient replication is quite a big "break" in the line.
Your argument might apply to ribosomes, however. The nucleus needs the ribosome for replication every bit as much as the ribosome needs the nucleus. And the ribosomal DNA is one of the very, very rare things that has hardly changed at all in the history of life -- humans and yeast have 75%-identical ribosomal DNA. Yeast!
I think you miss the point. Every scrap of membrane in every cell in every known organism -- and cells have a lot of different membranes in them -- was once part of a membrane in the parent cell, or was one of several in a parent cell that became part of this or that daughter cell. We don't know of any organism that constructs any membrane for any purpose de novo.
In a very real sense, life may be defined as a membrane with apparatus to aid in growing it. So, in that sense, every evolutionary change is ultimately a refinement to enable growing more membrane. You, personally, are a lot of membranes all folded and wrapped up and carrying around a skeleton.
Nonsense. If cell walls ever had the ability to replicate themselves, totally autonomously, without the rest of the cell -- they've very certainly lost that ability. That loss of self-sufficient replication is quite a big "break" in the line.
Your argument might apply to ribosomes, however. The nucleus needs the ribosome for replication every bit as much as the ribosome needs the nucleus. And the ribosomal DNA is one of the very, very rare things that has hardly changed at all in the history of life -- humans and yeast have 75%-identical ribosomal DNA. Yeast!
https://en.wikipedia.org/wiki/Ribosomal_DNA