And from grandmother Zina - a line of spiders. From
grandmother Veronica - a line of monkeys.
But since they are very distant ancestors (and the very first grandmother was
the simplest unicellular bacterium: the Universal LCA), grandmother Diana was an ordinary fish,
and grandmother Zina is an ordinary spider. Veronica is a monkey in your genus.
The modern bacterium (named Tomy) was produced by his mother Huna, who was
also a bacterium. The bacterium-grandmother Vika has produced Huna, and so on.
All creatures in Tomy's lineage were bacteria.
Why the evolution into humans does take place with some
bacteria but not with the genus of Tomy? And you don't need to tell me the
parable, that "a factory worker can become a factory director, although other
workers are simply unlucky and they will remain unskilled forever." Nature and
biology are not a factory! And this also means that the Theory of Evolution
includes non-computable randomness. Therefore, it is possible that on the best
planet for living nothing special will happen, except the boring life of a
colony of bacteria.
The modern bacteria Tomy and LUCA look the same. Because the genus of Tomy was not evolution-ing. The explanation for this is the "factory" parable in the thread: namely genus of Tomy was not lucky enough. Thus, the modern fish are looking the same way as their ancestors the time the grandmother Diana (look up the name in the thread) has started their genus lines. Therefore, Diana was ordinary fish.
Do not deny your 10000000000 grandmothers' existence if you believe in them. Be respective to the original grandmother named LUCA. Do not call her the most primitive creature ever existed! Without her, there would be no grandmothers at all. Why? Because we need to feel our blood-relation to each other: we are someone's daughter, we are someone's son.
The C. Darwin has discovered not Evolution, but Adaptation. Surely, he would deserve the Nobel Prize for that. Namely, he rightly has seen the process of the appearance of new species. But within one kind. LUCA has produced this kind. The Creational Science however enlarges his Evolutionary theory in such a way, that introduces several LUCA-s, namely several kinds each with its own LUCA. The LUCA of the Bible is Adam and Eve. And each with its own species. For example, dog-kind. Within this dog-kind, there are many breeds. Each breed is a different specie inside this kind. The development of variants of SARS-CoV-2, or the way cancers become resistant to chemotherapy:
those examples are called Adaptation, which produces new species, but not new kinds.