What is ontogenetic depth? Sounds sciency enough:
https://en.wikipedia.org/wiki/Ontogenetic_depth
Oh that. No thanks.
And I daren't bother clicking on your link for if the site is safe in
form, the ideation content might sink a nasty parasite into my noggin
and suck out my brains like those roving sentinel balls in the classic
horror flick _Phantasm_.
But I did google part of the quote from this Arthur fellow and my
assumptions were correct. It is Wallace Arthur from his evodevo book
_The Origin of Animal Body Plans: A Study in Evolutionary Developmental
Biology_. Nice try. He would have no truck with creationist clap trap.
The part "only if cells 'know' what to do in all these respects" comes
from a part (page 103) where he is talking about cellular context, such
as the intercellular matrix, cell-cell signaling and transduction.
Arthur, a pioneer in evodevo, had developed a concept of the
morphogenetic tree that I found nifty years ago. If memory serves it was
a hierarchical cascading gene theory based on differences of phenotypic
effect between early acting and late acting genes. Those were the days.
But I think from his 2011 book _Evolution: a Developmental Approach_ he
has abandoned that nifty concept as too simplistic a model for evodevo.
In this 2011 book he also explicitly excludes "creation scientists" from
"the *entire* scientific community" which accepts evolution as fact.
Wallace Arthur is not your friend.