See the chords connecting with the genes to each other and to the phenotype in the righthand image? This is an early depiction of gene regulatory networks. More on this here. academic.oup.com/ije/article-...

I’ve tried to find one but with no success. ☹️

I loved reading Waddington's essays. I think he presented such a nuanced and easy to understand metaphor for gene regulation.
I made a model of his landscape to demonstrate how it could be used in an education setting. It doubles as a marble toy for my daughter.
www.printables.com/model/671135...

Of course. The claim is not that the intelligence exhibited by an earthworm is identical to the intelligence exhibited by a human. It is merely that earthworms have intelligence. And, more generally, that intelligence is more widely distributed across the tree of life than is often credited.

If we believe, as I do, that human intelligence is an evolved attribute,
what do we imagine to be so special about the human lineage that all intelligent behavior is likely to have evolved only in that lineage?

He actually analyzed evolved behaviors that involved no intelligence in extensive detail. He was also insistent, in my view correctly, that a lot of animal behavior exhibits intelligence.

And I’m not sure about “no new functions” being added. Sure, no new *genes* are being added, but there’s no reason that I know of why changes in gene regulation cannot result in new functions. Maybe not in this case, which seems to be the modification of an existing function, but in principle.

You’re probably right. And Lamarck didn’t understand how genes work, but nobody did at the time. But his idea that there are many different pathways by which traits can be inherited—rather than just one—seems to have been vindicated by this and lots of other recent work.

Well, is that exactly right? Something like histone modification acts on existing genes, but the micro-RNAs here are not modifications of existing genes. They are *products* of genes, but only in the sense that all phenotypic traits—from bodily structures to behaviors—are gene products.