Antigen response is universal to all domains, arguably even/including viruses.
“Selection” as an inside out process rather than outside in.
“Positive pressure” is an artifact of sympathetic immune response for offspring, “Negative pressure” is an artifact of “incompatible” immune response.
Physical attributes are largely irrelevant to the organism itself. As we’ve seen with dogs and humans for example, there’s a tremendous amount of diversity in physical attributes which still fall into the same species compatibility.
Immune response is the gap between “micro” and “macro” evolution.
Adaptive immune response provides immediate temporal response, RNA provides direct multi-generational response (“epigenetic”), DNA provides longitudinal encoding/stabilization of response.
In vertebrates, immune system shapes “learned” response. In humans for example, microglia are functionally responsible for consolidation (“pruning”).
Inflammation is an immune response.