According to N.K. Jerne the somatic generation of immune recognition occurs in conjunction with germ cell evolution and precedes the formation of the zygote, i.e. operates before clonal selection. We propose that it is based on interspecies inherent, ancestral forces maintaining the lineage. Murine oogenesis may be offered as a model. So in C57BL/10BL sera an anti-A reactive, mercapto-ethanol sensitive glycoprotein of up to now unknown cellular origin, but exhibiting immunoglobulin M character, presents itself "complementary" to a syngeneic epitope, which encoded by histocompatibility gene A or meanwhile accepted ancestor of the ABO gene family, arises predominantly in ovarian tissue and was detected statistically significant exclusively in polar glycolipids. Reports either on loss, pronounced expressions or de novo appearances of A-type structures in various conditions of accelerated growth like germ cell evolution, wound healing, inflammation and tumor proliferation in man and ABO related animals might show the dynamics of ancestral functions guarantying stem cell fidelity in maturation and tissue renewal processes. Procedures vice versa generating pluripotent stem cells for therapeutical reasons may indicate, that any artificially started growth should somehow pass through the germ line from the beginning, where according to growing knowledge exclusively the oocyte's genome provides a completely channeling ancestral information. In predatory animals such as the modern-day sea anemone, ancestral proteins, particularly those of the p53 gene family govern the reproduction processes, and are active up to the current mammalian female germ line. Lectins, providing the dual function of growth promotion and defense in higher plants, are suggested to represent the evolutionary precursors of the mammalian immunoglobulin M molecules, or protein moiety implying the greatest functional diversity in nature. And apart from any established mammalian genetic tree, a common vetch like Vicia cracca, may represent an ancient model of protected reproduction mirroring A-reactive "complementarity" already in a plant. The in its seeds developed, and from the number of chromosomes depending amount of an anti-A(1) specific glycoprotein suggests promotion of germination while simultaneously exerting protection from a soil bacterium, which intriguingly is immobilized by human anti-A immunoglobulin as well. Moreover, in a mammalian ovary the lectin of Dolichos biflorus detects again histo (blood) group A-determining N-acetyl-d-galactosamine epitopes, here signalizing activity of embryonic stem cells. So apparently based on identical, ancestral structures, the dual function of growth promotion and defense, predetermined in a plant genome, might be preserved right up to dominate early mammalian ontogeny.