Modern science is strange for its lack of interest in strangeness.
Darwin himself was deeply fascinated by the phenomenon of xenia, which happens when the traits of the male parent manifest in the seeds or fruit of a hybrid. While the father of biology described the phenomenon as “of the highest theoretical importance”, when you point it out modern biologists they will shrug and go back to shuffling gene sequences.
Before the discovery of genes or DNA, Darwin hypothesised that some form of “gemmules” are thrown off by cells that circulate throughout the organism and transmit some form of information. In the last century, the focus on nuclear DNA, imagined to be some kind of impenetrable fortress containing “blueprints” that dictate cellular development and which can only be modified by random mutation, led 20th century biology down a narrow alley. The gemmules were only much later discovered in the form of exosomes, small membrane bound blobs that cells put into circulation, containing DNA, RNA, proteins and hormones, and which distant cells absorb and use to alter their behaviour. Having just noticed this system exists, we are only a little ahead of Darwin in understanding it.
For a long time in the 20th century, xenia was explained away as a result of plant hormones somehow leaking out of the developing embryo into the surrounding tissue. When a flower is pollinated, the resulting embryo only forms the core of the seed. The seed coat and fruit come from purely maternal tissues, so according to a strict interpretation of genetics should only contain maternal DNA and display maternal traits. Plant hormones, or at least the ones composed of small, fairly simple organic molecules which were isolated, synthesised and manipulated with 20th century technology, were used as an explanation for xenia since they were uncontroversial, even though there were very few studies into the mechanism that allowed complex traits to transmit into the seed coat or even the whole fruit based on production of a few simple molecules. Much of the focus of science is a like a “drunk looking for their lost keys under the street light” phenomenon. DNA is much easier to isolate and sequence than RNA, hence why the significance of the latter has been overlooked for so long. Small molecule plant hormones are likewise much easier to handle than the countless large signalling proteins and peptides that serve comparable roles.
The reason this topic has been on my mind lately comes from my own observations of the phenomenon. When I applied pollen from white and pink seeded sword beans onto the stigma of a species with black seed coats, the resulting F1 hybrid seed had distinctly olive-coloured coats. I also recently processed seed from hybrid tomatoes, mostly using my beloved Principe Borghese as the mother plant. This strain has fairly large seeds (a trait I like since it makes direct sowing a bit easier). When this strain was hand crossed with pollen from wild S. pimpinellifolium, a very small seeded variety, the resulting F1 hybrid seed was almost as small. Another Principe Borghese pollinated with my huge seeded Chile bronze tomato developed larger than average seed. A passionfruit breeding friend of mine (hat tip to Taylor) observed distinct changes in the fruit colour and texture of outcrossed species.
When Taylor explained the phenomenon to a biologist friend, they dismissed it as uninteresting. I’ve been pondering how scientists went from being deeply fascinated by such mysteries in Darwin’s time, only to end up with their current attitude. It could be partly due to the institutionalisation of research. Science is just a job today, where the majority of workers do what they are told from higher ups, who themselves are driven by cycles of fashion in funding. I remember the blank or slightly terrified stares I got whenever my curiosity made me ask wild and uncomfortable questions during lab meetings. When your job is threatened by the potential answers then it makes sense that the people who learn to avoid asking or answering them end up dominating academia.
I also think the lack of interest in xenia is related to its lack of obvious commercialisation potential. You might observe that playing jazz music makes cancer cells rotate clockwise instead of counterclockwise, but there is no quick way to turn that into a clinical cash cow. That is despite the majority of big discoveries of the 19thcentury being driven by pure curiosity. The unexpected xenia effects of wide hybridisation are transient in time and space. Just a curiosity, except curiosity is all that the scientific mind really has at the end of the day. For amateur breeders of crops with large, colourful seeds (like many legumes) it could be a useful mechanism to identify hybrid seeds among a mostly self-pollinating crop. I might be able to use xenia to get around my difficulties hand crossing lima bean strains.
Amateur crop breeders have riches beyond the most prestigious university. We have the freedom to pursue whatever catches our interest, with no great pressure to reach a key performance indicator on a deadline. We can attempt crazy experiments that are almost certain to fail, but could be revolutionary if they succeed. And most importantly, many of us are just ignorant enough of the accepted theories to value curiosities and welcome their strangeness into our gardens.
Sad to read about the corralled, capitalized, and institutionalized state of modern science today. I was hopeful that maybe we’d answer some of the big questions about the universe and life/consciousness (although we seem to be coming full circle back to lots of indigenous views) in the twilight years of industrialization, but it seems like we will just circle the drain a few years longer.
Is this what happens consistently with corn?