The information that developing and maintaining a trait is costly to an organism (as it has to reproduce the DNA that encodes the trade with every cell division) can be found in many scripts and textbooks. An example being the ability of plants to survive temperatures below 0°.
A plant that does not need this ability but maintains it, would need more energy to synthesize the alleles where this information is stored. Energy that it cannot allocate in reproduction or growth. The principle is easy to understand and intuitive. On the other hand, again, I cannot seem to find any experiments on it in literature. Can anyone help?
That the genes themselves have costs due to storage, replication effort etc. and thus are subject to selection sounds (plausible but) like a rather heterodox view on evolution.
Usually selection is assumed to act mediately through the phenotype and there is the concept that genes not used do not undergo selection and thus gradually accumulate mutations until they are no longer functional.
Dear Klemens, the cost of being frost-tolerant is not in additional gene synthesis. It is usually in accumulation of additional chemicals (amino acids, polysaccharides) or membrane lipids that protect cytoplasm from freezing/freezing damage. Such chemicals slow down rate of growth and propagation. You can take club root-resistant turnip ECD04 or Brussels sprout, or Russian kale (tolerate -14oC) and compare it to Chinese kale (B. alboglabra). Another example - yellow flowering vs. white/blue flowering wild radish plants. Your example with cost of DNA propagation can be validated only for bacteria with plasmids, pro-phages, or new gene islands. Th additional cost of new gene propagation in huge plant genome will be too small to measure it...
Actually, you can measure a cost of genome duplication in polyploid genotype, like tetraploid brassica. Most of plants (~80%) of North with cold adaptation are polyploids.
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