>Alas, rubisco is, by biological standards, a sluggard, a lazybones, a couch potato. ... Years ago I talked with biologists about photosynthesis for a magazine article. Not one had a good word to say about rubisco.<p>That idea seems to have changed - and frankly was always a little unlikely. From the wiki page on RuBisCO (<a href="https://en.wikipedia.org/wiki/RuBisCO" rel="nofollow">https://en.wikipedia.org/wiki/RuBisCO</a>):<p>> A recent theory explores the trade-off between the relative specificity (i.e., ability to favour CO2 fixation over O
2 incorporation, which leads to the energy-wasteful process of photorespiration) and the rate at which product is formed. The authors conclude that RuBisCO may actually have evolved to reach a point of 'near-perfection' in many plants (with widely varying substrate availabilities and environmental conditions), reaching a compromise between specificity and reaction rate<p>Which seems more consistent with one of the highest copy number proteins around with a vital role to play.