Only if you leave out the paragraph directly afterwards, where they tested it experimentally: > The researchers grew two types of famine weed, one invasive and

Only if you leave out the paragraph directly afterwards, where they tested it experimentally: > The researchers grew two types of famine weed, one invasive and the other non-invasive, and exposed them to the atmospheric levels of carbon dioxide recorded in 1950 and 2020. In the invasive variety, parthenin concentrations peaked at the highest carbon levels. The results suggest that modern levels of carbon dioxide have contributed to the noxious weed’s toxicity.