Generative AI tools, such as ChatGPT, have demonstrated impressive capabilities in summarisation and content generation. However, they are infamously prone to hallucination, fabricating plausible information and presenting it as fact. In the context of legal research, this poses significant risk. This paper, written by Sally McLaren and Lily Rowe, examines how widely available AI applications respond to fabricated case citations and assesses their ability to identify false cases, the nature of their summaries, and any commonalities in their outputs. Using a non-existent citation, we analysed responses from multiple AI models, evaluating accuracy, detail, structure and the inclusion of references. Results revealed that while some models flagged our case as fictitious, others generated convincing but erroneous legal content, occasionally citing real cases or legislation. The experiment underscores concern about AI’s credibility in legal research and highlights the role of legal information professionals in mitigating risks through user education and AI literacy training. Practical engagement with these tools is crucial to understanding the user experience. Our findings serve as a foundation for improving AI literacy in legal research.

Dolichousnea longissima is famous as the world’s longest lichen, which typically reproduces asexually. Factors impacting its length and reproductive strategies are of theoretical interest and important for conservation. We discovered a Dolichousnea population with apotheciate thalli in Western China. Phylogenetic analyses using ITS sequence data confirmed specimens were D. longissima. Multiple phylogenetic branches included both apotheciate and non-apotheciate thalli, thus genetic differences within the ITS region were not related to apothecia production. There was no indication that apotheciate Dolichousnea specimens from this region belong to a separate, morphologically and genetically distinct population. In a field experiment, we transplanted non-apotheciate thallus strands of 10, 20, 40 or 80 cm length from higher to lower elevations: c. 4000 to 3400 m. Elevational gradients in temperature, relative humidity and vapour pressure deficit simulated future climatic change. We tested hypotheses regarding the impact of climatic stressors on D. longissima growth and reproduction. After three years of growth, thallus mortality was highest at the lowest sites. Of surviving thalli, 23% had fragmented, with fragmentation rates increasing with length. Other thalli thrived, reaching a maximum main stem length of 321 cm, with a maximum total length of 764 cm. Intact thalli showed negative length-dependent growth. Lower elevations were associated with initiation of sexual reproduction, reduced relative thallus length growth rates (RTLGR) and lower photobiont abundance, with apparent shifts of photobionts from the main stem to fibrils and reallocation of resources from length to central cord and fibril mass. Probability of switching to sexual reproduction increased with thallus length, but shorter thalli made greater relative investment in apothecia production. Detrimental impacts of climate change could reduce D. longissima range and biomass production, thereby also decreasing food availability for the endangered lichenivorous monkey, Rhinopithecus bieti. Conservation efforts should be prioritized at sites currently hosting abundant, fast-growing thalli, and high-elevation mature forests where D. longissima is most likely to persist under future climatic change. Apotheciate populations need protection because sexual reproduction theoretically generates genetic variability, increasing the likelihood of generating mycobiont genotypes adapted to altered climatic conditions.

Green and Tao’s arithmetic regularity lemma and counting lemma together apply to systems of linear forms which satisfy a particular algebraic criterion known as the ‘flag condition’. We give an arithmetic regularity lemma and counting lemma which apply to all systems of linear forms.

This reflection considers the contribution of Prof Larry Gostin to global health law and the lessons for climate action.