Recent developments have revolutionized the study of biomolecules. Among them are molecular markers, amplification and sequencing of nucleic acids. The latter is classified into three generations. The first allows to sequence small DNA fragments. The second one increases throughput, reducing turnaround and pricing, and is therefore more convenient to sequence full genomes and transcriptomes. The third generation is currently pushing technology to its limits, being able to sequence single molecules, without previous amplification, which was previously impossible. Besides, this represents a new revolution, allowing researchers to directly sequence RNA without previous retrotranscription. These technologies are having a significant impact on different areas, such as medicine, agronomy, ecology and biotechnology. Additionally, the study of biomolecules is revealing interesting evolutionary information. That includes deciphering what makes us human, including phenomena like non-coding RNA expansion. All this is redefining the concept of gene and transcript. Basic analyses and applications are now facilitated with new genome editing tools, such as CRISPR. All these developments, in general, and nucleic-acid sequencing, in particular, are opening a new exciting era of biomolecule analyses and applications, including personalized medicine, and diagnosis and prevention of diseases for humans and other animals.

Archaeological cobs from Paredones and Huaca Prieta (Peru) represent some of the oldest maize known to date, yet they present relevant phenotypic traits corresponding to domesticated maize. This contrasts with the earliest Mexican macro-specimens from Guila Naquitz and San Marcos, which are phenotypically intermediate for these traits, even though they date more recently in time. To gain insights into the origins of ancient Peruvian maize, we sequenced DNA from three Paredones specimens dating ~6700–5000 calibrated years before present (BP), conducting comparative analyses with two teosinte subspecies (Zea mays ssp. mexicana and parviglumis) and extant maize, that include highland and lowland landraces from Mesoamerica and South America. We show that Paredones maize originated from the same domestication event as Mexican maize and was domesticated by ~6700 BP, implying rapid dispersal followed by improvement. Paredones maize shows no relevant gene flow from mexicana, smaller than that observed in teosinte parviglumis. Thus, Paredones samples represent the only maize without confounding mexicana variation found to date. It also harbors significantly fewer alleles previously found to be adaptive to highlands, but not of alleles adaptive to lowlands, supporting a lowland migration route. Our overall results imply that Paredones maize originated in Mesoamerica, arrived in Peru without mexicana introgression through a rapid lowland migration route, and underwent improvements in both Mesoamerica and South America.

Vallebueno-Estrada M, Hernández-Robles GG, González-Orozco E, Lopez-Valdivia I, Rosales Tham T, Vásquez Sánchez V, Swarts K, Dillehay TD, Vielle-Calzada J-P, Montiel R. 2023. Domestication and lowland adaptation of coastal preceramic maize from Paredones, Peru. eLife 12:e83149. doi: 10.7554/eLife.83149.

The Inka empire's expansion incorporated diverse cultural and ecological elements in microcosmic representations of their empire. Imperial practices included the resettlement of communities from various regions into labour enclaves near Inka ceremonial, administrative and economic hubs. This degree of imperial control might suggest a limitation on Inka subjects’ freedom to integrate non-local food resources into their diets. Employing starch grain analysis from stone tools, we seek to identify the range of plant food sources and examine the extent to which the Inka imposed constraints on inter-community interactions and the exchange of comestibles. Focusing on a translocated labour force residing near the Inka provincial centre of Vilcashuamán, our findings reveal the consumption of a variety of edible plants originating from multiple, occasionally distant, ecological regions. The results indicate that, in contrast to the restrictions on trade of other commodities as recorded in ethnohistorical accounts and previous archaeological research, the exchange of edible plant species among the subjugated peoples may have been less regulated. This study demonstrates how food landscapes potentially served as loci of resistance to the Inka empire's manipulative cosmopolitanism.