Archaeogenomic insights into the adaptation of plants to the human environment: pushing plant–hominin co-evolution back to the Pliocene

Abstract

The colonization of the human environment by plants, and the consequent evolution of domesticated forms is increasingly being viewed as a co-evolutionary plant-human process that occurred over a long time period, with evidence for the co-evolutionary relationship between plants and humans reaching ever deeper into the hominin past. This developing view is characterized by a change in emphasis on the drivers of evolution in the case of plants. Rather than individual species being passive recipients of artificial selection pressures and ultimately becoming domesticates, entire plant communities adapted to the human environment. This evolutionary scenario leads to systems level genetic expectations from models that can be explored through ancient DNA and Next Generation Sequencing approaches. Emerging evidence suggests that domesticated genomes fit well with these expectations, with periods of stable complex evolution characterized by large amounts of change associated with relatively small selective value, punctuated by periods in which changes in one-half of the plant-hominin relationship cause rapid, low-complexity adaptation in the other. A corollary of a single plant-hominin co-evolutionary process is that clues about the initiation of the domestication process may well lie deep within the hominin lineage.

Gourds and squashes ( Cucurbita spp.) adapted to megafaunal extinction and ecological anachronism through domestication

“…This result suggests either (i) a widespread ancient distribution of this subspecies and the emergence of domestic forms across a broad geographic range, illustrating a range-wide shift to human landscapes as an adaptive strategy; or (ii) prolific human-mediated dispersal of this taxon throughout Mesoamerica, illustrating the massive reproductive and dispersal potential for plants under cultivation. Either possibility underscores the adaptive potential of domestication (36). One ancient C. pepo ssp.…”

Geographic mosaics and changing rates of cereal domestication

“…This can be regarded as a form of coevolution [2][3][4][5], in which the human side of the relationship takes place primarily through cultural evolution, i.e. development of techniques and technologies of ecological management transmitted culturally, while the plants or animals evolve through normal biological evolution (genetic transmission).…”

Eels, Beavers, and Horses: Human Niche Construction in the European Late Upper Palaeolithic

“…This can be seen as part of the co-evolution of plant-human relationships (Allaby et al 2015) and which we argue here includes co-constructed riverine niches. These niches would also have been relatively stable in the face of climatic instability during this period (Bignon et al 2005) and may have provided an expanded season of both protein and carbohydrate/fat.…”

“…Seen as such this is part of the deeper time-depth of co-evolutionary process with selective pressure that lead eventually to domestication of key species such as the horse (Allaby et al, 2015). This behaviour is also part of an evolving socio-ecological cognition that some have argued forms part of modern human behaviour.…”