Sunflower Domestication in Space and Time
Lecture | October 23 | 12-1 p.m. | 101 2251 College (Archaeological Research Facility)
Native American farmers living ~4000-5000 years ago transformed the common sunflower from a highly branched wild plant with small disks and small seeds into a staple oilseed crop that sports a single large head with large seeds on an unbranched stalk. We have assembled a time series of archaeological samples that spans the majority of this period, and we are using endogenous DNA sequences obtained from these samples to reveal how human cultivation altered genetic diversity through time. My talk will focus on how the genomic libraries obtained from these samples and from ethnographic collections from the historic period are proving fruitful for examining hypotheses about where in North America sunflower was domesticated and for highlighting reductions in sequence diversity at multiple time points in the history of sunflower cultivation. The intriguing patterns of haplotype turnover we observe through time also suggest that shifts in agricultural practices have occurred over this period. In addition, my talk will discuss our efforts to define candidate domestication genes through population genomics and transcriptomics approaches with extant germplasm, which will allow us to leverage our archaeological material further to learn how the sunflower domestication syndrome was assembled by Native American farmers through time.