Deficiency in TIM-3 immune checkpoint induces the formation of subcutaneous panniculitis-like T cell lymphoma (SPTCL), a rare skin lymphoma subtype with characteristics of autoimmune inflammation. SPTCL is restricted largely to the adipose layer under the skin without lymph node involvement. Here cytotoxic lymphocytes are seen surrounding the adipocytes they target.

See Gayden et al.

Modern sugarcane cultivars are polyploid interspecific hybrids, combining high sugar content from Saccharum officinarum (pictured) with the hardiness, disease resistance and subterranean budding (ratooning) of Saccharum spontaneum. The sequenced genome is a haploid accession, AP85-441, generated by anther culture from the octoploid S. spontaneum SES208.

See Zhang et al.

The village of Tiscali is an archaeological site located in Sardinia built entirely inside a sinkhole and surrounded by rocky walls. A nuraghe is one of the over 7000 Bronze Age megalithic buildings typical of Sardinian civilization between 1900 and 730 BCE and an enduring symbol of the island’s distinctive population history.

See Chiang et al.

View from above onto the wild river valley alluvial land of Yarlung Tsangpo Jiang (Brahmaputra) in Tibet, China. A braided river inspires models of population and species histories that may be richer and more complex than the bifurcations of a tree.

“The genome revolution has taught us that great mixtures of highly divergent populations have occurred repeatedly. Instead of a tree, a better metaphor may be a trellis, branching and remixing far back into the past.”

David Reich, Who We Are and How We Got Here: Ancient DNA and the New Science of the Human Past (Pantheon, New York, 2018)

“Evidence for genome-wide contradictions between gene trees and species trees is rapidly accumulating in a wide range of species, raising the question of whether this should lead to a reevaluation of the utility of the tree as model for speciation.”

Polina Yu Novikova et al. Nat. Genet. 48, 1077–1082, 2016

The uniquely adapted and indigenous koala faces restricted resources and climate change. Its challenges are those that aboriginal people, and soon all people, will face.

See Johnson et al.

This work explores how the emergence of human cognition and our search for meaning depend upon environmental sustenance and animal health, depicting parallels between scientific and fantastic ancestral concepts of chimera, work, food and drugs, visions, birth and burial. A bored stone tool used by women to dig tubers meshes with an incised ostrich egg surrounded by protein-rich shellfish, and with the leaf fan of the psychotropic plant Boophone disticha, symbolic of prehistoric burial sites. The rock art shows human-animal figures with the shaman as eland, whose nose bleeds during the trance state, amid visions of entoptic stars and circles.

Clockwise from top: Rosa gallica ‘Versicolor’ (Rosa Mundi), Mme. Isaac Pereire, Maiden’s Blush, Rosa gallica ‘Officinalis’ (Apothecary’s Rose); center: Baron Girod de l’Ain.

See Raymond et al.

Thousands of years of southern African flora changing with the climate are recorded in the middens of the dassie among the rocks where our ancestors left their paintings.

African Origins I. Shellfish-cognition-adornment.

Image: Art by Ree Treweek. Cover Design: Erin Dewalt.

Cape porcupine quills by Tony Cunningham (tonysartandnature.com)

Here rice grains are cheerleading to celebrate this issue that features the genomes of 13 domesticated and wild rice relatives (Stein et al.) and a survey of the genetic variation in the rice pan-genome (Zhao et al.).

This issue features epigenetic analysis of cell commitment at many levels in mammalian genomes: during early embryonic development, in stem cells, and in cancer cells. These studies provide fundamental insight into the functional consequences of genome variation. On the cover: Red-tailed black cockatoo feathers (tonysartandnature.com).

See Editorial.