Polyploidy in Gymnosperms: Revisited

The polyploidy revolution then…and now: Stebbins revisited.

Polyploidy has long been considered a major force in plant evolution. G. Ledyard Stebbins, Jr., an architect of the Modern Synthesis, elegantly addressed a broad range of topics, from genes to chromosomes to deep phylogeny, but some of his most lasting insights came in the study of polyploidy. Here, we review the immense impact of his work on polyploidy over more than 60 years, from his entranc...

Evolution and biogeography of gymnosperms.

Living gymnosperms comprise only a little more than 1000 species, but represent four of the five main lineages of seed plants, including cycads, ginkgos, gnetophytes and conifers. This group has huge ecological and economic value, and has drawn great interest from the scientific community. Here we review recent advances in our understanding of gymnosperm evolution and biogeography, including ph...

Polyploidy

Polyploidy is defined as an increase in genome DNA content. Throughout the plant and animal kingdoms specific cell types become polyploid as part of their differentiation programs. When this occurs in subsets of tissues within an organism it is termed somatic polyploidy, because it is distinct from the increase in ploidy that is inherited through the germline and present in every cell type of t...

Thrips pollination of Mesozoic gymnosperms.

Within modern gymnosperms, conifers and Ginkgo are exclusively wind pollinated whereas many gnetaleans and cycads are insect pollinated. For cycads, thrips are specialized pollinators. We report such a specialized pollination mode from Early Cretaceous amber of Spain, wherein four female thrips representing a genus and two species in the family Melanthripidae were covered by abundant Cycadopite...

Dermatoglyphs in human polyploidy.