Tree ant family tree reveals swimming evolution

Molecular evolution: Old branches on the phytochrome family tree

Phytochromes are a divergent family of plant photoreceptors that mediate a wide range of developmental and physiological responses to changes in light intensity and spectral quality. In the flowering plants, phytochromes regulate seed germination, circadian rhythms, leaf and stem development, and the timing of floral initiation [1]. Each phytochrome molecule exists as one of two distinct photor...

Analyzing the Family Tree

FamilySearch holds one of the largest collections of linked family history data in the world. Nearly one billion records of individuals, both deceased and living, have been recorded and placed together into a common tree (“The Family Tree”). The study of this ancestral relationship graph consists of the largest family history network ever analyzed. We have found a number of interesting properti...

Evolution of the angiosperms: calibrating the family tree.

Growing evidence of morphological diversity in angiosperm flowers, seeds and pollen from the mid Cretaceous and the presence of derived lineages from increasingly older geological deposits both imply that the timing of early angiosperm cladogenesis is older than fossil-based estimates have indicated. An alternative to fossils for calibrating the phylogeny comes from divergence in DNA sequence d...

An AAA family tree.

Ant Colony Optimization for Tree Decompositions

Instances of constraint satisfaction problems can be solved efficiently if they are representable as a tree decomposition of small width. Unfortunately, the task of finding a decomposition of minimum width is NP-complete itself. Therefore, several heuristic and metaheuristic methods have been developed for this problem. In this paper we investigate the application of different variants of Ant C...