East Gondwana ancestry of the sunflower alliance of families

The sunflower alliance of families comprises nearly 10% of all flowering plant species and includes the largest of all plant families, the sunflower family Asteraceae, which has 23,000 species, and the bellflower family Campanulaceae. Both are worldwide in distribution, but the majority of their species occur in the northern hemisphere. Recently it has been shown that a number of small, woody families from the Australian–Southwest Pacific area also belong in this relationship. Here we add yet another such family and present phylogenetic, biogeographic, and chronological analyses elucidating the origin of this large group of plants. We show that the ancestral lineages are confined to Malesia, Australia, New Guinea, and New Zealand and that the sunflower and bellflower families represent phylogenetically derived lineages within a larger group with a Cretaceous and southern-hemisphere, presumably East Gondwana, ancestry. Their highly derived position in the flowering plant phylogeny makes this significant for understanding the evolution of flowering plants in general.

Lifespan depends on month of birth

Month of birth influences adult life expectancy at ages 50+. Why? In two countries of the Northern Hemisphere–Austria and Denmark–people born in autumn (October–December) live longer than those born in spring (April–June). Data for Australia show that, in the Southern Hemisphere, the pattern is shifted by half a year. The lifespan pattern of British immigrants to Australia is similar to that of Austrians and Danes and significantly different from that of Australians. These findings are based on population data with more than a million observations and little or no selectivity. The differences in lifespan are independent of the seasonal distribution of deaths and the social differences in the seasonal distribution of births. In the Northern Hemisphere, the excess mortality in the first year of life of infants born in spring does not support the explanation of selective infant survival. Instead, remaining life expectancy at age 50 appears to depend on factors that arise in utero or early in infancy and that increase susceptibility to diseases later in life. This result is consistent with the finding that, at the turn of the last century, infants born in autumn had higher birth weights than those born in other seasons. Furthermore, differences in adult lifespan by month of birth decrease over time and are significantly smaller in more recent cohorts, which benefited from substantial improvements in maternal and infant health.

Subparsec-scale structure and evolution of Centaurus A (NGC5128).

We present a series of 8.4-GHz very-long-baseline radio interferometry images of the nucleus of Centaurus A (NGC5128) made with a Southern Hemisphere array, representing a 3.3-year monitoring effort. The nuclear radio jet is approximately 50 milliarcseconds in extent, or at the 3.5-megaparsec distance of NGC5128, approximately 1 parsec in length. Subluminal motion is seen and structural changes are observed on time scales shorter than 4 months. High-resolution observations at 4.8 and 8.4 GHz made in November 1992 reveal a complex morphology and allow us to unambiguously identify the self-absorbed core located at the southwestern end of the jet.