THE HIMALAYA AS A CENTRE OF CONCENTRATION FOR THE SOUTH-EASTERN ASIATIC POLYPODIACEOUS FERNS

Before summing up the essential points brought forward in the present paper,it seems desirable at the outset to circumscribe briefly the geographical boundary of the Himalaya.We all know that the Himalaya is an extraordinarily gigantic upheaval of the landmass in the world,yet,up to the present,geologists and geographers are still divided in the concept of its geographical boundary.It has so far unequivocally been recognized that the mountain range west of the great bend of the famous Tsangpo Gorge in southeastern Tibet running     

DO REEFS DRIVE DIVERSIFICATION IN MARINE TELEOSTS? EVIDENCE FROM THE PUFFERFISH AND THEIR ALLIES (ORDER TETRAODONTIFORMES)

A major challenge in evolutionary biology lies in explaining patterns of high species numbers found in biodiversity hot spots. Tropical coral reefs underlie most marine hot spots and reef-associated fish faunas represent some of the most diverse assemblages of vertebrates on the planet. Although the standing diversity of modern reef fish clades is usually attributed to their ecological association with corals, untangling temporal patterns of codiversification has traditionally proved difficult. In addition, owing to uncertainty in higher-level relationships among acanthomorph fish, there have been few opportunities to test the assumption that reef-association itself leads to higher rates of diversification compared to other habitats. Here we use relaxed-clock methods in conjunction with statistical measures of species accumulation and phylogenetic comparative methods to clarify the temporal pattern of diversification in reef and nonreef-associated lineages of tetraodontiforms, a morphologically diverse order of teleost fish. We incorporate 11 fossil calibrations distributed across the tetraodontiform tree to infer divergence times and compare results from models of autocorrelated and uncorrelated evolutionary rates. All major tetraodontiform reef crown groups have significantly higher rates of diversification than the order as a whole. None of the nonreef-associated families show this pattern with the exception of the aracanid boxfish. Independent contrasts analysis also reveals a significantly positive relationship between diversification rate and proportion of reef-associated species within each family when aracanids are excluded. Reef association appears to have increased diversification rate within tetraodontiforms. We suggest that both intrinsic factors of reef habitat and extrinsic factors relating to the provincialization and regionalization of the marine biota during the Miocene (about 23-5 MY) played a role in shaping these patterns of diversity.     

THE CALIFORNIA MORBIDITY SURVEY—A Progress Report

In May of 1954 the California State Department of Public Health began a one-year household sample survey covering the health status of the population of California.Preliminary results from the survey indicate that chronic conditions cause approximately three-quarters of the disability in the California population, while acute conditions are responsible for the remainder. Acute upper respiratory tract disorders account for about half of the total disability from acute conditions. In the older population group, there is a greater amount of disability outside than within metropolitan areas. No significant differences in disability status appear between recent migrants to California and longer term residents.Forthcoming results from the survey, answering more detailed questions, will provide information needed by a number of private and state agencies.