Life: Complexity and diversity

Living organisms continually evolve to occupy newer environmental regimes. In the process they develop more complex structures and grow to larger sizes. They also evolve more intricate ways of relating to each other. The larger, more complex organisms do not replace the simpler, smaller ones, rather they come to coexist with them in increasingly complex ecosystems. This promotes a continual increase in the diversity of life over evolutionary time.     

Life: Complexity and diversity

With rare exceptions, each sexually reproduced individual is endowed with a distinctive genetic constitution. Nevertheless living organisms share many genes, the greatest level of sharing characterizing those belonging to the same species. The total number of such species is unknown, but probably exceeds ten million, the vast majority of them being small invertebrate animals.     

Chern and total curvature

Shiing-Shen Chern was one of the great mathematicians of the twentieth century, and a towering figure in the field of differential geometry, where one studiescurvatures of spaces. In this article we give the reader a glimpse into differential geometry and the work of Chern.     

Equivalent but not the Same: Teaching and Learning in Full Semester and Condensed Summer Courses

Research on teaching and learning in condensed-course formats is varied and difficult to generalize. We analyze this research and identify factors that may account for the varied findings. Additionally, we present a mixed methodology study of 20 matched-pair courses (i.e., full and condensed formats) from 11 disciplines which examines student learning and student and faculty perception data. We find that faculty and students perceive condensed courses as more effective, but that student learning varies depending upon the measures used to assess it. We conclude by considering the implications of our study for teaching and assessment practices.     

The Indian monsoon 5. Prediction of the monsoon

In this article we first consider the importance of prediction of the monsoon, and events such as the intense rainfall event over Mumbai in July 2005. We then discuss how meteorologists make short-, medium-, and long-range forecasts and the concept of the limit of predictability in a chaotic system such as the atmosphere. Problems and prospects of prediction on different time-scales are discussed by using one example of short-range forecasts and the prediction of the monsoon by dynamical and statistical methods. Finally we consider measures of the skill of a forecast and how high the skill has to be for it to be useful for applications.     

Life: Complexity and diversity

Diversity of life is unevenly distributed over the surface of the earth; especially rich are the tropics, mountainous regions and island archipelagos. Lying at the trijunction of Africa, temperate Eurasia and tropical Southeast Asia and enjoying a great diversity of environmental regimes, India ranks about the 10th amongst nations in terms of its diversity of species.     

Life: Complexity and diversity

Early life on earth arose in an environment without oxygen. In an atmosphere with increasing oxygen concentrations, co-operation among teams of biomolecules led to the emergence of multicellular organisms which over time evolved to give rise to higher plants and animals.