Why Are There So Many Species of Beetles and So Few Crocodiles?

ScienceDaily (Aug. 28, 2012) — There are more than 400,000 species of beetles and only two species of the tuatara, a reptile cousin of snakes and lizards that lives in New Zealand. Crocodiles and alligators, while nearly 250 million years old, have diversified into only 23 species. Why evolution has produced "winners" -- including mammals and many species of birds and fish -- and "losers" is a major question in evolutionary biology.

Scientists have often posited that because some animal and plant lineages are much older than others, they have had more time to produce new species (the dearth of crocodiles notwithstanding). This idea -- that time is an important predictor of species number -- underlies many theoretical models used by biologists. However, it fails to explain species numbers across all multi-cellular life on the planet, a team of life scientists reports Aug. 28 in the online journal PLoS Biology, a publication of the Public Library of Science.

Continued:  http://www.sciencedaily.com/releases/2012/08/120828171744.htm

Is it possible to predict the formation of new species? - Probably

Predicting the formation of new species

June 2012. Why do some groups of species diversify - in just a few thousand years - to the point of forming a wide variety of new species, while others remain essentially unchanged for millions of years? This is one of the key questions for scientists investigating the emergence and decline of biodiversity.

From various studies, it is known that speciation is influenced both by environmental factors (e.g. habitat diversity, climate) and by species-specific traits (e.g. coloration, behaviour patterns). However, little is known about how the extrinsic and intrinsic factors interact.

Cichlid diversification
These interactions have now been explored in more detail by a team of researchers led by Eawag and the University of Bern. In a study published in the latest issue of Nature, they demonstrate for cichlids from 46 African lakes that the probability of diversification, or "adaptive radiation", depends on a combination of environmental factors and sexual selection. African cichlids are particularly suitable for this type of study because of the extremely high species richness that developed over time from what was originally a small number of species in large African lakes. For Lakes Victoria and Malawi alone, more than 800 endemic cichlid species have been identified.

Read on: http://www.wildlifeextra.com/go/news/new-species-formation.html