Evolutionary Biology

How many ways are there to measure biological shape?

New research supports the use of cladistic data for quantifying the range of skull variation in a group of legless amphibians – the caecilians. The rich and diverse array of biological shapes around us is astounding. Shape, however, may be an elusive concept. What do we actually measure, and...

How the shape of eggs may explain evolutionary history of birds

The eggs of amniotes – mammals, reptiles and birds – come in a remarkable variety of shapes and sizes. Evolutionary biologists have now addressed shape variety in terrestrial vertebrates’ eggs, pinpointing morphological differences between the eggs of birds and those of their extinct relatives, the theropod dinosaurs. Researchers from...

Population density and testes size: more than meets the eye

A team of researchers has discovered that changes in population density can affect the size of animals’ testes and therefore impact on reproduction. Across the animal kingdom, there is usually a positive relationship between sperm competing to fertilize eggs and the male reproductive effort in producing large ejaculates. This...

Marine worms reveal the deepest evolutionary patterns

The study of ancient worms could offer a more solid understanding of evolutionary patterns and processes, according to new research. Scientists from the universities of Bath and Lincoln have revealed new findings on the evolutionary relationships and structure of priapulids – a group of carnivorous mud-dwelling worms living in...