If oxidative damage is more or less of a cost of any or all of these traits, that may affect the life history evolution of the animal. (sciencedaily.com)
Collectively, these fossils were termed «weird wonders» by the evolutionary biologist Stephen Jay Gould; they possess some, but not all, of the characteristics shared by their modern relatives, and so are crucial for understanding the early evolution of animal phyla. (palaeontologyonline.com)
According to Drs. Moran and Sunagar, «The «two - speed» mode of evolution of animal venoms involves an initial period of expansion, resulting in the rapid diversification of the venom arsenal, followed by longer periods of purifying selection that preserve the now potent toxin pharmacopeia. (sciencedaily.com)