Convergence; feather crests & patterns (Introduction)

by David Turell , Friday, July 03, 2015, 22:54 (3431 days ago) @ David Turell

In two very distant species feather neck crests are controlled by the same gene. this is evidence of convergence and also patterns in evolution:-http://www.sciencedaily.com/releases/2015/06/150623180305.htm-"Evolutionary biologist Michael Shapiro and his team from the University of Utah made international headlines in 2013 when they found that a prominent change in pigeon plumage, head crests, could be traced to a mutation in a single gene.-"Now, in the new advanced online edition of Molecular Biology and Evolution, the research team has found an almost exact repeat in the evolutionary playbook. A mutation in the same gene, EphB2, has led to a similar result in domesticated ringneck doves. The mutation causes the feathers on the back of the head and neck to grow up toward the head in a striking look.-"Domesticated rock pigeons have more than 300 varieties that have been bred and chosen for their prized looks and vibrant feather colors. The head crested birds had one version of the gene, a single mutation that made an aberrant protein (Arg758Cys) responsible for the feather difference between them and uncrested birds.-***-"'Crested birds from both species have mutations in the same gene, and even in the same functional part of the gene," said Shapiro. "This suggests that only a limited number of genes -- perhaps only genes in the EphB2 pathway -- can cause crest formation without causing other problems that affect survival of the embryo or adult. Studying other species will help us understand if this same genetic mechanism is used repeatedly throughout crested bird species, or if it's a mechanism that's limited to the pigeon and dove family."-"Given that the ringneck dove is a domesticated species that last shared a common ancestor with the rock pigeon 23-35 million years ago, the study shows that the same gene can be implicated as a prime driver of feather variation in completely different species, separated over a great evolutionary distance.-"'We know that many genes are involved in feather development, so it's rather remarkable that the same gene appears to control the same trait in two distantly related species," said Shapiro."-Comment: I am convinced more than ever that evolution had patterns set up in the beginning to make the process easier to develop.