Scientists study germline mutation in vertebrates to understand how fast species evolve

Blood and tissue samples were collected from the mother, father, and offspring of these 88 selected species in this study. 

Following that, the DNA of the parents and offspring was compared in order to estimate genetic differences between generations. Reportedly, the researchers determined the signs of germline mutation with a DNA mutation of 50 percent. 

The germline mutation rates were compared and studied using sample sequencing. This thorough comparison aided in determining the genome mutations that occurred on a yearly basis as well as between generations of each species.

The report states that the individual germline mutation rates varied across all species. In terms of generation rate mutation, reptiles were found to have the highest. Birds had the most variable mutation rates when compared to other species.

In addition, species with "higher long-term effective population sizes" had lower mutation rates per generation, according to the comparison. 

The mutation rate per generation was relatively low (40-fold), whereas mutation rates per year were approximately 120-fold, as per the WIRED report.

This study provides valuable insight into what causes the mutation to occur and the traits that most influence mutation rates. Additionally, quantifying germline mutation rates could tell scientists when species diverged and the rate of evolution of so many other species found on the planet.

The findings have been published in the journal Nature. 

Study abstract:

The germline mutation rate determines the pace of genome evolution and is an evolving parameter itself1. However, little is known about what determines its evolution, as most studies of mutation rates have focused on single species with different methodologies2. Here we quantify germline mutation rates across vertebrates by sequencing and comparing the high-coverage genomes of 151 parent–offspring trios from 68 species of mammals, fishes, birds and reptiles. We show that the per-generation mutation rate varies among species by a factor of 40, with mutation rates being higher for males than for females in mammals and birds, but not in reptiles and fishes. The generation time, age at maturity and species-level fecundity are the key life-history traits affecting this variation among species. Furthermore, species with higher long-term effective population sizes tend to have lower mutation rates per generation, providing support for the drift barrier hypothesis3. The exceptionally high yearly mutation rates of domesticated animals, which have been continually selected on fecundity traits including shorter generation times, further support the importance of generation time in the evolution of mutation rates. Overall, our comparative analysis of pedigree-based mutation rates provides ecological insights on the mutation rate evolution in vertebrates.