A Perspective summarizes the risks of bypassing natural selection when using assisted reproductive technologies (ART) in humans and livestock. The authors call for dialogue between the fields of assisted reproduction and evolutionary biology.
Jonathan P. Evans and Francisco Garcia-Gonzalez detail how techniques used in ART, including in vitro fertilization, artificial insemination, and intracytoplasmic sperm injection, can stress and damage gametes and embryos and lead to deleterious epigenetic changes in offspring.
Some ART techniques also bypass a system of filters in the female reproductive tract that select healthy sperm and may lead to better genetic matches with the egg. ART-conceived offspring have higher risk of certain health problems than spontaneously conceived offspring, including preterm birth, congenital abnormalities, low birth weight and associated mitochondrial genotypes, childhood cancers, asthma, obesity, metabolic syndrome, diabetes, cardiovascular diseases, and neurodevelopmental and psychiatric disorders.
Some of these health risks could potentially be ameliorated by sorting sperm with techniques that mimic the filters in the female reproductive tract and incorporating female reproductive fluids—which play a critical selective role in filtering high quality sperm in vivo—into ART protocols. According to the authors, applying evolutionary principles to the future development of ART may improve outcomes both for human ART and animal production.
