Gavin Douglas and colleagues published a paper assessing microbiome research and assertions that the human microbiome explains missing heritability in nature. 

He discusses this issue and explains

• What are classic ways of understanding genetic variation in humans and how recently microbiome research has entered this understanding,
• What the holobiont model is and how it involves claims regarding the microbiome and missing heritability in nature, and
• How their paper views the microbiome as more of potential element in genetic variation in humans and necessitates more consideration regarding how to integrate it outside of the strict, holobiont model.

Gavin Douglas is a PhD Candidate in the Langille Lab in the Deptartment of Microbiology and Immunology at Dalhousie University. His background is in human genetics and he has just published an intriguing paper called "Re-evaluating the relationship between missing heritability and the microbiome" in the journal Microbiome.

He helps listeners understand the basics regarding the issue by explaining heritability as the proportion of variation in a phenotype in a given population explained by genetic variance. He offers more background to this standard and then explains the "case of the missing heritability," which basically indicates the variation that isn't explained. 

Several hypotheses have emerged to explain this missing heritability, several of which are tied to the human microbiome. He describes how, for example, a holobiont model of a human organism puts forward a hologenome—a combined genome that includes the microbiome and might capture the missing heritability. The article discusses this theory and points out ways it doesn't quite fit.

For example, the holobiont doesn't present a combined evolutionary unit that transmits over generations. But he does think the microbiome plays a role in this mystery. He explains how and why and different ways scientists use these ideas. 

For more, follow him on twitter as @gavin_m_douglas and read the open-access paper here: Re-evaluating the relationship between missing heritability and the microbiome.

Available on Apple Podcasts: apple.co/2Os0myK