Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Microbes can influence evolution of their hosts

You are not just yourself. You are also the thousands of microbes that you carry. In fact, they represent an invisible majority that may be more you than you realize.

These microscopic fellow travelers are collectively called the microbiome. Realization that every species of plant and animal is accompanied by a distinctive microbiome is old news.

But evidence of the impact that these microbes have on their hosts continues to grow rapidly in areas ranging from brain development to digestion to defense against infection to producing bodily odors.

Now, contrary to current scientific understanding, it also appears that our microbial companions play an important role in evolution. A new study, published online on July 18 by the journal Science, has provided direct evidence that these microbes can contribute to the origin of new species by reducing the viability of hybrids produced between males and females of different species.

This study provides the strongest evidence to date for the controversial hologenomic theory of evolution, which proposes that the object of Darwin's natural selection is not just the individual organism as he proposed, but the organism plus its associated microbial community. (The hologenome encompasses the genome of the host and the genomes of its microscopic symbiotes.)

“It was a high-risk proposition. The expectation in the field was that the origin of species is principally driven by genetic changes in the nucleus.

Our study demonstrates that both the nuclear genome and the microbiome must be considered in a unified framework of speciation,” said Associate Professor of Biological Sciences Seth Bordenstein who performed the study with post-doctoral fellow Robert Brucker.

They conducted their research using three species of the jewel wasp Nasonia. These tiny, match-head sized wasps parasitize blowflies and other pest flies, which make them useful for biological control.

“The wasps have a microbiome of 96 different groups of microorganisms,” said Brucker. Two of the species they used (N. giraulti and N. longicornis) only diverged about 400,000 years ago so they are closely related genetically. This closeness is also reflected in their microbiomes, which are quite similar. The third species (N. vitripennis), on the other hand, diverged about a million years ago so there are greater differences in both its genome and microbiome, he explained.

The mortality of hybrid offspring from the two closely related species was relatively low, about 8 percent, while the mortality rate of hybrid offspring between either of them and N. vitripennis was quite high, better than 90 percent, the researchers established.

“The microbiomes of viable hybrids looked extremely similar to those of their parents, but the microbiomes of those that did not survive looked chaotic and totally different,” Brucker reported.

The researchers showed that the incompatibilities that were killing the hybrids had a microbial basis by raising the wasps in a microbe-free environment. They were surprised to find that the germ-free hybrids survived just as well as purebred larvae. But when they gave the germ-free hybrids gut microbes from regular hybrids, their survival rate plummeted.

“Our results move the controversy of hologenomic evolution from an idea to an observed phenomenon,” said Bordenstein. “The question is no longer whether the hologenome exists, but how common it is?”

This research was supported by award DEB 1046149 from the National Science Foundation's Dimensions of Biodiversity program.

Further information can be found at the Bordenstein Lab, the author's blogs at Symbionticism and Live In Symbiosis, and the author's twitter feeds @Symbionticism and @LiveInSymbiosis.

Visit Research News @ Vanderbilt for more research news from Vanderbilt. [Media Note: Vanderbilt has a 24/7 TV and radio studio with a dedicated fiber optic line and ISDN line. Use of the TV studio with Vanderbilt experts is free, except for reserving fiber time.]


Contact: David F. Salisbury, (615) 322-NEWS

David F. Salisbury | Vanderbilt University
Further information:]

More articles from Life Sciences:

nachricht The gene of autumn colours
27.10.2016 | Hokkaido University

nachricht Polymer scaffolds build a better pill to swallow
27.10.2016 | The Agency for Science, Technology and Research (A*STAR)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

The gene of autumn colours

27.10.2016 | Life Sciences

Polymer scaffolds build a better pill to swallow

27.10.2016 | Life Sciences

Greater Range and Longer Lifetime

26.10.2016 | Power and Electrical Engineering

More VideoLinks >>>