Back in the 1980s, Richard Jefferson used the enzyme to develop a powerful technique now relied upon by thousands of genetic engineers around the world. At the same time, he was intrigued by the enzyme's normal role. Its recycling effect helps determine the blood levels of many compounds, including important substances such as sex hormones. Jefferson realised that the bacteria within us, far from being passive hangers-on, must affect us in profound ways.
In the past decade, this view has started to become mainstream. Study after study has shown how the microbes living in us and on us - the microbiome - can affect our health and even happiness. But back in the 1980s, Jefferson took this idea even further. If microbes are so important, he reasoned, they must play a big role in evolution too. He came up with what he called the hologenome theory of evolution. "The hologenome is the biggest breakthrough in thinking I've had in my life," he says.
A couple of decades later, another researcher come up with much the same idea, even giving it the same name. And although this approach is only starting to be explored, hints are beginning to emerge that symbiotic microbes can indeed play a much bigger role in evolution than anyone thought.
What struck Jefferson is that our microbiome plays a critical role in some key processes. Levels of sex hormones obviously affect us in many ways, for instance - and yet as much as 65 per cent of circulating testosterone cycles through microbes, according to one study Jefferson came across at the time.
It's gets more interesting....
Early in the 19th century, Jean-Baptiste Lamarck devised a theory of evolution incorporating the then-popular idea that organisms could pass on adaptive traits acquired during their lifetime. Thus, giraffes evolved their long necks because they were in the habit of stretching their necks. Darwin believed something similar, but such ideas became discredited with the development of modern genetics. The hologenome theory does suggest that animals can sometimes evolve via the inheritance of acquired characteristics, Rosenberg says, but it does so in a way that can be verified by experiment.
After he published his ideas, he and his wife Ilana Zilber-Rosenberg began combing the literature to find related studies. They stumbled across a 1989 paper by Diane Dodd, then a postdoc at Yale University, who had found that changing the diet of a fruit fly could alter the flies' mating choices after just two generations.
"When I read this, I started jumping up and down," Rosenberg said. "It had to be the microbes. I just knew it. Nothing else could explain such a rapid change."
To prove this, Rosenberg got his PhD student Gil Sharon to try replicate Dodd's results. Sure enough, after two generations, flies fed on molasses would no longer mate with flies on a regular starch. Next, Sharon gave the flies rifampicin to kill off their bacteria. Afterwards, starch flies happily copulated with molasses flies, showing that bacteria were indeed responsible.
- More Here
In the past decade, this view has started to become mainstream. Study after study has shown how the microbes living in us and on us - the microbiome - can affect our health and even happiness. But back in the 1980s, Jefferson took this idea even further. If microbes are so important, he reasoned, they must play a big role in evolution too. He came up with what he called the hologenome theory of evolution. "The hologenome is the biggest breakthrough in thinking I've had in my life," he says.
A couple of decades later, another researcher come up with much the same idea, even giving it the same name. And although this approach is only starting to be explored, hints are beginning to emerge that symbiotic microbes can indeed play a much bigger role in evolution than anyone thought.
What struck Jefferson is that our microbiome plays a critical role in some key processes. Levels of sex hormones obviously affect us in many ways, for instance - and yet as much as 65 per cent of circulating testosterone cycles through microbes, according to one study Jefferson came across at the time.
It's gets more interesting....
Early in the 19th century, Jean-Baptiste Lamarck devised a theory of evolution incorporating the then-popular idea that organisms could pass on adaptive traits acquired during their lifetime. Thus, giraffes evolved their long necks because they were in the habit of stretching their necks. Darwin believed something similar, but such ideas became discredited with the development of modern genetics. The hologenome theory does suggest that animals can sometimes evolve via the inheritance of acquired characteristics, Rosenberg says, but it does so in a way that can be verified by experiment.
After he published his ideas, he and his wife Ilana Zilber-Rosenberg began combing the literature to find related studies. They stumbled across a 1989 paper by Diane Dodd, then a postdoc at Yale University, who had found that changing the diet of a fruit fly could alter the flies' mating choices after just two generations.
"When I read this, I started jumping up and down," Rosenberg said. "It had to be the microbes. I just knew it. Nothing else could explain such a rapid change."
To prove this, Rosenberg got his PhD student Gil Sharon to try replicate Dodd's results. Sure enough, after two generations, flies fed on molasses would no longer mate with flies on a regular starch. Next, Sharon gave the flies rifampicin to kill off their bacteria. Afterwards, starch flies happily copulated with molasses flies, showing that bacteria were indeed responsible.
- More Here
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