Bacteria that we carry in our bodies may help decide who we marry, according to a new study that analyzes the gut of...a small fruit fly.
A group of molecular biologists recently demonstrated that the symbiotic bacteria inside a fruit fly greatly influence its choice of mates. They propose that the basic unit of natural selection is not the individual living organism, plant or animal, but rather a larger biological milieu called a holobiont. This milieu can include plant or animal life as well as their symbiotic partners. In the case of animals, these partners tend to be microorganisms like intestinal bacteria.
The first experiment repeated a study carried out two decades ago by a Yale University researcher, in which a fly population was divided in half and fed different diets ― malt sugar versus starch. A year later, when the flies were re-integrated as one group, those who had been fed starch preferred starch-fed mates, while the sugar-fed flies preferred mates of a similar nutritional background. The repeat experiment carried out by the researchers shows that this dietary influence takes effect within just a generation or two rather than over an entire year.
"Up to now, it was assumed that the host organism undergoes evolution on its own, while its symbiotic bacteria undergo their own evolution. The mechanism that we discovered enables evolution to occur more rapidly in response to environmental changes. Since a generation is shorter for bacteria than for multicellular organisms, they genetically adjust more quickly to changes in the holobiont," says Prof. Eugene Rosenberg of Tel Aviv University's Department of Molecular Microbiology and Biotechnology.
In their second experiment, the team repeated the first, but with the addition of an antibiotic, which killed the bacteria and eliminated the specific mate preference. The mating process became random, with no dietary influence.
In subsequent experiments, the researchers successfully isolated the bacterial species responsible for reproductive isolation in flies with diet-related mating preferences, and found the bacteria Lactobacillus plantarum to be present in greater numbers in starch-fed fruit flies than in sugar-fed flies. When L. plantarum was reintroduced into the antibiotic-treated flies, the preferential mating behavior resumed, proving that this bacterial species is at least partly responsible for the mating preference.
Finally, in cooperation with Prof. Avraham Hefetz of Tel Aviv University's Department of Zoology, the team analyzed the sexual pheromones produced by the fruit flies. There turned out to be differences in pheromone levels between the two groups of flies − differences that again disappeared after administering antibiotics.
"The finding indicates that pheromone alterations are a mechanism by which we can identify mating preferences. We therefore hypothesize that it is the bacteria that are driving this change," Rosenberg says. He states that these discoveries have implications for our entire understanding of natural selection, something which may even lead to the development of a new theory of evolution.
Of course, once a month someone is rewriting Darwin and natural selection so we won't get new biology text books printed just yet.
- PHYSICAL SCIENCES
- EARTH SCIENCES
- LIFE SCIENCES
- SOCIAL SCIENCES
Subscribe to the newsletter
Stay in touch with the scientific world!
Know Science And Want To Write?
- Lichen: Apparently Happy Couple Really A Threesome
- Why A Planet Can't Hide Behind The Sun Or Above The South Pole
- The Daily Physics Problem - 1
- Curcumin And Silymarin Plant Compounds Give '1-2' Punch To Colon Cancer
- Are Think Tanks More Credible To Government Employees? Not Really
- The Daily Physics Problem - 2
- Blood Of King Albert I Identified After 80 Years
- "Okay, sorry I can't see the post you are talking about. I just see lots of posts about dogs. But..."
- "Reply on FB regarding your article from one Kenny MacBride ( https://www.facebook.com/kenny.macbride..."
- "I thought you were speaking more broadly indeed ! Text looses something in the translation or more..."
- "This is correct, but you need to put in the numbers for your answer to be valid.And you do not..."
- Parasite proteins prompt immune system to fight off ovarian tumors in mice
- Behavioral activation as effective as CBT for depression, at lower cost
- The Lancet: Simpler, cheaper psychological treatment as effective as cognitive behavioural therapy for treating depression
- Ultrasensitive sensor using N-doped graphene
- Brain activity and response to food cues differ in severely obese women, UTSW study shows