The Evolution of Social Bees

Scientists describe the genetic changes associated with solitary-to-social transitions throughout bee evolution.

By | May 14, 2015

WIKIMEDIA, DR. AJAY BALACHANDRANSome bees are solitary, some live in small groups, and some live in colonies with many thousands of individuals. Studying the genomes of 10 bee species that represent these different living arrangements, scientists have now identified the genetic signatures of communal living. The results, published today (May 14) in Science, reveal that one key feature of increased sociality is an elaboration of gene regulation capacity.

“By doing this comparative analysis they show several clear changes associated with the evolution of the two eusocial groups of bees [including] changes in the regulation of gene expression,” said evolutionary ecologist Laurent Keller of the University of Lausanne in Switzerland who was not involved in the work. “Bees are highly social and we are highly social . . . so it’s interesting to see what are the mechanisms that lead to the evolution of such a complex system.”

While humans are highly social, cooperative creatures, people are not eusocial. A key feature of eusociality is the confinement of reproduction to select individuals—such as the queen in the case of bees. The switch from solitary living to eusociality, much like the transition from unicellular to multicellular organisms, “is one of the major transitions in evolution,” said Karen Kapheim of Utah State University who led the study. Indeed, some eusocial groups have even been referred to as superorganisms, Kapheim said, “because they function like a multicellular organism where the queen could be thought of as a gamete . . . and the workers are the body, or the non-reproductive parts of the organism.”

And, much like gene expression increases or decreases across different cell types in multicellular organisms, some researchers have predicted that the evolution of eusociality would require a species to increase its capacity to regulate genes in individuals. To investigate whether this is indeed the case, Kapheim and her colleagues analyzed the genome sequences of 10 bee species: three that lived solitary lives and seven social species that represented two independent ancestral origins, as well as differing degrees of eusociality.

The analyses revealed a “clear pattern of increased potential for gene regulation” in both evolutionary branches of eusocial bees, Kapheim told The Scientist. For example, there was an increase in the number of genes predicted to be methylated (a form of epigenetic regulation) and an increase in the number of transcription factor binding sites in the promoters of genes—particularly those genes that appeared to be linked to the evolution of eusociality. “The study suggests that there has been an increase in the complexity of gene regulation with increased social complexity,” said insect sociogenomics researcher Amy Toth of Iowa State University who was not involved in the work.

Kapheim and her colleagues also found a decrease in the number of transposable genetic elements and more constrained protein evolution in eusocial bees compared with their solitary counterparts. But perhaps the most surprising result, said Kapheim, was that “the independent transitions that we studied really seemed to be independent. . . . We don’t see a whole lot of evidence for convergent evolution.” That is, although the overall genomic signatures of eusociality were similar irrespective of origin, the genes involved were different.

For the purpose of making comparisons, Kapheim chose bee species that were either solitary or eusocial, but across the 20,000 or more species of bees (and indeed, across all animal taxa), sociality is a continuum, said Kapheim.  “There’s all kinds of variation in social behavior . . . and I think now, we’re going to have to dig in and start filling in those gaps.” 

And not just for bees, said Toth. “The next step would be to broaden the comparison to a wider variety of social species.” For example, “this could be done with primates,” she said.

K.M. Kapheim et al.,Genomic signatures of evolutionary transitions from solitary to group living,” Science, doi:10.1126/science.aaa4788, 2015

Add a Comment

Avatar of: You

You

Processing...
Processing...

Sign In with your LabX Media Group Passport to leave a comment

Not a member? Register Now!

LabX Media Group Passport Logo

Comments

Avatar of: James V. Kohl

James V. Kohl

Posts: 442

May 15, 2015

See also: From Fertilization to Adult Sexual Behavior (1996)

odor perception is more akin to the immune system workings where multitudes of receptors are each uniquely responsive to chemical structures (Bartoshuk and Beauchamp, 1994; Buck and Axel, 1991). Moreover, these receptor proteins are chemically and structurally similar to those that bind neurotransmitters and hormones (Buck and Axel, 1991).

Nutrient-dependent/pheromone-controlled adaptive evolution: a model

The honeybee already serves as a model organism for studying human immunity, disease resistance, allergic reaction, circadian rhythms, antibiotic resistance, the development of the brain and behavior, mental health, longevity, diseases of the X chromosome, learning and memory, as well as conditioned responses to sensory stimuli (Kohl, 2012).

Elekonich and Robinson (2000) extended our 1996 model of RNA-mediated hormone-organized and hormone-activated behavior to insects and Elekonich and Roberts (2005) extended it to the life history tranisitions of the honeybee model organism.

Ecological variation leads to ecological adaptations via the biophysically constrained chemistry of RNA-mediated protein folding in all genera via the conserved molecular mechanisms we detailed in the molecular epigenetics section of our 1996 Hormones and Behavior review. Fixation of nutrient-dependent RNA-mediated amino acid substitutions occurs via the physiology of reproduction.

Concluding sentence from above: “The next step would be to broaden the comparison to a wider variety of social species.” For example, “this could be done with primates,” she said.

The comparison was done with primates in 1973. Dobzhansky (free pdf) wrote:

 ...the so-called alpha chains of hemoglobin have identical sequences of amino acids in man and the chimpanzee, but they differ in a single amino acid (out of 141) in the gorilla" (p. 127).

The Val158Met amino acid substitution links everything known about RNA-mediated cell type differentiation in species from microbes to man to life history transitions in humans. Oppositional COMT Val158Met effects on resting state functional connectivity in adolescents and adults

What aspect of nutritional epigenetics and/or pharmacogenomics does not extend across all genera via the conserved molecular mechanisms of biophysically constrained RNA-mediated protein folding chemistry? I ask because others seem to think that our model of RNA-mediated cell type differentiation must be exemplfied in more species before it is accepted as a model for cell type differentiation of all cells in all individuals of all genera.

Is there another model for that?

Avatar of: James V. Kohl

James V. Kohl

Posts: 442

Replied to a comment from James V. Kohl made on May 15, 2015

May 15, 2015

Now that Robert Karl Stonjek has posted this article from The Scientist to his Evoutionary Psychology yahoo group and Evoutionary Psychology New FB group, it will be interesting to see if someone answers the question from above:

Is there another model for that?

Avatar of: James V. Kohl

James V. Kohl

Posts: 442

May 15, 2015

See also: From Fertilization to Adult Sexual Behavior (1996) co-author TB wrote:

...odor perception is more akin to the immune system workings where multitudes of receptors are each uniquely responsive to chemical structures (Bartoshuk and Beauchamp, 1994; Buck and Axel, 1991). Moreover, these receptor proteins are chemically and structurally similar to those that bind neurotransmitters and hormones (Buck and Axel, 1991).

See also:

Nutrient-dependent/pheromone-controlled adaptive evolution: a model

The honeybee already serves as a model organism for studying human immunity, disease resistance, allergic reaction, circadian rhythms, antibiotic resistance, the development of the brain and behavior, mental health, longevity, diseases of the X chromosome, learning and memory, as well as conditioned responses to sensory stimuli (Kohl, 2012).

Elekonich and Robinson (2000) extended our 1996 model of RNA-mediated hormone-organized and hormone-activated behavior to insects and Elekonich and Roberts (2005) extended it to the life history transitions of the honeybee model organism.

Ecological variation probably leads to ecological adaptations via the biophysically constrained chemistry of RNA-mediated protein folding in all genera via the conserved molecular mechanisms we detailed in the molecular epigenetics section of our 1996 Hormones and Behavior review.

Fixation of nutrient-dependent RNA-mediated amino acid substitutions occurs via the physiology of reproduction.

Concluding sentence from the article posted here: “The next step would be to broaden the comparison to a wider variety of social species.” For example, “this could be done with primates,” she said.

The comparison with primates was done in 1973. Dobzhansky (free pdf) wrote:

 ...the so-called alpha chains of hemoglobin have identical sequences of amino acids in man and the chimpanzee, but they differ in a single amino acid (out of 141) in the gorilla" (p. 127).

The Val158Met amino acid substitution appears to link everything known about RNA-mediated cell type differentiation in species from microbes to man to life history transitions in humans. Oppositional COMT Val158Met effects on resting state functional connectivity in adolescents and adults

What aspect of nutritional epigenetics and/or pharmacogenomics does not extend across all genera via the conserved molecular mechanisms of biophysically constrained RNA-mediated protein folding chemistry?

I ask because others seem to think our model of RNA-mediated cell type differentiation must be exemplfied in more species before it is accepted as a model for cell type differentiation of all cells in all individuals of all genera.

Is there another model for that?

Avatar of: Raoul Rubinstein

Raoul Rubinstein

Posts: 13

May 15, 2015

From this article, it simply appears as though the bees were that way all along, and that the only thing that has "evolved" is the scientists' understanding. I would add that the interpretations and leaps of faith leave me breathless.

Avatar of: James V. Kohl

James V. Kohl

Posts: 442

Replied to a comment from Raoul Rubinstein made on May 15, 2015

May 16, 2015

What surprises me most is that Gene Robinson would  agree to frame this co-authored published work in the context of evolution.

Clearly there is a problem with RNA-mediated ecological adaptations that can be addressed at the level of nutrient-dependent ecological variation and amino acid substitutions due to dietary changes.

Colony collapse could be attributed to the substitution of high fructose corn syrup for pollen and/or robbing the bees of too much honey. If not, what are theorists claiming leads to the evolved changes in behavior of different bees with the same mophological traits and life history transitions?

 

Avatar of: Sergio Meirelles

Sergio Meirelles

Posts: 4

May 19, 2015

What ????!!!  We are highly social ??? !!!! LOL . Please...

Popular Now

  1. Major German Universities Cancel Elsevier Contracts
  2. Running on Empty
    Features Running on Empty

    Regularly taking breaks from eating—for hours or days—can trigger changes both expected, such as in metabolic dynamics and inflammation, and surprising, as in immune system function and cancer progression.

  3. Most of Human Genome Nonfunctional: Study
  4. Identifying Predatory Publishers
AAAS