Wild sparrow study traces social behaviors in the field to specific gene

Jan 14, 2014 by Carol Clark
The white-throated sparrow is considered a good model organism for the genetic basis of behavior. Credit: Cephas/Wikipedia

A unique study of the white-throated sparrow has identified a biological pathway connecting variation in the birds' aggression and parenting behaviors in the wild to variation in their genome.

The Proceedings of the National Academy of Sciences (PNAS) is publishing the results of the experiments, conducted by the lab of neuroscientist Donna Maney in Emory University's Department of Psychology.

The research, which comprised behavioral observations of the study subjects in the field and laboratory analyses of their in the brain, showed that variation in the expression of the estrogen receptor alpha (ER-alpha) gene strongly predicts the birds' behavior.

"We believe this is the most comprehensive study yet of how the rearrangement of a chromosome affects in a vertebrate," says Brent Horton, a post-doctoral fellow in the Maney lab and lead author of the study. "So much of the process of genetic discovery is restricted behind closed doors in a laboratory. But our study began in the woods, where we first observed the social behaviors of the actual subjects of our experiments in their natural setting. The results provide valuable insight into the mechanistic basis of and parenting in all vertebrates, including humans."

Such integrated studies "are exceedingly rare," Horton adds, "because they require such a variety of resources, expertise and well-balanced collaboration."

In addition to Horton and Maney, the principal investigators included Eric Ortlund, a biochemist and an expert in the ER-alpha gene at the Emory School of Medicine; and James Thomas, a human geneticist who was formerly with Emory and now works at the National Institutes of Health. Co-authors include William Hudson, a graduate fellow in Ortland's lab; Wendy Zinzow-Kramer, a post-doc in the Maney lab; Sandra Shirk, a research associate; and Emily Young, an undergraduate student of biology at Georgia Tech.

The white-throated sparrow is considered a good model organism for the genetic basis of behavior due to a genetic event that has divided the species into two distinct forms that differ in their behavior. These two forms, the white-striped morph and the tan-striped morph, are easily distinguished by their plumage markings.

At some point during the evolution of the species, a chromosome broke and flipped. This process, called an inversion, rearranged the sequence of the chromosome.

The white-striped birds, which all possess at least one copy of the rearranged chromosome, tend to be more aggressive and less parental than the tan-striped birds, which do not have the rearranged chromosome.

"The two morphs work beautifully in evolution because one color morph almost always mates with the opposite color morph," Horton says. "They complement each other."

For the past decade, the Maney lab has been a leader in documenting the neuroendocrine and genetic differences between the white-throated sparrow morphs. For the current study, funded by the National Institutes of Health, Maney recruited Horton, a field biologist and an expert in the natural history of the white-throated sparrow.

"At heart, I'm a behavioral ecologist," Horton says. "I want to integrate neuroscience and genetics into my work to understand the behaviors that I see in the wild."

The scientists knew that the different behaviors of the two sparrow morphs were linked to the chromosome inversion. "We wanted to know what genes captured by that chromosome also differ between the morphs, in order to identify the genetic mechanisms that may explain the behavioral differences," Horton says.

The white-throated sparrow winters in the South, but mates and raises its young during spring and summer in the North. "In a sense, I migrated with these birds," Horton says, explaining how he conducted fieldwork over three years. Each summer, he packed up his family and left Atlanta for Argyle, Maine, to tag birds for the study and spend weeks observing their behaviors in a forest.

White-throated sparrows nest on the ground under shrubs or low in trees. They are one of the most common birds seen in the forest and at suburban bird feeders. Their distinctive song is often likened to the phrase, "Old Sam Peabody … Peabody … Peabody."

To measure parental behaviors in the birds, Horton recorded the number of feeding trips they made for their young during a specified time. To measure aggression, he recorded their song rate in response to a simulated territorial intrusion: A live sparrow in a cage was displayed in the breeding territory of the wild study subjects, accompanied by the broadcast of a male song.

"The song of the birds is a form of aggression," Horton explains. "They're saying 'get out of my territory.' The rate at which they sing gives a measure of their level of aggression."

The field observations were followed by laboratory analyses of the study subjects, to hone in on differences in their neuroendocrine gene expression.

The researchers focused on ER-alpha as a primary candidate, since it is one of the genes captured by the chromosome inversion and had been previously linked to social behaviors in vertebrates.

Their analyses documented how the genetic differentiation between the morphs affects the transcription of ER-alpha. In one brain region thought to be important for aggression, white-striped birds had three times the level of ER-alpha than did the tan-striped birds. By looking at both the behavioral data and the lab data together, the researchers found the expression of ER-alpha in that region and others predicted variation in territorial aggression and parenting.

"The behaviors that differ between the morphs are known to rely on sex steroid hormones such as testosterone," Maney says. "But we already showed in 2009 that even when their testosterone levels are equal, the white-striped males still sing more than the tan-striped males. This finding led us to suspect that brain sensitivity to hormones differs between the morphs. ER-alpha has a hormone receptor that makes the brain sensitive to testosterone, so it makes sense that the white-striped birds have higher levels."

The researchers hypothesize that the mechanism they have identified may have played a major role in behavioral evolution.

"Humans also show variation in aggression and parenting," Horton says, "but we know little about what contributes to this variation and how our behavior can in turn affect our brains. This bird gives us important clues about what to look for as we try to understand the complex interplay between genes, proteins and our own social behaviors."

The ER-alpha findings conclude the first phase of the work. The research team is also investigating a suite of other neuroendocrine genes captured by the chromosome rearrangement that are thought to be important players in the regulation of social behavior.

Explore further: Testosterone in male songbirds may enhance desire to sing but not song quality

More information: Paper: www.pnas.org/content/early/201… 165111.full.pdf+html

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JVK
1 / 5 (2) Jan 17, 2014
"...the mechanism they have identified may have played a major role in behavioral evolution."

Horton et al. (2014) clearly refutes the idea of mutation-initiated natural selection. They help establish the biological basis of cause and effect via conserved molecular mechanisms of ecological adaptations in all species.

Their chromosomal rearrangement hypothesis of species divergence was dismissed in its entirety by PZ Myers, who labeled John A. Davison a "crank" for touting it, and labeled me a "crank" after a series of my posts elsewhere provided experimental evidence that supports the findings in THIS report on amino acid substitutions, chromosomal rearrangements, differences in morphology, and differences in behavior in sparrows.

http://freethough...s-place/

PZ Myers banned me from further participation after accusing me of homophobia, just as this report from Donna Maney's group became the focus of discussion.
antialias_physorg
5 / 5 (3) Jan 17, 2014
PZ Myers banned me

So you come here to cry about it? Poor you. Have a sweetie. Grow up.
JVK
1 / 5 (2) Jan 17, 2014
I commented on the nonsense serious scientists must put up with from anonymous fools and biology teachers who have rejected a detailed model of how ecological adaptations occur in species from microbes to man. First, they reject or eliminate chromosomal rearrangements. Then they reject the nutrient-dependent pheromone-controlled conserved molecular mechanisms of alternative splicings of pre-mRNA and amino acid substitutions that facilitate the chromosomal rearrangements.

After labeling me a "crank," I am then dismissed as a "homophobe" although I detailed how human sexual orientation arises via the same model we used to explain sex differences in yeasts in 1996 -- in an award-winning review article and book chapter. Author's copy here: The Mind's Eyes: Human pheromones, neuroscience, and male sexual preferences. http://www.sexarc...kohl.htm

I'm not crying. I thanked PZ for providing his blog as an example of unequaled ignorance and suppression of biological facts.
JVK
1 / 5 (2) Jan 17, 2014
http://gbe.oxford...abstract

(p.196): "Selective advantage of the mutation is determined by the type of DNA change, and therefore natural selection is an evolutionary process initiated by mutation."

Only when people like Nei ignore the ecological facts of nutrient-dependent chromosomal rearrangements, are others encouraged to display their ignorance. Watch for more ignorance here or see PZ Myers blog: "Pharangula."
JVK
1 / 5 (2) Jan 17, 2014
http://gbe.oxford...abstract

Excerpt 1: "...we will not consider geographical and ecological factors because of space limitation. Our primary purpose is to clarify the roles of mutation and selection..."

Excerpt 2: "This type of speciation by chromosomal rearrangements is also known to occur in yeasts and mammals..."

Horton et al (2014) help to clarify how speciation by chromosomal rearrangements occurs in sparrows. See how that was addressed in the book "Mutation-Driven Evolution" http://www.amazon...99661731
RealScience
5 / 5 (1) Feb 19, 2014
Horton et al. (2014) clearly refutes the idea of mutation-initiated natural selection.


From the article with an interview of Horton:
"At some point during the evolution of the species, a chromosome broke and flipped. This process, called an inversion, rearranged the sequence of the chromosome."

This is commonly classified as a mutation, and so SUPPORTS the role of mutations in evolution through natural selection.

If you claim that this is inversion in not a mutation, then show EVIDENCE that it is controlled.
JVK
1 / 5 (1) Feb 19, 2014
I already did that!

"In wasps, manipulation of the genetics of evolved species-specific pheromones characterized the change in a pre-existing signaling molecule triggered by a glucose-dependent (Yadav, Joshi, & Gurjar, 1987) stereochemical inversion (Niehuis et al., 2013)." -- cited in Kohl (2013)

The glucose-dependent stereochemical inversion is controlled by the metabolism of glucose to species specific pheromones. I don't have time to educate you further on the biophysical contraints on chromosomal rearrangements, so tell me: what evidence suggests that mutation-driven evolution resulted in a new molecular mechanism that caused the chromosomal inversion in the sparrows?

Why wouldn't conserved molecular mechanisms of nutrient-dependent pheromone-controlled ecological adaptations be the best explanation of biologically-based cause in insects and vertebrates and every other species on the planet?
anonymous_9001
5 / 5 (3) Feb 19, 2014
Stereochemical inversion =/= chromosomal inversion

Those are completely unrelated processes.
Maggnus
5 / 5 (2) Feb 19, 2014
Horton et al. (2014) clearly refutes the idea of mutation-initiated natural selection.
It does not! Horton describes chromosomal polyophism and makes no overt claim (pro or anti)regarding mutation-driven natural selection. Despite the lack of specific comment, Horton alludes to genetic variation (ie mutations) as being the underlying cause of the behavioral change, and specifically the change in the chromosome resulting in a change in the enzyme expressed by that chromosome.

PZ Myers DOES NOT dismiss the idea that chromosomal rearrangement can lead to species diversion, rather he says that chromosomes get rearranged as a result of mutations, especially those which result in a polymorphism or transcription error. That's the mutation Kohl!

Whether or not the change is retained by species is then dependant on whether or not that change creates a benefit to the individual expressing the mutation, such that it lives to pass the mutation on to its offspring.
Maggnus
5 / 5 (2) Feb 19, 2014
who labeled John A. Davison a "crank" for touting it,
No, he labelled Davison a crank for touting the idea that chromosomal rearrangement was the result of actions by an intelligence as opposed to spontaneous mutations. You know, creationism.

And I laugh and laugh!
Maggnus
5 / 5 (2) Feb 19, 2014
I commented on the nonsense serious scientists must put up with
Really! Do you actually know any? How do you know what a serious scientist has to put up with?
Then they reject the nutrient-dependent pheromone-controlled conserved molecular mechanisms of alternative splicings of pre-mRNA and amino acid substitutions that facilitate the chromosomal rearrangements.
Can you please elucidate for us poor anonymous biology teachers? What mechanism is responsible for making specific base sequence changes that lead to the retention of chromosomal rearrangements that differentiate species?
JVK
1 / 5 (2) Feb 19, 2014
Stereochemical inversion =/= chromosomal inversion

Those are completely unrelated processes.


Sorry, I thought both were nutrient-dependent because there's model for that.

Exonic Transcription Factor Binding Directs Codon Choice and Affects Protein Evolution

http://www.scienc...abstract

Why haven't you commented on that, when I asked you about it elsewhere? Could it be because you are an anonymous fool everywhere you are?
JVK
1 / 5 (2) Feb 19, 2014
No, he labelled Davison a crank for touting the idea that chromosomal rearrangement was the result of actions by an intelligence as opposed to spontaneous mutations. You know, creationism.


Does he think Sean B. Carroll is a crank for touting ecological adaptations without mentioning mutations? Is Sean touting creationism?

A Single Gene Affects Both Ecological Divergence and Mate Choice in Drosophila

http://www.scienc...abstract

JVK
1 / 5 (2) Feb 19, 2014
Can you please elucidate for us poor anonymous biology teachers? What mechanism is responsible for making specific base sequence changes that lead to the retention of chromosomal rearrangements that differentiate species?


Haven't I asked you before to tell me where to start your lesson on biophysics? Shall we start here, for example:

http://figshare.c...a/938190

I think it may be a bit too much for me to explain everything from atoms to ecosystems to someone like you. But, if I could start with the role of sodium ions if you like.
Captain Stumpy
5 / 5 (1) Feb 19, 2014
I think it may be a bit too much for me to explain everything from atoms to ecosystems to someone like you. But, if I could start with the role of sodium ions if you like

@jvk
why not just keep it on common ground

Here is a question:
DOES your model make any changes to the nucleotide sequence of the genome of an organism, virus, or extrachromosomal genetic element?
This is a YES or NO answer

in the past your descriptions have included changes that are considered MUTATIONS
are you going to change them now?
RealScience
5 / 5 (2) Feb 19, 2014
Does he think Sean B. Carroll is a crank for touting ecological adaptations without mentioning mutations?


@JVK - Do you think that Sean B. Carroll would agree or disagree with the statement that "mutations are NEVER selected for by natural selection"?
JVK
2 / 5 (2) Feb 19, 2014
DOES your model make any changes to the nucleotide sequence of the genome of an organism, virus, or extrachromosomal genetic element?
This is a YES or NO answer


YES!

--Thanks for asking. If it didn't, there could be no increased organismal-level thermoregulation in species from microbes to man via alterations in hydrogen bonds (glucose & glucose dehydrogenase interactions). Obviously, you must first break the bonds before they can be strengthened.

http://figshare.c..._/643393

in the past your descriptions have included changes that are considered MUTATIONS
are you going to change them now?


I don't care what you think should be considered in the context of MUTATIONS unless you can explain HOW they alter the course of evolution in species from microbes to man. Obviously, mutations that perturb protein folding aren't going to be beneficial. Which MUTATIONS are beneficial? Is there a model for that? I've only ever heard about a ridiculous theory.

JVK
1 / 5 (2) Feb 19, 2014
Does he think Sean B. Carroll is a crank for touting ecological adaptations without mentioning mutations?


@JVK - Do you think that Sean B. Carroll would agree or disagree with the statement that "mutations are NEVER selected for by natural selection"?


I don't think it makes any difference what he agrees or disagrees with. The biological facts don't change and there is no experimental evidence that suggests mutations that perturb protein folding, which is what mutations do, are ever selected for by natural selection.

Doesn't SB Carroll have a blog site? Why don't you ask him why suddenly he seems to be touting ecological adaptations?
RealScience
5 / 5 (2) Feb 19, 2014
A previous comment of yours implied that Carroll not mentioning mutations was evidence is distancing himself from them:
the senior author of this article is Sean B. Carroll, and he appears to have dismissed mutation-driven evolution in flies and now attributes ecological adaptations and speciation to a single gene. He will not be the only atheistic biology teacher to begin to acknowledge the reality of what is currently known. Watch for others to quickly distance themselves from nonsensical theory.


An equally plausible explanation is that the role of mutations in adaptation is so well known that Carroll didn't bother mentioning it in a paper on other factors involved in adaptation.

If you don't think it makes any difference what he agrees or disagrees with, why did you bother to make that comment?

JVK
1 / 5 (2) Feb 19, 2014
If you think that the role of mutations in adaptation is so well known that Carroll didn't bother mentioning it, why don't you tell me what you think the role of mutations in adaptation is?

I made the comment because anyone who does not distance them self from the ridiculous theory of mutation-initiated natural selection and start reporting results in terms of ecological adaptations will no longer be grant-funded.

Tell me what you have read in the past year that makes you think you can challenge me with your nonsense about whatever you think mutations contribute to evolution and how they do it.

It's been all about the nutrient-dependent pheromone-controlled microRNA/messenger RNA balance for more than a decade. People like SB Carroll have taken a bit longer to realize what's happened, and they're not telling their students, since it would be like telling them --we've all been teaching nonsense for more than 10 years.
RealScience
5 / 5 (2) Feb 19, 2014
If you think that the role of mutations in adaptation is so well known that Carroll didn't bother mentioning it, why don't you tell me what you think the role of mutations in adaptation is?

I already have, but I will again: Mutations provided variations that natural selection selects among.
I made the comment because anyone who does not distance them self from the ridiculous theory of mutation-initiated natural selection and start reporting results in terms of ecological adaptations will no longer be grant-funded.

That's really funny - I chair the evaluation committee for a fund-granting agency.

Tell me what you have read in the past year that makes you think you can challenge me with your nonsense about whatever you think mutations contribute to evolution and how they do it.


I have read the papers that you have cited, and pointed out how they disagree with your position.

Shall I repeat a few?
- continued -
RealScience
5 / 5 (2) Feb 19, 2014
JVK citation:
See for example: Gene duplication as a mechanism of genomic adaptation to a changing environment http://rspb.royal...full.pdf "One of the main duplicated gene families are the olfactory receptor proteins..."


Response:
The paper you cited CONTRADICTS your posts, detailing how duplication mutations of non-nutrient-uptake/pheromone genes can have positive impact (e.g., cold resistance).
Furthermore in the section on Pranting & Andersson's work the paper you cite clearly describes mutations having a role in antibiotic resistance in evolution.

RealScience
5 / 5 (2) Feb 19, 2014
JVK citation:
"In the light of recent advances in the characterization of the β-globin cluster, we propose that the complex patterns of diversity observed in this genomic region arose from distinct functional constraints related with the intricate process of chromatin and protein interactions coordinating the differential expression of genes at the β-globin cluster during development." http://www.ncbi.n...3622298/


Response:
Even the article YOU cite supports that the sickle cell variants arose through mutation and confers malarial resistance "Mutations in the β-chain of human HbA are associated with ... sickle cell disease", "alleles, which are known to confer resistance to Plasmodium falciparum".
RealScience
5 / 5 (2) Feb 19, 2014
JVK Citation:
"The remarkable advances of molecular biology in recent years have made it possible to understand how it is that diverse organisms are constructed from such monotonously similar materials: proteins composed of only 20 kinds of amino acids and coded only by DNA and RNA, each with only four kinds of nucleotides."

http://img.signal...nsky.pdf


Response:
Here is a quote from the "remarkable advances" reference that you cited:
"Much work has been done in recent years on individual variations in amino acid sequences of hemoglobins of human blood. More than 100 variants have been detected. Most of them involve substitutions of single amino acids-substitutions that have arisen by genetic mutations in the persons in whom they are discovered or in their ancestors. As expected, some of these mutations are deleterious to their carriers, but others apparently are neutral or even favorable in certain environments."
RealScience
5 / 5 (2) Feb 19, 2014
JCK Citation:
Ivo M. Chelo, Judit Nédli, Isabel Gordo & Henrique Teotónio. An experimental test on the probability of extinction of new genetic variants. Nature Communications, September 2013 DOI: 10.1038/ncommsS3417

http://www.nature...417.html


Repsonse:
The Chelo et al paper that you cite shows that harmful alleles can persist and the beneficial alleles are not ALWAYS successful…

It also discusses the probability of fixation in the case where an allele is beneficial regardless of frequency, and shows the expected probability of fixation over 100 and 1000 generations. The expected probability of fixation is quite high even for a 15% benefit, although this experiment was not run long enough to confirm the model.

Thus your reference supports that fixation of beneficial alleles can occur with high probability (see graphs 2b and 4a), although it does not prove it.

And there are many more.
So all it takes to challenge you is reading the papers that you cite!
JVK
1 / 5 (1) Feb 19, 2014
Biophysical constraints on protein folding prevent mutation-driven evolution.

Discover Magazine

FROM THE MARCH 2014 ISSUE
Mutation, Not Natural Selection, Drives Evolution

Molecular evolutionary biologist Masatoshi Nei says Darwin never proved natural selection is the driving force of evolution — because it isn't.

http://discoverma...volution

anonymous_9001
5 / 5 (3) Feb 20, 2014
Molecular evolutionary biologist Masatoshi Nei says Darwin never proved natural selection is the driving force of evolution — because it isn't.


THE driving force of evolution, not A driving force of evolution. Just as Shapiro and Noble did, Nei is saying natural selection isn't the ONLY thing driving evolution. The relative contribution is up for debate, but none of them deny it happens at all.
Captain Stumpy
5 / 5 (2) Feb 20, 2014
DOES your model make any changes to the nucleotide sequence of the genome of an organism, virus, or extrachromosomal genetic element?
This is a yes or no answer


YES!

--Thanks for asking

@jvk
I edited here because there should be a FULL STOP
THERE IS NO REASON TO GO ANY FURTHER!

IF your models show changes to the nucleotide sequence of the genome of an organism, virus, or extrachromosomal genetic element
THEN they show MUTATION

END OF STORY
you dont have to add anything more
I don't care what you think should be considered in the context of MUTATIONS unless you can explain HOW they alter the course of evolution in species from microbes to man

in this you are WRONG
YOUR MODEL CAUSES MUTATIONS

therefore YOUR MODEL SUPPORTS EVOLUTION

the HOW is irrelevant to the question
I have said from the first time I ever met you that your model causes MUTATION and therefore it is a part of evolution
PERIOD
END OF STORY

BTW- this is pretty much the same thing that Myers argued as well. Your model is a functional part of evolution, NOT a replacement.
It adds/supports the theory
PERIOD
JVK
1 / 5 (2) Feb 20, 2014
Embryonic Cerebrospinal Fluid Nanovesicles Carry Evolutionarily Conserved Molecules and Promote Neural Stem Cell Amplification http://dx.doi.org....0088810

The conserved molecular mechanisms of nutrient-dependent pheromone-controlled socio-cognitive niche construction would not be possible without biophysical constraints that are exemplified in the link above, which shows the conserved molecular mechanisms enable differentiation of cell types in rats and humans.

Anyone who thinks mutation-driven evolution explains how we evolved from rats should try to explain it to others who have been convinced by PZ Myers or Masatoshi Nei that constraint-breaking mutations best explain our evolution -- not ecological adaptations.
Captain Stumpy
5 / 5 (1) Feb 20, 2014
@jvk
one last thing that you cannot seem to comprehend that I will reiterate
RealScience said it best, so I will use his quote:
No one here has argued against factors in addition to mutations being involved in adaptation.
That other factors are sometimes involved does NOT mean that mutations are never involved.

THAT is why I have used the same argument over and over...
your models cause mutations
your models are just more empirical data supporting evolution
PERIOD

there is NO NEED for discussion past this point because all it does is make it look like you cant comprehend basic English!

it also makes it look like you cant comprehend the basic jargon of your own field!

my argument has always essentially been that the jargon in your field uses a specific term for changes to the nucleotide sequence of the genome of an organism, virus, or extrachromosomal genetic element: that term is MUTATION

THERE IS NO NEED FOR FURTHER DEBATE AFTER THAT

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