Male crickets attract females with their chirping, but some males are incapable of chirping. Now, new research shows that those silent males are affected by their singing comrades. Specifically, silent males that develop in the presence of abundant male song tend to be larger, with more reproductive potential, than male crickets growing up in a silent environment. Insects are more complicated than thought. As one researcher explained:people often think of insects, especially the non-social insects, as mindless automatons, pre-programmed to carry out simple procedures throughout their lives
Of course, after all they simply happened to evolve.
Our research shows quite the opposite, and demonstrates how even small, inconspicuous animals respond to the vagaries of their social environment by capitalizing on conspicuous signals that are intended for a different receiver.
So now we know that a blind mutation made the crickets sensitive to the songs in their environment. And another blind mutation connected that sensitivity to increased growth and reproductive potential. This research demonstrates the power of evolutionary change.
ReplyDelete"people often think of insects, especially the non-social insects, as mindless automatons, pre-programmed to carry out simple procedures throughout their lives"
Of course, after all they simply happened to evolve.
Non sequitur. Why should evolution only produce mindless automatons? Such a claim demonstrates a jaw-dropping misunderstanding of the theory of evolution.
Epic fail.
Come on, Cornelius. Even YOU can do better than that.
The idea that a complex phenotype might have arisen by way of a single mutation does seem improbable.
ReplyDeletePerhaps that is not the most apposite hypothesis.
False expectations, indeed.
ZOMG IT'S SOOOOOOOO COMPLICATED!!
ReplyDeleteI don't understand how it evolved SO IT MUST BE DESIGNED!!!!
Why won't you evo meanies take my PERSONAL INCREDULITY as evidence?????
...sheeesh.
Thorton,
ReplyDeleteThe problem is that the theory of evolution hasn't explained much about anything actually evolving in the real world... if one is to expect more than hand-waving generalizations and assumptions grounded on other assumptions.
It's sooooooo complicated therefore lets appeal to the magical box called "natural selection" where anything can happen... just keep a designer out of the conversation because we are doing real science with this natural selection stuff.
Evolution is great at rhetoric and taking ignorance to some kind of moral high ground. Its been a great run taking ignorance and putting the onus on the skeptics to prove that it couldn't happen. The masses are catching on to the game. The emperor is naked.
Cornelius, I am beginning to suspect that you are simply mocking creationists. It seems like you randomly pick science articles, assert that they in some way refute evolution, and sit back in your arm chair and have a chuckle at the expense of the ignorant (though probably well-meaning) individuals who try to defend your baseless and ridiculous assertions.
ReplyDeleteIf this is the case you should be ashamed of yourself.
And if it isn't the case, you should still be ashamed of yourself.
Neal Tedford: "The problem is that the theory of evolution hasn't explained much about anything actually evolving in the real world... if one is to expect more than hand-waving generalizations and assumptions grounded on other assumptions."
ReplyDeleteRight. That's why hundreds of thousands of professional biologists, geneticists, paleontologists, botanists, etc. go to work every day in thousands of top level colleges, universities, and bio-tech companies and sit around all day playing tiddly-winks. Because there's nothing to evolutionary theory.
NT: "It's sooooooo complicated therefore lets appeal to the magical box called "natural selection" where anything can happen... just keep a designer out of the conversation because we are doing real science with this natural selection stuff.
Yeah, much better to use ID 'theory':
"An unknown Designer at an unknown place and unknown time using unknown materials with an unknown process and for unknown reasons manufactured this".
..and you guys still wonder why you get laughed at.
"So now we know that a blind mutation made the crickets sensitive to the songs in their environment."
ReplyDeleteA blind mutation? What mutations 'see'? How many times does it have to be stated--that it has been empirically observed--that natural selection, acting on genetic random variation produces complex features. The variation is 'blind' I suppose, but the products of selection are anything but.
BTW, here's a webpage on the 'silent' crickets. Their silence allows them to escape predation. Apparently, the females will still mate with them. It maybe less efficient than singing, but if the options are silent and some mating vs singing and death, guess which wins? Oh, and the mutation seems to be a single X-linked gene. Excellent study of evolution in action.
http://evolution.berkeley.edu/evolibrary/news/061201_quietcrickets
I'm not sure what the pathway is in this case, but there is considerable literature in plasticity, and impact of competition on phenotype regarding in mating strategy in insects:
http://www.ncbi.nlm.nih.gov/sites/entrez
search: silent cricket
Essentially, an abundance of song means the crickets are going to have to fight it out for a mate. Apparently, this conditions them to larger, more competitive phenotypes. Considering the females respond hormonally to song, are we shocked juvenile males might also?
BTW, crickets aren't quite the genetic organism, that Drosophila is.
Here are some single genes contributing to the control of complex mating behavior in them. Oh, and in some cases, 'blind' mutations lead to adaptive changes:
Control of sexual differentiation and behavior by the doublesex gene in Drosophila melanogaster.
http://www.ncbi.nlm.nih.gov/pubmed/20305646
Shaping of Drosophila male courtship posture by a gustatory pheromone.
"The fruitless (fru) gene plays a pivotal role in the generation of male-typical courtship behavior by instructing the formation of the central circuitry underlying this behavior during development. The fru gene expression can be monitored by a reporter, fruNP21, that labels approximately 800 neurons in the adult male brain. Among these fru-expressing neurons, a male-specific neural cluster called P1 initiated male-typical courtship behavior; when the P1 cluster was ectopically produced in the female brain, many such females displayed male-typical courtship behavior toward a target female"
http://www.ncbi.nlm.nih.gov/pubmed/19686184
Rapid evolution of sex pheromone-producing enzyme expression in Drosophila.
http://www.ncbi.nlm.nih.gov/pubmed/19652700
"While the evolution of chemical communication has been suggested to cause sexual isolation and speciation, the mechanisms that govern evolutionary transitions in sex pheromone production are poorly understood. Here, we decipher the molecular mechanisms underlying the rapid evolution in the expression of a gene involved in sex pheromone production in Drosophilid flies."
"The Drosophila TRPA channel, Painless, regulates sexual receptivity in virgin females."
http://www.ncbi.nlm.nih.gov/pubmed/19531155
"Compared with wild-type females, pain mutant females copulated with wild-type males significantly earlier. Wild-type males showed comparable courtship latency and courtship index toward wild-type and pain mutant females. Therefore, the early copulation observed in wild-type male and pain mutant female pairs is the result of enhanced sexual receptivity in pain mutant females. Involvement of pain in enhanced female sexual receptivity was confirmed by rescue experiments in which expression of a pain transgene in a pain mutant background restored the female sexual receptivity to the wild-type level. "
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ReplyDeleteBut if singing crickets are more likely to get eaten, how did singing evolve?
ReplyDeletenatschuster: "But if singing crickets are more likely to get eaten, how did singing evolve? "
ReplyDeleteThe increased probability of finding a mate due to singing is worth more than the cost/increased risk of being eaten. It's a net gain in evolutionary fitness.
"But if singing crickets are more likely to get eaten, how did singing evolve?"
ReplyDeleteIn this case, the Hawaiian crickets evolved without the fly/maggot predator. The predator was accidentally introduced into the environment, and wam, evolution in action.
See here: http://evolution.berkeley.edu/evolibrary/news/061201_quietcrickets
But that's another case of the loss of something that has a side benefit.
ReplyDeletenatsch-
ReplyDeleteNot all evolution is about gain. Sometime losing a song, losing coloration, sticklebacks losing spines, or humans losing hair ends up beneficial.
As long as the phenotype enhances survival, the pathway matters little. I know you like this for the creationist 'genetic entropy' logic, but biologists also directly observe plenty of gain-of-function contributions to evolution.
Above, I listed several gain-of-function mutations affecting behavior in insects.
It seesm to me that the first two show male behavior in females. I don't think thatthis would be helpful. The third talks about differences in different existing species that exist now. The differences duoto evolution are assumed to have happened. The forth seems to be trivial change in the timing of mating.
ReplyDelete"The differences due to evolution are assumed to have happened."
ReplyDeleteOr rather, evolution is the best explanation for the observed differences.
You can always argue the difference in sequence between two modern organisms is not a mutation from a common ancestor, but rather the interference of a designer that changes a few bases that make it look evolved (not along with the meaningful changes, we find drift- changes to the DNA that yield the same amino acid, changes to similar amino acids without change of function, etc.
But that is an untestable, unfalsifiable hypothesis. There is no detection of design.
At any rate, you asked for gain-of-information mutations. The papers provide a number of inferred gain-of-function mutations.