Any ideas why you get blue tarantulas? or tarantulas with 'horns'?

[Anoplogaster]

Uh oh.... the poison/venom debate again

 

[viper69]

Uh oh.... the poison/venom debate again

Nah, there's no real debate here. No one knows why some Ts are blue, and some aren't. I HIGHLY doubt it's due to them having venom, particularly as they are food for everything else.

 

[Ungoliant]

I want a sweater made of tarantula setae.

Urticating setae would put a whole new spin on the hairshirt as penance.

 

[Anoplogaster]

They're hoping that they can use this study to color our goods instead of using toxic (hehe) pigments.

I want a sweater made of tarantula setae. Or a replica of the setae, at least.

That would be a terrible sweater

 

[awiec]

Blue is a weird color, many animals can't see it and some suggest that humans have recently evovled the ability to see it less than 20000 years ago. Granted this theory is based off color use in art, blue isn't a common color in the first place so it simply could be a lack of blue pigment source for people to use. But still many animals can't see blue, so having this odd color could let one blend in.

Of course I feel like I say it every time in these threads, but just because something is present doesn't mean it has a purpose. Many traits get dragged along because they aren't harmful to the organism but not selected upon by evolution. This doesn't mean that horns and blue colors don't do anything but it's not sure thing if they do something.

 

[HybridReplicate]

I want a sweater made of tarantula setae.

Cruella de Vil much?

 

[Abyss]

Obviously these features are part of a complex evolutionary process designed to make them more appealing to collectors. The prettiest or most unusual tarantulas will be welcomed into our homes, protected from predators, and served a lifetime supply of food. They are practically waited on, pedipalp and foot, with willing servants who cater to their every need, even procuring mates for them. With no need to concern themselves with basic survival, they are free to plot the next steps toward their ultimate goal of world domination.

Or it could actually help them to blend in to their natural environment, as suggested here: http://www.livescience.com/52945-blue-tarantula-color-mystery.html

Gotta trust this is the most valid answer of all

 

[runCMD]

Some new research was recently published. I've yet to read the actual paper, but here is the report of it.
http://newatlas.com/blue-tarantula-iridescence/47828/

EDIT: I found a pretty good excerpt from the full article. Gives a decent idea of what's happening.
http://www.frogheart.ca/?tag=tarantula-inspired-noniridescent-photonics-with-long-range-order

very interesting read, thanks!

 

[viper69]

Many traits get dragged along because they aren't harmful to the organism but not selected upon by evolution.

True indeed, makes you wonder on the blue though, because it evolved independently in Ts 8 different times through its history.

 

[awiec]

True indeed, makes you wonder on the blue though, because it evolved independently in Ts 8 different times through its history.

Mother nature uses the same ideas many times all across the animal kingdom. Also tarantulas kinda have a small genepool to derive variation from, especially aboreals, so having a trait pop up multiple times is not uncommon.

 

[viper69]

Mother nature uses the same ideas many times all across the animal kingdom. Also tarantulas kinda have a small genepool to derive variation from, especially aboreals, so having a trait pop up multiple times is not uncommon.

I really don't think Ts that are obviously blue, such as a GBB, arose independently by chance. 8 independent events is impressive to me, though I'm not a geneticist. More surprising is that it's the color blue, the more rare color in nature as we know.

You know even human culture blue is rare oddly. For example, I read an article which found that in all cultures surveyed (and it was A LOT), of all colors in the visible spectrum, blue was the last color for which a word was developed in all the cultures for the visible spectrum, interesting stuff!

 

[awiec]

I really don't think Ts that are obviously blue, such as a GBB, arose independently by chance. 8 independent events is impressive to me, though I'm not a geneticist. More surprising is that it's the color blue, the more rare color in nature as we know.

You know even human culture blue is rare oddly. For example, I read an article which found that in all cultures surveyed (and it was A LOT), of all colors in the visible spectrum, blue was the last color for which a word was developed in all the cultures for the visible spectrum, interesting stuff!

I work with plants amd right off the top of my head, plants that have a special form of photosynthesis called c4 (maize is the poster child for it) has evovled separatly 67 times with 4 different subtypes across drastically different genera and this is a trait that was actually selected for. Though I feel the blue color is a good camouflage though I certainly can't prove it. As for the horns, I find that to be more likely to be something that got dragged along.

 

[Crone Returns]

True indeed, makes you wonder on the blue though, because it evolved independently in Ts 8 different times through its history.

Do you have a link for that? It'll make great reading.

 

[BorisTheSpider]

Here's a theory :

Sometime in the past two tarantulas , let's say light grey just for the sake of argument , mated and produced a sack . Let's suppose that they both by chance shared a similar imperfection in their genetic code . When combined that imperfection caused a full blown mutation and the slings came out blueish instead of grayish like their parents . For whatever reason that blue coloration gave them an advantage over their grayish predecessors . Therefore more made it to adulthood and produced more blueish slings . Over time the grayish colored Ts die out and are replaced by the new blueish colored ones . I believe that evolution doesn't happen slowly over millennia but instead it happens quickly over a few generations . Nature favors those that have advantages and turns her back on those that don't . Just look at the Peppered Moth . Someone opened up a factory that drenched the trees in the moth's habitat with black soot . The normally grey moths vanished almost over night and a new black color form appeared . This happened in the span of just a few decades .

 

[viper69]

Do you have a link for that? It'll make great reading.

My friends at Google do The paper is from a group out of Akron, Ohio. Believe the first author has an Asian name. It's the easiest T paper to find.

 

[viper69]

I believe that evolution doesn't happen slowly over millennia but instead it happens quickly over a few generations

Except science tells us it happens over a long time

 

[Crone Returns]

My friends at Google do The paper is from a group out of Akron, Ohio. Believe the first author has an Asian name. It's the easiest T paper to find.

Grrrr.

 

[awiec]

Except science tells us it happens over a long time

There are some exceptions to the rule but for the most part but viper is correct, the change in population allele frequencies (ie evoluation) usually is the result of selection on said population over generations. An allele can be any where on the spectrum of no selection to intense selection for or against, all depends on the environment. Now in my job we work with a leaf blight called Cercospora beticola, and that things has gained resistance to several main classes of fungicides in the past 6-7 years due to A) intense selection pressure in the form of spraying B) a lucky mutation that imparts resistance, C) this is a cyclic disease and is releasing new spores every two-three weeks during the season and D) it sexually reproduces. This is the ultimate recipe for evolution as you have gene recombination, a very intense selection pressure, genetic variation to select from and fast generation times. Viruses, insects,plants and fungi can evolve much faster than us mostly due to their fast generation times, it literally can happen right in front of your eyes. Though in the case of tarantulas, I think they are more in the same boat as us when it comes to evolution, they have been around way longer than we have and have gone through several major extinctions that may have narrowed their gene pool considerably in the process or eliminate/create some selection pressures in the process.

 

[Crone Returns]

There are some exceptions to the rule but for the most part but viper is correct, the change in population allele frequencies (ie evoluation) usually is the result of selection on said population over generations. An allele can be any where on the spectrum of no selection to intense selection for or against, all depends on the environment. Now in my job we work with a leaf blight called Cercospora beticola, and that things has gained resistance to several main classes of fungicides in the past 6-7 years due to A) intense selection pressure in the form of spraying B) a lucky mutation that imparts resistance, C) this is a cyclic disease and is releasing new spores every two-three weeks during the season and D) it sexually reproduces. This is the ultimate recipe for evolution as you have gene recombination, a very intense selection pressure, genetic variation to select from and fast generation times. Viruses, insects,plants and fungi can evolve much faster than us mostly due to their fast generation times, it literally can happen right in front of your eyes. Though in the case of tarantulas, I think they are more in the same boat as us when it comes to evolution, they have been around way longer than we have and have gone through several major extinctions that may have narrowed their gene pool considerably in the process or eliminate/create some selection pressures in the process.

When did they go through major extinctions and why? I'd love to read about that.

 

[awiec]

When did they go through major extinctions and why? I'd love to read about that.

Tarantulas have been kicking around for at least 200 million years, in that time several extinction events have happened on Earth, so it isn't unreasonable to assume that spiders had some pressure on them too. As to why, couldn't really tell you, we still don't even know why the dinosaurs died (K-2 extinction).