Deep Thoughts: By Bugwitch

There’s been a lot of talk tonight about the “debate” between Bill Nye and Ken Ham.  Some attempt to be the placating middle man by saying both raised valid points and we should all just learn to get along.  Sorry, but the stated topic of the debate, “Is creation a viable model of origins in today’s modern, scientific era?” has a very simple answer; at least in regard to how Ham views creationism.  Nye was very good about qualifying his statements by saying “Ken’s creation model” or similar because he knows that Ham doesn’t represent all creationists.  If you are one of those who thinks similarly to Ham, that humans and dinosaurs coexisted and the planet is only around 10,000 years old with all modern live springing from the 7000 “kinds” which were on the ark 4000 years ago then NO, your model does not fit with a modern scientific era.

Not all creationists believe the same as Ham.  There are even a select few out there who would accept evolution in the same manner as modern scientists only with the added notion that God gave it a push in the beginning and then everything took off from there.  I say select few because this is not the same thing as Intelligent Design.  ID lies somewhere closer to Ham’s notion, only with a little more leeway for actual science.  The acceptance of evolution and natural selection does not preclude one from believing in a deity.  It should preclude you from a fundamentalist interpretation of whatever belief system you have.  “Nothing in biology makes sense except in the light of evolution” are some pretty famous words spoken by a devout Catholic scientist.

I have absolutely NO problem with theology being taught in schools, public or private.  However they should be taught in the context of a theology class, not a science class.  Theology is a very fascinating field and happens to be one of my favorites.  But it does not belong in a science classroom.  Period.

Some parting thoughts regarding those who think like Ham I’ll put it simply for you: To believe the Earth is only a few thousand years old is to deny every branch of science. You must deny and reject all of the scientific understandings and advancements based on clear and objective observation, experimentation, and analysis. Therefore you can no longer accept the treatment recommendations made by your doctor; nor undergo surgery for any medical condition. All of these things are based on reasoning which you find invalid.

 

 

Bizarre Mimicry in Nature

I was just referred to an interesting post on the absolutely amazing blog Why Evolution is True (seriously, check them out).  The post is a somewhat old one regarding possible mimicry in a moth species found in Malaysia and Borneo.  According to the post, some entomologists look at this and see….well, you look first, think about what you see and then highlight my “…” text below the image.

 

“…The researchers debated back and forth and have determined they believe those are two flies flying towards bird droppings…”

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(Spoilers Below)

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Bird dropping moths are not a new idea (just Google it, you’ll find a number of species) but this idea that it is two flies on the forewings going towards the droppings is a new one on many.  What’s also interesting about this case is that the researchers associate an odor with the moth.  Stinky moth!

It’s a very interesting idea and one that shouldn’t be dismissed right off hand.  It also shouldn’t be accepted right off hand.  A few of us who first looked at the image saw beetles, not flies.  And what evolutionary occurrences would have take place in order for such an adaptation to arise?  We don’t know.  I encourage you all to check out the post and subscribe to their blog too.  It’s a hoot.  See below for my comment on their post.

 

Comments: Bugwitch

There are hundreds of chemical compounds/scents emitted by a decomposing human (or other species) corpse.  Not every odor attracts a fly and not every species is attracted/repelled by such odors.  If we go with the hypothesis that this is an adaptive mechanism that results in fooling potential predators, such predators could:

A) smell it and think it’s rotten,
B) see it is something which is attractive to flies and therefore not of food-value

Eyespots are normally on the outer portions of wings and serve to distract predators from the main dish (their body) and instead result in getting nibbled on the wing tips which can result in higher survival rates for the butterfly.

I personally don’t see flies and I have to *really* look to “see” flies.  I see beetles more immediately, as others have mentioned.  Just going by general size and shape.  And just because you can’t think of a beetle species with a red head just remember…400,000 species of beetles.

All too often we entomologists (and my fellow wannabees) want really-super-duper-hard to find something and then we eventually see it.  I’m not saying that’s what this is; but confirmation bias is something we all need to be wary of.  Does it look like a type of mimicry?  Yeah, sure.  Especially with the odor association.  But as all of my fellow graduate students like to say when we end our presentations: More research is required.

A bird! A plane! A…moth that’s a spider? Whaaaaa?????

If you check out THIS link, you’ll see a pretty interesting example of mimicry…or is it?  This moth is a member of the family Crambidae, a very large group of insects which includes a quite a lot of diversity in both form and function.  Siamusotima

Lygodium Fern Food source for caterpillar stage.

aranea has been dubbed the “Lygodium Spider Moth”.  It’s not the Lygodium that’s the interesting part of this little guys name…nope, it eats the Lygodium fern.  That makes sense.  It’s not the moth part so it must be the “Spider” part!  Yes, there are some that look at this moth and see a spider.  What do you think?

At first glance it can be quite convincing.  The patterning on the wings while in resting pose gives it that creepy spider vibe, right?  But is it really a mimic?  Mimicry has been called “…the greatest post-Darwinian application of natural selection.” (Fisher, 1930)  And it truly is!  Organism ‘A’ looks like something that you don’t want to eat…you don’t eat it…it survives and procreates, making more things that look like something you don’t want to eat!  Crazy, I know.  But that’s what natural selection is.  Organisms which have traits that lead to it and its offspring being more likely to survive to make more offspring is natural selection.  Do that enough times and you have evolution of a new species.

So we all agree, mimicry is cool, right?  But when is a mimic really a mimic?  The Viceroy Butterfly is generally agreed to be a mimic of the Monarch Butterfly.  Everyone loves the Monarch so they must love the Viceroy too…I wonder how many amateur butterfly nuts have Viceroy’s in their collections mislabeled as Monarchs…but I digress…again.  Looking at the image below, we can easily see how these two butterflies are similar.  In order for mimicry to be an actual “thing” observed in the organism there has to be evolutionary pressure that leads to its occurrence.  The Viceroy and Monarchs survive because they feed on plants that have chemicals that pool up inside the insects which makes them unpalatable to their predators.  Look alike, eat nasty food, taste nasty, predators get the message to not eat them.  Environmental events/pressure cause traits in better adapted individuals to be more likely to survive, so they do..

Monarch Butterfly | Viceroy Butterfly The Viceroy was once believed to be an example of Batesian Mimicry (non-toxic to the Monarch’s toxic) but it has recently been observed that the Viceroy is also unpalatable. This qualifies the relationship as Mullerian mimicry.

How can that sort of idea be translated into a moth coming to look like a spider?  There’s really not enough information yet to make a determination.  Some ideas I have rolling around in my head include:  Spiders are predators so perhaps it discourages other small arthropod predators from wanting to eat the moth…but that probably would do nothing to prevent larger invertebrates or vertebrates (lizards, birds, etc) from wanting to eat them.  As I am not familiar with habitat in which this insect evolved I simply cannot say what pressures there have been which could lead to this.

For the moment, I remain skeptical if this is really mimicry or not.  It could just be another instance of humans getting a little excited about cute fuzzy creatures.

Lygodium Spider Moth (Siamusotima aranea, Musotiminae, Crambidae)
http://www.flickr.com/photos/itchydogimages/8537550359/

For more information on mimicry and natural selection, check out these two sources:

Insect Mimicry

Mathematizing Darwin