
Are Butterflies Two Different Animals in One? - nreece
http://www.npr.org/blogs/krulwich/2012/08/01/157718428/are-butterflies-two-different-animals-in-one-the-death-and-resurrection-theory
======
gus_massa
This was submitted a few month ago (4 points, 3 comments):
<http://news.ycombinator.com/item?id=4334906>

I will quote a comment that I made that time (beacuse I don't want to write
the same thing again):

 _This article doesn't have any scientific base._

 _Insect have exoskeleton so they can't grow like ducks or bats. They have to
make a series of metamorphosis to grow. Usually the form for change from one
stage to the next step, because they are adapted to different lifestyle.
See:[http://en.wikipedia.org/wiki/Metamorphosis#Insect_metamorpho...](http://en.wikipedia.org/wiki/Metamorphosis#Insect_metamorpho..).
._

 _Butterflies are one of the most well known and extremes cases of changes.
The caterpillar shape is adapted to eat a lot and be camouflaged, the
butterfly shape is adapted to travel and mate. (Both shapes share the same
general blueprint. For example, if you see a caterpillar carefully, it has
only 6 small real legs in the front, and some prolegs in the back.)_

~~~
bennysaurus
It's an intriguing idea though if nothing else. A question here (I don't know
your background if it's biology mind you): what actually happens in the
metamorphosis between caterpillar and butterfly/moth or any larval animal for
that matter?

It does seem rather radical to switch off a massive amount of genes and switch
on a bunch of others in adulthood, drastically changing your physical form.

~~~
robbiep
I don't know exactly what happens but apparently they mostly turn to mush then
reassemble. Interestingly their nervous system/memories have been shown to
survive between the different stages.

Re genes turned off: as another poster mentioned huge numbers Of genes are
switched off and on at different stages in our life cycle. It's kind of the
same as saying 'but neurone don't need the same genes as skin cells so isn't
it wasteful having all those extra genes doing nothing?' DNA is relatively
cheap so while some 'skin' genes may never Be used in 'neuron' cells the cost
is not prohibitive To the organism.

Http://bit.ly/VNYxx2 (a link to livescience.com - apologies am moving between
different devices, blocked HN on my mac!)

~~~
polyfractal
A lot of insects have a fully intact, if immature, nervous system during their
adolescence. For example, fruit flies (drosophilla) have brain features called
"mushroom bodies". These grow during larval development then hit a state of
hibernation until the larva changes into an adult fly, at which point growth
continues and the mushroom body fully develops.

I'm not familiar with a lot of other insects, but I believe it is fairly
common for the bulk of structures to form, hibernate, and then finish growing
during metamorphosis.

------
georgecmu
DNA transfer in higher life forms occurs far more frequently than the
geneticists of 60 years ago could have suspected.

 _Astonishingly, only 1.5% of the genetic material in our cells codes for
human life. Half of the rest is sometimes described as "junk DNA" with no
known function, and the other half consist of genes introduced by viruses and
other parasites._

[<http://www.bbc.co.uk/news/science-environment-17809503>]

~~~
a_bonobo
The term "junk DNA" is not used in science anymore, much of it is repetitive
regions that serve regulatory functions, or other unknown reasons. "Junk" DNA
has been renamed to "noncoding DNA", the recent ENCODE-project stated that 80%
of human DNA has some purpose. See:
<https://www.sciencemag.org/content/337/6099/1159>

P.S.: That article reads like the ENCODE-project killed the term "junk DNA",
however, that term wasn't in use before the release of ENCODE, either.

------
sswezey
This is eerily similar to the biology on the planet of Lusitania in the
Ender's Game series book 'Xenocide' in which every remaining species has a two
part life cycle which is the result of an virus's effect on two previously
separate species. They start as one form, die and are reborn into another
form.

~~~
Uhhrrr
Bit of a spoiler for the previous novel in the series, that.

~~~
sswezey
Ah, I'm sorry, I completely forgot about spoiling it given it being so old.
Too bad HN doesn't have spoiler tags :(

------
jamesjporter
This is extremely silly. Genes that act in larval, pupal, and adult
development are all mixed up together in the same chromosomes; there's no
plausible way for them to have integrated in the manner suggested. Moreover,
the same genes and used and reused again and again in different contexts in
insect development. Again, this is absurdly unlikely under the scenario he
proposes.

~~~
robbiep
I agree that it is extremely silly, however what you suggest about the genes
being all mixed up in the same chromosomes as disproving it I don't buy..

I'm not sure if you've ever seen chromosome maps showing gene locations on
chromosomes between different species but this is instructive in this matter:
between species and thus, as numbers of chromosomes flux up and downwards, the
genes which may have started in one chromosome end up spread throughout many-

I am sure you will find the following links interesting

Background: on chromosome rearrangement:
[http://scienceblogs.com/pharyngula/2008/04/21/basics-how-
can...](http://scienceblogs.com/pharyngula/2008/04/21/basics-how-can-
chromosome-numb/)

Synteny map - cool explination
[http://scienceblogs.com/pharyngula/2006/06/08/pufferfish-
and...](http://scienceblogs.com/pharyngula/2006/06/08/pufferfish-and-
ancestral-genom/)

mouse human synteny map <http://www.mun.ca/biology/scarr/MGA2-11-33smc.html>

~~~
jamesjporter
Yes, to some extent genes are mobile and do get shuffled around, but if this
hypothesis were true, it would be obvious. Whole genomes don't just merge on
the time scales we're talking here. If this hypothesis were true, there would
be clear genomic anomalies indicating it (e.g. biases of genes used at the
same developmental stage tending to cluster in similar genomic regions); no
such anomalies have been found.

------
rcthompson
One way I've heard it described is that the caterpillar effectively develops
an organ that is analagous to an egg from which the butterfly hatches. Then
the rest of the caterpillar's body becomes food for the newly-hatched
bufferfly. This all occurs inside the chrysalis so that we are spared from
witnessing the carnage.

I have no idea if this is a valid way of looking at it or not, but it's one
explanation that I've heard. The appealing part about this is when you realize
that some wasps lay their eggs inside other insects, which then become food
for the wasp larvae in the same way that the caterpillar's body is supposed to
become food for the butterfly.

------
scotty79
Mating between two different speciecs? Rather carying over significant dna of
the host inside the parasite that grew out of it.

There are a lot of the winged insects that lay egs inside other insects. Maybe
some freakish viral infection long time ago carried over lots of dna of the
host into the parasite egg.

It's still insane but at least it's imaginable.

~~~
adekok
IIRC, from an article long ago in New Scientist, there are precedents for this
in small marine animals. i.e. plankton or hydras. The "adult" form grows
inside of the "larval" form. And then breaks out, fully formed. The "larval"
form continues as a separate individual for a few days, before dying.

The eggs are then produced by the "adult" form, and the process continues.

It's easier to do with smaller animals. The process is also simpler (grow new
"adult" as a parasite of the "larva"). The caterpillar to butterfly change is
much more complex.

~~~
polyfractal
I suppose you could look at it as a parasitic relationship. But it's actually
much simpler than that. (Hydra are super cool, so allow me to geek out for a
sec)

Basically, every cell in the hydra knows how to become a new hydra. What
prevents a single hydra organism from trying to become a thousand hydras is a
dual chemical gradient. The head emits one chemical, the tail emits another.
Cells respond to this gradient depending on how concentrated it is in one
particular direction

At the "head" end, the "head" chemical is very strong. Those cells respond by
being the "head". At the other end, the "head" chemical is very weak (and the
"tail" very strong). Those cells respond by becoming the appendages.

If you chop a hydra in half, the gradient becomes altered. On one half of the
hydra, there is only "head" chemical diffusing. The other half only has "tail"
chemical. These changes in chemical gradients signal the cells to start
producing the parts of the body that were just lost. Eventually, you end up
with two identical, smaller hydra.

Theoretically, you could keep chopping hydra in half and keep getting
identical, smaller hydra. Obviously you hit a point where you are just going
to kill the poor thing, but in theory it doesn't matter...the hydra will
always be capable of regenerating.

Cool, right!

------
mullingitover
I have a hypothesis of equal scientific merit: Caterpillars are turned into
butterflies by an invisible wizard in the sky.

------
charonn0
_According to this theory, long, long ago, two very different animals, one
destined to be wormy, the other destined to take wing, accidently mated, and
somehow their genes learned to live side-by-side in their descendants._

This is simply rubbish, and demonstrates a fundamental misunderstanding of
genetics.

~~~
Daniel_Newby
No, it is entirely possible. Entire chromosomes could modified, as by
methylation, and the transcription machinery could switch between the two at
the appropriate developmental stage.

What it is is (1) extremely unlikely, and (2) easily checked by looking at the
DNA sequence of any insect that metamorphoses.

~~~
charonn0
The only somewhat similar thing I can think of would be mitochondria, but even
mitochondria retain their own unique DNA outside of the nucleus.

~~~
rcthompson
True, mitochondria contain functional DNA, but the majority of mitochondrial
genes have migrated to the eukaryotic nucleus. The transcripts are transcribed
in the nucleous, translated in the cytosol, and the protein products are
translocated into the mitochondria. There's not necessarily anything
preventing the remainder of the mitochondrial genome from making the same
transition, although perhaps the mitochondrion would still require a
"placeholder" chromosome because its cycle of reproduction is tied in with
replication of that chromosome as it is in bacteria.

------
carbocation
Betteridge's Law of... oh, whatever. Is the fetal human form a different
animal from the adult human form? Different genes are switched on, but this
doesn't mean that the baby growing inside of you is some alien that you're
nurturing that just happens to become an adult human.

Anyway, genetic analysis should make the actual question–if it were a serious
scientific question–answerable: are butterflies the result of some prehistoric
mating between different species? Is the genetic architecture vastly different
between the two sets of genes? Is there evidence of what one or both of these
two progenitor species were, and if so, can we identify the direction of gene
flow and relative contributions?

------
stcredzero
Dissolving into the liquid oblivion of sleep, we are caterpillars to the
butterflies of our next morning's waking selves.

~~~
Luyt
Brrr, reminds me of <http://en.wikipedia.org/wiki/The_Metamorphosis>

(A novel by Franz Kafka, in which a traveling salesman, Gregor Samsa, wakes to
find himself transformed into a monstrous vermin.)

------
dspeyer
Is there any actual evidence that supports this hypothesis?

------
mmanfrin
Biological Ship of Theseus.

------
Camillo
If the headline is a yes/no question, the answer is always no.

------
frozenport
I once smashed two clocks together and a butterfly came out.

