Sticklebacks, Manatees, and Creationists
The other night our local PBS station re-aired a NOVA two-hour special, What Darwin Never Knew. It was pretty cool stuff, and incidentally featured Sean Carroll of UW Madison. I mention that because I want to digress for a moment. I live in Madison and since July of 2009 have been organizing Madison Science Pub. Every month I invite a different UW science professor to come to Brocach Irish Pub on the downtown square and talk about their field to a very interested, attentive, and inquisitive audience. I have an open invitation to Dr. Carroll to come talk, but he always seems to be too busy or something. Yes, yes, I know he runs a lab, and is Vice President for Science Education at the Howard Hughes Medical Institute, teaches, publishes, has a family, etc., etc., but come on, Sean... free beer! There. I've said my piece, back to the matter at hand.
The show was full of great stuff, but I had an authentic "oh wow!" moment about halfway through the program. The scene switched to a lake in British Columbia populated by fish called sticklebacks. Species of sticklebacks in the ocean have "a pair of fins on its belly that are like spikes. They are for defense. The spikes make the stickleback hard to eat," but the lake sticklebacks have lost them.
Researchers David Kingsley and Dolph Schluter wanted to find out how the lake sticklebacks lost their spikes, and went digging through the fish's DNA. "We know these genetic switches exist. But they're still very hard to find," Kingsley said. "We don't have a genetic code that lets us read along the DNA sequence and say, 'There's a switch,' to turn a gene on in a particular place."
(In the show transcript Kingsley is identified with the HHMI. Hey, Kingsley, next time you see Carroll getting something out of the vending machine in the hall, remind him about Science Pub.)
Eventually Kingsley and colleagues found the switch, and sure enough it was mutated and no longer turns on the gene that makes spikes. They believe that this has implications for other more distantly related species and might even explain why manatees lost their legs when they left land for water. (I've developed this habit whenever I hear something like this to immediately wonder what Answers in Genesis has to say on the matter. Keep reading to find out.)
Additionally, the sticklebacks teased the researchers with a tantalizing clue. From the show, "the lake stickleback may have lost its spikes, but evolution has left behind some tiny remnants: the traces of bones. And they are lopsided, bigger on the left than on the right."
"Wouldn't it be amazing if, in fact," Kingsley said, "this classic unevenness is the signature of using the same gene to control hind-limb-loss in incredibly different animals?" Well, the evidence continued to mount, because Kingsley and team then examined "boxes" of manatee bones and found the same left-right lopsided pattern. Manatees have left pelvic bones bigger than their right.
After the show I plugged "sticklebacks manatees limb loss" into Google and started clicking links. The most laydude friendly post I found, unsurprisingly, was on one of my favorite sites, sciencedaily.com, published on June 4, 2009. It's an interesting piece and I highly recommend you read it, but I'll touch on a few points here.
Mike Shapiro, first author on the paper cited in the Science Daily post, said, "We knew that in many cases of evolution, the same gene has been used over and over again - even in different species - to give the same anatomy." But here the story gets more complicated, because, at least according to this post, different genes may be responsible for the spike loss in different species of stickleback. "This is very surprising because these species are fairly closely related," said Shapiro.
What's noted in this piece that was absent from the PBS show is the actual gene responsible for the sticklebacks spikes: Pitx1. Interestingly, in the last paragraph of the post we read, "While the new study shows different genes can control the same trait in two closely related species of sticklebacks, researchers already knew that in some cases, the same gene can control similar traits in distantly related species. Pitx1 controls loss of the pelvis in threespine sticklebacks and is tied to club foot in humans."
In fact, it looks like Pitx1 was suspected even further back then the NOVA show, or the 2009 Science Daily post, because I also found this paper from the April 2004 issue of Nature. Shapiro and his co-authors closed the paper saying, "Many other populations show the same left-right asymmetry that is a characteristic feature of Pitx1-linked pelvic reduction in mice ... Mutations in or closely linked to the Pitx1 locus may contribute
to many other examples of evolutionary reduction of pelvic structures in natural populations, a possibility that can now be tested by further genetic studies and direct analysis of Pitx1 structure and
regulation in multiple populations, species and genera."
So it looks like a pretty compelling case for Pitx1, and regulatory switches related to its expression, being responsible for limb loss in many different species, including manatees. What's interesting after reading up a bit on a topic like this is to search for it on the Answers in Genesis site. The sheer breadth of topics AiG manages to cover is pretty impressive, until you realize that the depth with which they cover them is, well, very unimpressive.
Plugging Pitx1 into AiG's search engine finds an article called "How Manatees Lost Their Legs?" by Dr. Georgia Purdom. After recapping the basics of the research, she states that "[t]he changes in the regulatory region of the gene are thought to be quite 'young' (10,000-20,000 years ago)." Wait, what? I thought that the world was only about 6000 years old! But it's okay; she's just reporting what scientists think. She then adds, "[f]rom a creationist standpoint, this change may have happened as a post-Flood event [after about 2304 BC, that is] when rapid speciation occurred as a result of the drastic changes in environment and predator-prey interactions."
Now prepare yourself for some weapons-grade irony, folks. In the very next section, under the heading "Where's the Evidence," Purdom faults the research for extrapolating the possibility that manatees lost their hind limbs through the same mutation and mechanisms that sticklebacks have in the wild, that have caused club feet in humans, that have caused reduced limbs in lab mice (more in the 2004 Nature paper), because the actual genes in manatees have not yet been sequenced to show the mutations.
There is more research to do, no doubt, but it's more than reasonable after the work the researchers have done so far to think about Pitx1 in other species, including manatees. But for Purdom to make this the central point of her objection to the research after proposing spikeless sticklebacks the result of "a post-Flood event when rapid speciation occurred" is hilarious. If only AiG were held to the same standard for evidence as actual scientists!
If Purdom's main problem with the research is that Shapiro "has not examined the Pitx1 gene in manatees yet," wouldn't this be a golden opportunity for Dr. Purdom, who has a PhD in molecular genetics, to ask Ken Ham for a budget to do the research and show that there is no correlation between Pitx1 and limb loss or reduce pelvis size in manatees? (This is yet another project for the list of unfunded creationist research that I started assembling in my previous post, of course.) I'm sure that Shapiro, Kingsley and a lot of other scientists, would welcome the opportunity to review her published results as she has done theirs.
(This piece is cross-posted to ScienceDenial.com.)
60 Comments
https://www.google.com/accounts/o8/id?id=AItOawnGC16qYMqiY8hAm8pDGruMPBarMrsshhg · 18 January 2012
Interestingly, Pitx1 is also involved in early pituitary patterning and cellular differentiation during embryonic development (at the Rathke's pouch stage) and in the maintenance of anterior pituitary cell identity and function in the mature gland. It's full name is actually "pituitary homeobox-1".
Mary H · 18 January 2012
I am SO GLAD to see Panda'sThumb back up. This is the type of entry I missed. Welcome back "thumb" it is so much easier to "grasp" things with you back in place.
fnxtr · 18 January 2012
I'm stealing a friend's words here:
"This is, like, 27 different kinds of awesome."
Thank you!
DS · 18 January 2012
The No Answers in Genesis reply:
1) They are still fish
2) We don't have to do any actual research. We'll let real scientists do the actual work, then we'll just say that we have "different conclusions". It doesn't matter if our conclusions make any sense or not, it doesn't matter if all of the real experts who actually know what they are talking about say we are wrong, what matters is that we must disagree and make it appear that there is some other interpretation. After all, then kind of people we are trying to convince are not generally going to know the difference, so we can fool everybody and never actually do anything. If anyone objects, we can just call them elitist and claim there is some big conspiracy. Yea that's it, a conspiracy. It doesn't matter if that make s any sense either, the gullible will lap it up.
_Arthur · 18 January 2012
I expect biologists are finding that genes are turned off or regulated in hundreds of different ways, as if Nature was finding ways to regulate and turn off genes entirely by accident...
Science Avenger · 18 January 2012
DS, you forgot "all this proves is that evolution can destroy, but not create, so it really supports ID".
TomS · 18 January 2012
And, "that shows a Common Designer". (Or is that covered by DS's #2, under the provision that it doesn't have to make sense?)
https://me.yahoo.com/a/c5rNlpg124BVj4kCj2yBtmmOk9jw#8caf8 · 18 January 2012
Creationists can't afford to do too much research into rapid speciation. If they don't find any, then their young Earth hypothesis is trashed, but even if they do, then they have to explain why, if there was such rampant and rapid speciation that it transformed a few dozen "kinds" into thousands of highly diverse and widely distributed species in just a few decades, they always claims that mutations and speciation are so terribly hard to come by.
The dirty little secret of creationism is that post-flood evolutionary processes are evolution on a huge dose of steroids -- far beyond anything any credible scientist would claim was possible.
Thaumas · 18 January 2012
Kudos to the author, Skip, for a very sharp observation!
Good find. I will be sure to use this one the next time the opportunity arises.
It's a great example of how evidence-based reasoning (e.g. science) is true because it makes predictions that turn out to be accurate, and how faith-based reasoning (e.g. creationism) is false because when it makes any predictions at all, those predictions turn out to be just wrong.
This is the one test that faith will always fail on: It just doesn't work. Fact.
Doubt me? Let's put it to the test! Just be prepared to admit that you were wrong when it turns out my prediction that "Faith fails" turns out to be accurate (yet again). Not willing to put your faith to the test? Then your faith has failed (to convince us; yet again). Either way: evidence wins; faith fails.
DS · 18 January 2012
DS · 18 January 2012
Let's say that AIG did fund some research. How would they explain the following if they found it:
1) All of the genes required for limb development are present in the Manatee
2) Pitx 1 is present in the manatee but down regulated due to mutations in the promoter or enhancer
3) Pitx 1 is present in the manatee but down regulated due to mutations similar, but not identical, to those found in the sticklebacks
Would these features be due to an incompetent designer who lacked any ability for foresight or planning? Would they be due to an unimaginative designer who only knew one trick and used it indiscriminately? Would they be due to an ignorant designer who couldn't even remember the trick he used on one species? Would they be due to the "fall" of the manatees? How could they rule out the possibility that these adaptive changes could be produced due to random mutations? How could they rule out the role of selection in shaping these adaptive features? How could they explain all of the other example of such things in thousands of different organisms?
Maybe this is the real reason why creationists don't publish anything, even in their own journals. Maybe everything they discover when the actually do some research really supports evolution.
https://me.yahoo.com/a/JxVN0eQFqtmgoY7wC1cZM44ET_iAanxHQmLgYgX_Zhn8#57cad · 18 January 2012
But if Darwin didn't know that, clearly his theory must be false...or something.
After all, Darwin is just the atheist Bible, and evolution the atheist myth.
At least if your mind is too small to imagine something that isn't just a version of creationist myth.
Glen Davidson
ksplawn · 18 January 2012
Robert Byers · 18 January 2012
Several points here.
Finding creatures can change is fine with creationism and like creationists like me a very welcome thing.
I love the sickleback stuff.
I
In fact you are making the case not for random mutations but a single mutation happening everywhere.
I don't accept its a mutation out of the blue but more likely a part of another mechanism process to let creatures adapt.
In fact i don't see why finding a single mutation happening everywhere is welcome to evolutionism.
It seems unlikely to be that random but has purpose.
Yes I'm confident marine mammals were first land creatures who adapted in a post flood world.
Yes we need a mechanism but no not random mutationism.
Finding genetic indicators for change is by the way finding nothing about its origin.
It could only be that biological change is intimately genetic and has a trail.
Finding genetic elements turned off is not finding the origin of why that is so.
They are trying here to make the case for mutations leading to all biological change and the skys the limit on that.
All facts here fit fine with creationist ideas.
DS · 18 January 2012
SA called it.
https://me.yahoo.com/a/c5rNlpg124BVj4kCj2yBtmmOk9jw#8caf8 · 18 January 2012
harold · 18 January 2012
apokryltaros · 18 January 2012
Robert Byers, in your latest mental vomiting, I noticed you again failed to explain why or even how Young Earth Creationism is supposed to be a science magically superior (Evolutionary) Biology.
So, where is all this research you did to prove that manatees were actually land animals that magically transformed themselves into sea animals using magical non-evolutionary hyperevolution over the course of 4000 years?
Oh, wait, no, you've made a complete Idiot for Jesus out of yourself again.
apokryltaros · 18 January 2012
Robert Byers · 19 January 2012
DS · 19 January 2012
Robert,
Take a course in biology. Learn the meaning of the term natural selection. Then come back and explain to us why the same mutation must have occurred in every organism that now possesses it. Until then, take my word for it, you haven't got a clue. Mutations are not a reaction to need. There is a vast literature of elegant experiments that disprove this. You are almost as wrong as you are ignorant.
apokryltaros · 19 January 2012
So, Robert Byers, where in the Bible did it say that whales and all other marine mammals are descended from land-dwelling refugees from Noah's Ark, having magically transmuted themselves into sea-dwelling animals in less than 4,000 years?
Where are the evidence you found and the research you did to support this inane claim of yours?
Otherwise, your so-called "creationist criticism" is childish nonsense.
harold · 19 January 2012
harold · 19 January 2012
DS · 19 January 2012
John_S · 19 January 2012
Michael · 19 January 2012
"In fact you are making the case not for random mutations but a single mutation happening everywhere."
Whenever creationists argue about the chances of such-and-such protein evolving "by chance," they always make the same error that would get marked wrong in an undergrad probability course: they split joint probabilities of events that aren't independent. And yet here you are, talking about a very situation where the events in question (transcription errors in the genes of two different species) has much weaker correlation.
The only way for your claim to make sense at all is to invoke a deity. This is why real scientists, even the religious ones, leave their gods at the door: they are idealizations, crutches like the frictionless pulleys of physics textbooks, useful to simplify concepts at the beginning, but soon failing to adequately explain observed phenomena. Of course, where in physics this results in epicycles, in theology this results in projection, and the people lose the ability to distinguish between themselves and their gods.
Oh, my. How did that become a rant? I guess I get a little overprotective of math.
Robert Byers · 20 January 2012
Robert Byers · 20 January 2012
ogremk5 · 20 January 2012
Robert, 5 words:
Whale
Fossils
In
The
Desert
Those 5 words disprove all of your notions. Unless you invoke multiple miracles. That is the only recourse you have to any actual science is to require multiple miracles.
BTW: If you have no interest in math and think that it doesn't apply to Biology, then I would encourage you to answer this question without math: What is the percentage chance of an offspring being homozygous for a particular allele if both parents are heterozygous. That's 7th grade stuff... just wait until you get to actual science (ever heard of statistics?).
xubist · 20 January 2012
DS · 20 January 2012
ksplawn · 21 January 2012
apokryltaros · 22 January 2012
Scott F · 22 January 2012
Scott F · 22 January 2012
Robert Byers · 23 January 2012
Robert Byers · 23 January 2012
Robert Byers · 23 January 2012
Dave Lovell · 23 January 2012
DS · 23 January 2012
Mike Elzinga · 24 January 2012
Statistics is used a lot in biology. Comparing experimental groups against control groups is stuff that 9th graders begin to do in the lab portions of their biology classes. That requires using various statistical tests and understanding what they mean. And many of these kids take statistics either in the form the Advanced Placement statistics courses or as part of their Integrated Math courses.
In either case, the mathematical methods are usually taught as part of the biology course.
Man, the trolls that hang out here seem to be some of the stupidest people on this planet. They not only don’t know what most high school students learn, they all seemed to have stopped learning somewhere before middle school. It’s as though most of these trolls have dropped out before ever getting to high school; yet they think they can make expert claims about science and what should or should not be taught.
Dave Luckett · 24 January 2012
A sudden great Earth upheaval, a few centuries after the Flood, eh?
Which would put it at around 2300 BCE, right?
Byers, I know you don't know this, and you don't want to know this, but there isn't any possible way that could happen and not leave marks that could be easily be seen now. The Sahara Desert, which is where not one, not two, but generations of basilosaurus whale fossils have been found, could not possibly be a sea four thousand years ago and bone-dry now. It can't happen.
There was a major literate civilisation building large monuments right by there, right then, and that civilisation never noticed, never even considered, the existence of a wide open sea a hundred miles to their west? What are you, crazy? (Why do I ask such questions? Of course you're crazy!)
All Egyptian legends, stories, knowledge about the land to their west emphasised that it was a stark, waterless, lifeless desert. "To go west" was to die. Nothing came out of that empty waste but dust and wind. There was no sea there then, nor at any time in human history.
And the Egyptians never noticed this "great Earth upheaval", either, sez you. The land rose out of this sea, and they never even realised it was happening. Their great buildings remained intact while cataclysmic tectonic events, with upthrust on a time-scale unheard-of today, were happening a few hundred miles away. Earthquakes that would have made the last Japanese shift and tsunami - over eight on the Richter at point of origin - look like a minor twitch, were happening every couple of days for a century, and nobody took any notice? Oh, come on!
On the same scale, the Thera explosion of around 1570 BCE would be like popping a zit, but its effects can be clearly read on Minoan civilisation. A little digging on Thera itself turns up a whole shattered city, ruined, destroyed, never resettled. Thebes or Luxor would have been hit much worse by this "great Earth upheaval". Were they? Why, no, they weren't. The archeology of both cities testify to thousands of years of almost completely peaceful continuous occupation.
You're nuts, Byers. You're barking, gurgling, rolling-eyed, drooling, foaming at the mouth, wetting your pants doolalli. You're insane. I've found you occasionally entertaining in the past - but that is now, for me, overlaid with the shame of realising that in the eighteenth century people went to Bedlam Hospital to be amused by the mad, and I am doing the same. I am ashamed of myself for that.
ogremk5 · 25 January 2012
First, Byers, thanks more making me look up more stuff to refute you and learning something very cool in the process.
http://en.wikipedia.org/wiki/Livyatan_melvillei
Livyatan melvillei (literally Melville's Leviathan (from the original Hebrew spelling) was found 23 miles south of Ica, Peru. A quick check of Ica, Peru shows that the altitude is 406 meters and it is a desert climate. L. melvillei was dated at 12-13 million years old... that's only about 5 orders of magnitude more than you think the entire Earth has existed.
Of course, Wadi Al-Hitan, 150 kilometers SW of Cairo (as Dave mentioned) contains not one, but multiple species of whale that are A) 100% marine whales and 2) do not exist today. BTW: 150 km SW of Cairo is something we call desert. The Wadi Al-Hitan fossils are 30-40 million years ago.
Ten million years after Livyatan melvillei lived, a large group of whales seems to have become stranded and are now fossils in the Chilean desert. http://news.yahoo.com/whales-desert-fossil-bonanza-poses-mystery-135321328.html
So we have three different groupings of whale fossils, all currently in desert environments, over a span of nearly 48 million years. Even the most recent of which is still several orders of magnitude older than you believe the entire Earth to be.
You might also want to study desertification and how long that process takes... and fossilization and how long that process takes... and, well, 7th grade Biology.
BTW: Even TEXAS requires knowledge of basic genetics in the 7th grade. Including population dynamics and natural selection.
apokryltaros · 25 January 2012
John_S · 26 January 2012
Robert Byers · 26 January 2012
DS · 26 January 2012
Dave Luckett · 26 January 2012
Robert Byers · 28 January 2012
Just Bob · 28 January 2012
apokryltaros · 28 January 2012
Mike Elzinga · 28 January 2012
Multiply the height of a pyramid by the height to the center-of-mass of the pyramid. This gives the potential energy of the pile of stones. This tells how much work is involved in just stacking up the pyramid without accounting for the work done in the stone quarries and the friction in dragging the stones to and up the pyramid.
That additional work can also be estimated fairly accurately. Totaling it all up gives the total amount of work to build a pyramid. Divide that by the energy consumed by an average human in a year and that will tell you how many humans cut, dragged around, and piled up those stones in a year.
In other words, we can calculate the number of man-years required to build a pyramid. This was one of the end-of-chapter problems in a popular physics textbook I taught out of many years ago.
If one can get further estimates on what the human population in Egypt was at the time and what proportion of them were pyramid-building slaves, you can get an estimate of the number of years it took to build the pyramid.
The bottom line to all this is that there is no way one could have obtained such large populations in Egypt after the supposed Noachian Flood.
Mike Elzinga · 28 January 2012
TomS · 29 January 2012
Red Right Hand · 29 January 2012
In fact Egypt was settled suddenly, lots or people, and the ease of food brought instantly other agendas to build the area up. No need for slow dumb guys getting their act together. They were smart people who simply had easy access to food and beat everyone else.
Sort of suburban sprawl writ large, huh! Some hardhats drain swamps and build shopping malls. These guys drained oceans erected the pyramids. They need their own reality TV show.
Modern construction workers are pussies compared to these guys. Walk like an Egyptian, Baby!
apokryltaros · 29 January 2012
prongs · 30 January 2012
apokryltaros · 30 January 2012
SWT · 30 January 2012