[Janean Van Beckum]

Janean Van Beckum asked the Naked Scientists:
   
I want to let you know how much my husband and I love your show.  I listen to all the naked podcasts and I force him to listen to old episodes of the podcast on long journeys (he really does enjoy them, though)!

My question is about the swallows that return to Capistrano, CA every year on St. Joseph's day (March 19th).  How do they end up there on the same day every year?  I would think it would vary a bit every year based on the weather.  Any idea why they are so punctual?

Thanks, and keep up the good science!

Janean Van Beckum, Milwaukee, Wisconsin, USA

What do you think?

[Asyncritus]

Hi Janean

You might like to have a look at the topic 'How does Instinct Evolve' here:http://www.thenakedscientists.com/forum/index.php?topic=16535

I'm afraid the supporters of evolution on this site have no answers to your question.

Mine is quite simple: the Lord God made them so.

Gen 1.20 ¶  And God said, Let the waters bring forth abundantly the moving creature that hath life, and fowl that may fly above the earth in the open firmament of heaven.
21  And God created great whales, and every living creature that moveth, which the waters brought forth abundantly, after their kind, and every winged fowl after his kind: and God saw that it was good.
22  And God blessed them, saying, Be fruitful, and multiply, and fill the waters in the seas, and let fowl multiply in the earth.
23  And the evening and the morning were the fifth day.

After all, it takes intelligence to design a clock, and a calendar, and combine them with a GPS navigating system, not to mention the ability to fly, and to fly 7,500 miles and back every year.

As far as I can make out, no bird has ever created such a complex series of interacting systems, or is ever likely to do so. So Who did?

[lyner]

I might find some such statement in Lord of the Rings or Harry Potter, too. Could I quote that as evidence?

[Asyncritus]

Do answer the question Sophie. It's quite easily understandable and clear, isn't it?

[_Stefan_]

The bible is not science. There is no scientific alternative to evolution.


For evolution by natural selection to operate, 2 main factors are necessary:

1. Selection pressures (climate, resources, competition, predation, etc)
2. Variation in heritable traits

1. There are clear, strong evolutionary incentives for migration. For example, different geographical locations provide different climatic conditions and resource availability at different times of the year.

2. Many behaviors are under genetic control. That's because brains and bodies produce behaviors, and genes build brains and bodies. Any behaviors that confer survival advantages to the genes that influence them, are more likely to be passed on to future generations.

Even modern birds that don't migrate over large distances will take advantage of local areas with the most favorable conditions. Birds that do this are more likely to survive and reproduce than birds that don't. It is no stretch then to gradually increase the range over which the birds will move to find suitable environments. Modern migratory birds even sometimes stop at intermediate distances during their migrations.

To answer how the birds navigate, and how they know when to migrate:

They respond to environmental and internal biological cues.

Factors including day length, temperature, and resource availability, signal birds to begin their migration. These factors may influence hormone regulation and their internal body clocks.

Birds navigate by several methods. Apart from relying on mental maps of landmarks and other visual cues, they use smell, and can even detect the Earth's magnetic field.

Of course the receptivity of birds to these cues, and how they respond to them, is influenced by their genes.

Because these variables are not constant from year to year, slight variations in departure and arrival dates do occur. Even in one year, it is likely that birds will be departing and arriving on a range of dates before and after the expected date.

More information here: http://en.wikipedia.org/wiki/Bird_migration


Isn't all that a much more satisfying answer than "GOD DID IT!!!"?

[lyner]

Do answer the question Sophie. It's quite easily understandable and clear, isn't it?

Did your answer make any more sense than mine?
Look at stefan's post for a succinct answer.

[Asyncritus]

I have to give you full marks for making the best of a lousy case, Stefan. Unfortunately, like so many 'answers' evolution provides, it is a crack-papering exercise, in which the glaring holes are smeared over with verbal paint, as I shall now demonstrate.

The bible is not science. There is no scientific alternative to evolution.

The Bible is not intended to be a textbook of science - but that does not prevent it from speaking the truth about the scientific matters it does touch upon. There are very many such matters. And perhaps we can touch on a few others apart from creation at some other time.

If by 'scientific' you mean 'excluding God from any discussion' then you're probably right. But that is question-begging of a very high order.

My understanding of 'scientific'is that we examine the facts, and draw conclusions from them - conclusions which can be tested in some way or other. Neither evolution nor creation can be tested, and as I have shown previously, evolution is as much a faith as ever creation is.

For evolution by natural selection to operate, 2 main factors are necessary:

1. Selection pressures (climate, resources, competition, predation, etc)
2. Variation in heritable traits

This is basically correct - but completely inadequate to the task of accounting for the origin of new species in the quantities required to sustain your faith in evolution.

As I pointed out previously the Cambrian 'Explosion' produced zillions of new species, families, orders, and phyla. The body plans laid down then have remained basically unchanged till now. So where did all that come from? And why has nothing like it happened since?

The only reason I can see is that there was a burst of creative activity by God - just as the Bible indicates.

1. There are clear, strong evolutionary incentives for migration. For example, different geographical locations provide different climatic conditions and resource availability at different times of the year.

This, in connection with para 3, is crack-papering with a vengeance.

Yes, I agree that there may be good reasons for a bird to migrate away from unfavourable environmental conditions. But that is not what we are discussing here.

These birds fly 7,500 miles - to get away from unfavourable conditions - and then fly back straight into them 6 months later! You would have thought, wouldn't you, that a few hundred miles or less (as many other birds do) would be enough. But 7,500 miles? No amount of environmental evolutionary incentives can force such a thing.

And remember, the species has remained exactly the same since they first dug them up! There is no evolution there.

And then we have the GPS problem, the calendar problem, the ability to fly problem - the whole shoot of evolutionary inexplicables! I think you're on to a loser here Stefan, and the sooner you realise it, the better for us all.

2. Many behaviors are under genetic control. That's because brains and bodies produce behaviors, and genes build brains and bodies. Any behaviors that confer survival advantages to the genes that influence them, are more likely to be passed on to future generations.

Again perfectly true. Again severe question-begging. Because the real question is HOW DID THIS GET INTO THE GENES IN THE FIRST PLACE? Once it's in, fine. But how did it get there is what Janean asked.

Even modern birds that don't migrate over large distances will take advantage of local areas with the most favorable conditions. Birds that do this are more likely to survive and reproduce than birds that don't. It is no stretch then to gradually increase the range over which the birds will move to find suitable environments. Modern migratory birds even sometimes stop at intermediate distances during their migrations.

Once again perfectly true - even though I can't really see what arriving in Capistrano on March 18th has to do with anything evolutionary. If they arrived a month earlier or later, I can't see what difference it would make.

But no, I think God did this just to ruffle your feathers severely!

Let me mention the golden plovers again, in case you've forgotten them. They fly from Hawaii to Alaska, about 2000 miles, ENTIRELY OVER WATER, with no stopping points. How do they know where they're going, Stefan? Over land, maybe, there are possible visible land marks. But over the ocean? Isn't that a perfect recipe for extinction? I mean, undertaking a journey of that magnitude over water, AND BEING UNABLE TO SWIM!

And just to add insult to injury, the young leave without any parents in attendance to show them the way!

http://www.naturia.per.sg/buloh/birds/Pluvialis_fulva.htm
"Phenomenal long-distance travellers, after breeding in the Arctic, these plovers migrate to spend winter almost half way around the world (5,000-13,000km away one-way). Some winter on tiny islands in the Pacific and Indian Oceans, a feat which requires precise navigation. Alaskan breeders winter in Hawaii, Fiji, South Pacific Islands, all the way to New Zealand. Siberian breeders migrate to Africa, India, Indochina, Southeast Asia all the way to Australia. Most winter on coastal mudflats, beaches, reefs."

To answer how the birds navigate, and how they know when to migrate:

They respond to environmental and internal biological cues.

Factors including day length, temperature, and resource availability, signal birds to begin their migration. These factors may influence hormone regulation and their internal body clocks.

Yeah. True. But um, haven't you left out the biggest point of all? HOW DO THEY MAKE SUCH ENORMOUS MIGRATIONS, to such precise locations? A Tomahawk missile (intelligently designed) can go through somebody's window. A golden plover goes right back to the same nest. A bit smaller than the window, methinks!

Birds navigate by several methods. Apart from relying on mental maps of landmarks and other visual cues, they use smell, and can even detect the Earth's magnetic field.

Of course the receptivity of birds to these cues, and how they respond to them, is influenced by their genes.

Yeah. HOW DID IT GET IN THE GENES IN THE FIRST PLACE is the question here, Stefan.

Isn't all that a much more satisfying answer than "GOD DID IT!!!"?

Well, if it was an answer, perhaps it would be better. But since it is most emphatically NOT an answer, I'm afraid you're back up the same old gum tree. Must be a lot of evolutionists up there twittering happily away!

[Asyncritus]

Do answer the question Sophie. It's quite easily understandable and clear, isn't it?

Did your answer make any more sense than mine?
Look at stefan's post for a succinct answer.

You didn't give an answer.

[Don_1]

Asyncritus, you have hijacked this thread to, yet again, argue for God. Janean Van Beckum has asked a perfectly straightforward and reasonable question, please allow TNS members to give an answer.

Take your God Vs Nature, creation Vs evolution arguments elsewhere please.

[_Stefan_]

You must be incredibly thick, Asyncritus. All the answers to your IDiotic migration objections where already in my post.

"HOW DID IT GET IN THE GENES IN THE FIRST PLACE?"
It's called genetic mutation and recombination. Genes encoded proteins, some of which became involved in complex brain chemistry. Brain chemistry is what produces and controls behavior, so changes to brain chemistry can change behavior.

And the Cambrian "Explosion" was nothing of the sort. 20 million years is merely short on a geological scale. How can you honestly consider 20 million years to be too little time? Not to mention that comparative genetic analysis of modern species has demonstrated actual divergence some time prior to the "explosion".

You are intellectually bankrupt. You add nothing to TNS except misinformation. Please go away.

[blakestyger]

_Stefan_ is right, it's genetic. The migratory process occurs at regular intervals at approximately the same time - go too soon and you may encounter adverse weather, go too late and you have a shorter breeding time provided you can still establish a territory.

The internal rhythmicity that birds have is genetic and therefore inherited - it's due to rhythmic physiological processes in which the hypothalamo-hypophysical system of the brain and a series of other hormonal feedback mechanisms play an important role.
The existence of internal calendars shed light on the question of how migration is temporarily organised. The necessary time mark is set, as both field observations and experiments have shown, by an internal physiological clock. Deviations from this internal setting from biological seasons are corrected by environmental synchronizers, mainly photoperiod. The seasonal changes of day length is one of the most reliable fluctuations.

It's worth noting that experiment has not supported the popular idea that migrants have an innate knowledge of environmental cues of their winter quarters, such as characteristic star patterns.

(Source: Cambridge Encyclopedia of Ornithology)

[BenV]

From what I understand, it's to do with the ratio of day/night.  This shouldn't vary from year to year, so the time at which they set off should be the same.  There will be a speed that is most efficient for flight, so the time it takes should be relativelt constant.

I think the weather does have a part to play, and a number of migrating birds get blown off course every year.  It could be that given the distances involved, the different weather systems they encounter will tend to cancel out.

[Asyncritus]

Asyncritus, you have hijacked this thread to, yet again, argue for God. Janean Van Beckum has asked a perfectly straightforward and reasonable question, please allow TNS members to give an answer.

Take your God Vs Nature, creation Vs evolution arguments elsewhere please.

Marvellous.

Why don't you move this to the Instinct thread?

What did that red face evolve from, I wonder?

[Asyncritus]

_Stefan_ is right, it's genetic. The migratory process occurs at regular intervals at approximately the same time - go too soon and you may encounter adverse weather, go too late and you have a shorter breeding time provided you can still establish a territory.

The internal rhythmicity that birds have is genetic and therefore inherited - it's due to rhythmic physiological processes in which the hypothalamo-hypophysical system of the brain and a series of other hormonal feedback mechanisms play an important role.
The existence of internal calendars shed light on the question of how migration is temporarily organised. The necessary time mark is set, as both field observations and experiments have shown, by an internal physiological clock. Deviations from this internal setting from biological seasons are corrected by environmental synchronizers, mainly photoperiod. The seasonal changes of day length is one of the most reliable fluctuations.

It's worth noting that experiment has not supported the popular idea that migrants have an innate knowledge of environmental cues of their winter quarters, such as characteristic star patterns.

(Source: Cambridge Encyclopedia of Ornithology)

Stefan is right - but inadequate. HOW DID ALL THIS GET INTO THE GENOME? As I said, all this is fine - once the info has got into the genome. BUT HOW DID IT GET THERE?

[_Stefan_]

I just explained to you in general terms how behaviour "GETS INTO THE GENOME". Take your blinkers off for once.

But you don't even accept that mutation can have positive effects or that DNA is the real substance of inheritance/genetic relationship, do you? Stop wasting our time.

[Asyncritus]

I just explained to you in general terms how behaviour "GETS INTO THE GENOME".

Where? And I'm looking for SPECIFIC, not general information, please.

But you don't even accept that mutation can have positive effects or that DNA is the real substance of inheritance/genetic relationship, do you? 

Don't be so silly, Stefan. This is crass misrepresentation, and you know it.

[Asyncritus]

_Stefan_ is right, it's genetic.

The fact that the golden plover's young find their way back across the Pacific ocean without any adults present confirms this statement.

The migratory process occurs at regular intervals at approximately the same time - go too soon and you may encounter adverse weather, go too late and you have a shorter breeding time provided you can still establish a territory.

The internal rhythmicity that birds have is genetic and therefore inherited - it's due to rhythmic physiological processes in which the hypothalamo-hypophysical system of the brain and a series of other hormonal feedback mechanisms play an important role.

Quite so. But the question before us is not being answered. WHERE DID THE BEHAVIOUR COME FROM, AND WHY DID IT ARISE?

The existence of internal calendars shed light on the question of how migration is temporarily organised. The necessary time mark is set, as both field observations and experiments have shown, by an internal physiological clock. Deviations from this internal setting from biological seasons are corrected by environmental synchronizers, mainly photoperiod. The seasonal changes of day length is one of the most reliable fluctuations.

Quite so - BUT HOW DID ALL THIS ARISE, and WHY?

It's worth noting that experiment has not supported the popular idea that migrants have an innate knowledge of environmental cues of their winter quarters, such as characteristic star patterns.

So what does that leave? Only one explanation will do. God did it.

[_Stefan_]

The explanations I have given are applicable to almost any question regarding the origin and evolution of genetically controlled behaviors. I doubt you would accept it even if specific molecules were named. For example, http://www.sciencedaily.com/releases/2008/01/080108083008.htm

But you don't even accept that mutation can have positive effects or that DNA is the real substance of inheritance/genetic relationship, do you? 

Don't be so silly, Stefan. This is crass misrepresentation, and you know it.

In previous posts you have actually repeatedly, vehemently denied that mutation can produce anything but negative or at best neutral changes.
You also ignore the mountains of evidence produced by comparative genetic analysis, developmental biology, etc. So my comment was hardly "silly".


Your demands for evidence of evolution are ridiculous, considering you unquestioningly believe GOD DID IT, with next to zero evidence of that. Instead of trying to find out how wrong evolution is, you should be researching what has already been discovered about the things you "think" are questionable.

Information is not supplied on a platter. Research is resource-intensive work. Just because some questions have not yet been answered 100%, does not mean the theory has failed.

[Asyncritus]

The explanations I have given are applicable to almost any question regarding the origin and evolution of genetically controlled behaviors. I doubt you would accept it even if specific molecules were named. For example, http://www.sciencedaily.com/releases/2008/01/080108083008.htm

The fact is, you have given not the slightest vestige of an explanation for the origin of any of the migration patterns we see.

Janean asked: "My question is about the swallows that return to Capistrano, CA every year on St. Joseph's day (March 19th).  How do they end up there on the same day every year?  I would think it would vary a bit every year based on the weather.  Any idea why they are so punctual?"

What answer have you provided? As far as I can make out, you (and Ben) have said that a combinaton of genetic and environmental triggers start the behaviour off i.e. the swallows fly off.

With all due respect, that doesn't even start to explain anything really. The unanswered points require far more detail that anything you, or anybody else for that matter, have been able to provide.

Those unanswered points include:

1 If they arrive on the same date, then that means they leave Argentina on the same date. The weather conditions must vary from year to year - yet they leave at the same time and return at the same time.

2 How do they manage to navigate over such an enormous distance - and so accurately that they find the same city, and even the same nests every time and on the same DATE?

3 How did this fantastic behaviour 'evolve' - and HOW DID THE REQUIRED INFORMATION ENTER THE GENOME?

MUTATIONS

As we all know, or should know, mutations are  invariably damaging or at best neutral. Have a look on Google at the effects of mutations on the human genome and phenotype if you doubt this.

I assert that it is impossible for these destructive or useless mutations to generate anything like this amazing behaviour pattern.

I don't think it is ridiculous to ask for proof that something as big as this (evolution, I mean) did occur.

I do think that you don't have to meet the designer to know that a Mercedes Benz was designed - because all of the brilliant engineering that goes into the design of the car shows conclusively that there WAS  a Designer.

You don't need to meet the designer to know that a GPS was designed. You don't need to meet the calendar makers to know that our calendar was intelligently constructed.

You've never met Orville and Wilbur Wright - yet you know they existed from the fact that planes fly everywhere today!

Yet you persist in holding on to the quite foolish notion that the swallows' GPS and internal calendar and clock mechanisms could somehow have 'evolved' without a Designer! That they can fly without a designer!

Boeing would have your shirt if you made such foolish claims about their planes - that they were thrown together by an evolutionary explosion in some junkyard somewhere.

Information is not supplied on a platter. Research is resource-intensive work. Just because some questions have not yet been answered 100%, does not mean the theory has failed.

You're quite right - information is not supplied on a platter. OK. So where did the swallows get the necessary information to

a. build their flight systems
b. construct the aerofoils of their wings
c. construct the feathers with their amazing aerodynamic suitability to their task
d. construct their GPS system
e. construct their internal clocks and calendar

and so on?

Chance mutations? Or were these things Intelligently Designed? And if so, by whom?

 

[BenV]

1 If they arrive on the same date, then that means they leave Argentina on the same date. The weather conditions must vary from year to year - yet they leave at the same time and return at the same time.

2 How do they manage to navigate over such an enormous distance - and so accurately that they find the same city, and even the same nests every time and on the same DATE?

I'm afraid I'm too busy to respond to all of this, but I thought I would point out that you have missed my point about the time that they set off.  It's independant of weather, as it's to do with the ratio of day/night.  This will be the same each year, come rain or shine, and is reliant on a chemical cascade that is under genetic control.  An adapted version of the body clock chemicals that all animals have.

We know that birds, bats and some insects have heamatite particles in their brains which respond to the earth's magnetic field - this is what enables them to navigate so well.

You know that there is no evidence for a creator, and you also know that you are unwilling to engage in a genuine debate of the facts, so why do you insist on continuing?

People have been banned from this forum for crusading before, and with your acknowledgement that you are unwilling to accept any explanation other than your own, you have admitted to crusading against evolution.