Dei'ah veDibur - Information & Insight

A Window into the Chareidi World

29 Adar 5759 - March 17, 1999 | Mordecai Plaut, director Published Weekly







Opinion & Comment
Sylvia Curruca Proclaims "There Is A Borei Olom"
by Joshua Josephson

Part I

If anyone ever tells you "evolution," just say "sylvia curruca." That should put an end to the conversation rather quickly, unless of course you're the one who wants to do the convincing.

"Who's sylvia curruca?" you ask.

It's not who; it's what. Sylvia curruca is the scientific name for a little bird whose common name is the lesser whitethroat, a warbler (a type of songbird) that spends its summers in northern Europe and winters in sub- Saharan Africa. The point is that this bird can do some truly astonishing feats of navigation which make the proposition of evolution by chance virtually impossible to entertain.

Essentially, this little bird has a map of the night sky embedded in its genes. To suppose that this map got there by chance requires an incredible, and totally unwarranted, amount of faith in what chance can and cannot do. So if you ever find that you need to argue against evolution, it's a handy little bird to remember.

But let's not start with sylvia curruca. Its feats of navigation may represent an extreme capability that is not found in most other migratory animals. Rather let's begin by looking at a few slightly less astounding facts regarding animal migration and navigation. Even these simpler facts are amazing and worth knowing about.

A good place to begin is with the Arctic tern. It currently holds the world record for distance of migratory travel. During summer in the northern hemisphere, it nests in the Arctic. Come autumn, it heads south to enjoy summer again in the Antarctic. The total distance it travels round trip on its migratory journeys is close to 25,000 miles.

There is as yet no direct evidence that the tern's tendency to fly from north to south and back again is an inherited trait. Terns travel in flocks and the young fly with the adults. So the urge to fly, and the usefulness of flying, from one end of the globe to the other may be something that is learned by these birds and not purely an instinct.

But even if so, one must still wonder how the whole thing got started. What ever prompted any bird to fly about 12,000 miles in search of food or a more favorable climate? How did it know that it would be rewarded at trip's end?

Moreover, if other migratory animals are a guide, there is good reason to suppose that the tern is compelled by its genetic makeup to fly where it does and that its behavior is instinctive, not knowledge learned from others. If so, the question of why and how it does it, is all the more compelling.

In many migratory species, the young that are born in the spring or summer make their first migratory trip without parental guidance. And they travel to exactly the place where the adults winter, even though they leave after all the adults have already gone.

For example, many species of cuckoo have the nasty habit of depositing their eggs in nests belonging to other species of birds. They abandon their young, expecting that they will be raised by others, as indeed they are.

The adult cuckoos generally leave to their winter grounds well before the newborn cuckoos have matured or often have even hatched. Nevertheless, the newborn birds have an inborn guidance system which enables them to unhesitatingly arrive at the same winter grounds to which their elders have gone, making the trip about as quickly as the mature adults that have been there before.

The travel of one species, the New Zealand bronze cuckoo, is a case in point. After breeding in New Zealand, the adult birds fly about 1500 miles west across the Tasman Sea to Australia. After resting for a few days, they continue northwest for another 2000 miles, up along the east coast of Australia and over the Coral Sea, to New Guinea. From there they continue northeast for a few hundred miles more, again over open sea, to their final destination, a group of islands called the Bismarck Archipelago.

Cuckoos, by the way, are land birds. They cannot swim. So unless the entire flight over water is made in one trip, the birds are doomed. The genetic program thus has to be quite precise. Should it instruct travel of only 1000 miles west from New Zealand or in the wrong direction or even at a bad angle, these particular cuckoos would not be here for anyone to write about.

In fact the program is so good that young cuckoos who have never even heard of the Bismarck Archipelago are able to find the darn thing (it's only about 3500 miles away and a tiny speck on any map) a few weeks after they are born -- totally without any guidance from the adults.

What is true for cuckoos is also true for species of birds that flock together to migrate. In many cases, such birds as well have the migration route as an inherited program, not as something that is learned by experience. We know this from experiments that have been conducted on a variety of such birds.

Young birds were raised in isolation from other birds. These "naive" birds were then released well after all the other members of the species had left for their winter grounds. In virtually all reported cases, the naive birds, which had never been taught where to go and how to get there, ended up in the same wintering locales as their ancestors.

Inherited migratory behavior with detailed information about routes of migration is not restricted to birds. Very many other animals migrate: mammals, reptiles, fish, insects. In a good number of cases, young, inexperienced members of the species are capable of retracing the route taken by adults or finding their way back to ancestral homes.

Two of the most striking examples of this sort of behavior are presented by certain species of freshwater eel and by the Monarch butterfly. The facts in both these cases are absolutely astonishing. Details can be found in any good book on animal migration.

Consider the implication of this general phenomenon. Let's ignore for now the issue of exactly how these animals navigate to their migratory goal. That is a separate problem which is in some ways even more spectacular and will be considered in a follow-up article.

For now let us focus merely on the notion of the existence of a genetic program which instructs an organism to migrate -- a program which essentially says that for the animal's survival it must leave one locale, and which also maps out precisely where it must go.

Take the case of the Arctic tern. Assuming that its migratory behavior is governed by its genes (which in all likelihood it is), one must wonder how DNA was able by chance to hit upon a plan of migration that works so perfectly.

DNA has no knowledge about the outside world. Yet it has chanced upon a set of instructions that comports with geographic reality and that sends a bird flying more than ten thousand miles to a destination that is just right for it.

The life cycle of the Arctic tern requires it to live at the two extremes of the globe; probably no other place on earth would do for this particular bird. How did randomness happen upon a set of instructions that guides terns to these locations?

And DNA has to accomplish much more. Not only must the genes supply a flight plan, they also must provide for a whole complex of physical and behavioral changes that enable the tern to actually make the trip.

The tern's body is especially adapted for extremely long distance flights. It is lightweight, with long slender wings designed for energy-saving flight at low speeds, including hovering. It instinctively chooses the most efficient flight speed and behavior in relation to wind.

In preparation for the trip, the bird's body begins to store fat for weeks and sometimes months before the actual trip is taken. Migratory birds held in captivity under perfectly uniform conditions with no clue about seasons, automatically begin to gain weight at just the right time.

Then, when it comes time to migrate, the birds flock together at the perfectly appropriate time. Birds that have been scattered over hundreds of miles of Arctic terrain converge to predetermined meeting places exactly on cue.

In other words, a panoply of instinctive behaviors come together to make the whole thing work just right.

And isn't it incredibly lucky for DNA to have mapped out the route of the New Zealand bronze cuckoo?

"Head west (precise angle provided) for 1500 miles until you reach land. Rest and feed for a few days to gather strength for the next leg of the trip. (You're dead if you don't, since you cannot swim.) Travel 2000 miles northwest (again precise angle provided) to the next major island. Then turn northeast (of course, precise angle provided again) for several hundred miles until you get to a group of small islands. (Incidentally, you'll find your parents there because their genes also tell them to do the same thing)."

Imagine that! There actually is an island suitable for cuckoo habitation at the end of this flight plan. How could DNA, by chance, without any knowledge of geography or even that there is a planet Earth out there, ever have devised a flight plan as precise as this?

One does not have to be a rocket scientist or do fancy calculations to recognize that for blind chance to have devised a set of instructions that even remotely resemble what has just been presented seems more than what one would normally be willing to accept.

Of course, it is tempting to argue that maybe it's not chance. Maybe somehow DNA is impacted by the outside world. Maybe somehow the outside world impinges on the organism and causes its DNA to form in a certain way.

But, according to today's science, such a proposition is about as heretical as one can get. It's Lamarckism all over again. Any good evolutionist and biologist will tell you this is precisely what Darwin's theory came to counter. Today, such a theory is simply not at all accepted in any shape, manner or form.

The reason for this is that the central dogma of biology, and by inference of evolution as well, is that DNA is totally blind. It cannot know anything about the outside world. Information in the cell travels only in one direction, from DNA to end products, never the other way around. Without positing divine intervention, changes to DNA can occur only by chance. Nothing else.

So to believe in evolution of necessity means believing that DNA gets extremely lucky sometimes, that after a bit of trial and error, DNA will hit the jackpot. It will, evolution says, purely by chance, by total randomness, produce flight plans for birds and insects that are necessary for their survival.

And one must also believe that DNA will do it over and over again, for the Arctic tern and for the New Zealand bronze cuckoo and the eel and butterfly and hundreds or thousands of other migratory species.

And purely by chance, these flight plans actually work. They enable newborn land birds to fly thousands of miles over open ocean to hit precisely a dot of an island in a vast, uniform, uncharted sea.

The facts of animal migration and navigation are so overwhelming that scientists and authors who write about the subject, and who generally believe in evolution, tend to get carried away. They use terms that one does not generally see in biology, or for that matter in any other scientific subject. One repeatedly encounters words like, "remarkable," "astonishing," "incredible," "spectacular," "amazing."

And there are no real answers to the basic questions on how all this could have happened. Articles on the subject freely admit that in many cases there is as yet "no viable hypothesis" to explain how animals do it.

The abilities of animals to navigate and migrate are "mysterious," "intriguing." In fact, one author even referred to the abilities of one bird as a "miracle of navigation."

Bli neder, part II of this article will look at some of these miracles of animal navigation. That's when sylvia curruca will get a chance to show off.

All material on this site is copyrighted and its use is restricted.
Click here for conditions of use.