Tuesday, 9 February 2010

The Migration of the European Eels

The recent BBC program about eel migration has highlighted another great defeat for evolutionary theory by the phenomenon of instinctive behaviour.

In essence, eels (which grow to maturity in freshwater rivers, pools, streams, ponds) leave their growing areas, and make their way down to the sea. They even swim across wet grasslands in order to get into the rivers which will take them down to the sea.

Question: How do they know that they have to get to the sea, and how do they know that the rivers are flowing to the sea?

When they reach the sea off the coasts of the UK, they are immediately faced with a huge problem.

Salt water is extremely different in physical and chemical properties to fresh water, and usually, an organism which lives in the one kind of water will not survive in the other kind. The osmotic factors alone are very, very different.

But they survive somehow. How did natural selection produce such an organism one wonders.

They then swim to join one of the great south-flowing currents of the ocean, and in that way piggy-back on it, and save energy, and increase their speed of travel.

"The researchers suggest that what they do is swim down to Africa and then hitch a ride on a fast-moving ocean current which helps them to speed up and get the rest of the way much more quickly." http://www.thenakedscientists.com/HTML/content/news/news/1817/

They are headed for the Sargasso Sea, no less, all of 3,000 miles away to the south west.

It has not been observed, but scientists believe that they spawn there - and then, the adults die.

Millions of young eels are produced: transparent slivers of tissue: so transparent in fact that they are called glass eels. One can read a newspaper through them, it is claimed.

And these little pieces of living tissue now begin their 3,000 mile journey back to the freshwater pool, stream, lake where their parents came from. And they make it.

The details are sketchy, but in outline this is what happens, and is well known.

At once, evolution theory is rendered impotent. I have yet to see mention of the word 'evolution' in the accounts I've read - though there's got to be some plank who will mention the E word.There is no number of 'small beneficial variations' which can bring this titanic migration about. Consider - there is a journey of about 6,000 miles involved here. Underwater, at that.

In the air, as with the Capistrano swallows, it may be possible (though unlikely) for the birds to use visible landmarks to help in their navigation - maybe the stars or whatever.

The eels swim at a depth of 3000 feet during the day, and come up to shallower waters during the night:

"But one of the really intriguing bits of data was that the eels change their height in the water column between day and night. So during the daytime, they swim much deeper. They go down to about a thousand metres and at night time, they come up close to the surface." http://www.thenakedscientists.com/HTML/content/news/news/1817/

So stars,landmarks, whatever are unavailable - and yet they do it.

Navigating at a depth of 3000 feet in a submarine is a tricky business, requiring some very sophisticated equipment, especially if the destination is 3000 miles away. Yet this is exactly what the eels do, WITHOUT any equipment at all.

Just as remarkable as the Pacific Golden Plover, which we already described, the young migrate back home with no guidance whatsoever, and make it (apart from those, of course, that die, or are trapped in their millions by fishermen).

There is no way evolution can account for the phenomenon. The information is obviously inborn into the fish. But how did it get there? And again, we note that the whole information packet had to spring full blown to birth, or the eels and their young would have been lost long, long ago in the trackless depths and wastes of the deep ocean.

If the information is correct, there are fossil eels dating back 95 million years. So they haven't got lost in all that length of time. Whether they were making the same journey then is obviously unknown, but there's no good reason to suppose that they didn't.

So we have another evolutionary brick wall. When are we going to discard this useless theory?


One of the mysteries of the animal kingdom is the long-distance migration (5000–6000 km) of the European eel Anguilla anguilla L. from the coasts of Europe to its spawning grounds in the Sargasso Sea. The only evidence for the location of the spawning site of the European eel in the Sargasso Sea is the discovery by Johannes Schmidt at the beginning of the previous century of the smallest eel larvae (leptocephali) near the Sargasso Sea. For years it has been questioned whether the fasting eels have sufficient energy reserves to cover this enormous distance. We have tested Schmidt's theory by placing eels in swim tunnels in the laboratory and allowing them to make a simulated migration of 5500 km. We find that eels swim 4–6 times more efficiently than non-eel-like fish. Our findings are an important advance in this field because they remove a central objection to Schmidt's theory by showing that their energy reserves are, in principle, sufficient for the migration. Conclusive proof of the Sargasso Sea theory is likely to come from satellite tracking technology.


Tuesday, 2 February 2010

The Peregrine Falcon

by Vishesh Jain

Comments by Asyncritus

I was astonished to read the following blog article today, and take the liberty of reproducing it in its entirety.

The author Vishesh Jain is connected to Harker, which publishes a blog here:harkerbio.blogspot.com/ from which this article is copied in full. It is a marvellous description of this wonderful bird, and gives full rein to the inquirer's questions about just how this creature could have obtained the instinct package which powers its fantastic behaviour.


The Peregrine Falcon: Fastest Animal on the Planet
Peregrine Falcons are raptors with keen eyes, strong wings, powerful beaks, and tremendous speed. Outside their nesting season, peregrine falcons earn their name by traveling extensively, as much as 15,500 miles a year. Once endangered by DDT and human development, they have rebounded and are now found all over the world. Though they prefer open spaces such as plains and sea coasts, they live everywhere from tundra to desert to cityscape.

Peregrine falcons are known for their speed. When they plummet to catch an unsuspecting pigeon below them, they can reach velocities over 200 miles per hour (320 km/h). That's over a fourth of the speed of sound. Zoom. But what's also fascinating about these remarkable birds are the adaptations that allow them to use such power.

The Eyes:
If a peregrine falcon is flying or perched over a kilometer in the air, as they often are, it would be useful, perhaps, to be able to see what it's trying to strike. While they're no mantis shrimp in terms of spectral range, they do indeed have some of the keenest eyes on the planet. With full color vision and rapidly focusing lenses, their eyes have a resolving power up to 8 times greater than humans, enabling them to spot prey miles away and keep track of it while approaching at breakneck speed.

The Shape:
To achieve 70 mph speeds in pursuit of prey and 200 mph plummets to attack those below, the peregrine falcon has one of the most streamlined bodies in the air. The curved wings create an air foil effect in multiple dimensions, maximizing maneuverability, lift, and speed.

The Wings:
Besides the streamlined structure of the wings themselves, peregrine falcons maximize speed in every way possible. In pursuit, it can flap its wings up to four times a second, and in its dive it is able to let gravity pull it down with negligible air resistance, locking its wings in place to create minimum drag. The feathers themselves are stiff, slim, and unslotted, allowing them to literally slip through the air as they attack. As in all birds, their wings are hollow, enhancing flight and maneuverability in the air.

The Power:
Small tubercles and bones in the nose prevent the immense air pressure from flowing into and rupturing their respiratory system. In addition to tons of strong red muscle fibers, peregrine falcons have one-way lungs, like most birds, to maximize oxygen intake. To achieve torpedo-like speed both horizontally and vertically, peregrine falcons have an enormous keel, part of the sternum. As the attachment site for flight muscles, the larger the keel, the more powerful the flight, and this makes these birds some of the fastest in the world.

The Attack:
Now, if you were to drop a couple hundred stories, you'd probably be going pretty fast too. The question, then, is whether you'd be able to catch something, halt your dive, and be in a medical condition to eat it. From the muscle, to the talons, to the beak, these raptors are serious predators. When their keen eyes finish guiding their dive into their prey, if the impact of 200mph razor-sharp talons hitting a poor pigeon's back doesn't kill it, the tomial tooth of their strong beak can break the stunned bird's spine in a second. Then the falcon can leisurely eat it in the air or on the ground, after plucking its feathers, of course.

A National Geographic video tracking a peregrine falcon's flight speeds from the air.

-Vishesh Jain
Image Sources and Cool Links:

Speed and Strike:
Extreme Science - Fastest on Earth
HowStuffWorks - How Do Peregrine Falcons Fly So Fast?
National Geographic - High-Velocity Falcons

Science Daily: Peregrine Falcons May Face New Environmental Threat
Royal Belgian Institute of Natural Sciences: The Return of the Peregrine Falcons
Texas Parks and Wildlife: Peregrine Falcon

Cornell Lab of Ornithology - Peregrine Falcon
National Geographic - Peregrine Falcon
University of Wisconsin - BioWeb: Peregrine Falcon

U.S. Fish and Wildlife Service - Ozzie
Raptor Guide Gallery - Peregrine Falcon
TreeHugger - DDT Redux
Jerry Ting - Peregrine Falcon
Audubon - Signature Species: Peregrine Falcon
Posted by Harker Bio at 10:45 PM