What is your take on the evolution of birds?

Question

This is how I think it happened, based on my studies: http://img.photobucket.com/albums/v165/captmicha/New/1.jpg

I think that the "birds" that people think developed from dinosaurs were just amongst the first developments taking place to take advantage of the benefits of flight. It could have developed from small dinosaurs climbing from tree to tree and leaping. We have bats after all, gliding squirrels and lizards too.

I think that the birds we know today are offshoots of reptiles that developed flight and the characteristics needed for flight like enlarged hearts, warm "bloodedness" and such.

In response to the Hip girdle, a lot of the mammal traits aren't reptilian also but developed over time.

On a side note, I forgot to add that during the mass extinctions (more than one) that killed off dinosaurs, how would have birds have survived since they had taken to the sky?

It's believe that animals of small proportions, burrowing animals were only able to survive along with aquatic animals and insects.

Answer 1

I think there is considerable evidence to agree with your model of birds evolving from a separate lineage of reptiles than the ones that were actually dinosaurs.

However, I would definitely put that branch closer to the dinosaurs than I would the mammals, so I would swing that line in between mammal and dinosaur on your diagram, rather than having it way off to the side.

The probable thecodont antecedents of the birds was certainly more closely related to the dinosaurs (and living archosaurs, such as the crocodilians) than were the synapsid reptiles that gave rise to the mammals.

As to THA's comments:

While Archaeoraptor was a hoax, you will notice that the hoax was discovered and publicized by paleontologists (not religious scholars), and that the hoax fossil is no longer considered scientifically valid. This is what happens when hoaxes are discovered by scientists, they are disregarded. Religious scholars, however, keep harping on about them as if they actually prove some kind of point - this would be an excellent example of the 'fraudulent doctrines & teaching' from religion mentioned above.

Not all reptiles are as 'cold blooded' as all other reptiles. There isn't as definitive a line between 'hot' and 'cold' blooded as non-biologists tend to think there is. A large reptile has muscle mass that generates heat, and less surface area to lose that heat. Because of this, it naturally maintains a higher body temperature than its environment - it does not directly metabolically regulate its body temperature, but facultatively, it is warm blooded. Is that a cold blooded or hot blooded animal? Behavioural adaptations that cause crocodiles to drag themselves out into the sun to warm up, or seek shade to cool off are biological adaptations to regulate body temperature. Do these animals represent hot or cold blooded animals? There is considerable evidence to show that many dinosaurs may have been facultative, if not completely metabolically endothermic.

Birds don't have any 'unsatisfactory characteristics' that can only be explained through creation. Absolute creation would actually open far more questions about bird design than evolution does.

Birds are not the only ones to incubate their eggs. Alligators and crocodiles are noted for building nest mounds to incubate and protect their eggs. Even sea turtles, a rather primitive group of reptiles, incubate their eggs. While they don't sit directly on their eggs to incubate them, there are also many primitive birds that don't sit on their eggs either. The megapodes, or brush turkeys are the most famous example. Not all birds are 'designed' for it either. The brood patch mentioned is not present in all groups of birds, only the most advanced groups. And yes, increased care of young is a newer trait for these groups of birds - not so selfless and altruistic when you consider that they are working to advance the survival of their own gene line though. The gap is not so great though, when you consider the parental care given between say, a crocodile and a kiwi. There is also considerable evidence for nest building and care of altricial young in dinosaur groups, which closes that gap even farther.

Feathers are not unique to birds. While Archaeoraptor was proven to be a hoax, there are definitely other feathered dinosaurs known.

While comparing an alligator scale and a falcon's flight feather may seem to be incredulous leap in complexity, it is important to note intermediate conditions, such as the body feather of kiwis, emus, ostrich, penguins, grebes, anhingas and others. Look at those groups, and the transition from diffuse, almost hair-like frayed scale ends to the falcon's feather is a little more obvious.

Most known living reptiles have solid bones, but this does not apply to some of the lighter theropods and a few other species. Considering that there are known reptiles with hollow bones, the possession of hollow bones by birds doesn't seem that unique.

Yes, the airflow system through the bird's marvelous lung system is indeed amazing. It would be more amazing if all birds had it, and possessed it to the same degree. But they don't. The more advanced groups, i.e. the songbirds, have the full system you describe. Less advanced groups have less advanced systems, or do not have the full counter-current system at all. It would also be more indicative of 'intelligent design' or 'special creation' if the birds had a full flow-through design like a jet engine - with intake in front, and exhale in back, rather than having to modify the same nostril -> lung system that all of the tetrapods inherited from the modified swim bladders of their amphibian ancestors.

Eyes and feet: Again, you are taking the most advanced current systems. Looking at the feet of ostriches, penguins, grebes or rails, and you won't see that great a difference between bird feet and reptile feet. The tendon locking system is a characteristic unique to the most advanced group of birds - the songbirds. The melodious syrinx you mention is also unique to this group. The hisses and cries of primitive birds like ostriches, emus and cormorants aren't appreciably different from how those same sounds are created by reptiles. There is also a superlative set of gradual changes in the syrinx system represented by living species.

Beaks are also known from some dinosaur groups. A keratinous sheath over a toothless jaw is seen in groups like the psittacosaurs and the ceratopsians. Meanwhile, many of the most primitive birds don't have beaks, but like Archeopteryx, have socketed teeth. The transitions from developing a slender, long beak like in grebes or cormorants, through duck bills and heron beaks seems very credible to me.

While Archaeopteryx is not a direct link between birds and reptiles, it is a primitive bird which retains a lot of reptilian characteristics - showing transitional characters which religious evolution deniers always claim don't exist. As you do in the next paragraph.

The 'fully formed' fish that suddenly appear in the fossil record 520 million years ago lack many of the features of modern fish - they are jawless, have no bony skeleton (only cartilage), their appendicular skeleton is absent or very primitive - hardly 'fully formed', in fact they seem to almost exactly like a transitional form between earlier primitive chordates (i.e. Pikaia, Amphioxus) and later fish. But I forgot, you don't believe transitional fossils exist.

Answer 2

Interesting concept. What about the hip girdle? It's not particularly reptilian.

Answer 3

Due to our knowledge at this time were are using educated guesses at best. Outside of the afore mentioned hip arrangement etc. your idea is as good as anyone elses.

Answer 4

--EVOLUTION has been a fraudulent science right from the beginning. It is not a new fraud, for the Bablylonians had their own evolutionary teachings in their religions!

--RELIGIONS have their fraudulent doctrines & teachings that are just as serious as any scientific fraud.

*** g00 7/22 p. 28 Watching the World ***

Feathered Fossil a Hoax

A fossil found in Liaoning Province, China, was reported by National Geographic to be “a true missing link in the complex chain that connects dinosaurs to birds.” The fossil, named Archaeoraptor liaoningensis, was said to have the tail of a dinosaur and the chest and shoulders of a bird. Now, however, scientists are becoming convinced that “they have been snookered by a bit of fossil fakery,” reports Science News. Paleontologists who examined the fossil became suspicious after they noticed that the bones connecting the tail to the body were missing and that the rock slab showed signs of being reworked. Philip Currie, of the Royal Tyrrell Museum of Paleontology in Drumheller, Alberta, Canada, suspects that someone “sought to enhance the value of Archaeoraptor by pasting one part of the dinosaur’s tail to a bird fossil,” says the report."

*** ce chap. 6 pp. 75-80 Huge Gulfs—Can Evolution Bridge Them? ***

The Gulf Between Reptile and Bird

11 Reptiles are cold-blooded animals, meaning that their internal temperature will either increase or decrease depending upon the outside temperature. Birds, on the other hand, are warm-blooded; their bodies maintain a relatively constant internal temperature regardless of the temperature outside. To solve the puzzle of how warm-blooded birds came from cold-blooded reptiles, some evolutionists now say that some of the dinosaurs (which were reptiles) were warm-blooded. But the general view is still as Robert Jastrow observes: “Dinosaurs, like all reptiles, were cold-blooded animals.”8

12 Lecomte du Noüy, the French evolutionist, said concerning the belief that warm-blooded birds came from cold-blooded reptiles: “This stands out today as one of the greatest puzzles of evolution.” He also made the admission that birds have “all the unsatisfactory characteristics of absolute creation”9—unsatisfactory, that is, to the theory of evolution.

13 While it is true that both reptiles and birds lay eggs, only birds must incubate theirs. They are designed for it. Many birds have a brood spot on their breast, an area that does not have any feathers and that contains a network of blood vessels, to give warmth for the eggs. Some birds have no brood patch but they pull out the feathers from their breast. Also, for birds to incubate the eggs would require evolution to provide them with new instincts—for building the nest, for hatching the eggs and for feeding the young—very selfless, altruistic, considerate behaviors involving skill, hard work and deliberate exposure to danger. All of this represents a wide gap between reptiles and birds. But there is much more.

14 Feathers are unique to birds. Supposedly, reptilian scales just happened to become these amazing structures. Out from the shaft of a feather are rows of barbs. Each barb has many barbules, and each barbule has hundreds of barbicels and hooklets. After a microscopic examination of one pigeon feather, it was revealed that it had “several hundred thousand barbules and millions of barbicels and hooklets.”10 These hooks hold all the parts of a feather together to make flat surfaces or vanes. Nothing excels the feather as an airfoil, and few substances equal it as an insulator. A bird the size of a swan has some 25,000 feathers.

15 If the barbs of these feathers become separated, they are combed with the beak. The beak applies pressure as the barbs pass through it, and the hooks on the barbules link together like the teeth of a zipper. Most birds have an oil gland at the base of the tail from which they take oil to condition each feather. Some birds have no oil gland but instead have special feathers that fray at their tips to produce a fine talclike dust for conditioning their feathers. And feathers usually are renewed by molting once a year.

16 Knowing all of this about the feather, consider this rather astonishing effort to explain its development: “How did this structural marvel evolve? It takes no great stretch of imagination to envisage a feather as a modified scale, basically like that of a reptile—a longish scale loosely attached, whose outer edges frayed and spread out until it evolved into the highly complex structure that it is today.”11 But do you think such an explanation is truly scientific? Or does it read more like science fiction?

17 Consider further the design of the bird for flight. The bird’s bones are thin and hollow, unlike the reptile’s solid ones. Yet strength is required for flight, so inside the bird’s bones there are struts, like the braces inside of airplane wings. This design of the bones serves another purpose: It helps to explain another exclusive marvel of birds—their respiratory system.

18 Muscular wings beating for hours or even days in flight generate much heat, yet, without sweat glands for cooling, the bird copes with the problem—it has an air-cooled “engine.” A system of air sacs reach into almost every important part of the body, even into the hollow bones, and body heat is relieved by this internal circulation of air. Also, because of these air sacs, birds extract oxygen from air much more efficiently than any other vertebrate. How is this done?

19 In reptiles and mammals, the lungs take in and give out air, like bellows that alternately fill and empty. But in birds there is a constant flow of fresh air going through the lungs, during both inhaling and exhaling. Simply put, the system works like this: When the bird inhales, the air goes to certain air sacs; these serve as bellows to push the air into the lungs. From the lungs the air goes into other air sacs, and these eventually expel it. This means that there is a stream of fresh air constantly going through the lungs in one direction, much like water flowing through a sponge. The blood in the capillaries of the lungs is flowing in the opposite direction. It is this countercurrent between air and blood that makes the bird’s respiratory system exceptional. Because of it, birds can breathe the thin air of high altitudes, flying at over 20,000 feet for days on end as they migrate thousands of miles.

20 Other features widen the gulf between bird and reptile. Eyesight is one. From eagles to warblers, there are eyes like telescopes and eyes like magnifying glasses. Birds have more sensory cells in their eyes than have any other living things. Also, the feet of birds are different. When they come down to roost, tendons automatically lock their toes around the branch. And they have only four toes instead of the reptile’s five. Additionally, they have no vocal cords, but they have a syrinx out of which come melodious songs like those of the nightingales and mockingbirds. Consider too, that reptiles have a three-chambered heart; a bird’s heart has four chambers. Beaks also set birds apart from reptiles: beaks that serve as nutcrackers, beaks that filter food from muddy water, beaks that hammer out holes in trees, crossbill beaks that open up pinecones—the variety seems endless. And yet the beak, with such specialized design, is said to have evolved by chance from the nose of a reptile! Does such an explanation seem credible to you?

21 At one time evolutionists believed that Archaeopteryx, meaning “ancient wing” or “ancient bird,” was a link between reptile and bird. But now, many do not. Its fossilized remains reveal perfectly formed feathers on aerodynamically designed wings capable of flight. Its wing and leg bones were thin and hollow. Its supposed reptilian features are found in birds today. And it does not predate birds, because fossils of other birds have been found in rocks of the same period as Archaeopteryx.12

*** ce chap. 6 pp. 71-72 Huge Gulfs—Can Evolution Bridge Them? ***

Huge Gulfs—Can Evolution Bridge Them?

FOSSILS give tangible evidence of the varieties of life that existed long before man’s arrival. But they have not produced the expected backing for the evolutionary view of how life began or how new kinds got started thereafter. Commenting on the lack of transitional fossils to bridge the biological gaps, Francis Hitching observes: “The curious thing is that there is a consistency about the fossil gaps: the fossils go missing in all the important places.”1

2 The important places he refers to are the gaps between the major divisions of animal life. An example of this is that fish are thought to have evolved from the invertebrates, creatures without a backbone. “Fish jump into the fossil record,” Hitching says, “seemingly from nowhere: mysteriously, suddenly, full formed.”2 Zoologist N. J. Berrill comments on his own evolutionary explanation of how the fish arrived, by saying: “In a sense this account is science fiction.”3

3 Evolutionary theory presumes that fish became amphibians, some amphibians became reptiles, from the reptiles came both mammals and birds, and eventually some mammals became men. The previous chapter has shown that the fossil record does not support these claims. .....'


--ON THE POSITIVE SIDE:

*** g90 10/22 p. 16 How Did They Get Such Lovely Feathers? ***

How Did They Get Such Lovely Feathers?

LILAC-BREASTED ROLLERS are common residents of central and southern Africa. They often perch on trees or telephone wires alongside the road. This gives them a good vantage point from which to scan their surroundings for insects and other food.

If you travel through Botswana or Zimbabwe, you may see a streak of bright blue feathers as one of these birds flies across the road. As the name roller indicates, they sometimes show off their colorful feathers in a tumbling aerobatic display. The accompanying picture of the bird and the inset of its wing reveals the roller’s vibrant colors. The wing feathers are a blend of four shades of blue together with black and brown. How well this contrasts with the lilac breast, orange cheeks, white forehead, and light-green crown! This raises an important question: How did they get such lovely feathers?

If you examine the roller’s feet, you will notice that they are covered with scales, not feathers. Did their feathers develop by chance from the scales of a reptile, as evolutionists teach?

Well, consider that a feather is an engineering marvel. Spreading from the shaft of a feather are rows of barbs. “Should two adjoining barbs become separated—and considerable force is needed to pull the vane apart—they are instantly zipped together again by drawing the feather through the fingertips,” explains the science textbook Integrated Principles of Zoology. “The bird, of course, does this with its bill.”

Could the hundreds of efficient “zippers” that make up a single feather have arisen by chance? Do scientists have any evidence that a scale actually developed into a feather? “Strangely enough,” admits the above-quoted book, “although modern birds possess both scales (especially on their feet) and feathers, no intermediate stage between the two has been discovered on either fossil or living forms.”

Surely, feathers bear testimony to a Master Engineer who is also an expert at blending lovely colors. Creatures such as the lilac-breasted roller are included among the “winged birds” that “praise the name of Jehovah,” the true God.—Psalm 148:7, 10-13.

[Picture Credit Line on page 16]

National Parks Board of South Africa