"Credit must be given to observation rather than theories, and to theories only insofar as they are confirmed by the observed facts."

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Answers to Biology Questions
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  1. How could wings have evolved? Or an eye?

    Until complete, any of these improvements (and many others) would have been a tremendous handicap, not an advantage. A land animal which began to lose a pair of legs and evolve wings would have been eaten by an animal with four good legs.


    Mark Isaak:

    Creationist Claim CB921
    Creationist Claim CB921.2
    Creationist Claim CB300
    Creationist Claim CB301


    John Harshman:

    Darwin covered the eye in the Origin, citing a series of living forms intermediate between light-sensitive spots and camera eyes. Obviously, these intermediates are capable of surviving, so the claim is silly on its face. As for wings, the dinosaur in which wings first began to evolve was bipedal, so the problem doesn't arise. Further, incipient wings can still function as legs. Why shouldn't they?


    Aron-Ra:

    Eyes began as simple photo-receptive cells, and evolved independently on a number of lines. The recent PBS special documentary of the life and work of Charles Darwin and his "Dangerous Idea" gives a wonderfully simple illustration of optic development where every successive stage is accomplished by only slight alterations in proportion, in size, shape or composition, each improving the already functional organ by increasing focus (over about a dozen successive stages), achieving a grasp of color, and several other refinements all requiring no real revisions of the existing form. At no time was there any perceptible handicap during the development of the eye.

    The wings of pterygota, (one line of insects and the only flying arthropods) were a simple distention in the caphalothorax shell of an animal already so lightly-constructed that flight by any means was easily attained. Vertebrate wings of various types are much more complex, and all evolved differently. None of which ever presented any handicap at any point in their development, despite the claims of this site.

    The wings of flying fish are of course just oversized pectoral fins. Snake's "wings" such as those of Chrysopelea paradisi, (the flying snake of Paradise) are just extensions of the same rib-flattening technique used by hooded cobras. Draco volans, the "flying dragon" of Southeast Asia also distends and flattens its ribs in an exaggeration of the hiss-flattening that other local lizards use as a defense mechanism. But true wings never presented any disadvantage in their development either. Bat's wings are little more than an exaggeration of earlier gliding membranes like those of phalangers and flying squirrels. Pterosaur wings began much the same way, from elder reptilian versions of flying squirrels similar to Megalancosaurus from the late-Triassic period. Pterosaurs evolved before bats or even dinosaurs, appearing as an already increasingly diverse order even before the Mesozoic era. They share common ancestry with dinosaurs, but aren't otherwise related to birds at all.

    Bird's wings, (by far the most complex) began as the clawed arms of a particular line of early dinosaurs called maniraptors, or "hand-grasping birds-of-prey", which is what their name means. Maniraptors are descended from a line of very bird-like theropod dinosaurs called coelosaurs, many of which are now even known to have had feathers. These "half-wings" have been found on a bird-like dinosaur called Caudipteryx, and were probably used as a sexual display if not also to fluff up and deter uncertain aggressors. These are both valuable applications of flightless wings. These supposedly useless half-wings have also been evidenced on flightless dromeosaurs like the Ovaraptors as being crucial to the warming of a large clutch of eggs. Breeding, defense, and the successful rearing of more young are all powerful drives for the evolutionary development of something so useful as a feathered limb without ever needing it to fly. But once a flight advantage is discovered, that too could dramatically drive selective pressure. Early flying dinosaurs like Archeopteryx and Rahonavis, and even later aves like Confusiousornis and Protopteryx still had three prehensile clawed fingers in their wings. For most modern birds, as well as a couple lines of extinct orders, the fingers have been lost. Only one of two surviving orders of birds still has them, and those are the ratites. I have one of these living in my back yard. Its over six feet tall, and is literally the closest thing to a theropod dinosaur that still lives.

    http://locolobo.homestead.com/AviaryofEden.html



  2. How could DNA have replicated without the enzymes which it controls?

    DNA can only be reproduced with the help of certain enzymes which can only be produced by DNA which had to be produced by enzymes . . .



    John Harshman:

    Look up the RNA world. RNA can function both as template and enzyme. Obviously DNA and protein were not the first material of life.



  3. Why would DNA evolve when its purpose is the keep just that from happening?

    The basic function of DNA is to pass on a very complex and exact code or plan for development for the next generation.


    John Harshman:

    This question seems to deny that mutations happen. Otherwise it makes no sense. DNA's purpose may be to pass on an exact code, but it doesn't fulfill that function perfectly. And thus it evolves, as all imperfect replicators must.



  4. Why did some animals not evolve?

    Evolutionists state that some animals (like the duck billed platypus) have remained unchanged for millions of years. Why were these animals left out of the almost universal improvements that nature had "planned"?



    John Harshman:

    Nature makes no plans. Improvements are by no means universal. They are local events, benefitting particular species in particular environments. Rates of morphological evolution vary tremendously through time and taxa. Some taxa don't change noticeably over millions of years. (Though platypuses are not among them, since the only known fossil platypus has teeth, if I recall, which modern ones lack.) However, this is not true for molecules. DNA evolves all the time, and there are no living fossils as far as DNA is concerned. In what way is this supposed to be a problem for evolutionary theory?


    Aron-Ra:

    Nature didn't plan anything in advance. The main divisions of mammals are eutherians, (placental mammals) marsupials and monotremes which still exist, and the palaeoryctoids, multituberculates and triconodonts which no longer do. All the extinct groups may be monotremes as well, but weren't as successful as the marsupials who themselves weren't as successful as eutherians like ourselves. That's why most of the world's marsupials and the only two surviving monotremes are restricted to Australia, which separated from all the other continents before eutherians developed.

    Placental mammals didn't have to evolve, but if they didn't then some variants of monotreme mammals may have found an alternative adaptation to increase their reproductivity. But they didn't have to as long as they can get by without facing extinction. Since there are only two monotremes and very few marsupials, and all the other groups have become extinct since placental mammals arrived, then theirs is not the most competitive means. For all we know, modern monotremes have evolved, there being no platypuses or echidnas in the fossil record. What is in the fossil record shows a constant series of subtle changes far beyond triconodonts and into cynodonts and even older therapsids, themselves stemming from what some would call synapsid reptiles.

    And of course in every case, there is a degree of branching off from the main stock, and that branching off still continues in every group, even among scorpions, which are another group often cited as never evolving since they arrived. With 1,300 species of scorpions worldwide, not counting all the pseudo-scorpions, whip-scorpions and closely-related creepy-crawly things, there has obviously been a good deal of evolution still going on with them even though many of them are already considered perfect for their environment and need not change further.

    http://locolobo.homestead.com/chelicerates.html



  5. Why can we classify animals?

    Assuming that all animals evolved from a single cell, there should be no distinction between kinds. This would result in one branch rather than the tree of animals which zoologists have been able to classify.


    John Harshman:

    This is perhaps the most senseless of all claims made. The hypothetical single cell would have divided, and those cells would have divided. Add mutations in between cell divisions and you get -- what?: a branching tree. Of course all animals did not evolve from a single cell, but from some one species of single-celled organisms. But the principle is the same. Species divide -- we call it speciation -- and thus when fixation of novel mutations is added in to each lineage, we get, once more, a branching tree. You really can't avoid this in descent with modification and branching.

    Now: under the creationist theory, why can we classify animals? I'm waiting.


    Floyd:

    If evolution proceeded in a linear pathway, similar to the pathway proposed by Jean Lamarck we might have exactly this type of difficulty. However, evolution proceeds not by a process of linear progress, but by a process of branching and diversification. When a single species splits into two, systematists are able to compare those two and determine that they are more similar to each other than they are to other species. The pattern of evolution is more like a branching "tree" than like a ladder, and the twigs that are closest together on the tree represent species that are most closely related. More distantly located twigs are less closely related, but those on the same bough are more related than those on different boughs, and boughs from the same branch are more closely related to each other than those on other branches. Therefore, we are able to classify organisms on the basis of their physical similarity simply because organisms descended from a single ancestor share more in common with each other than they do with organisms who descend from a different ancestor. When we look at the DNA of these organisms, we find that there is almost a perfect match between the "tree" constructed from DNA and that constructed from the physical form ("morphology") of the organisms. This dual similarity is known as the "Twin Nested Hierarchy" (talkorigins.org and ebonmusings.org include informal discussions of the twin nested hierarchy in more detail).

    The pattern is also analogous to family structure. Each individual is most similar in DNA and usually in appearance to his or her own brothers and sisters, compared to other people. The obvious reason is that the siblings share the same parents. The individual is somewhat less similar to his or her cousins than to siblings, but still more similar than s/he is to unrelated individuals, since they all share the same grandparents and have inherited traits from those grandparents, by way of their parents. Second cousins are slightly less similar, but still more like the individual than unrelated people, because they share the same great-grandparents and have each inherited some of those great grandparents' characteristics, and so on. The same is true of species. Two species that derived from a single ancestral species will share in common more than they do with species whose immediate ancestor was different. Thus people are physically and genetically more similar to chimps than we are to babboons, and more similar to babboons than to bears, and more similar to bears than to fish, and more similar to fish than to rhotodendrons, and so on.


    Sverker Johansson:

    Classification is easy -- his favorite god made them distinct.

    More to the point, why can we, under creationist "theory", classify animals into nested hierarchies?



  6. Why are the missing links still missing?

    From vertebrates to invertebrates, reptiles to birds there should be billions of animals. The transition from legs to wings alone should have included a countless number of animals, yet none can be found.


    Mark Isaak:

    Creationist Claim CC200
    Creationist Claim CC200.1
    Creationist Claim CC200.3


    John Harshman:

    There were certainly billions of animals through time, but of course the fossil record only preserves a small percentage of these. Nevertheless there are plenty of intermediate fossils. My favorite recent discovery in the transition from legs (or arms, really) to wings would be Microraptor gui. Whatever, in the creationist universe, could this animal possibly be?


    Floyd:

    In fact, we have found thousands upon thousands of intermediate species in the fossil record. origins.tv includes links to several sites that describe some of the transitionals that have already been discovered, both living and extinct, and remember that we have only been looking for them for less than 100 years.

    But as it is phrased, this question has a more obvious answer. The so-called "missing links" are still missing because once we have discovered them, they are no longer missing, and we have to call them "found links." Of course in any historical sequence, each time a gap is "filled in," two smaller gaps are formed. If we are trying to discover the sequence of numbers between 1 and 5, we start out with one big gap between 1 and 5. If we then "discover" number 3, then we have two smaller gaps, between 1 and 3 and between 3 and 5. The same is true for fossil species in a lineage; each time we find a fossil species that fits into a known gap, we create two new gaps that need to be filled. In the reconstruction of the human lineage, our problem is not that we can't find the fossils, but that we have already found so many of them that we have a hard time determining which came first, second, third, and so on. The remaining difficulty in determining the historical pattern of human evolution is not the task of finding more fossils (although that remains important), but of sorting those that we already have.



  7. Why do insects and plants simply start with all their kinds?

    They should have evolved from less complex creatures.



    John Harshman:

    This question makes no sense. First, we need a definition of "kind" to understand it. Are kinds like species, or are they something else? At any rate, insects do not start with all their kinds. The earliest insect fossils are of collembolans only. Other sorts appear gradually in the fossil record over hundreds of millions of years. Whether this reflects their actual evolution is unclear, since the fossil record of insects is poor.

    Plants, on the other hand, have a pretty good fossil record, especially pollen. And we can tell that the earliest plants were quite primitive, being on the scale of organization of modern club mosses. They probably invaded the land in the Ordovician; at least there are plant spores of that age, and the first really good body fossils are from the Devonian. On the other hand, flowering plants don't appear until the mid-Cretaceous. Other types in what you might call a ladder of complexity appear at various times in between, just as you might expect from an evolutionary series. Creationists should be seriously embarrassed by the fossil record of plants.



  8. Why are there no animals in the salt flats?

    The salt flats were probably caused by evaporation of a large salty lake, yet there are no fossils of the animals that lived there.


    John Harshman:

    Sorry, this is unanswerable. What salt flats?




  9. Why couldn't all of those animals in a fossil column be put there at once - they all live together now?


    John Harshman:

    They do? Can you show me a spot where trilobites, graptolites, conodonts, and rudists all live together now?



  10. Why are there breaks between ages in a fossil column?

    No actual column is in one place. The largest sample is in the Grand Canyon, which is only 1 mile. The entire column should be about 100 miles thick.



    John Harshman:

    Because the geological history of any given spot tends to be complex, having periods of subsidence and deposition, and other periods of uplift and erosion. Plate tectonics drives this, and you should look into it.

    Hey, what's this doing in the biology section?



  11. Where are all of the people who have died?

    Assuming a population growth of only 1/2% (1/4 the present rate) the current population can be reached in only 4,000 years. If one assumes a growth rate slow enough to account for the current population in 1 million years, there would have been 3,000 billion human bodies.



    John Harshman:

    Yes, and where are all the dead flies? Have you calculated how many millions of tons of flies must have died in the last thousand years alone? Earth to creationists: most bodies are decomposed by the forces of decay.

    P.S. No constant rate of growth can possibly account for the variations in the human population. Try that sort of thing and you end up with stuff like 15 people being available to build the pyramids. Don't go there.


    Floyd:

    This question was originally proposed by Henry Morris in 1974, and to answer it takes a bit of exploration into anthropology.

    Humans adopted farming as a way of life less than 10,000 years ago. Prior to that date, we subsisted by fishing and collecting shellfish, hunting wild animals and gathering wild plants. Studies of modern hunting and gathering societies such as the Mbuti (Turnbull 1962 [1998]) and the !Kung (Lee and DeVore 1976) show that they can not stay in one place very long, because they deplete the plants and game that is available in that area. Therefore, hunting and gathering societies must move frequently. Infants have a hard time keeping up on their own when their community packs up and moves, so their mothers must carry them. Since mothers can only carry at most two infants at a time, they can not have another child until earlier siblings are old enough to walk and keep up on their own. As a result of the mothers restricting their rate of birth, hunting and gathering societies don't increase their population size. In fact, births of infants and deaths of elders ballance each other out, and hunting and gathering societies maintain a stable population.

    Once a society adopts farming, the restriction on reproduction is relaxed, and reproductive rates increase. However, settling in a larger farming community that stays in one place year round creates problems of its own. Most importantly, sanitation and epidemic disease become important issues. A mobile society can simply walk away from its waste, but a farming community can not, and diseases such as typhus, bubonic plague, and influenza can decimate communities. So even these early farming societies could not maintain a birth rate equal to today's. It is only since the development of reliable sanitation systems and medical treatment that we have been reproducing at today's rate.

    Because of these facts of history, using a "fixed rate" in the calculation of population size is inappropriate. Besides, using the calculation above leads us to several ridiculous scenarios, such as the Great Pyramid of Cheops (Kufhu) being built by a mere 40 people (talkorgins.org and www.geocities.com/CapeCanaveral/Hangar/2437/populate.htm contain detailed explanations of the problems with this argument).

    References Cited

    Lee, Richard B. and DeVore, Irven. Kalahari Hunter-Gatherers. London: Harvard University Press, 1976.

    Turnbull, Colin. The Forest People. New York: Simon and Schuster 1962 [1998 second edition]



  12. What held the first cell's stuff (DNA, RNA, etc) together - a cell wall?

    Without a cell wall of some kind, the delicately formed cell parts would have simply drifted apart, never to form life. A cell well speaks of fundamental building blocks far more complex than simply the parts alone.



    John Harshman:

    More likely a cell membrane. Cell membranes are pretty simple, actually. Just a phospholipid or some other soapy kind of molecule. They form themselves into bilayers all by themselves.



  13. Why did dinosaurs become extinct?


    John Harshman:

    There are of course many theories. I like the asteroid collision theory myself. And of course not all dinosaurs are extinct. One group survived to become the most diverse bunch of tetrapods today. Why do you ask?



  14. How were mammoths frozen alive?

    Mammoths have been found frozen with flowers in their stomachs, indicating a very rapid climate change.



    John Harshman:

    Not quite. The flowers in question are denizens of cold climates. There are all sorts of ways for this to happen. Perhaps the mammoth was grazing in tundra when it fell into a hole in the permafrost, and was buried by, say, a collapse of the walls of this hole. Do you really suppose that this is evidence for some sort of worldwide flood?



  15. Why does almost every mountain range have fossils of sea animals?



    John Harshman:

    Plate tectonics again. Because the sediments that compose the mountain were part of a depositional basin, under the sea, before they were uplifted to make mountains.



  16. Why are there still monkeys?



    John Harshman:

    Wow! Many creationists insist that this is an evolutionist strawman, and that no real creationists actually ask that question. Thank you, thank you for proving them wrong. Hey all you creationists! Look at this!

    There are still monkeys because they haven't become extinct and are doing fine in their own environments. One particular lineage of monkeys lost their tails and took up brachiating, and we call those the apes. One particular lineage of monkeys from that group starting walking around on the ground, moved into the savannnahs, and got big brains. (You may guess which lineage I meant there.) Other monkeys did other things. There are all sorts of ways to make a living.


    David Wise:

    I have only seen that claim actually used about three times in the 22 years I've been following the creation/evolution "issue" (quoted because it doesn't really exist, but rather is more a fabrication of "creation science") and each time I see it I get the same sick feeling of "the poor idiot, he just shot himself square in the foot again." It's the kind of really outlandishly stupid claim that somebody would dream up to spoof a creationist who is completely ignorant of even the most basic evolutionary theory, which is why I am always so shocked and appalled when I see somebody actually using it in earnest. I'm not trying to insult anyone here, but it just boggles the mind how anybody could not see what an obvious howler that claim is.

    Seriously, now, explain yourself. Why do you think that there shouldn't still be monkeys? What part of evolutionary theory do you think requires all monkeys to be extinct? What makes you think that evolution requires that the instant the first animal crawled up onto the land that all life in the seas died out? Do a little reading on "allopatric speciation" (not from a creationist source, please, they're much too likely to misrepresent it) and then you should realize your error. And you should start to realize how much this type of claim discredits you and your cause.



  17. Why can't we make anything but a fruit fly from a fruit fly?



    John Harshman:

    Has anyone tried? If so, I missed it.


    Sverker Johansson:

    We've tried to make a different species of fruit fly, with fair success.



  18. Why have so many animals stayed the same all over the world?



    John Harshman:

    There is too little in this question to go on. What did that mean?


    Floyd:

    I assume that the question is why some plants and animals alive today look so similar to the preserved fossil remains of organisms that lived long ago. The answer to this question is easy; as my father always said, "if it ain't broke, don't fix it."

    Bivalves (e.g. clams), ferns, ginko trees, and numerous other organisms look quite similar to their ancient ancestors simply because their form suits their environment quite well, and changing their form would probably cause them to do less well in their environment. In learning about evolution, we must remember that selection can be a stabilising force, as well as a force for change. If the environment is stable (and a clam's environment today is pretty much the same as it has been for an awfully long time) then once a lineage finds a successful adaptation to that environment, there is no impetus to change.

    One might just as well ask why building bricks today are shaped the same way they were thousands of years ago. The shape works for the task, and as long as we keep using them for the same task, there is no real reason to change them.

    Of course if the environment occupied by that organism changes, selection may favor changed variants. We need to look at evolution as an interaction between organisms and their environment, and in stable habitats, we simply don't expect to see much change.



  19. How did the first cell, formed from all this tremendous chemical magic, live in its hostile environment long enough to reproduce?



    John Harshman:

    What makes you think that its environment was hostile?



  20. How does natural selection produce increasingly complex creatures in light of genetic depletion?

    For natural selection to occur, some detrimental trait must be lost. The gene which carried that trait is therefore no longer, and the resultant offspring has fewer genes than its parent.



    John Harshman:

    Not at all. Selection general involves choosing among alleles. Look that word up in a dictionary. Genes are sometimes lost, though. Genes are also gained. This happens all the time.



  21. Why do all living creatures reproduce after their kind?

    Evolution relies on the fact that all of the kinds came into being by not reproducing after their kind.



    John Harshman:

    Well, they don't precisely reproduce after their kind. Unless you're talking about a clonal organism with a mutation rate of zero, and there aren't any of those. Children are different from their parents, and every child includes a fair number of new mutations. Most of these mutations have no effect on phenotype, but some do. Some of these mutations eventually become fixed in populations. Fix enough mutations and you get big differences from previous populations. See?



  22. Why in the past did mutations seem to be beneficial, while in the present most mutations are harmful?

    Mutations must obey the second law of thermodynamics. Most ancestors were larger than their descendants (saber tooth tiger, mammoth, . . .).



    John Harshman:

    Actually, there's a rule in paleontology called Cope's Law, stating that most ancestors are smaller than their descendants. It's not a law really, just an observation. There are theories to account for it if you're interested.

    Who says mutations were all beneficial in the past? There's this thing called natural selection, see. It filters out the bad mutations and duplicates the good mutations manyfold. As now, so in the past.



  23. How long would it take a beneficial mutation to change an entire population?


    John Harshman:

    This depends on how beneficial the mutation was, and how big the population was, and on all sorts of other factors, like what the fitnesses of other competing alleles were, whether the population was panmictic or not, whether there were any assortative mating or frequency effects, etc. You can read a population genetics text if you want particular answers. But why is this a problem for evolution?


    Sverker Johansson:

    The short answer is that it's geologically fast for any reasonable combination of paremeters, as long as the mutation is beneficial enough to be noticed at all.

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