The General Anti-Creationism FAQ
Evolution
by Jim MerittOriginally formatted for the web by
Tedd Hadley
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| The Meritt FAQ has been replaced by Mark Isaak's extensive Index to Creationist Claims which is superior in almost every respect. It deals with evolution issues in its biology section, especially in the evolution subsection. Meritt FAQ is preserved for archival purposes only and its text will not be updated. |
Mutations are never beneficial
The textbook example of the effects of radiation upon genes is the old "carnation seeds exposed to radiocobalt". Clearly some of the flowers produced are prettier than the originals. Therefore, the "never" is disproved.
Mutations are almost always harmful.
Note: "almost". A lot can happen in a large population over long times.
Mutations rarely occur.
Note: "rarely". A lot can happen in a large population over long times.
There have fairly good descriptions, on the net, of how eyes could have evolved, and of how bird lungs could have evolved. These were nice rebuttals of the claim that "it wasn't useful until finished, so it couldn't have got started".
And how many of these "numerous coordinated innovations" can be caused by one change? Check out, for instance, the effect of changing the age at which bone growth stops in human beings.
There are semi-venomous snakes, and in fact the issue was discussed earlier how some snakes "drip" the venomous saliva while ones with more developed systems "inject" the saliva via hollow teeth. Whales have semi-legs (ok, so they're not fish). How about the cooperating jawbones that have slowly become our hearing mechanisms, seen to be incrementally represented from reptilian jawbones.
The complete developmental flowchart of the nematode worm--what cells divide to form what other cells all the way from the 1-cell egg to the thousand-cell adult--has been determined. It contains numerous examples of repeated tricks that look very much like subroutines. For example (this is from memory and may not be precise) there is a pattern of a cell dividing twice to form two muscle cells, one neuron and one cell which dies that occurs dozens of times in the worm's development, not always in exactly the same situation-- different kinds of nerve cells are produced--but with exactly the same pattern (that is, it is the most posterior cell which dies, and so forth).
People often assume that to evolve a new structure requires new code. In this case at least, however, a new nerve with attendant muscle fibers could be made (and there are mutants which do this) just by triggering this subroutine in a cell which normally doesn't do it.
Also know as "adaptions", right? Thanks. Whale legs are definitely an adaption to their current environment. Thank-you.
The puzzle of how organs, once evolved, come to be lost (degeneration).
Evolution operating on the amplification and diminution of structures is well known. The appearance of vestigial structures, at all, reflects on the use of preexisting developmental pathways, rather than on the purposefulness or efficiency of the process.
"Use it or lose it" is a popular expression which may help the understanding. Maintaining something is a drain on materials and energy. Selection would go against a disadvantageous drain.
This is the appeal to progress and perfection that biases a lot of thinking about evolution, even by some biologists of the past. The changes seen are just adaptations of existing structures, not perfections or progress toward a goal.
Note: "fittest" is not "optimal".
Pre-adaptation: Organs appear before they are needed.
Now, how do you tell this?
Why did man lose his hair and tail?
Note that hair and tails ARE still present. The selection process is a statistical phenomena.
There is a theory that sometime within Man's evolutionary past he had an aquatic phase. This is upheld by:
Thus, we have the same amount of hair (almost) as any other marine mammal. And for the exact same reasons. We just didn't have a long enough marine phase for further adaptations (lose arms & legs).
No new species (alternately, "kinds") are evolving today.
Three species of wildflowers called goatsbeards were introduced to the United States from Europe shortly after the turn of the century. Within a few decades their populations expanded and began to encounter one another in the American West. Whenever mixed populations occurred, the specied interbred (hybridizing) producing sterile hybrid offspring. Suddenly, in the late Forties two new species of goatsbeard appeared near Pullman, Washington. Although the new species were similar in appearance to the hybrids, they produced fertile offspring. The evolutionary process had created a separate species that could reproduce but not mate with the goatsbeard plants from which it had evolved.
The article is on page 22 of the February, 1989 issue of Scientific American. It's called "A Breed Apart." It tells about studies conducted on a fruit fly, Rhagoletis pomonella, that is a parasite of the hawthorn tree and its fruit, which is commonly called the thorn apple. About 150 years ago, some of these flies began infesting apple trees, as well. The flies feed an breed on either apples or thorn apples, but not both. There's enough evidence to convince the scientific investigators that they're witnessing speciation in action. Note that some of the investigators set out to prove that speciation was not happening; the evidence convinced them otherwise.
[Sources: "Instant Evolution", Science Digest, July 1982 Saladin / Gish debate at Auburn University at Montgomery, 24 March 1984]
How can you say that no new species have arisen when dozens of previously undiscovered species are found each year in Costa Rica alone? Also, isn't the latest evidence that maize evolved about 4000 years ago?
What is a "kind"?
Just because two animals LOOK similar does not mean there is "common ancestry"
The interesting point is that, when checked, there IS.
Genetic comparisons reveal (objectively) a kinship where it was before predicted on evolutionary grounds.
I believe the error rate is less than 1%. What is fascinating about the comparisons of the numbers of genes shared between species is that when you draw a genetic tree of what species are related to what, it looks almost identical to the tree drawn by anthropologists who make their tree based on comparisons of morphology (humans look more like chimps than turtles therefore chimps are more closely related). This is the beauty of science that a hypothesis (relatedness of species) is shown by two completely differing mechanisms just as the age of artifacts can be determined by rock layers (those on top are newer) and carbon and other radioactive dating techniques.
How is this done? In brief: DNA similarity is measured by mixing fragments of DNA from the two species and measuring the thermal stability of the resulting hybrid molecules, which is proportional to the degree of matching. It can be calibrated by using DNAs of known composition, for example the genomes of completely sequenced viruses. Accuracy is limited by the ability to measure the melting temperature and by the slight difference in stability between A-T base pairs and C-G ones. There has been heavy theoretical debate (ending in an amazing shouting match at a meeting last summer, alas--I was there, and it was embarrassing) about whether the method is accurate enough to resolve the chimp/ human/gorilla trichotomy.
DNA similarity does measure overall composition, and two organisms could be very different morphologically while still having high DNA similarity (indeed, chimps and humans are much more dissimilar than most pairs with the same DNA distance). However, overall composition is probably a better guide to relatedness than specific genes, which are likely to be under different selection in humans and chimps.
What is the noise, and what is the signal? "Junk" DNA is the most useful for determining phylogeny, because it is more likely to evolve in a gradual time-dependent fashion. Coding and controlling regions are interesting in that they tell us about the differences.
They do. Tails, for instance. And other "ape" traits that happen to also be "human traits". Like toes, body hair, simian crease,...
This disregards the basic mechanisms of natural selection and genetics. It makes the wrong assumption that ape-like characters are recessive and that all of the traits in the ancestor population are present but usually unexpressed in the supposed descendant population. Neither idea is true.
The premise is incorrect. First, what is meant by "hybrid" is unclear in this context - is it a hybrid only if it is infertile? And even in those cases in which the offspring is usually infertile, that is not always the case. As witnessed the horse and the donkey.
It is not individuals that evolve but populations. A population evolves by gradual changes in gene frequency until it becomes a distinct species that is no longer capable of interbreeding with similar populations that shared a common ancestor. All of the individuals within the population can mate successfully with each other so there is no problem with "hybrids". There are quite a few examples of different populations of the same species which have trouble interbreeding, in other words the hybrids are not viable. These populations are evolving and may become separate species. It is a common mistake to assume that a new species begins when an individual "mutates" or "evolves" in a single step - this is simply not how evolution works.
The failure of some organisms to evolve at all.
If it passes the selection filter, no change required. These organisms are excellently adapted to their particular niche in their environment. (like sharks: the "perfect eating machine", right?)
Like the brachiopod Lingula, and the cockroach, identifiable through most of the phanerazoic and still with us. If an organism is well adapted to a niche it can readily occupy, then why should it evolve?
No new phyla, classes, or orders have appeared.
Subsequently to what?
Trees of descent for organisms are drawn by grouping organisms together based on common features. Twigs which are close together are organisms which differ only in few and minor respects. Main branches, down at the bottom of the tree, are groups of organisms that differ in many and major respects. One of the main premises of evolution is that this tree is (more or less) proportional to time. Asking for a phylum to appear today is asking for a major branch to be up at the tip of the tree--it makes no sense, considering the way such trees are drawn!
It is perfectly possible that in several million years there will be recognizable phyla which were just differentiating today, but there is no way to recognize a "new phylum" in the bud. For example, modern plants use two different photosynthesis reactions. It is quite possible that those two groups will eventually be so different that we will call them separate phyla, because the two reactions probably favor different evolutionary pathways. But how can we know in advance whether or not this will happen? That's what you're asking for when you want to see a new phylum arise today.
This is just not true. while most of the phyla present today were present at the beginning of the Cambrian, and their origin is shrouded, there is enough of a fossil record from the so-called eo-cambrain to suggest that some of the animals found in Australia are different phyla that became extinct by the time fossils became abundant. The affinities of several Cambrian groups is by no means clear, and they might be separate phyla, such as the archeocyathids. Our phylum, Vetebrata (Chordata), appears no earlier than Ordovician, and then only the cartilaginous and jawless fish are known. All the other classes appear later than that.
Vascular plants, and all more advanced plant phyla appear no earlier than Silurian time.
There are now five kingdoms known, based on their biochemistry and there are enough precambrain microfossils to document their appearance. The geochemistry of sediments in Precambrain rocks is understood well enough to establish when the oxygen level of the biosphere was high enough to support modern plants and animals, that comprise two of the five kingdoms. Before this date it can be inferred that the Plant and Animal kingdoms did not exist. I am not familiar with Precambrain events to fix this date, 1.8 billion years B.P. ?, or to document the micro fossils that might bear this out.
If you start with the same ancestor, they can only vary so much. Also, what he thinks are "different circumstances" are not necessarily so. Physics has an interesting set of constraints...
Many species have remained absolutely fixed throughout geologic time.
There are no known examples of organisms that have not evolved over a period of time and this includes cockroaches, lungfish, lampreys, sharks, bacteria, and all other organisms that some people claim are "frozen in time". Some of these species appear to be morphologically similar to ancestors that lived in the past but evolution is much more than external appearance. When the structure of their genes and proteins are examined it becomes obvious that they have evolved at the molecular level. In fact the rate of evolution of these species is similar to that of species whose external appearance has changed more drastically. It is incorrect to claim that some organisms have not evolved simply because their external morphology has not changed.
The problem here is that the fossil record only preserves some parts of an organism. The fact that these parts have not changed very much doesn't mean that the species has not evolved.
There is no hierarchy to evolution. There is no reason to suppose that modern organisms should be "higher" than extinct ones. Loss of a structure is just as much evolution as gain of one. If Creationists admit that some organisms have become "degenerate" then they are admitting to evolution.
All the great phyla appear quite suddenly in the fossil record.
Marvelous. As long as he gets to pick which ones he wants, they do. Collect the data to support you conclusion. Keep throwing out the outliers (97% discarded?) till it fits.
This can be explained by punctuated evolution, in this regard it is important to note that not all suggested lineages in the fossil record have such abrupt changes and gaps. There are several fossil successions that record critical evolutionary steps and at a fine taxinomic resolution. The development of the modern horse is a fairly complete succession, as is the development of mammal skull characteristics from the therapsida of Permean time. Other examples of pretty gradual evolution?
Instantaneous changes of taxa, on a geologic time scale, between long periods of stability does not pose insurmountable problems for neo-evolution since it is genetic equilibrium that allows long stable periods and stressing the gene pool into metastable states that allows for punctuated evolution.
Many extinctions lack obvious reasons.
The "obvious reasons" are obvious to him, and do not necessarily have anything to do with reality (i.e. 'cause he don't see it don't make it gone)
This may be a problem for compiling a history of life, but the existence of extinctions at all poses problems for anyone claiming life has teleology. If a divine creator is calling the shots then finding extinctions casts doubt on the perfection of his plan, or even the existence of a plan.
As for finding causes for extinctions, this is going to be an area of some debate for years to come. The ideas that have been advanced find some common collapse of habitat that is consistent with evolutionary biology. The suddenness, or seeming catastrophe of proposed events do not really threaten uniformitarianism because they are changes of rate, but not of process.
The "Lack of Obvious Reasons", may overstate the problem, for a series of events such as asteroid impact, continental collisions, destruction of barriers between habitats, all have been advanced and all point to the destruction of habitat and with it mass extinctions.
Selection cannot change the frequency of variants
Since evolution is, by definition, a change in the frequency of genes in a population, then this statement is equivalent to saying that selection cannot cause evolution. There are many experiments in the literature that directly demonstrate how false and ridiculous this statement really is. Perhaps the easiest examples for the non-biologist are those that involve human selection, as in breeds of dogs or cattle. In those cases selection for distinct characteristics has led to populations with differing frequencies of alleles (variants). Thus selection has been PROVEN capable of changing the frequency of variants or alleles in a population and we have every reason to believe that it did so in the past as well.
Directional selection (selection "for" or "against" something) in a static environment will lose variation. To get a more interesting result, you can look at either of two things:
1. Selection which is not directional. Here are some examples:
Frequency dependent selection. Forms which are rare are at an advantage. There are several decent real-world examples of this; female fruit flies prefer males who look "different", and animals which have immune system genes different from their neighbors' seem less likely to get diseases from them.
Heterozygote advantage. The organism with two different forms of the gene has an advantage over others. The classical example is sickle-cell anemia in humans, where the person with one sickle and one normal allele is protected from malaria.
Two kinds of selection pulling in different directions. For example, females may prefer brightly colored males, but so may predators. Some values for the parameters here will give a balance of different forms in the population.
2. Non-static environments. This is much harder to model, but interesting. You can easily get frequency-dependent selection out of an environment with two food sources, both subject to overexploitation. Environments which change over time either randomly or in a cycle can also maintain variability.
The simplest model I know in which something like speciation can be seen to happen is one that contains two factors:
There is a gene with two variants, and the heterozygote is worse than either homozygote.
There is the possibility for evolving reproductive isolation based on the first gene.
Reproductive isolation could be modeled in several ways. You could explicitly add a gene that controls mate recognition. You could arrange your simulated organisms on a grid and restrict most mating to near neighbors, and see if two populations separated from an initial mixture.
Don't forget that if you use random rather than strictly proportional selection (that is, if you use a random number to see who lives and who dies), population size makes a huge difference. It is almost impossible to maintain high variability in a tiny population, even with strong selection.
Eight impossible gulfs. Impossible to find gulfs.
1) Between the living and non-living or dead matter
This is the abiogenesis debate.
The rest is a taxinomy of man with the similarity argument turned into the gaps argument. Is the glass half empty or half full?
What is this gulf? I have yet (despite looking and asking many) found it at all, let alone found it to be an impossible gulf.
The spectrum between clearly living and singular elementary particles is wide, and not linear (few things really are) but it appears to be continuous.
2) Between the vegetable and the animal kingdoms
Animal cells have some similarity with plant cells, and indeed there are forms, euglena, with cloroplasts and flagellae, that look like intermediates. Cells from both kingdoms are eukeryots that are distinct from other cell types belonging to at least three other kingdoms.
There are quite a few plant/animals in the same creature. Most microscopic because a plant doesn't collect enough energy to be mobile in large scale. But there are plenty of small ones. What is a euglena? And where do protista & viri fit in here?
3) Between the invertebrates and the vertebrates;
The vetebrates are biochemically closest to the echinodermata, and urochordates. The free swimming soft chord animals are similar to the sessile forms.
See also sharks and squids.
4) Between marine animals and amphibians;
A steady change from fish to lobefined air breathing fish to amphibians with fish like larval stages can be observed in extant species and in the fossil record.
See also mudpuppies and frogs. An amphibian that never leaves the water is a marine animal. This gulf is not only impossible, it is non-existent.
5) Between amphibians and reptiles;
Amphibians predate reptiles in the fossil record. The development of the amneonic egg, with shell and the difference in the skin of extant reptiles and amphibians suggests that the reptilian characters were adaptations developed on amphibian ancestors. The time in the fossil record when the reptiles became important was one when amphibian habitats were being reduced and when reptiles could have succeeded on drier continents.
What is this gulf, and what was a dinosaur? (warning: trick question! Specifically what is the impossible gulf between, for instance, a salamander and a chameleon?
6) Between reptiles and birds;
The ornithischia, with bird-like pelvises appeared before the modern birds, whch began to appear in Cretaceous time. Intermediates are known.
7) Between reptiles and mammals;
The therapsida in permean time, Mammal-like reptiles appear before the first mammals, but intermediate forms are known, and a fairly complete record of the changes in the facial bones between these reptiles and true mammals is known from Permean time. Does anyone know if mammalian dentition is documented into this time. Did the Therapsida have differentiated dentition?
8) Between mammals and the human body;
The distinguishing characteristic of living MAMMALS is lactation. Despite the invention of baby bottles, human females still lactate.
"With the development of GUT, we see galaxy formation is no longer a problem at all but simply one more natural phenomenon with a perfectly natural explanation." [James S. Trefil, The Moment of Creation]
Evolution doesn't explain personality, emotions, abstract reason, conscience, etc.
Please read:
The Evolution of Behavior Smith, Scientific American, Sept 1978 Xenopsychology R. A. Freitas, Analog Apr 81
Directly Interacting Extra-terrestrial Technological Communities Viewing, JBIS, vol 28, pp 735-755, 1975
Computer Simulation of Cultural Drift: Limits on Interstellar Colonization Bainbridge, JBIS, vol 37, pp 420-429, 1984
The Improbability of Behavioral Convergence in Aliens Behavioral Implications of Morphology Coffey, JBIS, vol 38, pp 515-520, 1985
The climatic background to the birth of civilization Lamb, Advancement of Science vol 25 pp 103 - 120 1968
Embryology: "it is hard to see why the history of the species should be repeated by the embryo."
This is similar to the argument used by Bob Bales that it is hard to see evolution in the fossil or living evidence. The problem with this claim is that the understanding of what you would look for comes from first looking at living things, fossils, and in this case embryos. You must know how to describe these things in some detail before you can decide if the claims that similar structures indicate common ancestry, or that embryonic stages mimic ancestral forms. "It is hard ", means you haven't looked. Present an objection based on what all agree is evidence.
That is more a function of his "hard to see" than why it does.
Evolution doesn't explain abiogenesis or how genes are expressed.
To the creationists. And it does explain how to study the unknown, rather than bowing out.
The existence of long-term trends (orthogenesis).
So? Study any climatology? The environment has some VERY long-term trends.
"Overshoot" or evolutionary "momentum" occurs.
A not uncommon problem with non-linear search routines, and with systems with very long delay times in the feedback.
Over-specialization with no adaptive value.
How do you determine this? Besides, most nonlinear search routines I am familiar with have a tendency to overshoot... The process is not particularly efficient or purposeful.
How odd... Same data, different conclusion.
What is known to be true about evolution?
I am not sure what you mean by "KNOW". None of this is divine revelation. But I am as sure about the statement "There is plentiful genetic variation in natural populations", having worked first-hand with the data supporting it, as I am of just about anything else in the world. And I am as sure of the statement "Selection can change the frequencies of variants", since I've done computer simulation to test it. That's most of evolutionary theory right there.
Why are men alone so murderous of their own species?
We are not alone. Most social animals seem to have some similar sorts of behaviors. When a male baboon displaces the old dominant male, young baboons must watch their ass, as the new dominant male will often attempt to kill them.
The same thing happens with lions, I believe.
There are gaps in fossil record where you'd expect intermediate forms.
There are more fossils than Creationists will admit. Many intermediate forms are known--for example, the development of the mammal skull characteristics from the therapsida of Permian time.
What gaps remain can be explained by erosion, lack of proper conditions for fossilization, the punctuated equilibrium model, or simply not looking in the right places yet.
Heart Mountain, north of Cody WY
If you believe that a large block of limestone could be moved uphill for that distance without becoming pulverized I have some land in Fl. you would be interested in... Or would you be more interested in the Brooklyn Bridge?
aka
Heart Mountain, north of Cody WY A huge mountain of Paleozoic limestone setting on top of Eocene/Miocene clastics... no indication of friction... no indication of pulverization... yet in order to avoid the failure of uniformitarianism geologists predict that this "block" of material was broken off from Sunlight Basin and moved by the vibration of volcanic eruptions over a 3000 ft. structure (the Dead Indian hill block fault) for a distance of over 25 miles.
"in order to avoid the failure of uniformitarianism" is a biased judgement that does not address the issues, I will ignore it. William G. Pierce in his article "Heart Mountain and South Fork Detachment Thrusts of Wyoming" in American Association of Petroleum Geologists Bulletin Vol. 41 (1957), notes that the level Cambrian strata broke off along a bedding plane, and slid downhill. The thrust block slid over younger rocks, parts of the thrust block eroded away, and a volcano finally deposited some debris over the area where a piece of the block had once stood. The volcanic debris, not being a part of the original thrust block, never slid.
Pierce also notes that the thrust block strata are often grossly deformed even when the underlying strata are not. He shows how the strata from one piece of the thrust block are often sliced across at a slant, forming an angle with the horizontal strata underlying the thrust fault.
If you will allow me to quote from Strahler's book Science and Earth History (Note: Bill Jefferys mentions this book frequently. I advise everyone who reads this group to run not walk to the library and GET it. It would be most useful for Bob Bales and Joe Applegate to read this. Challange to Bob Bales. I will read any creationist book you wish me to, and post a critique to the net if you will read this book and post your critique of Strahler. Why do I think Bob won't take up the challenge?)
From Chapter 40 page 393:
For reasons as yet undetermined, the entire layer of post-Cambrian strata simply began to glide as a unit southeastward over a bedding surface located immediately under the massive Bighorn dolomite formation of Ordovician age and above the topmost Cambrian formation. This layer detached itself along a vertical breakaway fracture shown at the left. Movement was evidently on a very low downgrade, decling some 650 meters in elevation from the breakaway fracture to the end of the bedding slip zone, a horizontal distance of some 50 km. As the rock sheet traveled, it broke up onto blocks on a succession of vertical tension fractures. The blocks thus became separated by open gaps, in which the bedding plane of gliding (identified as the Heart Mountain fault) was exposed at the surface. Geologists have applied the term "tectonic erosion" to the surface exposure of a fault plane by sliding away of the overlying mass.
So it seems 1) it didn't move uphill as you claim. and 2) there was pulverization of the rocks.
But the point is, whenever one small area is undisturbed, its fossils are found in a very definite order from top to bottom. The fossils close to the top resemble modern species far more than the fossils closer to the bottom. When fossils are occasionally found in the "wrong" order, one finds that the rocks are in disturbed areas like mountain ranges, where the sediments are being squished up and out over the surface of the earth like an ice cream bar crushed in a vice. These mountain sediments show plenty of physical evidence of overturning and overthrusting that has nothing to do with fossils. Therefore, geologists who avoid overturned rocks when they determine the fossil sequence are not committing circular reasoning.
William Smith, a canal engineer, was the father of modern stratigraphy. He was the first to notice that the higher rocks consistently had different fossils than the lower ones did. He was also a creationist, and used his discovery only to make money, yet the whole of geology today is based on his discovery.
Geology is self-correcting, so of course, there is always an infinitesimal chance that it will someday contradict evolution, or perhaps render evolution a poorer explanation of the evidence than creationism. It will no doubt take something a bit more serious than the anomalies Joe mentioned here. We're still waiting.
Yeah, and it would probably kill everything, given the size it would have to be. see national geographic, june 1989, 'the march toward extinction', p. 662, especially the chart starting on p. 666.
Shifting the poles rapidly over Hapgood's waveguide zone would be just as effective and fast!
What's wrong with the possibility of shifting them slowly?
Can this all be just mutation and natural selection?
Two points: first, although Darwin invoked only variation and selection, modern evolutionary theory also gives a very important role to genetic drift, the occurrence of changes due to chance fluctuations in small populations. This force can work in the opposite direction than selection, and can override selection if the population is small enough. (Brown mice do better in the wild than white, but if I start with only two of each in an area I will end up with only whites some of the time.)
Second, "mutation" can cover some things which are much more powerful than single changes in genes--specifically duplication of genes and merging of two genes into a new one. These mechanisms can produce new yet highly non-random genes.
This doesn't make sense. The "major groups" are defined by human classifications that often are there for ancestral reasons that support evolution (via the "family trees") or are fairly arbitrary (for instance, by location or discoverer) and make perfect sense.
All of my statements, past, present and future express solely my opinions and/or beliefs and do not in any way represent those of any of my employer's unless such is specifically stated in the content of the text.
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