Kharakov

We have a theory that states that the traights that are most successful in passing on to succeeding generations are more likely to show up in succeeding generations (unless something happens, such as an asteroid, that interrupts the process).

Is this falsifiable?

Is this theory just useful in providing a mental framework in which man can encourage specific traights through genetic engineering?

(since the traight has a higher value to that which is able to pass it on (genetic engineer)- that traight has a greater chance at being passed on)

How is evolutionary theory different from ID theory except that it states that ID happens only after evolution? (What came first, the chicken or the egg?)

Corey Hammer

First, traits are phenotypes. It is the genotype that is passed on. The phenotype may or may not be expressed.

Secondly, it is easily falsifiable. You simply to look to see if the genotype is passed on in descendants (with bacteria this is very easy as generations last minutes, not decades).

Thirdly, the expression genes are useful only in certain situations (though some situations may be very broad). Outside of those situations, the genes may be neutral or even detrimental (e.g., large body type was a successful pattern in the Mesazoic right up until the asteroid hit and nothing above 24kg survived.).

Oolon Colluphid

Despite the garbled nature of the post, this sounds like a rehash of the 'survival of the fittest is a tautology' fallacy. (IIRC) As Maynard Smith has said, of course natural selection contains tautological elements. So does any two lines of algebra.

As to whether evolution is falsifiable...

<a href="http://www.talkorigins.org/faqs/comdesc/section1.html" target="_blank">These pages</a> give heaps of hypotheses, confirmations and potential falsifications. Have a read.

Meanwhile, here is something I’ve knocked up previously. (Some bits are, I’m afraid, a bit plagiaristic -- this was written originally as a one-off for my own pet creationist, so please forgive!)

These are all things that, if the evidence turned out differently, would refute evolution.

1. If life has evolved through time, we would expect there to be a sequence in the fossil record, with earlier fossils being simpler than later ones, and later ones being more like present species than earlier ones. This is what we do find under nature. (It should be noted that, though there is of course much overlap, testability is not quite the same as repeatability. When seeing if for instance cold fusion or polywater were real phenomena, the same experiments could be repeated by others. The inevitable inability of other palaeontologists to repeatedly dig up the same bone from the same place again does not mean palaeontology is untestable: not only can other palaeontologists study the finds, but most importantly, others can look for further fossils, and thus ‘repeat the experiment’ and test the predictions. It is a claim of pattern that is being tested each time a fossil is found. Not one fossil contradicts the claim (though often enough they contradict smaller claims about particular lineages).)

2. If life has evolved, we would expect that, with luck, with the vagaries of preservation allowing, the fossil record should yield examples of intermediate forms – ones that are similar to, but clearly distinct from, earlier and later creatures, and ones that share characteristics with later, separate groups. Thousands of such fossils have indeed been found, at the stratigraphic levels predicted. Of course the fossil record is hugely incomplete, as expected by what we know about fossil formation. But the fact – the observation – remains that fossilised remnants of creatures intermediate in form to earlier and later fossils have been found, at the ages expected. Never mind gaps, what’s important is that not one organism that has survived as a fossil has refuted this prediction. Some examples are Archaeopteryx, Confuciusornis sanctus and Caudipteryx zoui, Pachycetus, Merychippus, and Paranthropus robustus. In 1837 a creationist reported that during a pig’s foetal development, part of the incipient jawbone detaches and becomes the bones of the middle ear. After Darwin, it was predicted that there should be a transitional reptilian fossil species with a spare jaw joint near its ear. A whole series of such fossils has since been found, the cynodont therapsids.



3. If life evolves by selection of heritable variations, we should expect there to be such variation within modern species, even so much that it be difficult to tell some species apart, and to tell species from subspecies, and subspecies from mere varieties. (Creation wouldn’t seems to require this – in fact it is not clear to me why creation even requires variation between individuals – perhaps with man, but not with beetles or bacteria.) This is what we do find under nature.

4. On the principle of descent with modification (ie that organisms must have had ancestors), Darwin predicted that the <a href="http://www.swcp.com/~diamond/trilobites.html" target="_blank">precursors of trilobites</a> would be found in pre-Silurian rocks, and that <a href="http://members.aol.com/drjohnsea/Vendianfossils.html" target="_blank">Precambrian fossils</a> would be found. Both have been found.

5. Darwin famously (and cautiously) wrote in Origin that “light will be thrown on the origin of man and his history”, predicting that under his theory further links would be found between humans and the rest of the animal world. This has been borne out, in spades. Not only have genetics, molecular biology and medicine shown our close affinity, but many fossils of human-like apes have been found – where they ‘ought’ to be considering our similarity with the African apes, and geologically when they ought to be on the hypothesised ‘family tree’ (and backed up by Sarich and Wilson’s molecular clock). See <a href="http://www.talkorigins.org/faqs/homs/" target="_blank">www.talkorigins.org/faqs/homs/</a>

6. If life evolved from a common ancestor as a branching family tree of descent with modification, we should expect that recently separated species should share many common features, less recently separated ones fewer, and so on, producing nested homologies. That the whole science of taxonomy, with phylum, class, order, family, genus, species, etc, is at all possible implies that, maybe, this is a true observation. This nesting of homologies should also be true for various different (and thus mutually-confirming, before you claim circularity) factors. Guess what? The living world shares a single genetic code for inheritance. We can confidently predict that any new organism we find will use the DNA/RNA system. Many new species are described for the first time each year; every one uses DNA/RNA. The DNA of species taken to be closely related on anatomical grounds is more similar than is the DNA in species where apparent kinship is more distant. DNA in humans and chimpanzees, by the way, is 98.6% identical. All vertebrates use iron in haemoglobin to transport oxygen in their blood. All gastropods twist their bodies – and it is always anticlockwise. The same nesting of homology goes for proteins, immune systems, biochemical pathways and of course anatomy. Also, vertebrate embryos are hard to tell apart at first – for instance, during their development they all have tails and gill slits. At around four to six weeks, that included you. Embryos gradually become more distinguishable – with more closely related creatures staying similar for longer. This is not to affirm Haeckel’s ‘ontogeny recapitulates phylogeny’ dictum, but rather to reverse it: that given information about an organism's ontogeny, we can confidently predict certain aspects of the historical pathway that was involved in its evolution. Thus embryology can provide confirmations and predictions about evolution. What’s the point of a camel starting off with fish-like characteristics?

7. If life evolves by descent with modification, by copying genetic material down generations, then we would expect that copying errors in non-functioning DNA would only be present in some groups. While there may be some reason why functioning DNA is similar in similar groups, there is no reason why there should be homologies in DNA that does nothing, unless it comes from a common ancestor. For instance, pseudogene equivalents are genes which are identifiable as some functional gene in another organism, but which have a mutation which has rendered them non-functional. There are three sets of genes found in many species that have pseudogene equivalents in primates, including humans, but not in other mammals: several odorant receptor genes; the RT6 protein gene; and the galatosyl transferase gene. The mutations which made these genes inoperable are shared among the primates. There are numerous mutations that can render a gene non-functional. Yet not only do primates have pseudogene versions of these genes that are functional in other creatures, but these pseudogenes have been made nonfunctional by the same mutations – they have the exact same errors in the genes. This makes perfect sense if this genetic material was inherited from a common ancestor. Similarly, retrogenes are molecular remnants of a past parasitic viral infection. Occasionally, copies of a retrovirus genome are found in its host's genome, and these retroviral gene copies are called retrogenes. Retroviruses, such as HIV and HTLV1 (which causes a form of leukaemia), make a DNA copy of their own viral genome and insert it into their host's genome. If this happens to a germ-line cell (sperm ‘n’ eggs, as my biology teacher used to call ’em), the retroviral DNA will be inherited by descendants of the host. Again, this process is rare and fairly random, so finding retrogenes in identical chromosomal positions of two different species strongly indicates common ancestry. There are three different instances of common retrogene insertions between chimps and humans. Within the Felidae (cats), the standard phylogenetic tree (based on the usual morphological, biochemical etc features) has small cats diverging later than large cats, with the blackfooted cat Felis nigripes being the first of the small cats to diverge. All small cats (from the jungle cat F chaus, European wildcat F silvestris, sand cat F margarita, African wildcat F lybica, blackfooted cat, to the domestic cat F catus) share a specific retroviral gene insertion. In contrast, the cat lineages that diverged before the small cat lineage (lion, cheetah, and leopard) and all other carnivores lack this retrogene. (Potential falsification: it is incredibly unlikely, evolutionarily, that the cheetah, or some other mammal (dogs, or cows, say), could have this same retrogene in the same chromosomal location. None do. Conversely, it is also very unlikely, given common descent, that one or more of the small cats which diverged after the blackfooted cat would lack it. They don’t.)

8. If evolution happens, we should expect different organisms to evolve different solutions to similar problems. Simple, valuable characteristics such as eyes or aquatic streamlining should evolve independently, homing in on ‘good design’ – and that when they do, they will most likely have differences not related to their function. In Nature, we find that the eyes of molluscs, arthropods and vertebrates do the same job but are extremely different, and ‘ears’ can appear on any of at least ten different locations on different insect species. From their body shape and dentition, dolphins, sharks and ichthyosaurs are all clearly designed for swimming after and catching fish; from the sorts of teeth they have, and many other anatomical features (such as two of them having to breath air), they are equally clearly each most like other, rather different, creatures. Similarly, a flexible flat blade at the rear makes a good propulsion unit in water . . . yet in fish it is vertical, while cetaceans have theirs horizontally aligned. (Is it just coincidence that terrestrial quadrupeds, like cetaceans’ putative ancestors, have a back end that is powered up and down, not side to side? Go watch an otter in action. Many shark species are viviparous – giving birth to live young. Some do this by retaining the egg within the body; in others, a system rather like that of mammals is present, with the mother supplying nutrients via a uterus. Yet despite this mammal-like similarity, in placental species which produce multiple offspring, unlike in mammals which also do so, the uterus is divided into separate chambers, each with its own embryo. And if placentas are ‘good design’ if you’re a shark, how come so many shark species do not have them (but do have various degrees of egg retention and embryo feeding)? Is it not strange that a Creator should have endowed bats, birds and pterodactyls with wings made out of the same bony elements that dogs use for running and penguins use for swimming? Is it not stranger still that instead of using these same bones in the same way, the Creator should have decreed that the bat’s wing be made by lengthening four fingers, the pterodactyl’s by lengthening only one finger, and the bird’s by shortening the hand and adding feathers? Surely an omniscient Creator should not have to experiment with different designs? Birds and mammals, being warm-blooded, have only one aortic arch instead of two as in amphibians and reptiles, for more efficient transport of blood from the heart. I’d be interested in hearing the creationist explanation of why birds have only the right aortic arch while mammals retain the left one. Or why amphisbaenians – ‘worm lizards’: elongated, mostly legless burrowing reptiles – have a reduced right lung, while in snakes it is the left that is lost or reduced.

9. If life evolves by adaptation of pre-existing genetic recipes (via selection of their phenotypic expression), as the ‘Modern Synthesis’ claims, we would expect there to be signs of this: genetics tells us that phenotypic effects are the result of genes being switched on or off during the making of a body (plus environment of course), so a feature being lost does not automatically mean that the DNA has been lost too – the genes may just be inactive. Evolution thus predicts not only genetic homologies (above), but also that sometimes there would be tell-tale ‘errors’, when normally unused old genes become expressed. No surprise to an evolutionist, then, that horses with three-toed feet are occasionally born, as are, more rarely, whales with hind limbs. Most living insects have two pairs of wings; flies (Diptera), which normally have a single pair, sometimes grow a second pair of wings instead of halteres (balancing organs). As at 1985, twenty-three cases of humans born with tails had been documented in the literature, and many more of congenital hypertrichosis (babies covered all over in thick hair). Need I mention that having a tail is typical of vertebrates, and being covered in hair is a distinguishing feature, the default, of mammals? And there’s more. Surgical manipulation of a chicken's foetus can induce structures to grow that normally would not. <a href="http://www.devbio.com/chap06/link0601.shtml" target="_blank">Experiments</a> have shown that chick embryonic jaw tissue can be persuaded to grow teeth in the right conditions, though no modern bird possesses teeth (but fossil ones do). The genetic instructions for their growth are present, even though they are not usually expressed. Furthermore, the growth of some structures induces the growth of others. The fibula in modern birds is normally just an (atrophied) splinter, and the tarsals are fused. Both reptiles and Archaeopteryx have full tibia and fibula and lots of separate tarsals. By simply inserting a piece of mica between the developing tibia and fibula of a chick embryo, Armand Hampé produced <a href="http://www.mun.ca/biology/scarr/Hampe_experiment.gif" target="_blank">an archaeopteryx-like leg, with not only a fibula fully to the ankle, but separate tarsals.</a>


10. Under evolution, geography should make a difference to biology. Since isolation is thought to be important for speciation, evolution predicts that organisms that become isolated, on islands, in lakes or caves, would be likely to evolve into different species from those not cut off. In general, closely related (similar in a variety of ways) species should be found in close proximity, while those less closely related (less similar) may be found further apart. What does Nature reveal? Innumerable species are endemic to one place, yet the most similar species to them are always found nearby. Okapi are forest-dwelling creatures that feed on a wide variety of leaves, twigs and fruits, yet the only forests they are found in are those in Africa. Is it coincidence that the creature they most resemble, the giraffe, is only found in Africa too? That though horse-type animals are quite widespread, zebras are only found in Africa (with subspecies found only in particular areas, not all mixed in together); Przewalski's horse (Equus przewalski) only in Mongolia, the kulan (Equus hemionus hemionus) in the Gobi desert, the slightly larger kiang (E h kiang) on steppes of Nepal, Sikkim and western Tibet, the onager (E h onager) in lower semidesert or desert environment in northeastern Iran, and so on? Evolution predicts that island species should appear most similar to species on the nearest mainland, and the older and more distant the island, the more distant the relationship. From Galápagos finches to Madagascan lemurs and fossas to Australasian marsupials, this is what we do find. The same applies for lake fish, such as the cichlids of Lake Tanganyika. A thousand years ago, almost every remote island on the planet had its own species of flightless bird. Evolution explains this by saying that flying creatures are particularly able to reach and establish themselves on remote islands; some birds, living in a place where there is no need to make a sudden escape, or where being airborne risks being blown out to sea, will take the opportunity to give up (highly energy-consuming) flight. Thus, evolution predicts that each flightless bird species arose on the island that it was found on, and so no two islands should have the same species of flightless bird. Now that all the world’s islands have been visited, we know this was a correct prediction. On the Galápagos, 34% of plant species (eg the cactus Jasminocerus thousari), 63% of reptile species (eg the land iguana Conolophus subcristus or pallidus, the marine iguana Ambyrhynchus cristatus and its seven subspecies) and 73% of land bird species (eg the hawk Buteo galapagoensis, the martin Progue modesta and the rail Laterallus spilontus, the penguin Spheniscus mendiculus, plus the finches of course) are endemic, found no-where else in the world. There are endemic rice rats (Oryzomys), bats (Lasiunis brachyotis), and a flightless cormorant (Nannopetrum harrisi). Lava lizards of the genus Microlophus are found only on the Galápagos and -- volcanic islands in the Atlantic and Indian oceans? No, South America, the nearest land mass. There are seven Microlophus species endemic to the archipelago – and each island that has Microlophus has a different species. We are far from having studied all cave systems, but the same is so far true for many of the species that inhabit them. The odd thing, were these species created each for its habitat, is that they are all variations on well-known families and genera; they are types of crustaceans, annelids, spiders, platyhelminths, insects, etc, not completely new, utterly different organisms.

11. Also, similar environments exist in different parts of the world. If life evolves by descent with modification, making do with what is in a particular place at the time, evolution predicts that the equivalent niches will often be filled, not by the same organisms all over the world, but by different ones in each locality: in each place a different design answer to the same problems. This we regularly do find in nature, with similar niches filled with (often radically) different organisms. Australia lacks wolves or big cats, but it did have thylacines; no ‘proper’ moles (Talpidae), but marsupial moles (Notoryctidae). A woodpecker finch is practical only in the absence of woodpeckers -- thus there is a Galápagos woodpecker finch, Cactospiza pallidus. The pattern is always by area, not by environment type.

12. If life evolves by natural selection, changing step-by-step from previous forms, there should be signs of this history in the bodies of organisms; their 'design' would be constrained by history. Any improvements have to be build step by step from what's already available, and there can be no getting less efficient as a prelude to eventually getting more efficient. (Any organism that tries that route will simply not leave as many descendants: natural selection operates in the here and now, and won't refrain from penalising anything that says 'I'll get a lot better eventually if you'll just let me get worse for a few generations'.) So evolution does not expect perfection, just 'design' that is good enough, compared to the competition. Guess what we find in nature? Here's an example: the ‘thumb’ with which giant pandas grasp bamboo is not actually a thumb, but a greatly enlarged wrist bone, the radial sesamoid, giving the panda, in effect, six digits. If it were designed, why not simply use the digit that is usually the thumb?



(At last count, I have a list of over 40 examples of poor and pointless design features, but I won’t bore the regulars with it yet again. Do feel free to ask though!)

13. If life has evolved by adaptation, the four billion years it’s had should mean it could achieve great diversity. We have so far named a million-and-a-half species; estimates for the total number of living species range anywhere between ten million to a hundred million (Gould 1996; Wilson 1992) -- in other words, a lot.

14. The same struggle that has led to the present diversity should also have led to countless forms’ extinction. We know that extinct forms vastly outnumber living ones. (Raup 1991; Mayr 1988: Toward a New Philosophy of Biology.)

15. Following from that, evolution predicts that there should be different populations of creatures at different times – that once a lineage has died out, there should be no more of it later, and later organisms will not be found massively earlier than their supposed ancestors. For example, it predicts that we will never find fossils of marine mammals with trilobites, conodonts or graptolite fossils. So far, this has most certainly been the case. The ‘Cretaceous Seaway’ deposits in Colorado and Wyoming contain almost 90 different kinds of ammonites, but no-one has ever found two different kinds together in the same rockbed. Despite creationist frauds, no human has ever turned up in the belly of a T rex; <a href="http://www.ucmp.berkeley.edu/mammal/eutheria/chirofr.html" target="_blank">fossil bats</a> are exquisitely preserved in the Eocene Messel Shale and Green River formations, yet nothing even vaguely like a vertebrate is found in the equally excellent preservations of the Burgess Shale; if carnivores such as Smilodon fell victim of the La Brea Tarpits, why did no theropods do so to?

******

This is another way in which creationists are hypocritical. If they claim evolution is irrefutable and so not scientific, how come they think it is refuted by the second law of thermodynamics, bombardier beetles and eyes, gaps in the fossil record, and so on? If evolution is untestable, no data could count against it. If data can count against it, it can’t be untestable.

That no data does, in actuality, count against it is not the same thing.

Cheers, Oolon

[ January 30, 2002: Message edited by: Oolon Colluphid ]</p>

Vorkosigan

A post like that really ought to get an award or something. That was a wonderful read.

Michael

Kharakov

First: This says absolutely nothing different- successful genotypes are more likely to produce better phenotypes, thanks for the clarification...

Second: That does not show that evolution is falsifiable. I'll leave you to show that it is falsifiable.

Third: So once again, you agree that the most successful genes survive. Does this show anything other than what happens: that what survives is what survives and passes on its genes?

Kharakov

Well, it is a tautology if evolutionary theory states that what is most suited to reproduce and survive reproduces and survives.

I am not denying that it is an observable phenomena- but it states nothing other than the logical conclusion that what is most suited for survival and procreation in an environment is what is most successful at survival and procreation in an environment. When the environment changes (asteroid strikes the earth) the creatures most suited for survival and procreation in the new environment are those that are most successful at survival and procreation in the new environment.

Gotta go... be back in 2 days.

Oolon Colluphid

Uh... I was under the impression that I just had. My mistake.

Uh... so what? If I say that a train travelling at 120mph (not a British train, of course ) will arrive at a given destination in half the time of one travelling at 60mph, the fact that I have just uttered a tautology makes not the slightest difference to its factuality, nor to our ability to analyse and use the information. Remind me again what the problem is?

Want me to post my similar list of creationary claims?

TTFN, Oolon

Quetzal

Oolon: Once again you have proven absolute mastery. <img src="graemlins/notworthy.gif" border="0" alt="[Not Worthy]" /> <img src="graemlins/notworthy.gif" border="0" alt="[Not Worthy]" />

PS: Can I steal it?

Oolon Colluphid

Aw shucks...

I am but a humble scribbler, making notes in the margins of the masters (ie people who really know their stuff -- like you and theyeti on genetics, OOL etc).

You'd better ask the incomparable <a href="http://www.cs.colorado.edu/~lindsay/creation/evo_science.html" target="_blank">Don Lindsay</a> and <a href="http://www.talkorigins.org/faqs/comdesc/section1.html" target="_blank">Douglas Theobald</a>, from which much of that was drawn. And maybe Douglas Futuyma. Whilst there's a lot of 'me' and my researches in it, they are the true masters.

Oolon

Daggah

Wow, Oolon, truly excellent post. While that was a great, detailed post looking into the topic question of this thread, you also presented it as a good list of general evidences for evolution! Nice job. <img src="graemlins/notworthy.gif" border="0" alt="[Not Worthy]" />