Extent of Mutational Capability

I'm not at all convinced. You say 'limited interbreeding', it's not at all clear that that was the case, and in anycase what does it mean? Was it the case that passing H.s tribes raped and pillaged H.n - and vice versa - or did they live together? If the latter, then what does it mean? We are almost a close genetically to chimps as H.n but we can't imagine H.s living and mating with them. Were they actually that different and over what timescale? Are they more different than I am from say an Australian aboriginal? It seems that there was interbreeding - I don't know what 'free' interbreeding is. Small groups might freely interbreed, others might never meet. They were identified from pieces of bone. The DNA tells us more and so does archaeology. Science now classifies them as a subspecies rather than a seperate species. I think the truth is somewhere in between and I find the whole idea fascinating as it's so recent.Edited by Tangle, : Spelling....

I read a book in college for a course on human evolution called Dance of the Tiger. I enjoyed it and it was really easy to read.It is a fictional story about some interactions between Neandertals and Cro-Magnons during a thaw in the Ice Age.The author took some artistic liberties to aid in the telling of the story:The Neandertals were depicted as white-skinned while the Cro-Magnons were dark-skinned.
The Neandertals had limited diction while the Cro-Magnons spoke like angels singing (too the Neandertals).
The Cro-Magnons were very beautiful to the Neandertals while the Neandertals were ugly to the Cro-Magnons (but not too ugly to mate).
The offspring between them were sterile.What the author set up was a situation where, over time, the Cro-Magnon out bred the Neandertals until there were no Neandertals left.
Since the offspring were sterile, and more Neandertals would want to mate with Cro-Magnon than Cro-Magnon would want to mate with Neandertals, you can see how eventually you'd just run out of Neandertals.There was a whole story to the book, a 'you-killed-my-father' type thing going on, but around that was the exploration of a potential scenario where competition between Neandertals and Cro-Magnon ended up with the modern humans winning in a way that wasn't through violence and on purpose.It was all very interesting and a good yet easy read and I'd recommend it if you're interested in the subject. And this is coming from a guy who doesn't read fiction.Edited by Cat Sci, : changed sub-title

I've often wondered if Neanderthals were the ogres and trolls in the oral tales.Now to add to the "confusions ..." Pacific Islanders appear to be carrying the DNA of an unknown human species

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Hints of an unidentified, extinct human species have been found in the DNA of modern Melanesians - those living in a region of the South Pacific, northeast of Australia.

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According to new genetic modelling, the species is unlikely to be Neanderthal or Denisovan - two ancient species that are represented in the fossil record - but could represent a third, unknown human relative that has so far eluded archaeologists.

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"We’re missing a population, or we’re misunderstanding something about the relationships," Ryan Bohlender, a statistical geneticist from the University of Texas, told Tina Hesman Saey at Science News.

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Bohlender and his team have been investigating the percentages of extinct hominid DNA that modern humans still carry today, and say they’ve found discrepancies in previous analyses that suggest our mingling with Neanderthals and Denisovans isn’t the whole story.

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And I thought that Denisovans were also a mosaic species ...... with Homo erectus?Perhaps these Melanesians have different DNA from earlier Homo erectus?EnjoyEdited by RAZD, : quoteEdited by RAZD, : added Homo erectus

Well I was making some notes from a TV programme I coincidentally watched last week - might as well drop them in here now....Modern humans co-existed with at least 4 other human species. We interbred with them and our DNA shows that there were more human species than we currently have fossil evidence for.Neanderthals have been found in caves in Gibraltar only 32,000 ago. They weren't the near apes we thought they were; they had culture, they planned, had abstract thought (art), clothing and tools. They buried their dead, made jewellery and body ornaments. Neanderthals and modern humans competed for the same resource and interbred.Our modern human genomes contain neanderthal DNA. Everyone of non-African descent carries neanderthal DNA - around 2-3%. At least half the neanderthal genome still exists in modern humans.Siberian finds show a third kind of human living with both modern humans and neanderthals. We have a complete genome from a 50,000 year old bone. A new extinct human form, the Denisovans. We have about 60-70% of Denisovan DNA. The archaic DNA is active in our immune system; Denisovans contributed genes that allow people to survive at altitude - Tibetan's now rely on it.Homo fluorientis - 'the hobbit people' - also lived at the same time as modern humans, neanderthals and the Denisovans. They had Island dwarfism and tiny brains. We don't know whether they inter-bred but it seems unlikely.DNA from a modern African tribe show that there is yet another human species - so far unidentified by fossil evidence - that also co-existed with modern humans, Neanderthals and Denisovans.So about 30,000 years ago there were at least 4 other human species co-existing and interbreeding with modern humans but after that only us were left. It's probably only a matter of luck H. sapiens sapiens survived.(Interesting question for the believers, were those other now extinct humans saved?)

Grendel's mother was a Neanderthal!

No they were drowned in the flood ... even though the strata they are found in is not typical of waterborn sediment deposits ... from wiki:

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... concluded that H. floresiensis was more similar to early humans and other apes than modern humans.[19][20] In 2009, the publication of a cladistic analysis[21] and a study of comparative body measurements[22] provided further support for the hypothesis that H. floresiensis and Homo sapiens are separate species.

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Being on an Island though, that gives them opportunity to mix with these Melanesians ...Enjoy

That doesn't follow. If you take a highly variable species then apply some intensive selection pressure to it, you'll eliminate a lot of that variability. A lot of the now dead members of the species will fall outside the range of variation of the more homogenous population you're left with. Obviously that doesn't mean it's a new species.And a lot of distinctive Neanderthal traits are completely within the range of variation of modern humans. If we extend 'modern humans' to prehistoric specimens classified as anatomically modern, then much more of them do; since neanderthalish features are more common in Upper Palaeolithic humans from Eurasia than they are today.

No, it's not false. Maybe you think I am using the term 'assumption' to mean "wild-ass guess with no evidential support." But that's not how I am using the word 'assumption.' Actually, I am glad you brought this up because it is an oft misunderstood term. In a scientific context assumption means:"a premise that must be true in order for the test and resulting conclusions to be valid."While this definition is not a standard dictionary definition, I think it best reflects how we use the term when doing scientific research. It is important that we recognize what our assumptions are and are able to justify them. In one of my classes recently, we were talking about a particular line of research and how it could be more transparent. My response was that researchers need to be more open about the assumptions they are making and what the weaknesses of those assumptions are. Otherwise it can be a bit deceptive. Not a valid analogy. By the very nature of a phylogenetic/cladistic program, a dendritic tree is generated with the following qualities:a) the subjects being studied are related by descent, ie. they share a common ancestor
b) each character state change is depicted by a branching event called a node
c) the subjects are grouped by shared character state changesThis is HOW phylograms/cladograms are built; there is not other ways to build them. In order for this to work, you must start with the premises (assumptions) I listed above. If this were a true test of common descent, then the trees could be built in ways other than a bifurcating, nested hierarchy; but they can't. They can ONLY be built as a cladogram/phylogram. Can you see how this would be circular reasoning? You group subjects into a cladogram to see if they form a clade.Think about it, let's say I do a phylogeny of 10 fungal species, 10 primate species, 10 fish species, 10 bacteria species and 10 reptile species. Would that really be a test to see if they shared a common ancestor? They would probably even have a very high confident index since there would be little homoplasy. But let's say reality is that they ARE separately created "kinds." A cladogram would still group them into a bifurcating tree with common ancestors because that's what cladograms do... Cladistics is a test of a particular hypothesis about HOW a particular set of taxa are related. If trees were unreliable, inconsistent or have low values of phylogenetic signal that would be an indication that one or more of our assumptions are violated.So, in a way, cladistic analysis IS a test of common ancestry, but through confirmation of the assumptions and not in and of the cladogram itself.ABE: If you don't agree with my list of assumptions for cladistics, perhaps you could describe what you believe the assumptions of cladistics actually are? /ABEHBDEdited by herebedragons, : No reason given.

I didn't say common ancestry itself was an assumption, I said that common ancestry is a basic assumption of cladistics. Not really. The outgroup establishes the ancestral character state. Since cladistics is based on synapomorphies (shared derived characters), it is important to establish what the character state was originally (which relies on the assumption that there IS an ancestral and derived character state). Simply put, because that is how cladistic programs are designed to work; they can't do anything else. Oh definitely! Many aspects of biology are best explained by common descent. But that is a different point than I was making.In order to do a cladistic analysis, you start with the basic assumption that the subjects are related by descent. This doesn't diminish the validity of common descent, it's just being honest about what our base assumptions are when doing cladistics.You wouldn't be able to build phylogenies that were consistent with separate lines of evidence (such as paleontological evidence or disparate morphological and molecular data) if they were not actually related by common descent. But this would indicate that one or more of our base assumptions are not valid; it wouldn't be because a cladogram could not be constructed.See my response to Taq in Message 128 for a little more discussion.HBDEdited by herebedragons, : clarification in last paragraph

What is the mutational capability of evolution.The mutation-selection process is quite limited in what it can achieve. A section of DNA is a string of coded information and a random change will probably damage that information; far more likely than producing an improvement. Like making a random change to a software subroutine there are many more ways to do damage than to improve it. Similarly a random mutation is far more likely to damage the genetic code than to add beneficial genetic information.Occasionally however a mutation that damages the normal function can have specific benefits. Blowing up a bridge you might want to cross in the future is a dis-benefit but can provide short term benefits if it prevents the advance of an attacking enemy. Most cases of antibiotic resistance are like this. If an antibiotic requires a particular channel through the cell membrane or attaches to a specific site then destroying those will sometimes provide a benefit greater than the harm they do; but only when exposed to antibiotics.Wild populations of bacteria often have a very small proportion of resistant individuals and the reason it is so small is that normally the mutation is harmful and is constantly being removed by selection. Only when exposed to antibiotics do these mutations give a net benefit allowing their proportion to increase and antibiotic resistant strains to develop. When antibiotics are removed the bacteria tend to revert to the original proportions. How quickly bacteria become resistant and how quickly they lose it depends on the selection coefficients in different environments.Similarly sickle cell trait damages the haemoglobin and is harmful but can provide some net benefit when malaria is prevalent. In this case even in high risk malaria areas the proportion of sickle cell trait doesn’t get to 20% before the harm outweighs the benefit.But what about nylonase (and similar examples)? Adaptations like this appear to be part of the genetic toolkit of bacteria. E. coli have been found to develop the ability to eat nylon reliably and quickly, sometimes within days. This is relatively simple mutation and bacteria have the advantage of very large populations and rapid reproduction.Is this information adding? Genes that are programmed to be adaptable have the information pre-loaded into their design, and in gaining the ability to eat nylon it loses the previous function; so No.Consider Chloroquinine resistance in malaria parasites. One of the most effective anti-malarial drugs because the parasite took longer to develop resistance to this. Behe shows that chloroquine resistance likely involves two specific mutations occurring together in the one gene. This explains why resistance to chloroquine took a long time to develop. Behe also points out that the chloroquine-resistant parasites do worse than the non-resistant ones where there is no chloroquine. This suggests that the double mutation is informationally downhill, as usual.When a chain of beneficial mutations lead to a favourable result we can expect evolution to find this fairly easily. A single point mutation is the easiest and can be readily achieved. When multiple non-beneficial mutations are required the probability is the multiplication of individual probabilities. This rapidly becomes prohibitive. Bacteria can compensate for this to some extent due to large populations and rapid reproduction but even then the waiting time can become excessive. For higher animals with small populations and long reproduction times, such as humans, waiting times can exceed all the time available since the beginning, even if you think that is billions of years.Now look at it from another point of view. How frequent are functional proteins in the sequence space of all possible combinations. Ann Gauger offers a neat analogy about the rarity of functional protein folds, calculated by her colleague Doug Axe. Hitting upon one is akin to standing outside the Milky Way and trying to strike a single quark held in the hand of a bather lying on the shore of Lake Michigan. It's that specific, mind-bogglingly beyond the reach of blind, unguided evolutionary groping. http://www.evolutionnews.org/...biologist_ann_g_2103194.html . Where there is a chain of beneficial mutations a result is achievable but a chain of a few neutral steps will blow the waiting time out of practical possibility, even for bacteria let alone humans.This is not a case of we don’t know; therefore God. We have the data and we can say we do know; therefore not Evolution.Evolution can achieve the trivial but is inadequate to achieve changes of even moderate complexity.

I picked this single statement out of all of the questionable ones in your paragraph. To avoid a dog pile, I'll leave the others to someone else. But those multiple beneficial mutations need not occur at once. If each of them can occur at different points in time after a previous one has become fixed in the population because it is somewhat beneficial, the probability that a mutation involving a multiple chain path way is increased substantial compared to the probability that all changes happened simultaneously. Let's see your math. Identify the changes that biology says have occurred during the time when humans/apes possessed their long gestation periods and show that millions of years that has passed is not enough time. I'm certainly not going to simply take your word for that.Edited by NoNukes, : No reason given.

First most of your post involves PRATTS -- points refuted a thousand times -- and I suggest you peruse An Index to Creationist Claims and Arguments to Avoid Topic | Answers in Genesis ... these should give you an idea about how bad creationist arguments are. This just illustrates why a computer program is not a good analogy for DNA. It is actually more like a cooking recipe, where results vary with variations in following the recipe: change the amount of sugar in a cake recipe and you still have cake, just some variations will be more appealing than others, and thus that variation will be more likely to be repeated.Computer programs do not reproduce themselves so there is no natural selection. So.Wrong. Normally the proportion of any "wild" bacteria that are resistant to antibiotics is small because they are not exposed to it. When they are exposed, then natural selection favors the ones with resistance. When they are no longer exposed, then there is no selection pressure to maintain the resistance, and it fades in the population.For an example of how evolution actually works in situations like this look at Peppered Moths and Natural Selection. I wonder if you read what you write ... certainly it appears that you do not see the irony of arguing that this occurs fast and reliably after starting out talking about how difficult it is to evolve a beneficial mutation ... " ... a random mutation is far more likely to damage the genetic code than to add beneficial genetic information."Oh but you pretend that there is a "genetic toolkit" to explain this. Curiously there isn't any evidence of any "toolkit" other than mutation and selection. If you disagree then demonstrate it, show the evidence for it. Wrong.Again.First let's deal with the information issue: see Irreducible Complexity, Information Loss and Barry Hall's experiments -- either "information" is added OR the concept of "information" is irrelevant to the process of evolution and to what can and does occur.There is no evidence of any such thing as "pre-loaded genes" ... and again, if you disagree then demonstrate it, show the evidence for it.If there are "pre-loaded genes" then (a) why does it take several generations for it to turn on and (b) why is it only turned on in a small set of the bacteria and not all of them? Inquiring minds want to know. Here's a hint: when a mathematical calculation purports to show that something is nearly impossible but we have evidence that, for instance, there are enough proteins for life to go on, then the math is missing some critical element.Math does not prove what can and cannot happen in the real world, it can only model it. If the answer doesn't match reality it is the math that is wrong, not reality.See the old improbable probability problem for more on this type of pratt. And yet, curiously, reality is not impressed with your argument, and life continues to evolve. What is the meaning of "complexity" and is it used by biologists?What do you think the evolutionary limits are for this creature: Care to discuss?Now I can go into the errors you make in more detail when I have more time, but this should give you something to chew on.EnjoyEdited by RAZD, : added info

I should like you to expand on this fantasy a little further. Are you suggesting that there is some mechanism other than random mutation that produces the adaptations necessary for bacteria to digest 6-aminohexanoate linear dimer and other such products of nylon manufacture? If so, do you have a shred of evidence for this speculation? If not, what do you mean? Please attach meaning to this vacuous phrase by telling us how you measure how high up a hill a sequence of information is. Math fail. And yes, it's that classic creationist trope, the Non-Quanititative Quantitative Argument. A number is asserted to be too big or too small for evolution to have occurred without the faintest effort at calculating the number. Neutral steps happen all the time. Are you trying to commit the Texas Sharpshooter Fallacy here, or what are you trying to be wrong about?

I think that we are still talkin past each other.For instance, even your example of taking distantly related groups will still produce a nested tree showing that somewhere much more closely related than others, with a high degree of confidence, which it need not do if they were truly unrelated.I suppose that selection of traits is also important - some traits can be more easily be produced than others (i.e. convergent evolution)

Tomanswer the actual arguments:

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When a chain of beneficial mutations lead to a favourable result we can expect evolution to find this fairly easily. A single point mutation is the easiest and can be readily achieved. When multiple non-beneficial mutations are required the probability is the multiplication of individual probabilities

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In the case where a specific chain of mutations is required in the short term this argument may be relevant. In the more general case it is not, as I have aleady explain. Neutral mutations continually appear and spread through the population. Those that are in the population are available, and newly-occurring mutations may take advantage of them. A simple multiplicative probability calculation is not relevant to that situation.

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Now look at it from another point of view. How frequent are functional proteins in the sequence space of all possible combinations. Ann Gauger offers a neat analogy about the rarity of functional protein folds, calculated by her colleague Doug Axe. Hitting upon one is akin to standing outside the Milky Way and trying to strike a single quark held in the hand of a bather lying on the shore of Lake Michigan. It's that specific, mind-bogglingly beyond the reach of blind, unguided evolutionary groping. http://www.evolutionnews.org/...biologist_ann_g_2103194.html . Where there is a chain of beneficial mutations a result is achievable but a chain of a few neutral steps will blow the waiting time out of practical possibility, even for bacteria let alone humans.

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I generally don't waste my time with watching videos, especially propaganda videos (and the text makes it clear that is what it is). If there are actual arguments there, you can produce them (and you will need to do a little better than offer the opinion of an ID proponent like Axe or Gauger). I would point out, for instance, that the probability of getting a functional protein by modifying another functional protein is rather different fromte probability of randomly assembling a functional protein from amino acids.

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This is not a case of we don’t know; therefore God. We have the data and we can say we do know; therefore not Evolution.

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Does this data of yours show that evolution requires specific sequences of mutations in the short term, rather than neutral mutations spreading through the population providing opportunities for beneficial changes ? If not, then your argument is something of a failure, relying on an unsupported and unlikely assumption.