Arete

Surgery would not alleviate the genetic incompatibilities between species http://en.wikipedia.org/wiki/Reproductive_isolation#The_genetics_of_reproductive_isolation_barriers

The key points are : 1) It is not possible for a population of our ancestors (e.g. our great-great grandparents) and our own to be simultaneously extant. 2) Thus, it is not possible for the common ancestor of two derivative species to be simultaneously extant as the derivatives.

OK... Let's go right back to the start. A) as the process of speciation is a population process and b) the categorization of species is effectively an arbitrary delineation on this continuous process; is it possible to consider "common ancestors" as "common ancestral populations"? The concepts and processes behind diversification are much easier to understand once we can discuss them as such. Now, are we in agreeance that you are not part of the homogenous population that your grandfather was? This means you are not free to breed with the same individuals he was due to the temporal gap and generational turnover that occurs in humans. As an aside, humans are unusual in the biological world by having overlapping generations - so the effect of population differentiation on generational scales is usually more pronounced in other organisms. Let's take it one more step backwards - the population, as defined above to which our great-great grandparents belonged to is no longer with us - in the sense that this population of humans is no longer contributing directly and significantly to the gene pool of the next generation. As such - it is not possible for the simultaneous existence of an interbreeding population of our great - great grandparents and a population of our own generation; thus it is not possible for a population of our ancestors and our own to be simultaneously extant. Now if we go even further backwards - the common ancestral population which became - through the population level process of diversification over several generations humans and chimps, by the same logic as the impossibility of the co-existence of our great-great grandparents and our own generation - cannot be extant. Now the difference here is that most biologists are content to place the arbitrary delimitation of this common ancestral population as being representative of a species distinct from its deruvatives - the chimps and the humans. As such, it is not possible for the common ancestor of two derivative species to be simultaneously extant as the derivatives. It's not reduction ad absurdum because we understand the process by which population differentiation occurs and based on this process we understand it to be not possible.

H.G. Wells thought of that one too. http://en.wikipedia.org/wiki/The_Island_of_Doctor_Moreau First, you'd need a solid definition of "species" which has proven elusive: http://www.sciencedirect.com/science/article/pii/S0169534706001649

There seems to be a rather straightforward explanation for one having experienced apparent telepathy whilst under the influence of a powerful hallucinogen - i.e. that one is hallucinating. Whilst conducting fieldwork in the tropics I managed experience some spectacular dysentery and subsequently some vivid hallucinations. Now either God was using Entamoeba histolytica to show me the workings of the cosmos, or perhaps I was extremely dehydrated, feverish and delirious and hallucinating was my brain's way of trying to help me cope.

For a start, these ones: fruit flies http://onlinelibrary.wiley.com/doi/10.1111/j.1558-5646.2010.01096.x/abstract;jsessionid=E1ED0862DC9DE17B4BCA27A7D467DEAE.d02t04?userIsAuthenticated=false&deniedAccessCustomisedMessage= birds http://rspb.royalsocietypublishing.org/content/early/2011/11/25/rspb.2011.2170.short mosquitoes http://www.sciencemag.org/content/330/6003/512.short shrimp http://epic.awi.de/22811/ fish http://www.springerlink.com/content/uml7526616862072/ lizards http://www.biomedcentral.com/1471-2148/11/347 you get the idea. Here's an overview of incipient speciation in general http://www.talkorigins.org/indexcc/CB/CB910.html

97% of surveyed Royal society members and 93% of National academy of sciences members answer "No" to the question "Do you believe in a personal god?" http://www.humanreli...telligence.html www.stephenjaygould.org/ctrl/news/file002.html, so given the available empirical data, one would have to conclude that most scientists are not Christians. njaohnt - let's say I have an R1 research laboratory at my disposal. Can you give me a prediction I can test that is only attributable to God? Say that if I put a beaker into the laminar flow hood and pray to God to tip it on its side, it will do so a significant number of times? Or perhaps I can set up a PCR, not put the Taq polymerase in and still get amplification if I put the bible on top of the thermocycler? This is the sort of experimental evidence I am expected to provide to support all the other positive claims I make in the realm of science. Now to preempt it - I am already fully aware that religion does not manifest in this manner. It is because belief in God relies on FAITH.

No - I'm saying that the phenotype has been conserved (and presumably the genes underlying the phenotypic traits in question also). Noncoding genetic regions and genes not under positive selection will of course be subject to stochastic drift.

Take a xanax? http://www.ncbi.nlm....lth/PMH0000807/ "Alprazolam is used to treat anxiety disorders and panic disorder (sudden, unexpected attacks of extreme fear and worry about these attacks). Alprazolam is in a class of medications called benzodiazepines. It works by decreasing abnormal excitement in the brain."

low rates of phenotypic evolution/strong stabilizing selection means that certain organisms don't change very much over long periods of time. Crocodiles are another good example. The forces of purifying selection on selectively advantageous traits can make diversifying to a novel fitness optima highly unlikely, and as a result, things that work well for an organism through the range of environmental fluctuations remain. It it ain't broke... I said it in my first post - speciation is largely a population process and "common ancestors" are better thought of as "common ancestral populations" rather than species.

Darwin didn't exclusively look at domestic animals then extrapolate what he saw to natural systems.

I have published using the phrase "We used a custom perl script available from the authors upon request". The reason is twofold - a) I want to know what you want it for - if it's an academic application, go nuts. If it's a commercial application well, we have to deal with the funding agency, my PI and my university to work out the intellectual property details, etc and so on. b) I'm not a programmer. The script did what we wanted it to on our data on our machine. It's probably buggy and not very nice to read. If you want to use it (with above-mentioned caveat) that's cool, but I don't want to get "It's not working" emails from people unaware/unable to troubleshoot the scripts themselves. If I wrote something amazingly useful and people were broadly excited by it, I might involve a non-computard to tidy it up and then host it for download to crank the citation index of our undoubtedly awesome paper, but as it stands my crappy little scripts are available if you read my paper and email me and tell me what you want it for.

Some do: http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0007595

Plenty of vertebrates, plants, invertebrates and other organisms of different species hybridize to produce viable hybrid offspring. It's a considerable area of research in population genetics. E.g. http://www.scienceda...70430123849.htm http://onlinelibrary...0049.x/abstract http://onlinelibrary...03.01905.x/full http://www.publish.c...paper=MU9870158 etc. Actually it was first proposed by John Ray. http://scienceblogs....l_species_c.php but popularized and refined by Mayr following the emergence of the field of genetics. A refinement of it - the evolutionary species concept is the most universally accepted species concept in biology today: http://sysbio.oxford...s=1&ssource=mfc As I tried to explain earlier - this concept allows for integrative/dynamic detection and delimitation of species, having defined them as metapopulations with independent evolutionary histories. A number of emergent delimitation methods are currently in various stages of development. There is no universal characteristic by which they are identified - which is a much better reflection of the reality of diversification than relying on a sole characteristic like reproductive isolation. http://www.pnas.org/...4/27/0913022107 http://sysbio.oxford...t/59/1/59.short etc. I linked you to scientific study on feralization in a previous post. The research was not specific to dogs. http://www.sciencedi...376635789900326 There's a fair bit or research on reversion to wild phenotypes in domesticated species. http://aac.asm.org/c...9/3175.full.pdf http://content.karge...roduktNr=230659 Wolf populations show genetic turnover and differentiation on much smaller time scales than 10,000 years. http://onlinelibrary...06.02877.x/full An example is melanistic differences between grey wolf populations driven by environmental selection http://www.sciencema.../5919/1339.full It's almost certain that the wolf population from which domestic dogs were originally derived from was genetically and phenotypically distinct from wolf populations today - especially given the sever bottleneck that wolves have been through in the intervening time. Physcial inability of domestic breed to give birth or copulate is not evidence of evolutionary distinction and therefore speciation - a great dane and a dachshund are still both dogs - albeit at different ends of a highly phenotypically diverse spectrum. As I tried to explain - dog breeding selects for phenotypic outliers and the outlier populations do not represent distinct metapopulations - but highly plastic phenotypes heavily selected for over a small number of generations. As an example of the lack of differentiation between wolves and domestic dogs:Gene flow between dogs and wolves happens: http://onlinelibrary...06.02995.x/full http://www.springerl...h6dbrfwhcl09t3/ and dogs were probably derived from multiple wolf populations and certain dog breeds are more related to wolves than they are to each other. : http://www.sciencema.../5319/1687.full Sorry you took offense, none was intended. I think a lot of the misunderstanding based on your use of reproductive isolation as a hard criterion for species delimitation, and the misapplication of that concept to dog breeds. Even in the absence of divergence, if a contemporary population arises from an ancestral population, The ancestral population cannot simultaneously exist at the same time point as the derived population (unless you have a DeLorean I guess). If we consider contemporary species to be the same as their ancestors, chickens are really velociraptors, which are really amphibians, which are really fish, etc.

A component of my current position is mentoring PhD students from developing nations, who come on extended visits to our lab in order to carry out the molecular biology components of their PhD programs - both the benchwork and subsequent analysis. I'm yet to meet one who wasn't under-equipped in terms of education and in some cases extremely ... optimistic to how much work I/we will actually do for them. The way I see it, they are being awarded a degree/a publication for having gained specific knowledge and done specific work. One day they will get a job /position where it is assumed that they have these skills/knowledge. So, by doing things for them and not imparting the skills and knowledge they are meant to have we are actually doing them and the field a disservice. Further - if we make a habit of producing graduates without the things that they are purported to have, we devalue the degree and the institutions which award them. Telling someone that mentorship does not involve me doing things for them and that I will not be carrying out the tasks they expect me to can be a difficult discussion. I know there are some former collaborators who hold an open dislike for me after I have made the situation clear. With our lab, it's also a bit of a rock and a hard place as we rely on the developing nation lab for sample material, so an ongoing mutually beneficial collaboration is important for us too. In your situation - a) you're obviously not being paid in accordance with the time you put in - I'd try to instill some form of hourly rate - or drop the financial connection if it is not important to you. b) Is she really going to be qualified to conduct the work her certificate will say she is able to do? If you push her through with too much hand holding, you're simply postponing the inevitable once she gains a position she is ill equipped to conduct. Strike a balance between hand holding and giving her enough rope - which I know from personal experience is easier said than done - good luck.

False. Plenty of species can hybridize and produce viable offspring. http://en.wikipedia...._hybrid_animals http://en.wikipedia....9#Hybrid_plants Reproductive isolation, while a secondary characteristic indicative of speciation has not been considered a prerequisite condition for recognition as a species since the advent of the biological species concept. http://www.pnas.org/...ppl.1/6600.full Since Ray and Mayr in the 40's, species have been defined primarily as "independently evolving metapopulations" by which defining characters such as genetic, morphological and ecological differneces, reproductive isolation, etc are secondary characteristics which are useful to identify these metapopulations - but the key factor is an independent evolutionary trajectory. Still, a) We don't see reproductive isolation between these domestic lineages and their wild congeners, b) we see a rapid return to a wild phenotype in feralized populations. This is evidence that the speciation process of these domestic populations and their wild relatives is incomplete. We also don't see two deruvative species and a remaining extant ancestor. By definition, if an ancestral population has evolved into one or more deruvative species, the ancestral population does not exist in the same state it did at the time of divergence. Precisely - the current population of wolves IS NOT the same either phenotypically or genetically as the ancestral population from which dogs were isolated from. That ancestral population no longer exists. The "common ancestral population" of wolves and dogs no longer exists. A population will evolve stochastically over time. At some point current wolves will be considered taxonomically distinct from the ancestral population from which domestic dogs split from 10-15,000 years ago. At that point we will have two derivative species evolved from a common ancestor - dogs and "post-wolves" but no wolves - is that any clearer? This is simply false. Domestic dogs of all breeds can produce viable offspring with wolves. Domestic breeds represent the most severe mutations possible in a population - the outliers of a distribution of phenotypic variation. They are the "tree men" "werewolves" and "dwarves" of the dog world. http://urbantitan.co...into-a-monster/ despite displaying severe mutations, "tree man" and "dog boy" are unequivocally human. If you ask prof. Bob Wayne who has worked extensively on dog ancestry, divergence between dogs and wolves isn't extensive enough to warrant species status and were reclassified back to Canis lupus in 1993 given genetic evidence. http://dogtalk101.bl...on-of-dogs.html http://en.wikipedia.org/wiki/Dog Your assertion that aurochs would be able to breed with modern day cattle is pure Jurassic Park science fiction. We have no DNA evidence to support such an assertion and the morphological divergence and temporal displacement between the two populations is highly suggestive of significant divergence representative of significant evolutionary distinction between the two.

A) Not sure what hybridization has to do with speciation in this sense - care to clarify? B) You've picked a suite of domesticated organisms as examples. These are by and large not representative of diversification under natural settings due to the extreme levels of selection placed on very small initial populations over series of generations - selection in the fast lane so to speak. You will not find natural analouges to these examples in the same time frames. Under a number of species definitions, these domestic variants would not be considered species given incomplete reproductive isolation and limited genetic divergence at neutral loci. In some feral populations of domestic animals, a rapid morphological transition back to a wild phenotype is observed. http://www.sciencedirect.com/science/article/pii/0376635789900326 C) Wolves, junglefowl and wild pigs didn't stop evolving at the point in time that humans separated a population from the whole and domesticated it. The original, homogeneous population from which these organisms were selected from exists at a time point in the past and the current populations are subject to ongoing evolution through stochastic and selective processes. There is a point at which the contemorary extant wolf will no longer be the same species as the wolf at the time of domestication. Without needing to infer and extinction event, the common ancestor of wolves and domestic dogs will no longer exist.

Because speciation occurs over a longer time period than two generations.

Rather by definition, a "common ancestor" of two extant species cannot itself be extant. Many groups/individuals/traits are derived in relation to others. E.g. in this example, the common ancestor of the fish groups was a generalist carnivore. Scale feeders have evolved from this common ancestor, while others have maintained the generalist carnivore trait. The scale feeders are derived in relation to the extant generalist carnivores, but none of the extant taxa are, or could be the common ancestor, as the common ancestor can no longer exist given it has evolved into a number of different forms. Also, the process of biological diversification is a continuum, with the category of "species" being somewhat arbitrary. One generation does not immediately give birth to another species - the parent and offspring remain the same species at all times - the process is incremental in nature. As such, pinpointing an exact phenotype/genotype "common ancestor" between two related species is not possible. In an attempt to explain better I will steal this image from Presgraves and Yi 2009. Imagine there is a Y axis with time along it. For the duration of t1 divergence is occurring between the populations which will become humans and chimps, but they are not yet at a point at which one would consider them separate species until the beginning of t2. The population that existed prior to the beginning of t2 has become the divergent chimp and human populations. In doing so, it cannot be extant at the same time as the species derived from it. In addition, the period of t1 will be a number of generations relative to effective population size. Prior to t1, stochastic drift will play a role in temporal divergence of the entire population, so the population may well be considered different species at different precise time point during the t1. So, in summary, the term "common ancestor" used in the literal sense, doesn't really take into account the continuous nature of evolution, the coalescent processes of speciation or the dynamic of stochastic drift. "Common ancestral population" may be a more appropriate way to phrase the term.

None, to my knowledge. Any inert substance is going to be at ambient temperature. Some substances facilitate heat transfer more readily than others. For example, helium loses and gains heat about 6x as fast as air. This makes it a poor insulator and in diving, most divers in cold water with trimix will take an independent argon gas source to fill drysuits with due to its thermal inertia.

The oral traditions of the indigenous Australians say that a giant snake created the earth and that droughts are caused by a greedy frog which drinks all the water in the land. Those of the Abenaki native Americans say the continents are giant turtles and corn was created by a man dragging a woman across the land by her hair, etc, etc, etc. Oral traditions have not inherent "truth" simply by being oral traditions, which means you need a criteria by which to decide which you will pay attention to and which you won't. In the same sense "revelations/revealed truth" is an appeal to authority: http://rationallyspe...al-fallacy.html At some point you need to trust the authority which has revealed this "truth" exclusively to you. There's a subjectively defined leap of faith at some point, regardless.

> −268.93 °C.

With a boiling point of −268.93 °C, (the lowest recorded temperature on earth is −89.2 °C for reference), helium is only in liquid form at temperatures which are too low for vertebrates to live at, so no known organism could have liquid helium in its blood. Helium in the bloodstream would generally be present in a dissolved gaseous state, the same as other gases, rather than a liquid. As a diver, sometimes we use helium as a component of breathing gas on deep dives, as breathing nitrogen at high partial pressure has a narcotic effect and too high a partial pressure of oxygen can cause convulsions and unconsciousness. As a result, I'm sure I and many other divers have had a much higher than normal quotient of dissolved helium in our bloodstreams. One issue is that helium dissolves into and out of blood and tissues faster then nitrogen, so additional decompression is needed to off-gas on the way up to avoid decompression sickness. en.wikipedia.org/wiki/Trimix_(breathing_gas)

No. In any test, multiple outcomes are anticipated. In the simplest model you'd have a test hypothesis and a null hypothesis. Sound experimental design doesn't rely on a particular a priori result from observation. Variation in any empirical test is virtually inevitable. Hence we replicate results and use statistical analysis to verify the probability of observations supporting a hypothesis. Read the link on confidence intervals. Variance in empirical results is not "human error" per se, it's simply how reality operates. We use replication and statistical verification, then apply a confidence interval. At least in my field marginal confidence is awarded to a result which supports the test hypothesis with >95% confidence and significance of the test is assumed when confidence is >99%. How firmly you can support a hypothesis is determined by the statistical robustness of the result in association with the number of replicates and support from independent, multivariate data sources. No scientific result is ever reported as 100% proof. Some level of potential error is always recorded as a possibility in any scientific result. However if a theory - such as evolution through random mutation and natural selection is supported by hundreds of thousands of experimental, genetic, morphological, fossil, observational, behavioral studies each with dozens to millions of replicates, I'm sure you can understand that the appreciable support value supporting the result is rather overwhelmingly positive.

Given that Villain started a thread in which they posted: It would seem that they are exploring the possibility that, as scientists are human with natural and inescapable biases, and the fact that scientific endeavor is conducted by humans, the results of scientific inquiry are inherently biased and thus amount to the same as opinions and faith. What Villain appears unaware of is that the scientific method and best practices are fully aware of potential bias. Not just personal biases of individual scientists, but sampling bias, ascertainment bias, autocorrelation, placebo effects, outlier events, etc and so on ad infinitum. There are entire fields of statistical methodology and experimental design which are entirely devoted to the reduction of bias. Experimental designs such as replication, statistical tests, double blind testing, experimental controls, random simulation, the peer review process, etc, etc, etc. are all in place to counter and reduce biases. Extreme lengths are gone to in order to reduce potential bias in experimental results, however no experiment of data collection method is perfect, which is why virtually every empirical result in science is reported with a measure of error. So in summary - scientists are fully aware of the role that biases play in the production of erroneous results. Rather serious lengths are gone to to eliminate and reduce bias in scientific results. It is widely acknowledged however, that no result is perfect. As such, results are reported with degrees of potential error in virtually all cases.