February 12 is a significant day for biologists - it's the date of Charles Darwin's birth. This year it's a biggie - if the old gentleman was alive today he'd be 200. There are various commemorative events lined up all around the world, plus TV & radio programs, books & articles, and blogging galore. Here's an early contribution from David Quammen:
January 2009 Archives
I came across an interesting article in yesterday's Herald. The headline read: Drug firms turn rivers into flowing medicine cabinets. (Not like any medicine cabinet I'd want to put a hand into!) It seems that some waterways in India contains alarmingly high concentrations of a whole range of antibiotics - the result of drugs companies dumping their manufacturing wastes into rivers & their tributaries. Enough of a powerful antibiotic was being spewed into one stream each day to treat every person in a city of 90,000, said the paper.
... is in the comments thread for the post.
Sorry, sorry, this feels like cheating - but I've been really busy at work today & not had much time for blogging :-(
A question in the 2007 Scholarship exam asked you to discuss the impact of various forms of genetic testing on the human gene pool. One of those techniques was pre-implantation genetic diagnosis, or PIGD: testing very early embryos for the genetic markers linked to a variety of conditions (or, where known, for the genes themselves).
Now I've come across a thought-provoking article dealing with some of the ethical issues associated with PIGD. Whether or not you agree with the points being made, the article's sure to stimulate ideas & discussion.
Here's a couple of paragraphs from the generally excellent book, The beak of the finch, by Jonathan Weiner.
Many paths lay open when the finches first arrived, and the smallest flights and trials of their descendants were rewarded. That is why they have traveled in more directions than any other creatures on the islands, that is why they have evolved farther and faster than any other creatures: because they got here early.
Our own line is now radiating farther, faster, and in more directions than any other single species in the history of the planet - and for a similar reason. We are the first creatures to arrive in the strange territory we now occupy. We stumbled into our new niche before any other creatures on the planet. We discovered it.
What's wrong with the idea conveyed in this quote?
(PS Don't get me wrong - I thoroughly enjoyed the book, & it's well-worth reading again. But still - that particular concept could be better-phrased...)
And this one's no exception: "Darwin was wrong" on the cover of New Scientist, no less. (& in smaller type: cutting down the tree of life.)
This leads to a story about the significance of horizontal gene transfer to our understanding of evolutionary relationships. But why the headline (which will probably be grist to the anti-evolutionary mill...)? The idea of HGT is neither new, nor particularly controversial. Scientists have known for at least a decade that prokaryotes are quite promiscuous about passing around bits of DNA. And we know, too, that it can happen in eukaryotes: transfer of DNA between chloroplasts (& mitochondria) & their host cells' nuclei has been well documented. (And this can sometimes make it difficult to work out prokaryote phylogenies.) So we can infer that HGT was just as rife among the prokaryote inhabitants of the early Earth - and hence, at that stage you couldn't really describe what was going on as being represented by a 'tree of life'.
We owe the metaphor of the 'tree of life' to Charles Darwin, who used it as a way of representing the concept of descent with modification. So, does the prevalence of HGT among prokaryotes, especially back on that early Earth, mean that Darwin was wrong?
... as the ancient knight said to Indiana Jones **. Okay, I'm talking about choice of subjects, so the outcomes won't be as life-threatening as the choice Indy faced, but these decisions can still have a big impact on your future study courses.
(& I'm aware that if you're considering Scholarship this year, you've most likely made those choices, so this one's really aimed at students who aren't so far through the system.)
What put me on to this topic is the fact that at the moment I'm involved in approving enrolments in my School for 2009. Most of the applications I see are fairly straightforward, but there are still quite a few students who can't get into some of the subjects they've chosen because they don't have the pre-requisites. And in some of those cases, they haven't actually studied the necessary subjects at school.
For example, biotechnology's a growing area in this country, as in many others. So for anyone wanting to take this as a major at uni, biology's an obvious subject to take at school. But so's chemistry. And you need maths, as well as physics, if you're wanting to take physics papers as part of a physics or engineering degree.
Now, of course there are ways round all this. At Waikato, for example, we've got a set of Foundation Science papers, in February, that I've been steering people into where necessary, to help bring them up to speed. (They're good for people who have UE but might not have all the required credits in a particular subject.) Or we might advise that you take what's called Certificate of University Preparation papers in the A semester, & pass those before moving on to degree-level study. But having to take the CUP papers, in particular, means that your degree may end up taking rather longer than you'd first planned. And costing a bit more too. Better to keep your options open for as long as possible, & choose wisely :-)
Oh yes, did I mention statistics? Statistics is a really useful subject to take if you're planning on a science career; I'd certainly recommend it to aspiring biologists. When I was an undergraduate stats was a compulsory paper for anyone doing science. I will confess that it wasn't my strongest subject & there were times when I wondered what I was doing. I mean, did I really need to be able to work out how many lightbulbs in a consignment were likely to be faulty?? But then I got into doing research & it all made sense :-) So do give it some thought.
** Harrison Ford and Sean Connery, in one film. My idea of movie heaven!!
Water fleas - Daphnia - are rather cute little freshwater arthropods:
In some circumstances (water temperature, presence of predators), rather than having that sharp little point on their heads (top of the picture, above the eyespot) some Daphnia will have a longer, spikier 'helmet'. And this is where it gets interesting: it depends on the mother. If a 'helmet-less' female Daphnia is in an environment where there are also predators, her offspring will sport helmets. If not, they won't. This observation has been described in one article as an example of Lamarckian inheritance.
But it's not. It's an example of epigenetics in action. And PZ does his usual excellent job of explaining what's going on, & why the original story was so far off the mark. As he says, "Genes don't execute rigid, predetermined programs of development — they are responsive to the environment and can express radically different patterns in different contexts." And this is what's happening with the waterfleas (where the contexts are presence & absence of predators). Great stuff.
ERV is on a roll this week. She's just put up this fascinating post about convergent evolution - at the level of enzymes - in tomatoes and (wait for it) the retrovirus HIV. I read it & thought, whoa! this is amazing! But this is ERV's field of expertise - go over there & read it; this is such cool stuff.
HIV = Human Immunodeficiency Virus. And there's an extremely large volume of evidence supporting the hypothesis that infection with HIV generally leads to the development of AIDS (Acquired Immune Deficiency Syndrome). I say 'generally' because there is a very small subset of people (called 'elite suppressors') in whom this progression doesn't seem to happen. But in everyone else, the HIV virus targets & ultimately leads to the destruction of the immune system's CD4 cells, leaving patients vulnerable to opportunistic infections.
The only medical treatments available to AIDS patients involve a combination of anti-retroviral drugs that inhibit the virus's ability to reproduce & infect CD4 cells. Unfortunately these treatments are not as widely available as they could be in countries such as Africa, which have a high prevalence of HIV infections and patients with AIDS. Now it seems that a homeopathy practitioner is offering homeopathy as a treatment for African AIDS patients, claiming that it will achieve a cure (something that modern medicine can't offer) by stimulating the patients' immune systems.
Now (quite apart from the effectiveness of water or sugar pills on the immune system), how likely is this? And doesn't it sound like a good idea - stimulating the immune system in people with a minimal ability to mount an immune response to infections?
Well, no. And ERV does a good job of explaining why not.
The earliest fossils we have are of prokaryotes - a major taxonomic grouping that includes both bacteria and members of the Archaea (things like blue-green algae, aka cyanobacteria). And like modern prokaryotes, those early life-forms were tiny. Most of us are far more familiar with some of the eukaryotes, and perhaps a major reason for this is that we can see them: they are orders of magnitude bigger than microbes. And an interesting question is: what sort of trajectory took some forms of life from the tiny to the ginormous? Was there a smooth upward trend in the maximum size of living things? Or did things progress like a learner driver - by bunny-hops?
One of the questions in last year's Level 3 Bio exam asked students to consider the impact of human predation on fish evolution.
Most fish stocks, in New Zealand & around the world, are intensively harvested by fishermen. The mesh sizes used in their nets mean that the fish they catch are mostly the larger and older indivduals. This is a form of selection.
Explain what is likely to happen to the fish populations if this pattern of selection continues to operate.
For those who don't necessarily read the 'comments' & so may have missed Heraclides' heads-up - in the US the education board in Louisiana has made it possible to teach intelligent design in the state's schools:
On Tuesday, the state's Board of Elementary and Secondary Education adopted a policy that sharpens those fears, giving teachers license to use materials outside of the regular curriculum to teach "controversial" scientific theories including evolution, origins of life, and global warming. Backers of the law, including the Louisiana Family Forum, say it is intended to foster critical thinking in students. Opponents insist its only purpose is to provide a loophole for creationists to attack the teaching of evolution.
I'd have to say that I agree with those opposing the law. (Well of course, some might say.) And I agree for all sorts of reasons. What I want to comment on here is that wretched word 'controversial'. I've said it before: in the scientific community there is no controversy about evolution. What we're seeing here is a "manufactroversy". The scientific consensus is that evolution has happened & is happening around us. Scientists may debate the finer details of how this happens ('punctuated equilibrium' vs 'gradualism', for example, or the relative significance of epigenetics, but they don't debate the fact of evolution. (And the same could be said for the other manufactroversies mentioned in the Louisiana bill.)
This is simply an attempt to sneak intelligent design materials into the science classroom, rather than a genuine attempt to foster critical thinking skills. There are plenty of ways to do that, using both good science & good educational techniques. (And for those teachers reading this who might be looking around for additional ways to do this within the specific context of evolution, the work of Passmore & Stewart might come in useful.)
Thanks, Heraclides :-)
"Gosh" said my husband, rustling the newspaper. "You'd better start drinking coffee!"
He'd just come across a report saying that drinking more coffee in one's middle years is associated with a decreased chance of developing Alzheimer's disease, or other forms of dementia, in old age. But is this enough to make me want to give up my jasmine dragon-pearl tea?
Not just yet. The actual paper isn't available yet; all you can read on-line is the abstract, in the up-coming volume of the Journal of Alzheimer's Disease. And what I can see there is not going to make me pass on my several-times-daily cuppa. Not yet.
The paper is based on data from a longitudinal population health study from Sweden & Finland: people were recruited into the study while middle-aged, in the 1970s, and in 1998 1409 of what was presumably a much larger original group showed up for the end-of-study followup examination. By this time these 1409 individuals were between 65 & 79 years old. They completed survey forms that asked a whole heap of lifestyle-related questions, including how much tea or coffee they drank daily, & were tested for signs of dementia. A total of 61 individuals were diagnosed with some form of dementia, and 48 of those 61 had Alzheimer's (AD). The study's authors stated that, after a range of potentially confounding variables had been accounted for, their data showed that those individuals who drank more coffee were less likely to develop either AD or other forms of dementia. And they said that "the lowest risk (65% decreased) was found in people who drank 3-5 cups per day" (Eskelinen et al. 2009).
But there are things left unsaid, & without them I can't tell whether holding my nose & drinking coffee will have any significant effect on my future health. Because - I don't know the
relative absolute risk. 65% of what??? Did all the AD occur in the non-coffee drinkers? If not, how many of the coffee-drinkers were affected? The abstract doesn't offer this information, & neither does the newspaper article based on it (it would have been nice if the journalists had asked these questions too...).
What else wasn't mentioned: the fact that caffeine in high doses can have negative health impacts. For example, it's linked to hypertension (high blood pressure) & can cause nausea & insomnia in people who regularly ingest large quantities. So until I've seen the paper itself (& maybe not even then) I won't be giving up my Camellia sinensis habit just yet.
(And for an excellent example in support of the statement that correlation does not equal causation: while high caffeine intake has been linked with loss of calcium from bones, coffee intake appears to be a marker rather than a cause. This is because this particular study found that those drinking lots of coffee also tend to lower their intake of dairy products.)
M.H. Eskelinen, T. Ngandu, J. Tuomilehto, H. Soininen, M. Kivipelto (2009) Midlife coffee and tea drinking and the risk of late-life dementia: a population-based CAIDE study. Journal of Alzheimer's Disease 16(1)
Islands can be home to rare and unusual species, which have often evolved in isolation for extremely long periods of time. On many - particularly oceanic islands - there may be no native land mammals, except, perhaps for bats. So when mammalian predators do make it to these islands the effects can be devastating. (Incidentally, it's wrong to say, as many do, that island species evolved in the absence of predators. There were predators all right - look at Harpagornis, New Zealand's extinct giant eagle. Or frogs, & tuataras. Just no mammalian predators.) This is particularly the case where the island's ecosystem is reliant on seabirds - or, more precisely, on seabird poo, which is an ongoing source of nutrients for the soil. Knock out, or just greatly reduce, the seabirds & the whole ecosystem suffers.
Anyway, most people would agree that the 'fix' to this problem is to remove the key introduced predators, & all will be well. But - they'd be wrong, & it's not. This is nature at work, & things are far more complicated than they first appear. As Bergstrom et al. (2009) say, taking out those top predators is only half the story.
The phrase 'scientifically proven' is not one you're likely to hear from a scientist - but it's often attached to claims about a whole variety of products. Why don't scientists use the phrase? Because - as I've said before - while we can offer the best possible explanation for a set of data or suite of observations, we can never be 100% sure that it's correct: it's always possible that new research might alter our current understanding. (Think of our changed perceptions about the cause of stomach ulcers, for example.)
Now I see that the reincarnated Charles Darwin has addressed this same issue in a recent blog posting. (And if you're skeptically inclined, one of his correspondents has what looks like a most interesting blog of their own.)
Perhaps one of the biggest unanswered questions we have is "how did life begin?" Scientists have been working in the area of abiogenesis for some time now, beginning with the Miller-Urey work on the early-Earth atmosphere (which I've commented on previously). And there's reasonable agreement that the precursors to life were probably some sort of self-replicating molecule, perhaps a proto-nucleic acid or enzyme (and remember that RNA can act as an enzyme).
Now PZ's written about an interesting paper describing how two researchers 'built' simple catalytic molecules that can self-assemble themselves from even simpler substrates - and used natural selection in the process.
And no, the researchers are not claiming that this is what actually happened way back when, but, as PZ says, "it's more like a proof of concept of the idea". Definitely an area to watch :-)
There's a new geology book coming out, written by a group of geologists and examining the geological evidence for evolution (& the lack of support it offers to creationism). It sounds like a good book & I'll look forward to getting my hands on it (hopefully one of my geology colleagues will buy a copy!) - but what I didn't like was Michael Shermer's comments:
Creationism began with the fossil record and there it shall end. Before Darwin, the geological strata with their accompanying fossils formed the first geological theory of life on earth--creationism coupled to flood geology. It was Darwin who stood that theory on its head and showed that, in fact, these same fossils could be used to support his new theory of evolution by natural selection. Ever since Darwin, geology has unequivocally supported evolution and not creationism, and yet today Intelligent Design thrives in popular culture. Here at last we have a definitive collection of world-class geologists and paleontologists who systematically demonstrate precisely why geology destroys all design arguments, and reveals instead a deep and rich history of life on earth. A perfect companion to all science courses.
As Brian points out, over on Laelaps, Shermer's phraseology verges on elevating Darwin to the sainthood. But - creationism hardly began with the fossil record: the creation story (including the idea of a global flood) has been around for a lot longer than that. Nor was Darwin the first person to begin to question the explanations for the fossil record that prevailed in the early 1800s. While a 'typical' creationist reading of the fossils might claim that they supported the Noachian flood, many of the geologists of Darwin's day - men who had a significant impact on his thinking, such as Charles Lyell - were most definitely not flood geologists.
And Darwin also recognised that the fossil record of his time presented some problems for his theory of evolution by natural selection. In fact, he spelled them out in Origins, and stated(correctly) that future scientists would find the transitional fossils that his theory predicted.
Yes, Darwin was a great scientist - but like all scientists he built on the work of others and made mistakes, and we shouldn't be viewing him almost as some sort of biological saint, or deifying him (as one of my students suggested last year). The story of evolution is interesting enough without that.
This year there'll be a wide variety of events & publications marking the 200th anniversary of Charles Darwin's birth. One of these is Origins: a history of beginnings, a blog on the website of the journal Science. It kicks off with a post by science writer Carl Zimmer (I've talked about some of his other work here & here) on the origins of life on Earth. One to bookmark for repeat visits, I think :-)
For anyone with a passing interest in global climates, present & past, the UK's Birmingham University has put out an excellent article looking at the conditions that could have prevailed on a'snowball Earth'.
The term 'snowball Earth' refers to a time (about 630 million years ago) when our planet was in the grip of a major ice age & almost entirely glaciated. Birmingham researchers have come up with evidence (in the form of oxygen isotopes from pre-Cambrian rocks) supporting the contention that such icy conditions could - paradoxically - have co-existed with an ancient atmosphere rich in carbon dioxide. It does sound odd, doesn't it? But once the Earth's land masses had acquired even a partial coat of ice & snow, this would do two things: it would increase the planet's albedo (reflectivity), & it would also reduce the rate at which rocks weathered - & weathering removes CO2 from the atmosphere. At the same time, volcanoes are constantly adding CO2 to the air. So you could indeed end up with an ice-shrouded planet that also had an enhanced greenhouse atmosphere.
This isn't to say that the whole planet was covered with ice - many scientists suggest there must have been open water near the tropics, & indeed, it's hard to see how living things could have survived without such refuges. But condtions would have been very cold indeed over much of Earth's surface.
(Fairly predictably, at least one major daily newspaper in the UK has misinterpreted the research to mean that increasing levels of CO2 could trigger the snowball state, which is most definitely not what the Birmingham research suggests!)
Recently I read an article in the local paper that made me think about the hierarchy of research journals. (The story itself is about a piece of research suggesting that carbohydrates can be addictive & this is why some people can't stop eating them. This isn't within my area of expertise & I have yet to read the paper itself, so I'm not going to comment on that here, beyond saying that this is likely to be a provocative finding given that our bodies rely on carbohydrates as their main source of energy.)
Grump grumpity grump - a headline like that & we don't have full access to the journal (only up to a year ago).... But anyway - on The Panda's Thumb there's a report of a research project which has achieved the full Neandertal mitochondrial DNA sequence. TPT quotes a conclusion from the summary of the paper:
Analysis of the assembled sequence unequivocally establishes that the Neandertal mtDNA falls outside the variation of extant human mtDNAs, and allows an estimate of the divergence date between the two mtDNA lineages of 660,000 +/- 140,000 years (Green et al. 2008).
On The Panda's Thumb, Jim Foley goes on to say that
The Neandertal mtDNA sequence was compared with mtDNA from chimpanzees and 53 modern humans. The human mtDNA sequences had between 2 and 118 differences from each other. The number of differences between the human mtDNAs and the Neandertal mtDNA varied from 201 to 234.
(There's a nice graph of the data too.)
A number of earlier studies of Neandertal mtDNA have also found differences between Neandertal & modern human sequences. Taken with these, the latest study certainly provides strong support for the current designation of Neandertals in a separate species, Homo neandertalensis (which shows how science operates: when I was a student, a long time ago, there was just fossil evidence to go on, & many scientists viewed Neandertals as a subspecies of H. sapiens).
And TPT also links to a more detailed examination of the paper by Green et al.
I just love the way molecular biology allows us to refine our understanding of evolutionary relationships (even though I like fossils better!).
R.E. Green, A-S Malaspinas, J. Krause, A.W. BRiggs, P.L.F. Johnson, C. Uhler, M. Meyer, J.M. Good, T. Maricic, U. Stenzel, K. Prufer, M. Siebauer, H.A. Burbano, M. Ronan, J.M. Rothberg, M.Egholm, P.Rudan, D. Brajkovic, Z. Kucan, I. Gusic, M. Wikstrom, L. Laakkonen, J. Kelso, M. Slatkin & S. Paabo (2008) A complete Neandertal mitochondrial genome sequence determined by high-throughput sequencing. Cell 134(3): 416-426
Following on from the reference to the Dover trial in my last post - this site has a link to the pdf of a review article, which looks at the Dover case & its implications for teaching evolution in the US. It's an interesting overview of the case & there's a lot to learn from it, even though we're not the 53rd state. (Or should that be 52nd?)
One of the threads at Open Parachute has had a discussion about the concept of 'academic freedom' - the idea that scientists should be free to state their opinions about those areas of science where they have expertise. (This concept isn't exclusive to scientists, either, but applies to researchers in all disciplines.) It's probably most apparent in the universities, which in NZ are expected to provide research, teaching (ie research-based teaching, where the people doing the research are also teaching their students about that research & how it fits into the existing body of knowledge) - & to be the critics & conscience of society.
This freedom may be constrained, to a greater or lesser degree, by intellectual property (IP) issues - if you've contracted to do a bit of research for another organisation, they aren't going to be pleased if you start talking about the results in public without their permission. And similarly, no sensible scientist is going to let the world know about the outcome of an important new piece of research via press release: they'll publish it first in a reputable journal & then the media release will follow. But outside those constraints, researchers can & do talk - with their students, with the media, with interested community groups - about topics within their areas of expertise. (We can & do talk about topics outside our own fields as well - but with no more authority than the next interested amateur.!)
But in the US, the phrase 'academic freedom' is being used (I should say, mis-used) in some states to suggest that science teachers should have the freedom to teach, or not teach, particular parts of the science standards... Oh, OK, to teach about the manufactured controversies** surrounding evolution, & about 'alternatives' to evolution as an explanation for life's diversity. This is both a mis-use of the phrase & a yet another, fairly blatant, attempt to get around the restrictions on teaching creationism in the classroom. First Oklahoma, & now Mississippi - it would seem that the legislators responsible have learned very little from the experiences of the Dover Board of Education, in Pennsylvania. (There's an excellent video about the Dover case available on-line.) It'll be interesting to see how these latest efforts pan out.
** As far as the scientific community is concerned, there is no controversy. In 2009, 150 years since the publication of On the origin of species, & 200 years since Darwin was born, evolution remains the only scientific explanation we have for the diversity of living things that live, & have lived, on this planet.
Say 'Charles Darwin' and (after 'evolution'!) many people would probably say 'Galapagos'. The tortoises, mockingbirds, finches & iguanas that he observed and collected on the Galapagos Islands contributed to his development of the theory of evolution by means of natural selection.
Darwin noted that there were two species of iguana on the islands - the land-living species, and the marine iguanas, which swim down to graze on algae that grow on the rocky seabed. Now, just a few weeks before we celebrate the 200th anniversary of Darwin's birth, comes the announcement of a third Galapagos iguana: a pink, or 'rosada', iguana (Gentile et al 2009).
I've just stumbled across a provocative - & thought-provoking - essay by Richard Dawkins. It caught my attention because I'm occasionally asked if there's ever been a chimp-human hybrid. (The answer, so far, is 'no' - well, not since the two species diverged around 6 million years ago.) To Dawkins, the creation of such a chimera would change everything about our understanding of humanity's place in nature.
Read his article, & see what you think.
Over on Respectful Insolence, one of Orac's specialties is the dissection of various forms of jiggery-pokery/hocus-pocus/pseudoscientific nonsense. This post of his is well worth reading: it takes a recent paper on a purported 'energy-healing' technique & explains why what was done is very far indeed from good science. (It's worth repeating the old aphorism that the plural of 'anecdote' is not 'data'.) You would have to wonder about the peer-review processes for that particular journal...
The 'human evolution' achievement standard expects you to be able to discuss trends in cultural evolution. You need to be aware of evidence relating to: use of tools (stone, wood, bone), fire, shelter, clothing, abstract thought (communication, language, art), food-gathering, and domestication of plants & animals. The earliest evidence for culture is the presence of stone tools, and the oldest such tools come from sites in Africa (Omo, Turkana, & the Middle Awash) that date date back to around 2.3 million years ago. But - is this likely to represent the earliest tool manufacture and use?
Here's a great set of short articles about evolution. Each one's only a page long, and talks about a piece of research that (as the authors say) demonstrate the 'breadth, depth, and power of evolutionary thinking' (Gee, Howlett & Campbell, 2009). My current favourite is the one about the origins of the vertebrate skeleton, but they're all good. Enjoy :-)
(And thanks to PZ for the heads-up! As he says - teachers, put this one in your classrooms.)
There's a discussion going on over at Open Parachute around the word 'Darwinism'. I want to talk about this word here because it's one that's often used in a pejorative sort of way by folks who don't agree with the concept of evolution. In this context, 'Darwinism' is equated with evolution in a negative sort of way (often accompanied by the claim that 'Darwinism' denies the existence of god).
This made-up word, 'Darwinism', is often used to suggest that the whole of evolutionary biology stands or falls on the work and writings of Charles Darwin. This just isn't so, & suggests a complete lack of knowledge of how biology has moved on since the late 1800s. (Or perhaps a wilful disregard of all that...) It also suggests that the users don't really have a good idea of how science operates. More than once I've seen it said that because Darwin repudiated his own theory on his deathbed, this means that evolution's wrong.
Happy New Year, everyone :-)
I was idly looking around for something to write about (definitely in holiday mood at the moment!) & came across a couple of websites that you might enjoy. And they're even educational...