Posted on 02/20/2003 2:30:45 PM PST by Junior
IT STARTED with a biologist sitting on a grassy river bank in York, eating a sandwich. It ended in the discovery of a scruffy little weed with no distinguishing features that is the first new species to have been naturally created in Britain for more than 50 years.
The discovery of the York groundsel shows that species are created as well as made extinct, and that Charles Darwin was right and the Creationists are wrong. But the fragile existence of the species could soon be ended by the weedkillers of York City Councils gardeners.
Richard Abbott, a plant evolutionary biologist from St Andrews University, has discovered evolution in action after noticing the lone, strange-looking and uncatalogued plant in wasteland next to the York railway station car park in 1979. He did not realise its significance and paid little attention. But in 1991 he returned to York, ate his sandwich and noticed that the plant had spread.
Yesterday, Dr Abbott published extensive research proving with DNA analysis that it is the first new species to have evolved naturally in Britain in the past 50 years.
Ive been a plant evolutionary biologist all my life, but you dont think youll come across the origin of a new species in your lifetime. Weve caught the species as it has originated it is very satisfying, he told the Times. At a time in Earths history when animal and plant species are becoming extinct at an alarming rate, the discovery of the origin of a new plant species in Britain calls for a celebration.
The creation of new species can takes thousands of years, making it too slow for science to detect. But the York groundsel is a natural hybrid between the common groundsel and the Oxford ragwort, which was introduced to Britain from Sicily 300 years ago. Hybrids are normally sterile, and cannot breed and die out.
But Dr Abbotts research, published in the journal of the Botanical Society of the British Isles, shows that the York Groundsel is a genetic mutant that can breed, but not with any other species, including its parent species. It thus fits the scientific definition of a separate species.
It is a very rare event it is only known to have happened five times in the last hundred years Dr Abbott said. It has happened twice before in the UK the Spartina anglica was discovered in Southampton 100 years ago, and the Welsh groundsel, discovered in 1948.
The weed sets seed three months after germinating and has little yellow flowers. The species, which came into existance about 30 years ago, has been called Senecio eboracensis, after Eboracum, the Roman name for York. According to the research, it has now spread to spread to several sites around York, but only ever as a weed on disturbed ground.
However, more than 90 per cent of species that have lived subsequently become extinct, and its future is by no means certain.
It is important for it to build up its numbers rapidly, or it could get rubbed out which would be sad. The biggest threat to the new species is the weedkillers from the council, Dr Abbott said.
However, he does not plan to start a planting programme to ensure his discovery lives on. The next few years will be critical as to whether it becomes an established part of the British flora or a temporary curiosity. But we will let nature take its course, he said.
Here's what I see: the emergence of a new species via an unusual hybridization.
Here's what I don't see: the emergence of a new species via random mutation or natural selection.
There may possibly have been random mutation at work, but there may also be some unknown genetic principle at work as a result of this unusual hybridization, which caused the mutation, in the same manner that groups of genes can be turned on or off given certain triggers.
Also, I don't see where natural selection would drive a hybrid species to be unable to reproduce with either of its parent species. Where's the advantage in that?
So, I see two species generating a third, but I don't see one species becoming a second.
That doesn't negate the importance of this discovery, it just adds a little perspective, as I see it.
Regards
Well, given that the DNA analysis indicates its relation to the parent species, and that one of the parent species was only introduced 300 years ago to the UK, that would seem to suggest that this hybridization event has taken place sometime in the last 300 years. Even if it didn't happen last week, or twenty years ago, it's still a quite recent occurrence, all things considered.
Since the British Isles are not a particularly large place, and there have been naturalists crawling around the country looking under rocks and leaves since long before Darwin, I think it's not unreasonable to assume that the local flora have been fairly exhaustively catalogued - and we have the testimony here of a bona fide expert in plant biology telling us that this is something never before seen.
In addition, I think you are confusing the time between events with the time it takes for the event itself. Even if it generally happens that there are millions of years between speciation events (and I don't know that this is necessarily required either), the event itself could really occur in a matter of minutes - just as long as it takes an organism to reproduce. The two parents interbreed, a seed is produced, the seed sprouts, and you've got a new species, all in the space of a few weeks.
I don't think there's necessarily an advantage in that particular aspect either, but it may turn out that this new species is somehow better adapted than its parents, inheriting adaptive qualities from both and combining them in some new way - e.g., it inherits some resistance to cold weather from parent "A", and some resistance to some sort of bug from parent "B". In which case, the new species may find life a bit easier than either of its parents did, and be successful where they are not.
Or, maybe it inherited the worst qualities from both, and it's not long for this world. Or maybe it's a mixed bag as to its traits, and we'll just have to wait and see how it shakes out. Which will probably be the case anyway - we'll just have to wait and see how it does on its own. If, in twenty years, this thing is gone, or it's turned into the British equivalent of kudzu, choking the life out of the country, we'll have a pretty clear answer ;)
Twenty years or so. What difference does that make, or is this where you play Barry Scheck? ;)
How many labs confirmed this relation?
At this point, probably none. Confirmation will no doubt be forthcoming, as other researchers attempt to replicate these results.
What is the basis of calling one species "related" to another?
Genomic similarity.
Is that a subjective question?
No, it's a matter of statistical tests.
How often are mistakes made?
Not very often, but they do occur, which is why replication is important.
It would be interesting to know how extensively British flora was chronicled in the year 1703.
These fine folks can probably help you out.
If the variety of recorded plant inventory was substantially lower than it is today, how are we to be sure whether an introduction or a discovery occured? IF we are counting on a ship's manifest as the basis for an introduction, how accurate are the drawings of the plant in question? Would those standards of accuracy be allowable today?
We certainly don't know any of that to be the case, so it's hardly worth speculating about. However, we do have expert testimony about the ages of these species available to us, if you'll cast your eyes upward momentarily...
Against a backdrop of few new species being found, the discovery of a "new" species can be attributed to the nearly complete, but still incomplete status of the record, or to the introduction of plants from abroad, or to genetic fraud without having to conclude evolution has occured.
IOW, every option is open but the obvious. And if all those possibilities are ruled out, you will then - quite rightly, too, I must say - point out that we cannot dismiss the possibility that God Himself personally placed this new plant right there, or that this new species arrived via meteorite from Mars, or that some fiendishly clever genetic engineer whipped it up in his lab and planted it right there next to the river, and so on and so forth.
But perhaps we ought to limit ourselves to the most likely explanations...
G = (T - (Lo1 * C)) / (Li * Lo2 * S * A)?
I assume you'll be proceeding with proof by induction? ;)
You are correct. In more than three years of doing this, I think maybe one person (whose name I forgot) has admitted been somewhat influenced by the information. All the other creationists are totally unmoved -- unless you call it "movement" when they descend into ever-darker levels of denial and invective. I have no expectation of changing anyone's mind. All I can do is present information, and demonstrate to the lurkers that conservatism isn't congruent with creationism.
The article says: "But Dr Abbotts research, published in the journal of the Botanical Society of the British Isles, shows that the York Groundsel is a genetic mutant that can breed, but not with any other species, including its parent species. It thus fits the scientific definition of a separate species."
So what you do see here is: (1) mutation; and (2) speciation. We've both observed creationists who say that mutation is always fatal and thus cannot be the source of speciation. We've also observed creationists claim that speciation itself is impossible, because that's (gasp!) macro-evolution.
You are correct in not seeing natural selection. Not yet. That takes time. This little weed may not have what it takes to become a well-established species. Neighboring weeds may choke it out; insects may devour all its seeds, etc. But this weed, whether it survives or not, is nevertheless very instructive.
Agreed. I just wanted to be clear on what specifically was being claimed.
Yes. My question was to the randomness of the mutation.
The basic evolutionary model is speciation by random mutation over time, as filtered by natural selection, correct? However, while that may yet prove to be true, it seems insufficient to me: not evolution, but the mechanism for it. It strikes me that since evolution is such a fundamental principle of life, that somewhere down in our genetic hardwiring there may be some yet unknown evolutionary impulse at work.
I've got nothing to offer in support of that, and I realize that it tiptoes close to Lamarck, but it's a door I leave open for the time being.
Also, it seems at least plausible that hybridizations like the one between the common groundsel and the Oxford ragwort can spontaneously induce mutuations.
Here's a question: suppose in the next few years someone is able to cross a York groundsel back to either a common groundsel or an Oxford ragwort, or both, and produce fertile progeny?
We know, because of exceptions, that the rules of hybridization are in a bit of flux, so it's not idle speculation. Would we then rescind the York groundel's species status, and rule that the groundsels unable to reproduce with their parent species suffered from "birth defects," so to speak?
I do a lot of work with tropical fish, and am aware of a number of instances of fertile hybrids from different species. Swordtails and platies of the genus Xiphophorus are an example. There are over 30 species described, on both sides of the continental divide of Central America, yet most can cross back and forth with each other. There's not a fancy swordtail or platy in a pet shop in the world that isn't the result of a lot of hybridization. I don't think that means that we only had one species to begin with, but that hybridization works differently in other organisms than the ways in which we're used to thinking of it working in mammals.
But if that's the case, then isn't one of our definitions of species, a population only able to reproduce fertile offspring among themselves, not always a good yardstick in all circumstances?
However, none of this casts any doubt on the fact that evolution happens. So the creationists can take no comfort from this thread.
Most genuine progress is controversial at first, but in due course the most accurate theory will prevail. And most frauds fool a few people at first; but in due course the experts will expose it. So what's your point? You think we should ignore experts and rely only on the opinions of the ignorant?
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.