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.
So many candidates; so little time.....
The rudest, on the other hand...
What does this mean? Are Birds a Kind in the Creationist sense of the word?
So species that are not reproductively isolated from other species, have not come about through evolution?
More like 99% .... but who's counting ...
I am willing to admit I don't have a good, succinct definition of macro-evolution from a scientific dictionary, but hybrid speciation (the combination of two independent species' characteristics) is not substantial evidence of the ability to create new classifications of life-forms through minute evolutionary steps. It is the greater leaps in differentiation that are at question with regard to evolution versus creation, not the hybridization of compatible and similar life-forms. I'd be interested to know where your definition of macro-evolution comes from
It's pretty mainstream. Here's a good explanation.
Also, your assertion that "from now on the new species will only diverge further from its parent species" is supposition, unsupportable from the evidence in this article. Unless there is a connected trail of evidence concerning the continued divergence of one life-form from another, then the conclusion you have drawn is only a conclusion - not an established fact.
The thing is, if the new species cannot interbreed with either of its parents, then no matter what new mutations arise & take over its genome, they will never be able to get transmitted back to the parent species. Meanwhile the chances of the same mutation also occurring in the same spot in the parent species' genes is infinitesimal. So this new species has no where to go but further away from its parent species.
BTW - Thanks for replying with information - I often avoid these kinds of threads because I prefer at least semi-informed debate to the smug ranting these threads often devolve into.
You're welcome. I try not to be the first one to descend into ranting. :-)
Wow! You need to meet the genetic drift theorists.
To what species does the cross of the new species and a parent belong, when the new species can interbreed with a parent?
How much wood would a woodchuck chuck if a woodchuck could chuck wood?
Oh, sorry. Um, why, strictly speaking they would all belong to the same species. Good thing that's not the case here, else you'd have scored a debating point. >:-)
Hmmm... déjà vu ;)
You are the one making the definitions. I was trying to give relevance to this "they will never be able to get transmitted back to the parent species." , in light of this "if the new species cannot interbreed with either of its parents". You are saying the "if" is not necessary. That makes the first statement superfluous.
Wow! You need to meet the genetic drift theorists.
Wow! You need to learn more about genetic drift.
Genetic drift applies when a trait is both a) not genetically linked to other traits and b) strictly neutral to selection.
That's not the case for wisdom teeth.
I will take this as an admission that there *are* precambrian fossils, and that you were wrong when you said that there weren't earlier in this thread.
Nice try at a tap dance, but your statement was a general one. if it is not needed, it is dropped from the genetic code because it is NO longer necessary for survival, just as the appendix...
Anyway your favorite place has this to say about drift
Suzuki et al. explain it as well as anyone I've seen;
"If a population is finite in size (as all populations are) and if a given pair of parents have only a small number of offspring, then even in the absence of all selective forces, the frequency of a gene will not be exactly reproduced in the next generation because of sampling error. If in a population of 1000 individuals the frequency of "a" is 0.5 in one generation, then it may by chance be 0.493 or 0.0505 in the next generation because of the chance production of a few more or less progeny of each genotype. In the second generation, there is another sampling error based on the new gene frequency, so the frequency of "a" may go from 0.0505 to 0.501 or back to 0.498. This process of random fluctuation continues generation after generation, with no force pushing the frequency back to its initial state because the population has no "genetic memory" of its state many generations ago. Each generation is an independent event. The final result of this random change in allele frequency is that the population eventually drifts to p=1 or p=0. After this point, no further change is possible; the population has become homozygous. A different population, isolated from the first, also undergoes this random genetic drift, but it may become homozygous for allele "A", whereas the first population has become homozygous for allele "a". As time goes on, isolated populations diverge from each other, each losing heterozygosity. The variation originally present within populations now appears as variation between populations." (Suzuki, D.T., Griffiths, A.J.F., Miller, J.H. and Lewontin, R.C. in An Introduction to Genetic Analysis 4th ed. W.H. Freeman 1989 p.704)
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