Again, the problem is not with the emergence of a new species, but its relevance to RMNS of Darwinian evolution. It is a new species apparently not due to any advantage of a particular mutation but quite possibly is just a close-ended reformation of a genome.
| Senecio squalidus | Asteraceae | Oxford Ragwort |
The oxford ragwort is so-called because it originated as an escape from the Botanic garden at Oxford where it was in cultivation from at least as early as 1690. Its spread in Northern Ireland dates from after about 1964 (the date of the earliest Northern Ireland record) and it rapidly became very abundant after about 1980 on motorway verges in north Belfast. At present it is a very common member of the weed flora of waste ground and road verges in the Belfast district. It is also spreading into other parts of Northern Ireland. The plant was introduced into Oxford Botanic Garden (and from there into the rest of the British Isles) from Mount Etna in Sicily. Recent investigations have proved that Oxford ragwort is not a true species but is actually a hybrid which occurs naturally on the Etna slopes and which is derived from two other Senecio species which grow there. The plants, with their masses of attractive bright yellow daisy-heads, can form large very conspicuous patches on waste ground and roadsides, |
Whoa, let's make sure we get causes and effects straight, in terms of mutations. Nobody I know suggests that species arise because mutations are advantageous - the first thing mutations do is either kill you, or not - but that species are adaptive based on whether mutations are advantageous. If mutation were the cause, then it would be a new species by virtue of the fact that the mutation exists, not because it is somehow advantageous. If it is advantageous, that will then influence the relative success of the plant in a competitive environment, and help determine whether it survives and flourishes better than its competitors.
For speciation to occur, that only requires that mutations happen. For natural selection to occur, that requires that some mutations are more advantageous than others. Whether this plant has some advantage in its genes remains to be seen. And, of course, I know of no requirement of evolution via natural selection that says that only mutation can produce speciation, even if I decide not to quibble over whether or not "reformation of a genome" is just mutation writ large.