Dear Liliya,

The recent literature shows that the speciation in SA is a rather complex process and cannot be connected to a single event. However, it is demonstrated in several groups that the diversification postdates the Andean uplift and frequently predates the Quaternary fluctuations. I think in your group the picture can be the same.

”Would you suggest that the vicariant events may reflect the formation of the Andes separating Chile and Peru from Central Argentina (40 million years ago)?”

Presume the related species are vicariant with respect to the Andes. If so, yes that is prime face evidence that the formation of the Andes contributed to their differentiation. However, the question is presented without details of phylogeny or geography. If you could provide the phylogeny and maps of the distributions one would be in a position to comment further. You can send them directly to me if you wish at [email protected]

“Or it is not possible considering the time scale of Andes formation and psyllid speciation?”

From what you have described there is nothing apparent that is wrong with the time scale of Andean formation and psyllid speciation

“Could insect species stay closely related (within the same genus) despite such a continual time period?”

Yes, relationship is relative, so has nothing to do with amount of time.

“Or is it possible that such speciation is linked to glaciation patterns?”

Perhaps – if there is something to suggest such.

“Do you think that an insect genus can survive during 50 million years?”

Is there any reason to think not? There is nothing absolute about taxonomic ranks.

Csaba makes some comments with which I would take a different view and will comment on  a little bit later.

Csaba asserts that “the recent literature shows that the speciation in SA is a rather complex process and cannot be connected to a single event.” But complexity is relative, and in this case is the diversification of taxa in SA necessarily any more ‘complex’ that anywhere else?

I took a look at the articles Csaba kindly provided in support of his assertion that “it is demonstrated in several groups that the diversification postdates the Andean uplift and frequently predates the Quaternary fluctuations.” With respect to trans-Andean relationships it was not clear from these papers what provided the empirical ‘demonstration’ of post Andean uplift and I would be interested to see what Csaba views as the critical evidence that demonstrates post Andean uplift origin. In particular I noticed that Smith et al refer to calculations based on ‘lineage age’ but they do not say how this was calculated (it might be in the supplementary data which I have not looked at).

A potentially interesting perspective if provided by Heads (2012) (Molecular Panbiogeography of the Tropics) where he notes that the diversity of endemism of primates in the lowlands of eastern Peru/Ecuador is associated with an area of Cretaceous coastlines that disappeared when the old topography of eastern Peru was incorporated into the Andes and their foothills.

Liliya:

Nancy Moran did a study on some aphids that shows that a life cycle has persisted for millions of years. I have asked her for a copy of the paper, which she send today. I will attach it.

Another thing to consider with psyllids is that they move around on plant materials. Our psyllid fauna in Florida is at least 20% exotic. Some new arrivals are serious pests, so their presence is noted immediately, but others just arrive and eventually are discovered by inspectors or other collectors. Human-assisted dispersal on nursery stock and by means of various kinds of plant movement can't be discounted in psyllid distributions.

Susan Halbert

Taxonomic Entomologist

Division of Plant Industry

Florida Department of Agriculture and Consumer Services

(352) 395-4670

[email protected]

www.FreshFromFlorida.com

Please note that Florida has a broad public records law (Chapter 119, Florida Statutes).

Most written communications to or from state employees are public records obtainable

by the public upon request. Emails sent to me at this email address may be considered

public and will only be withheld from disclosure if deemed confidential pursuant to the

laws of the State of Florida.

Please, you need to contact to Juan Morrone at UNAM in Mexico City,

Good loock!

Dear all,

Thank you very much for your replies and useful suggestions :)

Best wishes and good luck in your research,

Liliya

It is also possible that speciation of psyllid was partly made based on the diversification of plants, as psyllids are specialised on a plant species ?

Best wishes,

Valentin