feb 2009
Páramo congress
26-02-2009 22:08
A good friend sent me the annoucement of the 2nd
World Congress on Páramos,
Paramundi.
It will be held from 21-27 June in Loja, Ecuador.
Not sure yet if I will visit (would love to, but as always one has ones priorities...). Anyway, my priority for the next 10 days will be a private trip abroad. Stay tuned and I hope to continue after my return.
Not sure yet if I will visit (would love to, but as always one has ones priorities...). Anyway, my priority for the next 10 days will be a private trip abroad. Stay tuned and I hope to continue after my return.
Dominican snails
26-02-2009 21:25
This week I finalized the first draft of the
manuscript on
Dominica.
With additional localities visited a few months ago
by Ad Hovestadt, the total number is now 70. No bad
score for an island of 750 km2.
The picture shows the localities projected on a map with landcover data of the island. According to EarthTrends data, forest is still 61% of the total land area, although in the same data sheet it is stated that this percentage is as low as 3. Quite confusing. Anyhow, the yellowish colours on the map above is either grassland or ‘active agriculture’; I assume the former category should be seen as ‘passive agriculture’ (??). It can be seen that this land use is dominant in coastal areas, but also spreading into the inland. Still, the island is considered to be a biodiversity hotspot and our figures show that 16% of the land snails is endemic. That doesn’t seem to be much but is relatively not bad.
The picture shows the localities projected on a map with landcover data of the island. According to EarthTrends data, forest is still 61% of the total land area, although in the same data sheet it is stated that this percentage is as low as 3. Quite confusing. Anyhow, the yellowish colours on the map above is either grassland or ‘active agriculture’; I assume the former category should be seen as ‘passive agriculture’ (??). It can be seen that this land use is dominant in coastal areas, but also spreading into the inland. Still, the island is considered to be a biodiversity hotspot and our figures show that 16% of the land snails is endemic. That doesn’t seem to be much but is relatively not bad.
Niku-nuki, a Japanese tradition
24-02-2009 18:42
What can we learn from traditions? Today I may have
learned a tool that has proven to be useful and
passed from one generation to the following. In a
sense, survival of the fittest.
My colleague Menno Schilthuizen draw my attention to a useful technique for preserving live collected animals (see also my previous post on a similar, but possibly less effective technique). It was presented during a symposium on micro-molluscs at the WCM in Antwerp. I admit, I skipped this subject at that time, but this particular topic seems very useful. Fortunately, the papers from this symposium have already been published and the methodology is one of them. It is called niku-nuki. The essence is to quickly kill the animal and preserve the shell.
While normally it can be difficult to preserve the animal without tissue degradation, this method promises soft tissue preservation both for DNA and anatomical research, plus an undamaged shell. It consists of four relatively simple steps: 1. Put the animals in a vial and when they actively move around on the bottom kill them by pouring boiling hot water over them (A). 2. Separate the columellar muscle from the shell by pinching the animal and gently pulling it (B). 3. Unscrew the body from the shell (C). 4. Wash and dry the shell and fixate and preserve the soft parts (D).
Fukuda et al. (2008) describe the method in any detail for different groups. Although their method is especially geared to smaller species, it should be worthwhile to try also on larger ones.
Reference
Fukuda, H., Haga, T. & Tatara, Y., 2008. Niku-nuki: a useful method for anatomical and DNA studies on shell-bearing molluscs. - Zoosymposia 1: 15-38.
My colleague Menno Schilthuizen draw my attention to a useful technique for preserving live collected animals (see also my previous post on a similar, but possibly less effective technique). It was presented during a symposium on micro-molluscs at the WCM in Antwerp. I admit, I skipped this subject at that time, but this particular topic seems very useful. Fortunately, the papers from this symposium have already been published and the methodology is one of them. It is called niku-nuki. The essence is to quickly kill the animal and preserve the shell.
While normally it can be difficult to preserve the animal without tissue degradation, this method promises soft tissue preservation both for DNA and anatomical research, plus an undamaged shell. It consists of four relatively simple steps: 1. Put the animals in a vial and when they actively move around on the bottom kill them by pouring boiling hot water over them (A). 2. Separate the columellar muscle from the shell by pinching the animal and gently pulling it (B). 3. Unscrew the body from the shell (C). 4. Wash and dry the shell and fixate and preserve the soft parts (D).
Fukuda et al. (2008) describe the method in any detail for different groups. Although their method is especially geared to smaller species, it should be worthwhile to try also on larger ones.
Reference
Fukuda, H., Haga, T. & Tatara, Y., 2008. Niku-nuki: a useful method for anatomical and DNA studies on shell-bearing molluscs. - Zoosymposia 1: 15-38.
Photo of the day (41): Plekocheilus
23-02-2009 20:38
Another photo, sent by Jan Schlogl, of some live
specimens of
Plekocheilus
(P.)
fulminans
alticola
Haas, 1955.
They were also spotted on the Chimantá massif in Venezuelan Guayana. It is really exciting to see that snails are not so extremely rare in that area as previously thought. Provided that you are focussed on them.
They were also spotted on the Chimantá massif in Venezuelan Guayana. It is really exciting to see that snails are not so extremely rare in that area as previously thought. Provided that you are focussed on them.
Photo of the day (40): Plekocheilus
21-02-2009 16:11
Interestingly, the Slovakian geological-speleological
team that visited Venezuelan Guayana the past weeks,
found quite a number of snails. I reported on their
preliminary findings
here,
but today I got more information on two species that
were found on the Chimantá massif.
The first picture is from a juvenile specimen of Plekocheilus (Eurytus) juliani Haas, 1955. The picture shows the characteristic zig-zag striping and the light body colour, darker on the upper part. This species lives on bromeliads (Brocchinia sp.) that were found in canyons more than 100 m deep.
The second species is P. (E.) mundiperditi Haas, 1955. It has a dark-brown shell and also the animal is darker coloured throughout. This species was only encountered on top of the plateau, associated with low Bonnetia trees.
To me it seems that these species each occur in a narrow ecological niche, possibly with their own host plants.
Thanks to Jan Schlogl, who kindly sent me the pictures.
The first picture is from a juvenile specimen of Plekocheilus (Eurytus) juliani Haas, 1955. The picture shows the characteristic zig-zag striping and the light body colour, darker on the upper part. This species lives on bromeliads (Brocchinia sp.) that were found in canyons more than 100 m deep.
The second species is P. (E.) mundiperditi Haas, 1955. It has a dark-brown shell and also the animal is darker coloured throughout. This species was only encountered on top of the plateau, associated with low Bonnetia trees.
To me it seems that these species each occur in a narrow ecological niche, possibly with their own host plants.
Thanks to Jan Schlogl, who kindly sent me the pictures.
Snapshots
16-02-2009 21:44
Just some snapshots from last week’s congress
activities.
Together with Menno Schilthuizen (right) at the Town Hall’s reception.
Mark Lomolino during his key note
Together with Menno Schilthuizen (right) at the Town Hall’s reception.
Mark Lomolino during his key note
Evolutionary islands - some references
15-02-2009 10:03
Several speakers during the congress mentioned some
interesting papers. I have compiled a list of the
references that seemed to me most relevant. The
referring speaker is added between brackets, unless
it is a reference I added myself. Please note that
the links mostly take you to the journal websites,
not to the full text of the papers. Also note that
some authors presented an overload of information,
making it impossible to keep track of all references
supplied. And some kept me so focussed on their
presentation that I didn’t jot down their references.
Benton, M.J., 2009. The Red Queen and the Court Jester: species diversity and the role of biotic and abiotic factors through time. - Science 323: 728-732.
Etienne, R.S. et al., 2007. Modes of speciation and the neutral theory of biodiversity. - Oikos 116: 241-258. [Olff]
Givnish, T.J. et al., 2009. Origin, adaptive radiation and diversification of the Hawaiian lobeliads (Asterales: Campanulaceae). - Proceedings of the Royal Society, B. 276: 407-416. [Whittaker]
Gravilets, S. & Losos, J.B., 2009. Adaptive radiation: contrasting theory with data. - Science 323: 732-737. [Triantis]
Hubbell, S.P., 2001. The unified neutral theory of biodiversity and biogeography. Princeton University Press, Princeton. [Olff]
Ings, T.C. et al., 2009. Ecological networks - beyond food webs. - Journal of Animal Ecology 78: 253-269. [Montoya]
McKinney, M.L. & Lockwood, J.L., 1999. Biotic homogenization: a few winners replacing many losers in the next mass extinction. - Trends in Ecology and Evolution 14: 450-453. [Morin]
Montoya, J.M., Pimm, S.L. & Solé, R.V., 2006. Ecological networks and their fragility. - Nature 442: 259-264. [Montoya]
Sax, D.F. et al. 2007. Ecological and evolutionary insights from species invasions. - Trends in Ecology and Evolution 22: 465-471.
Sax, D.F. & Gaines, S.D., 2008. Species invasions and extinction: the future of native biodiversity on islands. - Proceedings National Academy of Sciences, 105 Suppl. 1: 11490-11497. [Morin]
Triantis, K.A., Mylonas, M. & Whittaker, R.J., 2008. Evolutionary species-area curves as revealed by single-island endemics: insights for the inter-provincial species-area relationship. - Ecography 31: 401-407. [Triantis]
Weng, C., Hooghiemstra, H. & Duivenvoorde, J.F, 2007. Response of pollen diversity to the climate-driven altitudinal shift of vegetation in the Colombian Andes. - Proceedings of the Royal Society, B 362: 253-262.
Whittaker, R.J., Triantis, K.A. & Ladle, R.J., 2008. A general dynamic theory of oceanic island biogeography. - Journal of Biogeography 35: 977-994. [Whittaker]
Finally, I like to mention that Dennis Uit de Weerd had a very nice poster on the phylogenitcs of Urocoptidae (to be published later) and my own poster dealing with Venezuelan tepui snails (see this post).
Uit de Weerd, D. & Lyras, G., 2009. The origin of Urocoptid land snail diversity on Caribbean islands: the role of colonizations and radiations. In: Cohen A. et al (eds.) Evolutionary islands: 150 years after Darwin, Abstracts: 65.
Benton, M.J., 2009. The Red Queen and the Court Jester: species diversity and the role of biotic and abiotic factors through time. - Science 323: 728-732.
Etienne, R.S. et al., 2007. Modes of speciation and the neutral theory of biodiversity. - Oikos 116: 241-258. [Olff]
Givnish, T.J. et al., 2009. Origin, adaptive radiation and diversification of the Hawaiian lobeliads (Asterales: Campanulaceae). - Proceedings of the Royal Society, B. 276: 407-416. [Whittaker]
Gravilets, S. & Losos, J.B., 2009. Adaptive radiation: contrasting theory with data. - Science 323: 732-737. [Triantis]
Hubbell, S.P., 2001. The unified neutral theory of biodiversity and biogeography. Princeton University Press, Princeton. [Olff]
Ings, T.C. et al., 2009. Ecological networks - beyond food webs. - Journal of Animal Ecology 78: 253-269. [Montoya]
McKinney, M.L. & Lockwood, J.L., 1999. Biotic homogenization: a few winners replacing many losers in the next mass extinction. - Trends in Ecology and Evolution 14: 450-453. [Morin]
Montoya, J.M., Pimm, S.L. & Solé, R.V., 2006. Ecological networks and their fragility. - Nature 442: 259-264. [Montoya]
Sax, D.F. et al. 2007. Ecological and evolutionary insights from species invasions. - Trends in Ecology and Evolution 22: 465-471.
Sax, D.F. & Gaines, S.D., 2008. Species invasions and extinction: the future of native biodiversity on islands. - Proceedings National Academy of Sciences, 105 Suppl. 1: 11490-11497. [Morin]
Triantis, K.A., Mylonas, M. & Whittaker, R.J., 2008. Evolutionary species-area curves as revealed by single-island endemics: insights for the inter-provincial species-area relationship. - Ecography 31: 401-407. [Triantis]
Weng, C., Hooghiemstra, H. & Duivenvoorde, J.F, 2007. Response of pollen diversity to the climate-driven altitudinal shift of vegetation in the Colombian Andes. - Proceedings of the Royal Society, B 362: 253-262.
Whittaker, R.J., Triantis, K.A. & Ladle, R.J., 2008. A general dynamic theory of oceanic island biogeography. - Journal of Biogeography 35: 977-994. [Whittaker]
Finally, I like to mention that Dennis Uit de Weerd had a very nice poster on the phylogenitcs of Urocoptidae (to be published later) and my own poster dealing with Venezuelan tepui snails (see this post).
Uit de Weerd, D. & Lyras, G., 2009. The origin of Urocoptid land snail diversity on Caribbean islands: the role of colonizations and radiations. In: Cohen A. et al (eds.) Evolutionary islands: 150 years after Darwin, Abstracts: 65.
Evolutionary islands - Day 2
13-02-2009 17:26
A continuation of my post from yesterday.
The morning session on Evolutionary islands through time started off with a keynote lecture by Matthias Harzhauser (Vienna). “Evolutionary lessons from ancient long-lived lakes”. This was an interesting speech on fresh-water palaeolakes in Europe. One of the remarkable observations was “you better be small if you want to survive a faunal turnover”.
Henry Hooghiemstra (Amsterdam) continued with “Evolution of high tropical Andean endemic floras”, in which he focussed on the Colombian Andes. One of the interesting aspects is the Cocuy area, which is geologically young (15Mya). It is an area of dramatic high biodiversity, yet there is no easy relationship between habitat diversity and species richness. Hooghiemstra stressed that using pollen analysis one must be extremely careful with calibrations to modern times; mostly there is a non-analogous situation. Comparing data from Last Glacial Maximum with modern biota show that shifts in the elevation range of biotas has had a dramatic influence on the area occupied. There is marked difference between e.g. paramo and puna; while paramos have increasingly become fragmented since the LGM, puna vegetation was first covered by ice but has become available as a large area since that time. LGM has led to temperature driven ecosystems shifts in the Andes and is best be timed at 30000 BPA.
After the coffee break, Hanneke Meijer (Leiden) talked about “The island ecosystem of the Hobbit”. The last lecture of this session was by Isaac Cananovas-Vilar (Barcelona) on “Neogene micromammal evolution and turnover between isolation and continuity”. Both lectures dealt with vertebrate paleontology.
The last session was entitled Human perspectives of evolutionary islands. Kenneth Rijsdijk (Leiden) talked on “The message of the dodo”. He elaborated the thesis that Mauritius is a good model island to study the impact of human-induced ecosystem changes. Extinction dates of many species are known, there is good record of deforestation and sufficient abiotic data available. The recent find of a spot with many, well-conserved fossils provide a good baseline for further research.
The second lecture by Frans Witte (Leiden), “Human induced revolutions in Lake Victoria”, showed that a few winners are replacing many losers in an ecosystem, as evidenced by ciclid fishes.
Interesting was the lecture by Gonçalo Ferraz (Manaus) on “Island fragments in the Amazon: a metaphor gone wild”. He dealt with the issue relevant for conservation of Single Large Or Several Small (SLOSS) reserves. He presented the results on bird observations in 23 sites of forest plots, of which 11 isolated. He concluded that the configuration of reserves matters, especially when the patches are small (<100 ha). It is best when a larger undisturbed area is nearby, from where immigations may take place. Isolation of forest still affects species richness, even when the patch is up to 1000 ha.
The closing lecture was by Tijs Goldschmidt (Amsterdam). “Temporary and perpetual effects of unplanned and calculated introductions”. Since I have reported on a similar lecture from him here, I will not repeat.
The morning session on Evolutionary islands through time started off with a keynote lecture by Matthias Harzhauser (Vienna). “Evolutionary lessons from ancient long-lived lakes”. This was an interesting speech on fresh-water palaeolakes in Europe. One of the remarkable observations was “you better be small if you want to survive a faunal turnover”.
Henry Hooghiemstra (Amsterdam) continued with “Evolution of high tropical Andean endemic floras”, in which he focussed on the Colombian Andes. One of the interesting aspects is the Cocuy area, which is geologically young (15Mya). It is an area of dramatic high biodiversity, yet there is no easy relationship between habitat diversity and species richness. Hooghiemstra stressed that using pollen analysis one must be extremely careful with calibrations to modern times; mostly there is a non-analogous situation. Comparing data from Last Glacial Maximum with modern biota show that shifts in the elevation range of biotas has had a dramatic influence on the area occupied. There is marked difference between e.g. paramo and puna; while paramos have increasingly become fragmented since the LGM, puna vegetation was first covered by ice but has become available as a large area since that time. LGM has led to temperature driven ecosystems shifts in the Andes and is best be timed at 30000 BPA.
After the coffee break, Hanneke Meijer (Leiden) talked about “The island ecosystem of the Hobbit”. The last lecture of this session was by Isaac Cananovas-Vilar (Barcelona) on “Neogene micromammal evolution and turnover between isolation and continuity”. Both lectures dealt with vertebrate paleontology.
The last session was entitled Human perspectives of evolutionary islands. Kenneth Rijsdijk (Leiden) talked on “The message of the dodo”. He elaborated the thesis that Mauritius is a good model island to study the impact of human-induced ecosystem changes. Extinction dates of many species are known, there is good record of deforestation and sufficient abiotic data available. The recent find of a spot with many, well-conserved fossils provide a good baseline for further research.
The second lecture by Frans Witte (Leiden), “Human induced revolutions in Lake Victoria”, showed that a few winners are replacing many losers in an ecosystem, as evidenced by ciclid fishes.
Interesting was the lecture by Gonçalo Ferraz (Manaus) on “Island fragments in the Amazon: a metaphor gone wild”. He dealt with the issue relevant for conservation of Single Large Or Several Small (SLOSS) reserves. He presented the results on bird observations in 23 sites of forest plots, of which 11 isolated. He concluded that the configuration of reserves matters, especially when the patches are small (<100 ha). It is best when a larger undisturbed area is nearby, from where immigations may take place. Isolation of forest still affects species richness, even when the patch is up to 1000 ha.
The closing lecture was by Tijs Goldschmidt (Amsterdam). “Temporary and perpetual effects of unplanned and calculated introductions”. Since I have reported on a similar lecture from him here, I will not repeat.
Evolutionary islands - Day 1
12-02-2009 17:04
A happy day for all those biologists all over the
world (and other believers). 150 years after the
Origin of species.... I’m not going to repeat all
obvious or not-so-obvious arguments pro or contra or
to comment on the brillance of the work of Darwin (or
the refutability of it, for the non-believers). You
will find ample blogposts on it elsewhere in the
blogosphere.
Rather I will concentrate on the meeting at Naturalis. For those not able to attend, I will briefly summarize the highlights of this congress.
The first keynote speech was delivered by Mark Lomolino (Syracuse), entitled “On the origin, evolution and preservation of island life: a historical and prospective overview”. The historical part showed how different authors (Linnaeus, de Buffon, Wildenow and Humboldt, but - of course - also Darwin, who added the time dimension) contributed to our present day knowledge on island biotas. For Darwin, his experiences at the Galápagos have been pivotal to his thinking. The fragility of island life was one of the themes that Lomolino addressed. The continuing archipelagization due to habitat loss and fragmentation makes island life especially vulnerable. It is hoped that insights from natural islands can help to manage the biotas of artificial islands in a better way.
The second keynote was held by Robert Whittaker (Oxford), who published a paper on a general dynamic theory of oceanic island biogeography. His presentation dealt with the further developemnt and initial evaluation of this model. With examples from the Canary Islands he showed that the highest species richness occurs on islands of intermediate age.
The morning session on Evolution in island systems continued with a lecture by Peter Linder (Zurich), “Plant diversification on islands on the continent: the Cape flora as an example”. Linder explained that ‘continental islands’ have a larger number of species than oceanic islands, have more complex habitats and topography and also more immigration (therefore less endemism). He compared two methods of analysis (sister species and independent clades). In the Cape flora ecological factors explained 80% of the variation.
Menno Schilthuizen (Leiden) delivered the next lecture, entitled “Evolution on a block of rock: landsnail speciation on limestone outcrops”. After having explained different modes of speciation, Schilthuizen showed a nice example of minute land snails exhibiting a non-adaptive radiation and a ‘Red Queen evolution’, driven by an arms race with a predator; in this case a slug.
The last morning lecture dealt with a marine subject, “Anchialine lakes: hidden islands within islands” by Nicole Voogd (Leiden). There is a preliminary evidence that evolution rates in these lakes are very fast.
The afternoon session on Evolutionary ecology of isolated ecosystems opened with a keynote by Peter Morin (New Brunswick) on “The ecology and evolution of island communities in a changing world”. The most remarkable example that Morin gave, was island hopping as an expression of metacommunity persistence over time. The showcase of that is the recently discovered pink iguana on Galápagos; the taxon proves to be at least 5.5 Mya old, while the island is relatively young (0.5 Mya). Further Morin stressed the fact that extinction due to global warming plays out non-randomly across trophic levels, affecting primarily herbivores and predators in the food web.
José Montoya (Barcelona) talked about “Unraveling Darwin’s entangled bank: The architecture of ecological fragility”. He further elaborated on the thesis that ecological networks are the craddle of evolution. In larger food webs many specialists do occur and few generalist species, and this heterogeneity increases. On islands nestedness occurs: smaller islands are subsets of larger ones.
After the tea break Han Olff (Groningen) continued with “Dynamics of metacommunities and metaecosystems”. He showed with two examples (tropical montane uplands in Eastern Africa and Barro Colorado Island) that the balance between stochastic and deterministic processes is likely scale dependent. Moreover, he convincingly showed that the dataset from Barro Colorado Island that was used in earlier studies, probably was biased due to plot selection. Plus the importance of multidimensional selection of plot locations.
Finally Kostas Triantis (Oxford) had the floor for his lecture “Evolutionary species-area curves”. Using species-area curves and single-island endemics of the Azores, Triantis elaborated on the thesis that the regression slope value may have a predictive value on future extinctions. He used forest-restricted taxa of beetles and spiders.
Rather I will concentrate on the meeting at Naturalis. For those not able to attend, I will briefly summarize the highlights of this congress.
The first keynote speech was delivered by Mark Lomolino (Syracuse), entitled “On the origin, evolution and preservation of island life: a historical and prospective overview”. The historical part showed how different authors (Linnaeus, de Buffon, Wildenow and Humboldt, but - of course - also Darwin, who added the time dimension) contributed to our present day knowledge on island biotas. For Darwin, his experiences at the Galápagos have been pivotal to his thinking. The fragility of island life was one of the themes that Lomolino addressed. The continuing archipelagization due to habitat loss and fragmentation makes island life especially vulnerable. It is hoped that insights from natural islands can help to manage the biotas of artificial islands in a better way.
The second keynote was held by Robert Whittaker (Oxford), who published a paper on a general dynamic theory of oceanic island biogeography. His presentation dealt with the further developemnt and initial evaluation of this model. With examples from the Canary Islands he showed that the highest species richness occurs on islands of intermediate age.
The morning session on Evolution in island systems continued with a lecture by Peter Linder (Zurich), “Plant diversification on islands on the continent: the Cape flora as an example”. Linder explained that ‘continental islands’ have a larger number of species than oceanic islands, have more complex habitats and topography and also more immigration (therefore less endemism). He compared two methods of analysis (sister species and independent clades). In the Cape flora ecological factors explained 80% of the variation.
Menno Schilthuizen (Leiden) delivered the next lecture, entitled “Evolution on a block of rock: landsnail speciation on limestone outcrops”. After having explained different modes of speciation, Schilthuizen showed a nice example of minute land snails exhibiting a non-adaptive radiation and a ‘Red Queen evolution’, driven by an arms race with a predator; in this case a slug.
The last morning lecture dealt with a marine subject, “Anchialine lakes: hidden islands within islands” by Nicole Voogd (Leiden). There is a preliminary evidence that evolution rates in these lakes are very fast.
The afternoon session on Evolutionary ecology of isolated ecosystems opened with a keynote by Peter Morin (New Brunswick) on “The ecology and evolution of island communities in a changing world”. The most remarkable example that Morin gave, was island hopping as an expression of metacommunity persistence over time. The showcase of that is the recently discovered pink iguana on Galápagos; the taxon proves to be at least 5.5 Mya old, while the island is relatively young (0.5 Mya). Further Morin stressed the fact that extinction due to global warming plays out non-randomly across trophic levels, affecting primarily herbivores and predators in the food web.
José Montoya (Barcelona) talked about “Unraveling Darwin’s entangled bank: The architecture of ecological fragility”. He further elaborated on the thesis that ecological networks are the craddle of evolution. In larger food webs many specialists do occur and few generalist species, and this heterogeneity increases. On islands nestedness occurs: smaller islands are subsets of larger ones.
After the tea break Han Olff (Groningen) continued with “Dynamics of metacommunities and metaecosystems”. He showed with two examples (tropical montane uplands in Eastern Africa and Barro Colorado Island) that the balance between stochastic and deterministic processes is likely scale dependent. Moreover, he convincingly showed that the dataset from Barro Colorado Island that was used in earlier studies, probably was biased due to plot selection. Plus the importance of multidimensional selection of plot locations.
Finally Kostas Triantis (Oxford) had the floor for his lecture “Evolutionary species-area curves”. Using species-area curves and single-island endemics of the Azores, Triantis elaborated on the thesis that the regression slope value may have a predictive value on future extinctions. He used forest-restricted taxa of beetles and spiders.
Borneo / Evolutionary islands - prelude
11-02-2009 19:02
Two topics kept me busy today. The first was the
Ph.D. promotion of Niels Raes at Leiden University.
He is a botanist at the National Herbarium and made a
study about plant distributions on Borneo. The reason
to mention his work here is the use of species
distribution modeling. One of the interesting things
mentioned in the discussion during the ceremony, was
a possible workaround on the limit of a minimum of 5
occurrences for a Maxent model.
Secondly, I attended the reception at the Town Hall in Leiden for the congress on Evolutionary islands. Already acquiainted with some participants, more to follow during the coming days.
Secondly, I attended the reception at the Town Hall in Leiden for the congress on Evolutionary islands. Already acquiainted with some participants, more to follow during the coming days.
Working in the shadow
09-02-2009 16:30
Before later this week “Darwin-mania” will start,
just a short note on Alfred Wallace. He evidently was
not the man at the right place, in the right moment
and with the right status. He submitted, together
with Darwin, a paper on evolution to the Linnean
Society of London in 1858 in which they expressed the
same lines of thought that have become famous by
Darwin’s “On the origin of species”. Later, Charles
Darwin wrote to his friend Lyell: “If Wallace had
seen my draft manuscript written in 1842, he couldn’t
have written a better summary”. Some people are just
working in the shadow of others.
Although Wallace will be reminded in the Austalasian Realm with the Wallacean Line, his writings on his travels to Amazonia are probably less known. No more time right now, but I hope to come back on this subject soon. The rest of this week I will be busy with Darwin-mania, viz. the congress on Evolutionary islands.
Although Wallace will be reminded in the Austalasian Realm with the Wallacean Line, his writings on his travels to Amazonia are probably less known. No more time right now, but I hope to come back on this subject soon. The rest of this week I will be busy with Darwin-mania, viz. the congress on Evolutionary islands.
Prey of a bird and a bird of prey?
06-02-2009 17:19
At the moment some Slovak and Czech geologists are
out in the field in Venezuelan Guayana. Their main
objective is further research on caves, but luckily
they have informed themselves on what they might find
in malacological terms.
As an interim report I received today some news about observations on Plekocheilus. They found shells “locally common, even inside under bird nests”.
It seems that a bird species (not yet sure which one) is sampling these snails on the tepuis and bring them to their nests inside the cave, where they feed them to their young. A nice, big meal of proteins! Broken shells drop down on the cave floor.
An intriguing story on which I hope to get more details later...
Thanks Jozef, for the information!
As an interim report I received today some news about observations on Plekocheilus. They found shells “locally common, even inside under bird nests”.
It seems that a bird species (not yet sure which one) is sampling these snails on the tepuis and bring them to their nests inside the cave, where they feed them to their young. A nice, big meal of proteins! Broken shells drop down on the cave floor.
An intriguing story on which I hope to get more details later...
Thanks Jozef, for the information!
Making simple things rewarding
04-02-2009 20:28
Making collections available means entering a lot of
data in a system. Not the most rewarding work, often
done unnoticed unless a scientist needs a
registration number to appear in a paper. Hard work
and mostly not rewarded at all.
Many museums have their registration system only in-house, few have it public in a web-based database. This can be a huge advantage for scientists abroad (like I can testify; e.g., the Florida State Museum database is a frequently used source for me).
Today I received notice from Paul Valentich-Scott that the Santa Barbara Museum of Natural History had updated their database on their website with the recently published material on Bostryx. They update now every evening and, as Paul said, it’s a great motivation for their cataloguers.
Perhaps an idea for all those collection managers who struggle with poorly motivated technicians, acting as data typists. Or perhaps are the managers part of the problem themselves? Too many chiefs, too few indians...
I like to acknowledge here the work of those ‘indians’, who provide the scientists indispensable support.
Many museums have their registration system only in-house, few have it public in a web-based database. This can be a huge advantage for scientists abroad (like I can testify; e.g., the Florida State Museum database is a frequently used source for me).
Today I received notice from Paul Valentich-Scott that the Santa Barbara Museum of Natural History had updated their database on their website with the recently published material on Bostryx. They update now every evening and, as Paul said, it’s a great motivation for their cataloguers.
Perhaps an idea for all those collection managers who struggle with poorly motivated technicians, acting as data typists. Or perhaps are the managers part of the problem themselves? Too many chiefs, too few indians...
I like to acknowledge here the work of those ‘indians’, who provide the scientists indispensable support.
Photo of the day (39): Scutalus
03-02-2009 22:20
Peru is very diverse in habitats, although this may
seem to be otherwise. Who would expect this desolate
looking site to harbour five different bulimulids?
One of them is a Scutalus (Scutalus) species that is depicted here. Looks like a S. proteus with colour bands, but is as yet unnamed.
One of them is a Scutalus (Scutalus) species that is depicted here. Looks like a S. proteus with colour bands, but is as yet unnamed.
A poorly known Nicaraguan endemic
02-02-2009 20:57
Central American land snails are not frequently the
subject of a publication. But in the latest issue of
Iberus, the journal of the Spanish malacologists,
there is a paper by Pérez and others on
Euglandina
obtusa
(Pfeiffer, 1844). The species is hitherto only known
from the type locality in Nicaragua.
The authors redescribe the shell of this poorly known species and add 15 new localities, all in the south-western part of Nicaragua.
As some localities are at the border of Honduras, I wonder how the authors can be sure that this species is a truly endemic of Nicaragua? Snails don’t mind administrative borders...
Reference
Pérez, M.A., Altonaga, K. & López, A., 2008. New data on the morphology and distribution of Euglandina obtusa (Pfeiffer, 1844) (Gastropoda: Spiraxidae) a Nicaraguan endemism. - Iberus 26: 127-131.
The authors redescribe the shell of this poorly known species and add 15 new localities, all in the south-western part of Nicaragua.
As some localities are at the border of Honduras, I wonder how the authors can be sure that this species is a truly endemic of Nicaragua? Snails don’t mind administrative borders...
Reference
Pérez, M.A., Altonaga, K. & López, A., 2008. New data on the morphology and distribution of Euglandina obtusa (Pfeiffer, 1844) (Gastropoda: Spiraxidae) a Nicaraguan endemism. - Iberus 26: 127-131.
Succineids untangled
01-02-2009 15:29
The Neotropical succineid systematics “is permeated
with misconceptions and contradictions” (Arruda &
Thomé, 2008)*. It is one of those groups which are
often identified on the basis of their anatomy; the
Veronicellidae - specialism of the second author - is
one of the others.
In their paper two species of Omalonyx, occurring partially sympatrical, are untangled using both morphological and anatomical characters.
This paper is an example how laborious it can be to know with which species you may be dealing. There are many similar problems to be solved within this family, which has a broad Neotropical distribution.
Reference:
Arruda, J.O. & Thomé, J.W., 2008. Revalidation of Omalonyx convexus (Heynemann 1868) and emendation of the type locality of Omalonyx unguis (Orbigny 1837) - Archiv für Molluskenkunde 137: 159-166.
In their paper two species of Omalonyx, occurring partially sympatrical, are untangled using both morphological and anatomical characters.
This paper is an example how laborious it can be to know with which species you may be dealing. There are many similar problems to be solved within this family, which has a broad Neotropical distribution.
Reference:
Arruda, J.O. & Thomé, J.W., 2008. Revalidation of Omalonyx convexus (Heynemann 1868) and emendation of the type locality of Omalonyx unguis (Orbigny 1837) - Archiv für Molluskenkunde 137: 159-166.