Area Cladograms Research Articles

New Guinea: A Correlation between Accreting Areas and Dispersing Sapindaceae.

A correlation between accreting (hybridizing) areas and dispersing taxa (several genera of Southeast Asian/Australian Sapindaceae) is theoretically impossible in cladistic biogeography. However, in particular circumstances (primitive absence followed by colonization and speciation) cladistic methods can reconstruct (part of) the historical sequence of accretion. In this example, the phases in the accretion history of more than 30 terranes of the northern half of New Guinea correspond reasonably well with the generalized area cladogram of the Sapindaceae.

New Guinea: A Correlation between Accreting Areas and Dispersing Sapindaceae

A correlation between accreting (hybridizing) areas and dispersing taxa (several genera of Southeast Asian/Australian Sapindaceae) is theoretically impossible in cladistic biogeography. However, in particular circumstances (primitive absence followed by colonization and speciation) cladistic methods can reconstruct (part of) the historical sequence of accretion. In this example, the phases in the accretion history of more than 30 terranes of the northern half of New Guinea correspond reasonably well with the generalized area cladogram of the Sapindaceae.

Patterns of animal dispersal, vicariance and diversification in the Holarctic

We analysed patterns of animal dispersal, vicariance and diversification in the Holarctic based on complete phylogenies of 57 extant non-marine taxa, together comprising 770 species, documenting biogeographic events from the Late Mesozoic to the present. Four major areas, each corresponding to a historically persistent landmass, were used in the analyses: eastern Nearctic (EN), western Nearctic (WN), eastern Palaeoarctic (EP) and western Palaeoarctic (WP). Parsimony-based tree fitting showed that there is no significantly supported general area cladogram for the dataset. Yet, distributions are strongly phylogenetically conserved, as revealed by dispersal-vicariance analysis (DIVA). DIVA-based permutation tests were used to pinpoint phylogenetically determined biogeographic patterns. Consistent with expectations, continental dispersals (WP↓EP and WN↓EN) are significantly more common than palaeocontinental dispersals (WN↓EP and EN↓WP), which in turn are more common than disjunct dispersals (EN↓EP and WN↓WP). There is significant dispersal asymmetry both within the Nearctic (WN⇒EN more common than EN⇒WN) and the Palaeoarctic (EP⇒WP more common than WP⇒EP). Cross-Beringian faunal connections have traditionally been emphasized but are not more important than cross-Atlantic connections in our data set. To analyse changes over time, we sorted biogeographic events into four major time periods using fossil, biogeographic and molecular evidence combined with a «branching clock». These analyses show that trans-Atlantic distributions (EN–WP) were common in the Early–Mid Tertiary (70–20 Myr), whereas trans-Beringian distributions (WN–EP) were rare in that period. Most EN–EP disjunctions date back to the Early Tertiary (70–45 Myr), suggesting that they resulted from division of cross-Atlantic rather than cross-Beringian distributions. Diversification in WN and WP increased in the Quaternary (< 3 Myr), whereas in EP and EN it decreased from a maximum in the Early–Mid Tertiary.

Patterns of animal dispersal, vicariance and diversification in the Holarctic

We analysed patterns of animal dispersal, vicariance and diversification in the Holarctic based on complete phylogenies of 57 extant non-marine taxa, together comprising 770 species, documenting biogeographic events from the Late Mesozoic to the present. Four major areas, each corresponding to a historically persistent landmass, were used in the analyses: eastern Nearctic (EN), western Nearctic (WN), eastern Palaeoarctic (EP) and western Palaeoarctic (WP). Parsimony-based tree fitting showed that there is no significantly supported general area cladogram for the dataset. Yet, distributions are strongly phylogenetically conserved, as revealed by dispersalvicariance analysis (DIVA). DIVA-based permutation tests were used to pinpoint phylogenetically determined biogeographic patterns. Consistent with expectations, continental dispersals (WP↔EP and WN↔EN) are significantly more common than palaeocontinental dispersals (WN↔EP and EN↔WP), which in turn are more common than disjunct dispersals (EN↔EP and WN↔WP). There is significant dispersal asymmetry both within the Nearctic (WN→EN more common than EN→WN) and the Palaeoarctic (EP→WP more common than WP→EP). CrossBeringian faunal connections have traditionally been emphasized but are not more important than cross-Atlantic connections in our data set. To analyse changes over time, we sorted biogeographic events into four major time periods using fossil, biogeographic and molecular evidence combined with a ‘branching clock’. These analyses show that trans-Atlantic distributions (EN–WP) were common in the Early–Mid Tertiary (70–20 Myr), whereas transBeringian distributions (WN–EP) were rare in that period. Most EN–EP disjunctions date back to the Early Tertiary (70–45 Myr), suggesting that they resulted from division of cross-Atlantic rather than cross-Beringian distributions. Diversification in WN and WP increased in the Quaternary (< 3 Myr), whereas in EP and EN it decreased from a maximum in the Early–Mid Tertiary.  2001 The Linnean Society of London

The Importance of Time/Space in Diagnosing the Causality of Phylogenetic Events: Towards a ‘Chronobiogeographical’ Paradigm?

A shift from a traditional biogeographical paradigm in cladistic biogeography to a chronobiogeographical paradigm is proposed. The chronobiogeographical paradigm aims to utilize temporal data in conjunction with spatial data in the detection of discrete historical events, such as vicariance and vicariant speciation, in cladograms. The concepts of primary and secondary congruency are introduced in relation to the distinction between repeated area relationships (primary congruency) and common extrinsic causality (secondary congruency). Simple hypothetical examples demonstrate that area cladograms cannot be safely interpreted purely as representing the sequence of area fragmentation; rather, they reflect recency of biotic interaction. Temporal data are shown to have a direct and potentially profound influence on the results of traditional cladistic biogeographical analyses, indicating the necessity of developing a chronobiogeographical approach. The implementation of the paradigm is considered first from a theoretical viewpoint and then in the context of the type of empirical data usually available. An as yet undevised "time/space algorithm" is deemed necessary for the latter, and guidelines are presented for the development of such an algorithm. Finally, we argue that the most rigorous and philosophically justified approach to the detection of phylogenetic causal events can be found only when temporal and spatial data are considered simultaneously. Consequently, the chronobiogeographical paradigm is seen as a logical elaboration of, not a replacement for, the biogeographical paradigm.

Exploratory phylogenetic and biogeographic analyses within three land-snail families in southeastern-most Madagascar

Abstract For Madagascan vicariance biogeography and phylogeny-based conservation, four land snail groups have been predicted as most readily informative: Acavidae, Boucardicus (Cyclophoridae), Reticulapex (Charopidae), and Streptaxidae. Acavids have been evaluated in a previous paper; this paper uses recently described taxa from three mountains in southeastern Madagascar to evaluate the other three groups, based on shell and reproductive characters. Phylogenetic analyses, using appropriate outgroups, were performed on all 17 Boucardicus (31 characters, 120 states), all nine Reticulapex (21 characters, 53 states), and all 15 streptaxids (19 characters, 68 states) known from the three mountains. The Boucardicus cladogram was marginally robust; it supported monophyly of the genus, and it implied evolutionary trends toward larger, more colour-patterned, more globose shells hatched from larger eggs; toward a dorsally and more weakly papillate penis with a large, external gland; and toward a broad-based, tightly convoluted fertilization pouch-seminal receptacle complex with an internal, muscular funnel. A convergence in high-spired shells supported the recent synonymization of Madecataulus under Boucardicus . According to the cladogram, a three-lobed apertural peristome was plesiomorphic, was lost, then reappeared convergently. Among the 12 dissected species of Boucardicus , morphology of the female reproductive system was extremely variable (11 of 14 character states autapomorphic). The Reticulapex cladogram supported monophyly of the genus but gave no robust resolution among species. Recent surveys also indicate that Reticulapex is rare to absent in northern Madagascar. The streptaxid cladogram suggested a sister-group relationship between the endemic clades Parvedentulina and Streptostele (Makroconche) , but provided no robust resolution among species within either clade or within Gulella . Anatomical material is relatively scarce for Madagascan streptaxids. Vicariance-biogeographic analysis resulted in the area cladogram (northern Vohimena mountain chain (southern Vohimena chain (southern Anosy chain))). The Vohimena chain, already known for its significantly greater diversity and endemism than the Anosy chain, thus also seems to harbour the older, more plesiomorphic species; this heightens the urgency for conservation and further survey within the Vohimena chain. Acavids (115 species known) remain the most accessible of Madagascar's major, widespread land-snail groups for island-wide phylogenetics and biogeography, mainly because of existing frozen-tissue collections, which have a limited shelf life. Boucardicus (177 species and 6 subspecies known) is clearly the second most accessible.

Exploratory phylogenetic and biogeographic analyses within three land-snail families in southeastern-most Madagascar

For Madagascan vicariance biogeography and phylogeny-based conservation, four land snail groups have been predicted as most readily informative: Acavidae, Boucardicus (Cyclophoridae), Reticulapex (Charopidae), and Streptaxidae. Acavids have been evaluated in a previous paper; this paper uses recently described taxa from three mountains in southeastern Madagascar to evaluate the other three groups, based on shell and reproductive characters. Phylogenetic analyses, using appropriate outgroups, were performed on all 17 Boucardicus (31 characters, 120 states), all nineReticulapex (21 characters, 53 states), and all 15 streptaxids (19 characters, 68 states) known from the three mountains. The Boucardicus cladogram was marginally robust; it supported monophyly of the genus, and it implied evolutionary trends toward larger, more colour-patterned, more globose shells hatched from larger eggs; toward a dorsally and more weakly papillate penis with a large, external gland; and toward a broad-based, tightly convoluted fertilization pouch-seminal receptacle complex with an internal, muscular funnel. A convergence in high-spired shells supported the recent synonymization of Madecataulus under Boucardicus. According to the cladogram, a three-lobed apertural peristome was plesiomorphic, was lost, then reappeared convergently. Among the 12 dissected species of Boucardicus, morphology of the female reproductive system was extremely variable (11 of 14 character states autapomorphic). The Reticulapex cladogram supported monophyly of the genus but gave no robust resolution among species. Recent surveys also indicate that Reticulapex is rare to absent in northern Madagascar. The streptaxid cladogram suggested a sister-group relationship between the endemic clades Parvedentulina andStreptostele (Makroconche) , but provided no robust resolution among species within either clade or withinGulella . Anatomical material is relatively scarce for Madagascan streptaxids. Vicariance-biogeographic analysis resulted in the area cladogram (northern Vohimena mountain chain (southern Vohimena chain (southern Anosy chain))). The Vohimena chain, already known for its significantly greater diversity and endemism than the Anosy chain, thus also seems to harbour the older, more plesiomorphic species; this heightens the urgency for conservation and further survey within the Vohimena chain. Acavids (115 species known) remain the most accessible of Madagascar's major, widespread land-snail groups for island-wide phylogenetics and biogeography, mainly because of existing frozen-tissue collections, which have a limited shelf life. Boucardicus (177 species and 6 subspecies known) is clearly the second most accessible.

How to do BPA, really

AimRecent comparisons of different approaches to historical biogeography have suffered in part because Brooks Parsimony Analysis (BPA) has been characterized as a one‐step process following protocols proposed in 1981. Subsequent modifications have resulted in a two‐step methodology. This contribution presents the mechanics and applications of those modifications.MethodsThe first step, or Primary BPA, which is similar to the original BPA but with modifications proposed by Wiley (1986, 1988a, b), is used to assess whether or not there is support for a single general area cladogram. The second step, Secondary BPA, proposed by Brooks (1990), depicts exceptions to the general area cladogram explicitly by duplicating areas having a reticulate history.ResultsThe analytical basis of area duplication in secondary BPA is explained more fully than in previous accounts, and the manner in which secondary BPA explicitly depicts falsification of the null hypothesis of simple vicariance is presented for four general cases.Main conclusionsBPA, as fully implemented, is capable of accounting for the complexity of speciation, dispersal and extinction events in a historical biogeographic context without removing or modifying input data from basic phylogenies, so long as at least three clades are analysed simultaneously to provide a distinction between general and special distribution elements.

Nothofagus Biogeography Revisited with Special Emphasis on the Enigmatic Distribution of Subgenus Brassospora in New Caledonia

Dispersals versus vicariance events and the presence of subgenus Brassospora in New Caledonia are two riddles of Nothofagus biogeography, a genus also distributed in New Guinea, New Zealand, South America, Southeast Australia, and Tasmania. Within a cladistic framework using the software COMPONENT 2.0, we demonstrate that most parsimonious area cladograms (areagrams) sensu cladistic biogeography need not always be the most plausible explanation nor reflect alternative geological hypotheses. The most parsimonious Nothofagus history sensu historical biogeography is reconstructed where a minimum of dispersed taxa is hypothesized and vicariance events are identified. A fully resolved well-established Nothofagus phylogeny was reconciled with three geological hypotheses (geograms) of East Gondwana break-up: (a) the conventional view, (b) an Australian—New Caledonian relationship, and (c) a biotic interchange between New Guinea and New Caledonia. Fossils determined to subgenus were optimized to the predicted lineages in the reconciled tree. Due to extensive extinctions, a maximum of three vicariance events are inferred, all being basal in the subgenera, an indication of subgeneric diversification prior to the break-up of Gondwana. Two taxa, N. gunnii and N. menziesii, are hypothesized as being long-distance dispersed. The most parsimonious solution suggests a close relationship between New Guinea and New Caledonia, supporting a Brassospora colonization route, but this hypothesis fails to predict numerous extinct lineages observed in the fossil record and thus must be rejected. The traditional break-up sequence of Gondwana is not the most parsimonious solution, indicating one incongruent node, but causes no overall incongruence with the fossil record. Considering all parameters, the occurrence of Brassospora in New Caledonia is most parsimoniously explained as a single colonization event from New Zealand where the subgenus subsequently went extinct in the Pliocene.

When simplicity is not parsimonious: a priori and a posteriori methods in historical biogeography

Despite using the same null hypothesis, a priori and a posteriori approaches in historical biogeography differ fundamentally. Methods such as Component Analysis (CA) and Reconciled Tree Analysis (RTA) may eliminate or modify input data in order to maximize fit to the null hypothesis, by invoking assumptions 1 and 2. Methods such as Brooks Parsimony Analysis (BPA) modify the null hypothesis, if necessary, to maintain the integrity of the input data, as required by assumption 0. Two exemplars illustrate critical empirical differences between CA/RTA and BPA: (1) CA rather than BPA may select the incorrect general area cladogram for a set of data (2) BPA, not RTA, provides the most parsimonious interpretation of all available data and (3) secondary BPA, proposed in 1990, applied to data sets for which dispersal producing areas with reticulate histories is most parsimonious, provides biologically realistic interpretations of area cladograms. These observations lead to the conclusion that BPA and CA/RTA are designed to implement different research programmes based on different conceptual frameworks. BPA is designed to assess the biogeographic context of speciation events, whereas CA/RTA are designed to find the best fitting pattern of relationships among areas based on the taxa that inhabit them. Unique distributional elements and reticulate (hybrid) histories of areas are essential for explaining complex histories of speciation. The conceptual framework for BPA, thus, assumes biogeographical complexity, relying on parsimony as an explanatory tool to summarize complex results, whereas CA/RTA assumes biogeographical simplicity, assuming conceptual parsimony a priori.

Phylogenetic and biogeographical analysis of the New Zealand Helicopsyche von Siebold (Trichoptera: Helicopsychidae)

AbstractThe phylogenetic relationship between the seven known New Zealand Helicopsyche von Siebold, 1856 species is outlined. The New Zealand Helicopsyche comprises Helicopsyche albescens Tillyard, 1924, Helicopsyche poutini McFarlane, 1964, Helicopsyche howesi Tillyard, 1924, Helicopsyche zealandica Hudson, 1904, Helicopsyche haurapango Johanson, 1999, Helicopsyche torinoJohanson, 1999, and Helicopsyche cuvieri Johanson, 1999 and the cladistic analysis revealed a single most parsimonious tree, ((albescens, (poutini, howesi)), (zealandica, (haurapango, (torino, cuvieri)))). The basal species in the two species groups formed, H. zeczlandica and H. albescens, are widely distributed in both North Island and South Island, while the derived species have more restricted distribution ranges and sister clades form non-overlapping distributions. New Zealand was divided into four and five separate geographical entities based on a) distribution patterns from the Helicopsyche and primitive Lepidoptera and b) distribution patterns from the Helicopsyche alone, respectively. To map the history of Helicopsyche in New Zealand reconciliation using COMPONENT 2.0 and Dispersal-Vicariance analysis by DIVA 1.1 was applied in the search for a reduced area cladogram and ancestral areas, respectively. The results indicate that the southernmost part was part of the ancestral area, and that the division of the earliest ancestor has a minimum age of 10 million years.

Molecular phylogeny and biogeography of Melaleuca, Callistemon and related genera (Myrtaceae)

To resolve the relationships of taxa within the Beaufortia suballiance (Myrtaceae), 72 ingroup taxa were analysed by parsimony methods and nrDNA sequence data from the 5S and ITS-1 ribosomal DNA spacer regions. Although basal nodes in the consensus tree (combined data set) are not supported by bootstrap or jackknife values, a number of clades are well supported, showing that Melaleuca is polyphyletic. Monophyletic groups include: endemic species of Melaleuca from New Caledonia (including species of Callistemon recently transferred to Melaleuca); the tropical Melaleuca leucadendra group; Australian species of Callistemon, which relate to species of Melaleuca predominantly from the South-East; and a group of south-western and eastern Australian melaleucas that relate to a clade of three south-western genera, Eremaea, Conothamnus and Phymatocarpus. Calothamnus, Regeliaand Beaufortiamay also relate to this latter group. Lamarchea is possibly related to northern melaleucas. The results have implications for generic revisions of the large genus Melaleuca. Biogeographic subtree analysis, based only on supported nodes of the taxon cladogram, showed New Caledonia, New Guinea, Eastern Queensland and the Northern Desert unresolved at the base of the area cladogram. The position of some of these areas is likely to be artifactual, but New Caledonia is interpreted as in the correct position. At a higher node, the monsoonal northern areas of Australia (Kimberley, Arnhem and Cape York), Atherton, the Pilbara and Western Desert relate to the southern regions, which form a group. The South-West of Australia is related to Eyre and Adelaide (designated area ‘South’) and Tasmania is related to the South-East and MacPherson–Macleay. The vicariance between northern and southern regions in Australia possibly relates to an early major climatic change (from the Early Tertiary). The biogeographic analysis helped illuminate taxon relationships.

Biogeographic area relationships of lowland Neotropical rainforest based on raw distributions of vertebrate groups

Hypotheses of the historic biogeography of Neotropical anurans inhabiting lowland forests were generated using Parsimony Analysis of Endemicity. In order to establish comparisons with the biogeographical patterns of other vertebrates, previous cladistic analyses reported in the literature (for lizards and primates) were extended and reanalysed to match the geographical scope of the anuran analysis. Cladistic analysis of the distribution of 335 anuran species at 14 localities showed two regions that form a basal dichotomy: (1) Central America+Chocó and (2) Amazon Basin+Brazilian Atlantic Forest. This result is interpreted as the first vicariance event that separated lowland Neotropical rainforests into Cis-Andean (east from the Andes) and Trans-Andean (west from the Andes) areas. Within the Cis-Andean localities, the earliest separation occurred between the Amazon Basin and the Brazilian Atlantic Forest. Within the Amazon Basin, three distinctive clusters are defined: (1) Belém, (2) Guianan Region, and (3) Upper Amazon Basin. Data sets on the distribution of anurans, lizards, and mammals have strong cladistic signal. Strong congruence exists among the area cladograms of anurans, lizards, and primates. All of them have, or at least did not conflict with: (1) a basal separation between Cis- and Trans-Andean regions, (2) a Central American clade, (3) the Chocó Region is sister to the Central American clade, (4) an Amazon Basin clade, (5) an Upper Amazon Basin clade, and (6) a Guianan clade. The area cladograms are dichotomous and therefore do not support biogeographic theories that hypothesize simultaneous isolations of biotas in the Neotropics.

Biogeographic area relationships of lowland Neotropical rainforest based on raw distributions of vertebrate groups

Hypotheses of the historic biogeography of Neotropical anurans inhabiting lowland forests were generated using Parsimony Analysis of Endemicity. In order to establish comparisons with the biogeographical patterns of other vertebrates, previous cladistic analyses reported in the literature (for lizards and primates) were extended and reanalysed to match the geographical scope of the anuran analysis. Cladistic analysis of the distribution of 335 anuran species at 14 localities showed two regions that form a basal dichotomy: (1) Central America + Choco and (2) Amazon Basin + Brazilian Atlantic Forest. This result is interpreted as the first vicariance event that separated lowland Neotropical rainforests into Cis-Andean (east from the Andes) and Trans-Andean (west from the Andes) areas. Within the Cis-Andean localities, the earliest separation occurred between the Amazon Basin and the Brazilian Atlantic Forest. Within the Amazon Basin, three distinctive clusters are defined: (1) Belem, (2) Guianan Region, and (3) Upper Amazon Basin. Data sets on the distribution of anurans, lizards, and mammals have strong cladistic signal. Strong congruence exists among the area cladograms of anurans, lizards, and primates. All of them have, or at least did not conflict with: (1) a basal separation between Cis- and Trans-Andean regions, (2) a Central American clade, (3) the Choco Region is sister to the Central American clade, (4) an Amazon Basin clade, (5) an Upper Amazon Basin clade, and (6) a Guianan clade. The area cladograms are dichotomous and therefore do not support biogeographic theories that hypothesize simultaneous isolations of biotas in the Neotropics.

Cladistic biogeography of the moth tribe Cidariini (Lepidoptera, Geometridae) in the Holarctic and Indo-Chinese regions

A cladistic biogeographic analysis for the Holarctic and Indo-Chinese regions was undertaken based on seven genera of the tribe Cidariini Cidaria Treitschke, Thera Stephens, Pennithera Viidalepp,Heterothera Inoue, Callabraxas Butler, Gandaritis Moore and Eulithis Hubner. Smallest coincident ranges of two species recognized 11 endemic areas. The study has two aims: to construct a hierarchical structure of those areas, and to recognize dispersal events. Under two assumptions [widespread taxa mapped (identical as assumption 0) and widespread taxa not mapped (identical as assumption 1)] the 11 endemic areas were mapped with 72 taxa. The best resolved area cladograms under the two assumptions differ in the placement of one endemic area, northern Europe. Area relationships found in this present analysis are congruent with the current landmass configurations: (North America, (Europe, (northern India, (southwestern Asia, (Baikal area, (south China, (Taiwan, (Russian Far East, Japan)))))))). These area cladograms postulate at least three vicariance events: (1) between North America and the Palaearctic; (2) western–eastern Palaearctic; (3) northern India—the rest of Asia. The approach to recognize dispersed taxa by pruning each taxon suggests that most dispersal events occurred in East Asia: from the Baikal area or south China to the Russian Far East; and from the Russian Far East to Japan. Relationships among endemic areas are briefly discussed.

Cladistic biogeography of the moth tribe Cidariini (Lepidoptera, Geometridae) in the Holarctic and Indo-Chinese regions

A cladistic biogeographic analysis for the Holarctic and Indo-Chinese regions was undertaken based on seven genera of the tribe Cidariini Cidaria Treitschke, Thera Stephens, Pennithera Viidalepp,Heterothera Inoue, Callabraxas Butler, Gandaritis Moore and Eulithis Hübner. Smallest coincident ranges of two species recognized 11 endemic areas. The study has two aims: to construct a hierarchical structure of those areas, and to recognize dispersal events. Under two assumptions [widespread taxa mapped (identical as assumption 0) and widespread taxa not mapped (identical as assumption 1)] the 11 endemic areas were mapped with 72 taxa. The best resolved area cladograms under the two assumptions differ in the placement of one endemic area, northern Europe. Area relationships found in this present analysis are congruent with the current landmass configurations: (North America, (Europe, (northern India, (southwestern Asia, (Baikal area, (south China, (Taiwan, (Russian Far East, Japan)))))))). These area cladograms postulate at least three vicariance events: (1) between North America and the Palaearctic; (2) western–eastern Palaearctic; (3) northern India—the rest of Asia. The approach to recognize dispersed taxa by pruning each taxon suggests that most dispersal events occurred in East Asia: from the Baikal area or south China to the Russian Far East; and from the Russian Far East to Japan. Relationships among endemic areas are briefly discussed.

Methods in Vicariance Biogeography: Assessment of the Implementations of Assumptions 0, 1, and 2

As we have argued previously, for the valid derivation of general area cladograms in vicariance biogeography, two requirements should be met. First, sets of area cladograms derived under assumptions 0, 1 and 2 should be inclusive (requirement I). Second, general area cladograms should be based on area cladograms, for different monophyletic groups, derived under the same assumption (requirement II). We now assess for their actual implementation of assumptions A0, A1, and A2 and for the extent to which they meet requirements I and II, the following methods (and correlated computer programs): Component Compatibility Analysis (CAFCA), Brooks Parsimony Analysis (PAUP), Component Analysis (Component 1.5), Reconciled Tree Analysis (Component 2.0), and Three Area Statement Analysis (TAS). For this purpose we use empirical (Heterandria, Xiphophorus, Cyttaria, Eriococcus/Madarococcus) and theoretical data sets. All programs appear to violate, to a different degree, requirement I (deriving inclusive sets of area cladograms under assumptions) when dealing with sympatric taxa under A1 or A2. Dealing with sympatric taxa a posteriori only prevents this violation. All programs examined appear to meet requirement II (deriving general area cladograms under a single assumption).

Methods in Vicariance Biogeography: Assessment of the Implementations of Assumptions 0, 1, and 2.

As we have argued previously, for the valid derivation of general area cladograms in vicariance biogeography, two requirements should be met. First, sets of area cladograms derived under assumptions 0, 1 and 2 should be inclusive (requirement I). Second, general area cladograms should be based on area cladograms, for different monophyletic groups, derived under the same assumption (requirement II). We now assess for their actual implementation of assumptions A0, A1, and A2 and for the extent to which they meet requirements I and II, the following methods (and correlated computer programs): Component Compatibility Analysis (CAFCA), Brooks Parsimony Analysis (PAUP), Component Analysis (Component 1.5), Reconciled Tree Analysis (Component 2.0), and Three Area Statement Analysis (TAS). For this purpose we use empirical (Heterandria, Xiphophorus, Cyttaria, Eriococcus/Madarococcus) and theoretical data sets. All programs appear to violate, to a different degree, requirement I (deriving inclusive sets of area cladograms under assumptions) when dealing with sympatric taxa under A1 or A2. Dealing with sympatric taxa a posteriori only prevents this violation. All programs examined appear to meet requirement II (deriving general area cladograms under a single assumption).

The shifting roles of dispersal and vicariance in biogeography

Dispersal and vicariance are often contrasted as competing processes primarily responsible for spatial and temporal patterns of biotic diversity. Recent methods of biogeographical reconstruction recognize the potential of both processes, and the emerging question is about discovering their relative frequencies. Relatively few empirical studies, especially those employing molecular phylogenies that allow a temporal perspective, have attempted to estimate the relative roles of dispersal and vicariance. In this study, the frequencies of vicariance and dispersal were estimated in six lineages of birds that occur mostly in the aridlands of North America. Phylogenetic trees derived from mitochondrial DNA sequence data were compared for towhees (genus Pipilo), gnatcatchers (genus Polioptila), quail (genus Callipepla), warblers (genus Vermivora) and two groups of thrashers (genus Toxostoma). Different area cladograms were obtained depending on how widespread and missing taxa were coded. Nonetheless, no cladogram was obtained for which all lineages were congruent. Although vicariance was the dominant mode of evolution in these birds, approximately 25% of speciation events could have been derived from dispersal across a preexisting barrier. An expanded database is now needed to estimate the relative roles of each process. Applying a molecular clock calibration, nearly all speciation events are of the order of a million or more years old, much older than typically presumed.

Evidence for reticulate palaeogeography: beetle diversity linked to connection‐disjunction cycles of the Gibraltar strait

AbstractAim Dispersal barriers between areas within some regions have appeared and disappeared throughout evolutionary time. Here we describe the distributional patterns displayed by three taxa living in such kind of regions. These patterns can be better explained considering a reticulated rather than a hierarchically branched palaeogeography.Location Western Mediterranean.Methods The taxa studied are Misolampus (Coleoptera, Tenebrionidae), Tentyria (Coleoptera, Tenebrionidae) and Thorectes (Coleoptera, Geotrupidae). All them are flightless and show a high degree of endemicity. The individual pattern of area relationships was determined separately for each genus by Brooks Parsimony Analysis (BPA). A theoretical general area cladogram was constructed based on the palaeogeographical history of the region. Finally, the general area cladogram is reconciled with the individual ones.Results The ancestor of Misolampus probably was North African. Land dispersal toward the Iberian Peninsula is proposed. Speciation within Iberia is related to specific vicariance events, and the presence of insular (Balearic Islands) populations is explained by sea‐surface or, more probably, human‐mediated dispersal. The ancestor of Tentyria was Iberic. The proposed hypothesis to explain the current species distribution mainly relies on the occurrence of specific vicariance events. However, the occurrence of some sea‐surface dispersal event is not discarded. Almost all possible vicariance events can be recognized in the first clade of the Thorectes genus. There is evidence for dispersal between Africa and Europe at different dates and in both directions. In spite of some uncertainties, the appearance of the second Thorectes clade can also be explained by the occurrence of specific historical events. An ancient dispersal toward the eastern Mediterranean and several dispersal events during the Messinian seem likely.Main conclusions The same historical events have specific outcomes in every tree (even in every branch within a tree) depending on the ability for dispersal and speciation of each taxon. Connection‐disjunction cycles of dispersal barriers have acted as diversity producers.