Evolution of New Zealand's Marine Caddisflies: A Phylogenetic and Phylogeographic Assessment of the Chathamiidae (Insecta: Trichoptera)

<p><b>The Chathamiidae are an interesting family of caddisflies, unusual as all of the five known species are believed to breed entirely within the marine intertidal, comprising one of very few known marine insect groups. Additionally the family approaches almost complete endemicity status in New Zealand, and may represent an ancient lineage representative of ancient vicariance from Gondwana. However one species, the common and widespread Philanisus plebeius is also known to have a disjunct population in New South Wales Australia, hypothesised to represent a recent anthropogenic dispersal. This thesis, using DNA information, examined the Chathamiidae at varying phylogenetic levels.</b></p> <p>Firstly the species Philanisus plebeius was incorporated into a thorough intraspecific phylogeography, including samples from both New Zealand and Australia. The population as a whole was genetically diverse, with the population divisible into two major haplogroups, each restricted to discrete geographic areas with no overlap being observed. One of these groups was restricted to just two localities in the central eastern North Island, whereas the remainder included most remaining samples from both Islands of New Zealand, and also Australia. All Australian samples were found to comprise a single haplotype, differing by a single base pair from the most common haplotype in New Zealand. It was decided that the Australian population therefore represents a recent dispersal event from New Zealand, although unless the Australian haplotype remains undiscovered in New Zealand the level of divergence found is not congruent with a human introduction. One sequence intermediate between the two major haplogroups was identified from a single haplotype from Tauranga. It seemed that much of the population of Philanisus plebeius has been affected by recent demographic expansion, likely due to the effects of the last glacial maximum (LGM).</p> <p>The five species of the Chathamiidae were then analysed in a phylogeny. It was found that the genus Chathamia was polyphyletic, with the species C. integripennis nested within the genus Philanisus. The remaining species, C. brevipennis from the Chatham Islands, was basal to all the remaining members of the family. A strict molecular clock found a recent Pleistocene age (roughly 0.5 Ma) for divergence of the Kermadec Island species Philanisus fasciatus, and a Pliocene-Pleistocene age (roughly 3 Ma) for the Chatham Island species Chathamia brevipennis. For a comparison with the species C. brevipennis, the other Chatham Island caddisfly taxa Oecetis chathamensis, and Hydrobiosis lindsayi were compared with New Zealand relatives; indicated to have late and early Pleistocene ages respectively. A short sequence of the gene COI was amplified for the species Philanisus mataua, however this was found to contain two sequences reflecting either heteroplasmy or sample contamination, inhibiting confident phylogenetic placement. Additionally a larval sample from Sydney was demonstrated to represent C. integripennis, recorded outside of Northern New Zealand for the first time. Finally the Chathamiidae was included in a higher level phylogeny with related families, and was show to comprise a monophyletic group, sister to the Australasian family of the Conoesucidae. A relaxed molecular clock estimated a Cretaceous (roughly 90 Ma) age for the Chathamiidae, congruent with a vicariant age in New Zealand.</p>

Evolution of New Zealand's Marine Caddisflies: A Phylogenetic and Phylogeographic Assessment of the Chathamiidae (Insecta: Trichoptera)

<p><b>The Chathamiidae are an interesting family of caddisflies, unusual as all of the five known species are believed to breed entirely within the marine intertidal, comprising one of very few known marine insect groups. Additionally the family approaches almost complete endemicity status in New Zealand, and may represent an ancient lineage representative of ancient vicariance from Gondwana. However one species, the common and widespread Philanisus plebeius is also known to have a disjunct population in New South Wales Australia, hypothesised to represent a recent anthropogenic dispersal. This thesis, using DNA information, examined the Chathamiidae at varying phylogenetic levels.</b></p> <p>Firstly the species Philanisus plebeius was incorporated into a thorough intraspecific phylogeography, including samples from both New Zealand and Australia. The population as a whole was genetically diverse, with the population divisible into two major haplogroups, each restricted to discrete geographic areas with no overlap being observed. One of these groups was restricted to just two localities in the central eastern North Island, whereas the remainder included most remaining samples from both Islands of New Zealand, and also Australia. All Australian samples were found to comprise a single haplotype, differing by a single base pair from the most common haplotype in New Zealand. It was decided that the Australian population therefore represents a recent dispersal event from New Zealand, although unless the Australian haplotype remains undiscovered in New Zealand the level of divergence found is not congruent with a human introduction. One sequence intermediate between the two major haplogroups was identified from a single haplotype from Tauranga. It seemed that much of the population of Philanisus plebeius has been affected by recent demographic expansion, likely due to the effects of the last glacial maximum (LGM).</p> <p>The five species of the Chathamiidae were then analysed in a phylogeny. It was found that the genus Chathamia was polyphyletic, with the species C. integripennis nested within the genus Philanisus. The remaining species, C. brevipennis from the Chatham Islands, was basal to all the remaining members of the family. A strict molecular clock found a recent Pleistocene age (roughly 0.5 Ma) for divergence of the Kermadec Island species Philanisus fasciatus, and a Pliocene-Pleistocene age (roughly 3 Ma) for the Chatham Island species Chathamia brevipennis. For a comparison with the species C. brevipennis, the other Chatham Island caddisfly taxa Oecetis chathamensis, and Hydrobiosis lindsayi were compared with New Zealand relatives; indicated to have late and early Pleistocene ages respectively. A short sequence of the gene COI was amplified for the species Philanisus mataua, however this was found to contain two sequences reflecting either heteroplasmy or sample contamination, inhibiting confident phylogenetic placement. Additionally a larval sample from Sydney was demonstrated to represent C. integripennis, recorded outside of Northern New Zealand for the first time. Finally the Chathamiidae was included in a higher level phylogeny with related families, and was show to comprise a monophyletic group, sister to the Australasian family of the Conoesucidae. A relaxed molecular clock estimated a Cretaceous (roughly 90 Ma) age for the Chathamiidae, congruent with a vicariant age in New Zealand.</p>

Anthropogenic Dispersal of Leishmania (Viannia) braziliensis in the Americas: A Plausible Hypothesis

There are several gaps in our knowledge on the origin and spread of Leishmania (Viannia) braziliensis, an etiological agent of cutaneous and mucocutaneous or American tegumentary leishmaniasis, to different biomes, hosts, and vectors, with important epidemiological implications, including the possible existence of an anthroponotic component. Historical, biological, and epidemiological evidence suggests that Leishmania (V.) braziliensis and its variants were preexistent in Amazonia with great genetic variability, where they dispersed with less variability to other regions (clonal expansion). During pre-Columbian times the parasite may have been transported by migrating humans and probably also their dogs, from western Amazonia to the high inter-Andean valleys and from there to other regions of South America. The same thing could have happened later, in the same way, when it spread to non-Amazonian regions of Brazil and other countries of South and Central America, between the late 19th and early 20th centuries, during the so-called Rubber Boom and construction of the Madeira-Mamoré Railway in the Brazilian Amazon, by migrant workers who later returned to their places of origin, transporting the agent. The parasite’s dispersal in genetic correlated clusters, involving unexpectedly distinct ecosystems in Brazil (Amazonian, Cerrado, Caatinga and Atlantic Forest biomes), has continued until the present through human displacement. The infection of certain species of domestic, synanthropic and even wild animals, could be secondary to anthropogenic introduction of L. (V.) braziliensis in new environments. We admit the same phenomena happening in the probable transference of Leishmania infantum (visceral leishmaniasis), and of Yersinia pestis (plague) from the Old world to the New world, generating domestic and wild enzotic cycles from these agents. These assumptions associated with human infections, chronicity and parasite persistence with possibility of recovery of Leishmania in peripheral blood, skin and scars of cured or asymptomatic patients, (that may provide an alternative blood meal), along with the sand flies’ adaptation to the peri-domicile and the high susceptibility of domestic dogs, horses, mules and cats to the parasite, can reinforce the evidence of anthropogenic spread of L. (V.) braziliensis.

Geographical distribution of the dispersal ability of alien plant species in China and its socio-climatic control factors

Dispersal ability is important for the introduction, establishment, and spread of alien plant species. Therefore, determination of the geographical distribution of the dispersal ability of such species, and the relationship between dispersal ability and socio-climatic factors are essential to elucidate the invasion strategies of the alien plant species. Analytic hierarchy process and inventory, risk rank, and dispersal mode data available on Chinese alien plant species were used to determine their dispersal ability, the geographical distribution thereof, and the relationship between socio-climatic factors and dispersal ability. High-risk alien plant species had a higher natural dispersal ability (or several natural dispersal modes) but a lower anthropogenic dispersal ability (or few anthropogenic dispersal modes) than low-risk alien plant species. The geographical distribution of the dispersal ability of the alien plant species showed an inverse relationship with species density. Alien plant species with low dispersal ability (i.e., with fewer dispersal modes and distribution in the southeast) showed a tendency to adapt to environments with mild climates, while those with high dispersal ability (i.e., with more disposal nodes and distribution in the northwest) showed a tendency to adapt to harsh environments. It is essential for land managers and policy makers to understand the geographical distribution of the dispersal ability of alien plant species and their socio-climatic control factors to formulate strategies to control the natural and anthropogenic dispersal of such plants.