Can long-distance dispersal be inferred from the New Zealand plant fossil record?

2001 ◽  
Vol 49 (3) ◽  
pp. 357 ◽  
Author(s):  
Mike S. Pole

New Zealand is generally thought to have been physically isolated from the rest of the world for over 60 million years. But physical isolation may not mean biotic isolation, at least on the time scale of millions of years. Are New Zealand’s present complement of plants the direct descendants of what originally rafted from Gondwana? Or has there been total extinction of this initial flora with replacement through long-distance dispersal (a complete biotic turnover)? These are two possible extremes which have come under recent discussion. Can the fossil record be used to decide the relative importance of the two endpoints, or is it simply too incomplete and too dependent on factors of chance? This paper suggests two approaches to the problem—the use of statistics to apply levels of confidence to first appearances in the fossil record and the analysis of trends based on the entire palynorecord. Statistics can suggest that the first appearance of a taxon was after New Zealand broke away from Gondwana—as long as the first appearance in the record was not due to an increase in biomass from an initially rare state. Two observations can be drawn from the overall palynorecord that are independent of changes in biomass: (1) The first appearance of palynotaxa common to both Australia and New Zealand is decidedly non-random. Most taxa occur first in Australia. This suggests a bias in air or water transport from west to east. (2) The percentage of endemic palynospecies in New Zealand shows no simple correlation with the time New Zealand drifted into isolation. The conifer macrorecord also hints at complete turnover since the Cretaceous.

Author(s):  
E. Punithalingam

Abstract A description is provided for Scirrhia pini[Mycosphaerella pini]. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On pines including Pinus radiata and its hybrids, P. halepensis, P. canariensis, P. carbaea, P. ponderosa, P. nigra and others, Pseudotsuga menziesii (46, 2860), Larix decidua (49, 273). DISEASE: Dothistroma blight; red band. GEOGRAPHICAL DISTRIBUTION: North America (Canada, USA including Alaska), South America (Argentina, Brazil, Chile, Uruguay), Australasia and Oceania (New Zealand), Asia (Brunei, India, Japan), Africa (Ethiopia, Kenya, Malawi, Rhodesia, Swaziland, Tanzania, Uganda), Europe (Austria, France, Rumania, UK, USSR (Republic of Georgia), Yugoslavia) (CMI Map 419, ed. 2, 1970; record in CMI Herbarium). TRANSMISSION: By airborne conidia released and dispersed by a splash take-off mechanism for short distances. Long distance dispersal may be by transport of infected material, such as nursery stock and, under special conditions, clouds may carry sporal inoculum (43, 2100). Survival time of inoculum in the form of cast, infected foliage on the forest floor is limited to 2-6 months under moist conditions (50, 2003).


2012 ◽  
Vol 44 (2) ◽  
pp. 189-246 ◽  
Author(s):  
Gintaras KANTVILAS

AbstractWith 30 species, Tasmania is a major area of species diversity in the genus Menegazzia. Seven of these are new to science: M. abscondita Kantvilas, known from Tasmania and New Zealand, and M. athrotaxidis Kantvilas, M. hypogymnioides Kantvilas, M. petraea Kantvilas, M. ramulicola Kantvilas, M. subtestacea Kantvilas and M. tarkinea Kantvilas, all endemic to Tasmania. An identification key, descriptions based exclusively on Tasmanian collections, and detailed discussion of distribution, ecology, chemical composition and inter-species relationships are provided. All literature records of Menegazzia species pertaining to Tasmania are accounted for. New synonyms include: Menegazzia prototypica P. James and Parmelia pertusa var. coskinodes F. Wilson [synonyms of M. myriotrema (Müll. Arg.) R. Sant.], M. fertilis P. James [a synonym of M. platytrema (Müll. Arg.) R. Sant.] and Parmelia pertusa var. montana F. Wilson (a synonym of M. subtestacea). Incorrectly recorded species that should be deleted from the Tasmanian census include M. castanea P. James & D. J. Galloway (present on Macquarie Island) and M. testacea P. James & D. J. Galloway (endemic to New Zealand). The South American species, M. sanguinascens (Räs.) R. Sant., is recorded in Australasia (Tasmania) for the first time, whereas the widespread south-eastern Australian M. norstictica P. James is recorded for Western Australia. Salient features of the genus are discussed, including morphology, anatomy and chemistry. The biogeography of the genus is explored briefly. Twelve species (40%) are endemic to Tasmania, a level of endemism unmatched by any other species-rich genus on the island. Twelve species are shared with mainland Australia, eleven are shared with New Zealand, and only four species are shared with southern South America, all of which are sorediate, suggesting they are products of long-distance dispersal.


2006 ◽  
Vol 84 (8) ◽  
pp. 1266-1281 ◽  
Author(s):  
Gabriel Bernardello ◽  
Gregory J. Anderson ◽  
Tod F. Stuessy ◽  
Daniel J. Crawford

We review the hypothesized origin and the methods of arrival of the angiosperm colonists to the Juan Fernandez Islands. We also summarize the dispersal capabilities of the current flora, including data on fruit type, fruit length, and dispersal unit length, correlating these features with dispersal and establishment. Most species originated from South America, followed by Pantropical, Australian, New Zealand, and Pacific colonizers. Sea and land birds were the most important initial long-distance dispersal agents. Most colonizing species are hermaphroditic flowered, and thus all dispersal methods are represented among them. Monoecious, andromonoecious and gynomonoecious, dioecious, and polygamous species were mainly carried by birds. Most wind- and bird-pollinated colonizing genera arrived with birds as did most annual herbs and species with bright-colored flowers. In the current flora, the majority of the species have dry fruits. In monoecious, andromonoecious and gynomonoecious, and dioecious species, achenes predominate. Fleshy fruits are limited to perennials. Most species have medium to small dispersal units, and generally, the larger the flower, the larger the fruit. Large- and medium-sized dispersal units are common in shrubs and trees. Abiotic dispersal is common in the current flora, which may reflect the ancestral dispersal capability of the colonizers, or adaptation to the absence of a fauna to disperse seeds and fruits. Anemochorous and autochorous species are mainly perennial and have medium to large, unisexual flowers. Anemochorous species have small dispersal units and dull-colored flowers, whereas large dispersal units and brightly colored flowers are frequent in autochorous species. Medium-sized dispersal units are represented in autochorous or ornithochorous species. The establishment and evolution of this flora was previously discussed to have occurred with very few pollination and (or) reproductive options. This study suggests that elements associated with dispersal are also analogously limited.


2012 ◽  
Vol 7 (3) ◽  
pp. 389-414 ◽  
Author(s):  
Arthur Downing

AbstractBritish clubs and societies spread around the English-speaking world in the long nineteenth century. This article focuses on one particularly large friendly society, the Manchester Unity Independent Order of Oddfellows (MU), which by 1913 had more than a thousand lodges around the world, especially concentrated in Australia and New Zealand. The MU spread so widely because of micro-social and macro-social forces, both of which this article investigates. It also examines the transfer of members, funds, and information between different districts of the society, and argues that such transfers may have smoothed internal and long-distance migration.


2016 ◽  
Vol 29 (6) ◽  
pp. 403 ◽  
Author(s):  
Alan de Queiroz

In The Monkey’s Voyage, I focused on the issue of disjunct distributions, and, in particular, on the burgeoning support from molecular-dating studies for long-distance dispersal over vicariance as the most reasonable explanation for many (but by no means all) distributions broken up by oceans. Michael Heads’ assessment of the book is founded on his long-standing belief, following Croizat, that long-distance dispersal is an insignificant process and, therefore, that disjunctions are virtually always attributable to vicariance. In holding to these notions, Heads offered a series of unsound arguments. In particular, to preserve an ‘all-vicariance’ perspective, he presented a distorted view of the nature of long-distance dispersal, misrepresented current applications of fossil calibrations in molecular-dating studies, ignored methodological biases in such studies that often favour vicariance hypotheses, repeatedly invoked irrelevant geological reconstructions, and, most strikingly, showed a cavalier approach to evolutionary timelines by pushing the origins of many groups back to unreasonably ancient ages. The result was a succession of implausible histories for particular taxa and areas, including the notions that the Hawaiian biota is almost entirely derived from ancient (often Mesozoic) central Pacific metapopulations, that the disjunctions of extremely mobile organisms such as ducks rarely, if ever, result from long-distance dispersal, and that primates were widespread 120 million years before their first appearance in the fossil record. In contrast to Heads’ perspective, a central message of The Monkey’s Voyage is that explanations for disjunct distributions should be evaluated on the basis of diverse kinds of evidence, without strong a priori assumptions about the relative likelihoods of long-distance dispersal and vicariance.


Zootaxa ◽  
2010 ◽  
Vol 2650 (1) ◽  
pp. 1
Author(s):  
MATTHEW J. COLLOFF

Three new species of oribatid mite belonging to the genus Crotonia are described: one from Lord Howe Island (C. gorgonia sp. nov.) and two (C. norfolkensis sp. nov. and C. utricularia sp. nov.) from Norfolk Island, South-west Pacific. Crotonia gorgonia sp. nov. belongs to the Capistrata species group which reaches its highest diversity in Australia but is absent from New Zealand. Crotonia norfolkensis sp. nov. is a member of the Cophinaria group, recorded from Australia, New Zealand and New Caledonia, but with closest morphological similarity to C. brachyrostrum (Hammer, 1966) from New Zealand. Crotonia utricularia sp. nov. belongs to the Unguifera group, which reaches its highest diversity in New Zealand, is absent from Australia, and is present on Vanuatu and the Marquesas. The distribution of members of the species-groups of Crotonia in the south-western Pacific indicates that the species from Lord Howe Island has affinities with species from Australia, while the species from Norfolk Island are both most similar to species from New Zealand, and represents further evidence of the capacity of Crotonia spp. for long-distance dispersal to oceanic islands.


2002 ◽  
Vol 50 (1) ◽  
pp. 127 ◽  
Author(s):  
Kitty Vijverberg ◽  
Louis Lie ◽  
Konrad Bachmann

The Australian and New Zealand Microseris is supposed to have evolved from one or a few diaspores after a unique event of long-distance dispersal from western North America. At present, the plant group includes two species, M. lanceolata (Walp.) Sch.-Bip. and M. scapigera (Forst.) Sch.-Bip., each with two morphologically and ecologically divergent ecotypes. In spite of this classification, the morphological variation within and among ecotypes is not entirely consistent, and molecular investigations show evidence for the, possibly recent, occurrence of hybridisations between plants of different ecotypes. The present study investigates the overall morphological similarities among 1–4 plants of each of 54 Australian and New Zealand Microseris populations. The aim of the study was to gain further insights into the delimitation of species and ecotypes, the placement of populations that could thus far not be assigned to an ecotype and the adaptive radiation of the plant group. The results confirm the previously defined ecotypes and assign all but two of the questionable populations to ecotypes. They show that a broad range of character states rather than a few 'diagnostic' ones are specific for the ecotypes. The data confirm our earlier conclusion from molecular results, indicating that ecotype characteristics are maintained or reestablished by selection or adaptation, after dispersal or hybridisation between ecotypes. Despite (incidental) genetic exchange among populations of different ecotypes, the process of adaptive radiation is progressing. The combined morphological and molecular results are not incongruent with the present species delimitation. However, they also may support the split up of M. scapigera into two species and other phylogenetic solutions.


2021 ◽  
Author(s):  
◽  
Joe Buchanan

<p>Genetic variation in Carpophyllum Greville and Cystophora J. Agardh (Fucales, Phaeophyceae) was investigated at a variety of scales. An extensive survey of mitochondrial spacer variation in Carpophyllum maschalocarpum from 32 populations around New Zealand shows strong population differentiation at relatively small scales (50–100 kilometres), but also pathways of long distance dispersal that connect populations over much greater distances. In addition, historical climate change appears to have restricted C. maschalocarpum to the northern North Island during the last glacial maximum, with subsequent southward range expansion revealed by low genetic diversity in southern populations. These results are consistent with limited dispersal at the gamete and zygote stage, expected in fucalean algae, but with occasional long distance dispersal by detached floating thalli. The genetic signature suggests these two modes of dispersal are decoupled. Internal Transcribed Spacers sequences show little differentiation between C. maschalocarpum and C. angustifolium, and hybridisation was found in several populations where these species are broadly sympatric. In the Bay of Plenty the two species had different ITS ribotypes, but most C. angustifolium specimens had a mitochondrial spacer haplotype that clustered with C. maschalocarpum haplotypes. This indicates mitochondrial introgression from C. maschalocarpum into C. angustifolium. In Northland species were difficult to separate by morphology or molecular markers, and some populations appear to be comprised entirely of hybrids. Genetic distances between different species of Cystophora are very variable, and in some cases intra-species distances are similar to interspecies distances. This is problematic for DNA barcoding methods that rely on thresholds between inter-species and intra-species genetic distances. In some (but not all) cases, the absence of molecular differentiation can be attributed to oversplitting of Cystophora species by morphological methods, and I synonymise C. congesta with C. retroflexa, and C. distenta with C. scalaris. These studies exemplify the difficulties of delimiting species in brown algae: Morphology is often misleading or uninformative; genetic differentiation of species is very variable and often low; and species’ histories show complex patterns of isolation and secondary contact. I argue for an explicitly historical concept of species, with species’ history included in species descriptions.</p>


Sign in / Sign up

Export Citation Format

Share Document