The Galápagos Islands: A History of Their Exploration

Cockroaches are an understudied group and the total number of described taxa increases every year. The last checklist of Ecuador species was published in 1926. The main aim of this study was to complete a new checklist of cockroach species recorded in Ecuador supplemented with a research history of cockroaches (Blattaria) on the territory of continental Ecuador. In addition, the checklist contains comments on Ecuadorian faunistic records, including the Galápagos Islands. A total of 114 species (105 in continental Ecuador and 18 in Galápagos Islands) belonging to 6 families and 44 genera are listed. Forty species (38.1 %) occur solely in continental Ecuador and five (27.8 %) are endemic on Galápagos Islands. The results indicate that further research on the cockroach fauna of Ecuador as well as determination of museum collections from this territory is needed

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Psidium guajava in the Galapagos Islands: population genetics and history of an invasive species

10.1101/402693 ◽

2018 ◽

Author(s):

Diego Urquía ◽

Bernardo Gutiérrez ◽

Gabriela Pozo ◽

María José Pozo ◽

Analía Espín ◽

...

Keyword(s):

Population Genetics ◽

Invasive Plant ◽

Psidium Guajava ◽

Galapagos Islands ◽

Historical Record ◽

Galápagos Islands ◽

Santa Cruz ◽

Island Populations ◽

Galapagos Archipelago ◽

History Of

AbstractThe threat of invasive plant species in island populations prompts the need to better understand their population genetics and dynamics. In the Galapagos islands, this is exemplified by the introduced guava (Psidium guajava), considered one of the greatest threats to the local biodiversity due to its effective spread in the archipelago and its ability to outcompete endemic species. To better understand its history and genetics, we analyzed individuals from three inhabited islands in the Galapagos archipelago with 11 SSR markers. Our results reveal similar genetic diversity between islands, suggestive of gene flow between them. Populations appear to be distinct between the islands of San Cristobal and Isabela, with the population of Santa Cruz being composed as a mixture from both. Additional evidence for genetic bottlenecks and the inference of introduction events suggests an original introduction of the species in San Cristobal, from where it was later introduced to Isabela, and finally into Santa Cruz. Alternatively, an independent introduction event for Isabela is also possible. These results are contrasted with the historical record, providing a first overview of the history of P. guajava in the Galapagos islands and its current population dynamics.

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Non-native small terrestrial vertebrates in the Galapagos

10.7287/peerj.preprints.26563 ◽

2018 ◽

Author(s):

Diego F Cisneros-Heredia

Keyword(s):

Native Species ◽

Galapagos Islands ◽

Current Status ◽

Ecosystem Functions ◽

Human Populations ◽

Tree Frog ◽

Galápagos Islands ◽

Species Introduction ◽

Terrestrial Vertebrates ◽

History Of

Humans have translocated thousands of species of flora, fauna and microorganisms to places they would never have reached on their own. Non-native species may have effects on biological communities, ecosystem functions and human populations. In island environments, the effects of spreading non-native species on native biodiversity can be severe and lead to native ecosystem transformation and even endemic species extinction. The Galapagos Islands are a region of particular interest and relevance to the issue of species introduction and invasiveness. In this paper, I analyse the current status of 25 non-native amphibians, reptiles and birds that have been reported in the Galapagos Islands. Six species have established self-sufficiently in Galapagos and may become invasive: Fowler’s snouted tree frog Scinax quinquefasciatus, common house gecko Hemidactylus frenatus, mourning gecko Lepidodactylus lugubris, dwarf gecko Gonatodes caudiscutatus, Peters’ leaf-toed gecko Phyllodactylus reissii, and smooth-billed ani Crotophaga ani. Domestic fowl Gallus gallus holds feral populations, which may have self-sufficient populations, but evidence is unclear. I provide information on the distribution and natural history of non-native species of amphibians, reptiles and birds in Galapagos, including new data about the introduction history of S. quinquefasciatus; evidence on the establishment of H. frenatus on Isabela and San Cristobal islands; the first published record of a non-native snake in Galapagos, Lampropeltis micropholis; the first evidence of predation on squamate reptiles by G. gallus in Galapagos; and evidence of a probable major impact by C. ani due to extensive predation on the endemic Galapagos carpenter bee Xylocopa darwini. I comment on the invasiveness and impact potential of non-native species in Galapagos, identify vulnerable islands for the arrival of non-native species, identify potential hitchhiker that could arrive in the future and propose that it is important to rethink about how we understand, manage and prevent introductions of non-native species. The new wave of introduced species in Galapagos is formed by small hitchhikers, species that are easily overlooked, may travel in high numbers and are highly linked to human-made environments.

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Origin and dispersion pathways of guava in the Galapagos Islands inferred through genetics and historical records

10.22541/au.161745825.56117059/v1 ◽

2021 ◽

Author(s):

Diego Urquia ◽

Bernardo Gutierrez ◽

Gabriela Pozo ◽

Maria Pozo ◽

Maria Torres

Keyword(s):

Genetic Diversity ◽

Psidium Guajava ◽

Galapagos Islands ◽

Genetic Distances ◽

Galápagos Islands ◽

Santa Cruz ◽

Historical Sources ◽

Introduction History ◽

Galapagos Archipelago ◽

History Of

Guava (Psidium guajava) is one of the most aggressive invasive plants in the Galapagos Islands. Determining its provenance and genetic diversity could provide valuable information for its control. With this purpose, we analyzed 11 SSR markers in guava individuals collected from Isabela, Santa Cruz, San Cristobal and Floreana islands in the Galapagos, as well as from mainland Ecuador. The mainland guava population appeared genetically differentiated from the Galapagos populations, with higher genetic diversity levels found in the former. By using different approaches for data analysis, we consistently found that the Central Highlands region of mainland Ecuador is one of the most likely origins of the Galapagos populations. Moreover, the guavas from Isabela and Floreana show a potential genetic input from southern mainland Ecuador, while the population from San Cristobal would be linked to the coastal mainland regions. Interestingly, the proposed origins for the Galapagos guava coincide with the first human settlings of the archipelago. By employing Approximate Bayesian Computation, we propose a model where San Cristobal was the first island to be colonized by guava from the mainland, from which it would have spread to Floreana and finally to Santa Cruz; Isabela would have been seeded from Floreana. An independent trajectory could also have contributed in the invasion of Floreana and Isabela. The pathway shown in our model agrees with the human colonization history of the different islands in the Galapagos. Our model, in conjunction with the clustering patterns of the guava individuals (based on genetic distances), suggests that guava introduction history in the Galapagos archipelago was driven predominantly by a single event (or events in rapid succession) instead of several independent introductions. We thus show that genetic analyses supported by historical sources can be used to answer questions on the variability and history of guava in the Galapagos Islands.

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Evidence of cannibalism in a population of western Galápagos racers Pseudalsophis occidentalis (Serpentes: Colubridae)

Herpetological Bulletin ◽

10.33256/hb157.611 ◽

2021 ◽

pp. 6-11

Author(s):

LUIS ORTIZ-CATEDRAL

Keyword(s):

Natural History ◽

Trophic Interactions ◽

Galapagos Islands ◽

Galápagos Islands ◽

Galapagos Archipelago ◽

Faecal Samples ◽

History Of ◽

Common Behaviour ◽

Prey Items

Cannibalism is a common behaviour among snakes, but it has not yet been verified for any of the nine species of Galápagos racer (Pseudalsophis spp.), a group endemic to the Galápagos archipelago, Ecuador. Galápagos racers are opportunistic generalists feeding on a variety of vertebrate prey. There are a few anecdotal and suspected attempts of cannibalism among Galápagos racers, but it is unclear whether this behaviour occurs and if so, how frequent it is. We analysed 61 faecal samples from western Galápagos racers (Pseudalsophis occidentalis). In addition to the remains of well known prey items such as lizards, we found snake teeth and skin fragments in 11 samples. Combined with previous observations of attempted cannibalism between western Galápagos racers, our results represent evidence that this species consumes other racers as prey. Our study contributes to a growing knowledge of the natural history of Galápagos racers and highlights the role of these reptiles in complex trophic interactions in the Galápagos islands.

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Reconstructing the history and biological consequences of a plant invasion on the Galápagos islands

10.1101/2020.09.26.313627 ◽

2020 ◽

Author(s):

Matthew J.S. Gibson ◽

María de Lourdes Torres ◽

Yaniv Brandvain ◽

Leonie C. Moyle

Keyword(s):

Endemic Species ◽

Native Species ◽

Evolutionary Biology ◽

Galapagos Islands ◽

Fruit Color ◽

Galápagos Islands ◽

Natural Experiments ◽

Wild Tomato ◽

Population Genomic ◽

History Of

AbstractThe introduction of non-native species into new habitats is one of the foremost risks to global biodiversity. Here, we evaluate a recent invasion of wild tomato (Solanum pimpinellifolium) onto the Galápagos islands from a population genomic perspective, using a large panel of novel collections from the archipelago as well as historical accessions from mainland Ecuador and Peru. We infer a recent invasion of S. pimpinellifolium on the islands, largely the result of a single event from central Ecuador which, despite its recency, has rapidly spread onto several islands in the Galápagos. By reconstructing patterns of local ancestry throughout the genomes of invasive plants, we uncover evidence for recent hybridization and introgression between S. pimpinellifolium and the closely related endemic species Solanum cheesmaniae. Two large introgressed regions overlap with known fruit color loci involved in carotenoid biosynthesis. Instead of red fruits, admixed individuals with endemic haplotypes at these loci have orange fruit colors that are typically characteristic of the endemic species. We therefore infer that introgression explains the observed trait convergence. Moreover, we infer roles for two independent loci in driving this pattern, and a likely history of selection favoring the repeated phenotypic transition from red to orange fruits. Together, our data reconstruct a complex history of invasion, expansion, and gene flow among wild tomatoes on the Galápagos islands. These findings provide critical data on the evolutionary importance of hybridization during colonization and its role in influencing conservation outcomes.Significance StatementThe isolation and unique diversity of the Galápagos Islands provide numerous natural experiments that have enriched our understanding of evolutionary biology. Here we use population genomic sequencing to reconstruct the timing, path, and consequences of a biological invasion by wild tomato onto the Galápagos. We infer that invasive populations originated from a recent human-mediated migration event from central Ecuador. Our data also indicate that invasive populations are hybridizing with endemic populations, and that this has led to some invasive individuals adopting both fruit color genes and the fruit color characteristic of the endemic island species. Our results demonstrate how hybridization can shape patterns of trait evolution over very short time scales, and characterize genetic factors underlying invasive success.

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Evolutionary history of the endangered shrub snapdragon (Galvezia leucantha) of the Galápagos Islands

Diversity and Distributions ◽

10.1111/ddi.12521 ◽

2016 ◽

Vol 23 (3) ◽

pp. 247-260 ◽

Cited By ~ 4

Author(s):

Beatriz Guzmán ◽

Ruben Heleno ◽

Manuel Nogales ◽

Walter Simbaña ◽

Anna Traveset ◽

...

Keyword(s):

Evolutionary History ◽

Galapagos Islands ◽

Galápagos Islands ◽

History Of

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The Non-Progress of Non-Progression: Two Responses to Lyell's Doctrine

The British Journal for the History of Science ◽

10.1017/s0007087400014758 ◽

1976 ◽

Vol 9 (2) ◽

pp. 166-174 ◽

Cited By ~ 14

Author(s):

Michael Bartholomew

Keyword(s):

Life History ◽

Environmental Conditions ◽

Galapagos Islands ◽

Ecological Niches ◽

Galápagos Islands ◽

Essential Point ◽

The Real ◽

History Of

‘Non-Progression’, the interpretation of life-history launched by Lyell in 1830 and defended by him for over twenty years, can be summarized as follows. Palaeontologists, Lyell contended, should assume that at every period of the earth's recoverable past, each class of plants and animals has been represented somewhere on earth. Species have been created solely as responses to perpetually shifting environmental conditions, and not as temporally conditioned stages in the unique unrolling of a grand plan. If certain environments are especially suited to reptiles, then the Creator tailors collections of beautifully adapted terrestrial, aquatic, and even aerial reptiles for them—as He did, for example, for the environments recorded in the British Jurassic; as He did, much more recently, for the Galapagos Islands; and as He will do again, if conditions somewhere on earth ever force mammals into extinction, leaving ecological niches which can more suitably be filled by reptiles. If, for example, changes in the topography and climate of the Sussex Weald eventually lead to the re-establishment of an environment that particularly suits iguanodons, then iguanodons will assuredly appear there again. The essential point about Lyell's interpretation is that time does nothing to determine a particular flora and fauna. When designing a new animal, the Creator, according to Lyell's view, has to take into account only the creature's or plant's destined environment: He has to consult no timetable, or lineage, governing the production of new forms. In notes for a speech given in 1852 Lyell reduced his interpretation to the epitome, ‘Adaptation to geographical circumst5 not progressive develop the real history of past changes’.

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