Devon Island Research Articles

Holarctic Collared Lemmings: Traces of Their Spread as Related to the History of the Arctic Biota

Among recent lemmings (D. torquatus from the Yamal Peninsula and D. groenlandicus from Somerset, Bathurst, Melville, and Devon islands), there are populations with archaic sets of morphotypes characteristic of the end of the Late Pleistocene. In some parts of the species range, lemming morphotypes follow the pattern characteristic of the Holocene stage of their evolution. Lemmings with the best developed tooth system live in the Bering Sea sector of the Arctic (Wrangel Island, Chukotka and Alaska). The correspondence of the boundaries of the groups distinguished by odontological traits to the phylogeographic data on mitochondrial DNA (mtDNA) and chromosomal groups is discussed.

The Muskox Patrol: High Arctic Sovereignty Revisited

... Canadian government activities in the High Arctic between 1900 and 1933 were carried out almost exclusively in response to the real or perceived intentions of other nations to challenge Canada's sovereignty claims. ... For 11 years, between 1922 and 1933, a small group of dedicated RCMP officers and their Native assistants had served to safeguard Canadian sovereignty against foreigners to the High Arctic islands. ... "The Muskox Patrol" is the story of the complex web of political events that culminated in sending the Mounties to the High Arctic. Perhaps surprisingly, the connecting thread in the web turned out to be muskoxen. For the first two decades following the 1880 transfer of the Arctic islands from Great Britain to Canada, Ottawa paid scant attention to the legality of the possession. The first jolt to the government's complacency was delivered from Norway .... For centuries, American and European whalers and explorers had frequented Arctic waters at will, living off the land and the seas as they saw fit, even operating land-based stations when it was convenient. Occasional protests by the Hudson's Bay Company had been ignored. ... the Canadian government realized that historical paper claims to land were a poor substitute for effective occupation .... The 1903 establishment of police authority on Herschel Island in the western Arctic was to be followed by extension of similar authority in the central and eastern Arctic. In the spring of 1903, the "Neptune" expedition sailed north under the command of A.P. Low .... In 1904, the "Neptune" sailed north to Cape Herschel on Ellesmere Island and later into Lancaster Sound and Pond Inlet. ... The Canadian flag was being planted in the eastern Arctic. ... In 1904, the "Arctic" entered Hudson Bay on the first of four extensive voyages into the Arctic islands. On subsequent voyages, Captain Bernier, government officials, and police officers travelled throughout the Arctic islands, placing official Canadian declarations of possession in large stone cairns.... As the years went by, the High Arctic sovereignty issue had become a personal quest for Bernier, just as pushing the Norwegian claim had become a life's struggle for Sverdrup. ... High Arctic sovereignty concerns slipped off the Canadian government's agenda until January 1920. In July 1922, Captain Bernier brought the "Arctic" north, loaded with building materials, supplies, and men to be stationed in some of the most remote outposts in the far North, lands that had not been occupied by Inuit for several hundred years. ... An Inuit family from Pond Inlet agreed to accompany the RCMP officers to a post yet to be established and remain for their first wintering. ... Lee's (1928) account shows how much the presence of Inuit families at the detachments meant to the RCMP officers in the High Arctic. Many of the young constables learned to communicate tolerably well in Inuktitut. ... From the outset, it had been the government's objective to establish a detachment on the shores of Bache Peninsula, at the entrance to Flagler Bay. ... A small hut was erected, with a sign board proclaiming the presence of the Kane Basin RCMP Detachment. ...The "Arctic" proceeded to the south coast of Devon Island, where the Dundas Harbour Detachment ... was established. ... Among the many Inughuit assistants who served with the RCMP in the High Arctic, the name of Nookapingwa is very prominent. ... he served practically throughout the entire first period of the RCMP presence in the High Arctic between 1924 and 1933. ... Our Muskox Patrol story ends with the closing of the Bache Detachment in 1933. ... Canada's concerns about the legality of its sovereignty claim to the High Arctic did not end there. However, the immediate challenge had been dealt with effectively through the huge efforts of the RCMP personnel and their Inughuit assistants from Greenland.

Palaeoenvironmental Interpretation of Late Quaternary Marine Molluscan Assemblages, Canadian Arctic Archipelago

This study examines neonto- logical and palaeontological data pertaining to arctic marine molluscs with the goal of reconstructing the palaeoecology of Late Quaternary ca. 12-1 ka BP glaciomarine environments in the Canadian Arctic Archipelago. A total of 26 taxa that represent 15 bivalves and 11 gastropods were recorded in shell collections recovered from Prince of Wales, Somerset, Devon, Axel Heiberg and Ellesmere islands. In spite of taphonomic bias, the observed fossil faunas bear strong similarities to modern benthic molluscan faunas inhabiting high latitude continental shelf environments, reflecting the high preservation potential of molluscan taxa in Quaternary marine sediments. The dominance of an arctic-boreal fauna represented by Hiatella arctica, Mya truncata and Astarte borealis is the product of natural ecological conditions in high arctic glaciomarine environments. Environmental factors controlling the distribution and species composition of the Late Quaternary molluscan assemblages from this region are discussed.

Heterotrophic microbial colonization of the interior of impact-shocked rocks from Haughton impact structure, Devon Island, Nunavut, Canadian High Arctic

The polar desert is one of the most extreme environments on Earth. Endolithic organisms can escape or mitigate the hazards of the polar desert by using the resources available in the interior of rocks. We examined endolithic communities within crystalline rocks that have undergone shock metamorphism as a result of an asteroid or comet impact. Specifically, we present a characterization of the heterotrophic endolithic community and its environment in the interior of impact-shocked gneisses and their host polymict breccia from the Haughton impact structure on Devon Island, Nunavut, Canadian High Arctic. Microbiological colonization of impact-shocked rocks is facilitated by impact-induced fissures and cavities, which occur throughout the samples, the walls of which are lined with high abundances of biologically important elements owing to the partial volatilization of minerals within the rock during the impact. 27 heterotrophic bacteria were isolated from these shocked rocks and were identified by 16S rDNA sequencing. The isolates from the shocked gneiss and the host breccia are similar to each other, and to other heterotrophic communities isolated from polar environments, suggesting that the interiors of the rocks are colonized by microorganisms from the surrounding country rocks and soils. Inductively coupled plasma–atomic emission spectroscopy (ICP-AES), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis were used to identify the chemical composition of the shocked materials and to document the in situ growth of microbes in their interiors. The identification of these heterotrophic communities within impact-shocked crystalline rocks extends our knowledge of the habitable biosphere on Earth. The colonization of the interiors of these samples has astrobiological applications both for considering terrestrial, microbiological contamination of meteorites from the Antarctic ice sheet and for investigating possible habitats for microbial organisms on the early Earth, and more speculatively, on Mars and other planetary bodies.

Impact‐induced microbial endolithic habitats

Abstract— Asteroid and comet impacts on Earth are commonly viewed as agents of ecosystem destruction, be it on local or global scales. However, for some microbial communities, impacts may represent an opportunity for habitat formation as some substrates are rendered more suitable for colonization when processed by impacts. We describe how heavily shocked gneissic crystalline basement rocks exposed at the Haughton impact structure, Devon Island, Nunavut, Arctic Canada, are hosts to endolithic photosynthetic microorganisms in significantly greater abundance than lesser‐shocked or unshocked gneisses. Two factors contribute to this enhancement: (a) increased porosity due to impact fracturing and differential mineral vaporization, and (b) increased translucence due to the selective vaporization of opaque mineral phases. Using biological ultraviolet radiation dosimetry, and by measuring the concentrations of photoprotective compounds, we demonstrate that a covering of 0.8 mm of shocked gneiss can provide substantial protection from ultraviolet radiation, reducing the inactivation of Bacillus subtilis spores by 2 orders of magnitude. The colonisation of the shocked habitat represents a potential mechanism for pioneer microorganisms to invade an impact structure in the earliest stages of post‐impact primary succession. The communities are analogous to the endolithic communities associated with sedimentary rocks in Antarctica, but because they occur in shocked crystalline rocks, they illustrate a mechanism for the creation of microbial habitats on planetary surfaces that do not have exposed sedimentary units. This might have been the case on early Earth. The data have implications for the microhabitats in which biological signatures might be sought on Mars.

Communities and paleoecology of Eifelian (mid-Devonian) brachiopods from the Bird Fiord Formation of Arctic Canada

The carbonate–siliciclastic strata in the Bird Fiord Formation of Arctic Canada contain a diverse brachiopod-dominated biota. A collection of 46 381 brachiopods from 126 sites at 35 localities on Ellesmere Island, North Kent Island, Grinnell Peninsula (Devon Island), and Bathurst Island includes 22 species assigned to 21 genera. Many of these taxa are endemic to Arctic Canada. Each collection of brachiopods is typically dominated by only one or two taxa. Cluster analysis, based on binary data, shows that the brachiopods can be divided into an Atrypa–Elythyna community group and a Spinatrypina–Desquamatia community group. The former encompasses the Atrypa–Elythyna and Atrypa–Elythyna–Perryspirifer communities, and the latter includes the Spinatrypina–Desquamatia and Spinatrypina–Desquamatia–Cranaena communities. The distribution of these communities was primarily related to water depth. Thus, the Atrypa–Elythyna community group, which belongs to benthic assemblage 3, lived in a shallow, proximal-shelf environment. The Spinatrypina–Desquamatia community group, which belongs to benthic assemblage 4, lived in a deeper, distal-shelf environment.

Polar endoliths – an anti-correlation of climatic extremes and microbial biodiversity

We examined the environmental stresses experienced by cyanobacteria living in endolithic gneissic habitats in the Haughton impact structure, Devon Island, Canadian High Arctic (75° N) and compared them with the endolithic habitat at the opposite latitude in the Dry Valleys of Antarctica (76° S). In the Arctic during the summer, there is a period for growth of approximately 2.5 months when temperatures rise above freezing. During this period, freeze–thaw can occur during the diurnal cycle, but freeze–thaw excursions are rare within higher-frequency temperature changes on the scale of minutes, in contrast with the Antarctic Dry Valleys. In the Arctic location rainfall of approximately 3 mm can occur in a single day and provides moisture for endolithic organisms for several days afterwards. This rainfall is an order of magnitude higher than that received in the Dry Valleys over 1 year. In the Dry Valleys, endolithic communities may potentially receive higher levels of ultraviolet radiation than the Arctic location because ozone depletion is more extreme. The less extreme environmental stresses experienced in the Arctic are confirmed by the presence of substantial epilithic growth, in contrast to the Dry Valleys. Despite the more extreme conditions experienced in the Antarctic location, the diversity of organisms within the endolithic habitat, which includes lichen and eukaryotic algal components, is higher than observed at the Arctic location, where genera of cyanobacteria dominate. The lower biodiversity in the Arctic may reflect the higher water flow through the rocks caused by precipitation and the more heterogeneous physical structure of the substrate. The data illustrate an instance in which extreme climate is anti-correlated with microbial biological diversity.

The biology of impact craters--a review.

Impact craters contain ecosystems that are often very different from the ecosystems that surround them. On Earth over 150 impact craters have been identified in a wide diversity of biomes. All natural events that can cause localized disruption of ecosystems have quite distinct patterns of rccovery. Impact events are unique in that they are the only extraterrestrial mechanism capable of disrupting an ecosystem locally in space and time. Thus, elucidating the chronological sequence of change at the sites of impacts is of ecological interest. In this synthetic review we use the existing literature, coupled with our own observations at the Haughton impact structure, Devon Island, Nunavut, Canada to consider the patterns of biological recovery at the site of impact craters and the ecological characteristics of impact craters. Three phases of recovery are suggested. The Phase of Thermal Biology, a phase associated with the localized, ephemeral thermal anomaly generated by an impact event. The Phase of Impact Succession and Climax, a phase marked by multiple primary and secondary succession events both in the aquatic realm (impact crater-lakes) and terrestrial realm (colonization of paleolacustrine deposits and impact-generated substrata) that are followed by periods of climax ecology. In the case of large-scale impact events (> 10(4) Mt), this latter phase may also be influenced by successional changes in the global environment. Finally, during the Phase of Ecological Assimilation, the disappearance of the surface geological expression of an impact structure results in a concomitant loss of ecological distinctiveness. In extreme cases, the impact structure is buried. Impact succession displays similarities and differences to succession following other agents of ecological disturbance, particularly volcanism.

Distribution and abundance of Canadian High Arctic belugas, 1974-1979

We conducted >236,000 km of aerial surveys and some supplementary studies of belugas (Delphinapterus leucas) in the central and eastern Canadian High Arctic in 974-79. Belugas that wintered in the “North Water” in Baffin Bay moved southwest into Lancaster Sound in April and early May. The main westward migration into Lancaster Sound occurred over a 2 to 3 week period during late June to late July. Estuaries along Somerset Island were occupied for <3 weeks from mid-July to mid-August. Little feeding occurred in estuaries. From mid-August until fall migration began in mid-September belugas occupied estuaries and offshore waters in Peel Sound. Fall migration eastward through Lancaster Sound was exclusively along the south coast of Devon Island, highly co-ordinated, and rapid; most of the population passed through the sound in <1 week. The whales then moved north along the east coast of Devon Island; some entered Jones Sound while others crossed directly to SE Ellesmere Island. Most calving occurred in July and early August; calving was not seen in estuaries and probably occurred offshore. Excluding calves, adults and yearlings formed 77% and 8.4%, respectively, of the population. The proportion of calves during mid-August was consistent with a triennial calving cycle. During late summer, belugas fed on coastal concentrations of polar cod (Boreogadus saida), under pan ice offshore (probably on cod), and in deep offshore waters. The size of the Canadian High Arctic population in the late 1970s was estimated to be at least 10,250 to 12,000 animals without allowing for animals that may have passed between surveys or that were below the surface at the time of the counts.

New brachiopod genera from Bird Fiord Formation (Devonian), arctic Canada

Brachiopods are common in the lower part of the late Early to Middle Devonian Bird Fiord Formation that is a carbonate-clastic transition succession found in Arctic Canada. These brachiopods, which lived in a shallow, near-shore, marine environment, includes three new genera: Borealistrophia, Arcticastrophia, and Grinnellathyis. The strophomenid Borealistrophia, which is characterized by two pairs of straight side septa, prominent and thick socket ridges, a thick but short median septum, and a cordate ventral muscle field, is found in the Baad Fiord, Blubber Point, and Norwegian members on Bathurst, Devon, North Kent, and Ellesmere islands. The strophomenid Arcticastrophia, which is distinctive because of its stout transmuscle septa, its narrow and low medium septum, and elevated ventral muscle field, is found in the Baad Fiord Member on Bathurst and Devon islands. The athyridid Grinnellathyris, which is characterized by an imperforated cardinal plate and inverted U-shaped jugum, is found in the Baad Fiord Member on Bathurst, North Kent, and Devon islands. The similarities between Grinnellathyris and Johnsonathyris Savage, Eberlein, and Churkin, 1978, in terms of their shell size and internal structures, may indicate that the latter evolved from the former.

Lacustrine Sedimentary Environments in High Arctic Proglacial Bear Lake, Devon Island, Nunavut, Canada

Combined catchment, subbottom acoustic, and sedimentary studies of high arctic, proglacial Bear Lake, Devon Island, were carried out to evaluate the role lacustrine processes and Holocene catchment evolution have had on the sedimentary record. In the proximal basin, bottom deposits up to 60 m thick are generated in part by turbid underflows associated with peak meltwater flow from the Devon Island Ice Cap. These underflows produce rhythmically laminated structures that are likely varves. In shallower locations, accumulation is slower and results from homopycnal distribution of fine suspended sediment throughout the proximal basin, resulting in a simple varve couplet. The distal basin is isolated from glacial meltwater by a shallow sill, although some fine-grained detrital carbonate transported by the glacial meltwater is deposited in both basins. In most locations in the distal basin Holocene sediments are less than 10 m thick. They are composed primarily of massive clay and some carbonate interrupted by irregular graded carbonate units produced by sporadic heavy summer rainfall and sediment transport from small plateau tributaries. Eolian sedimentation is also important throughout the lake, especially when high accumulations melt through the ice in the proximal basin, producing isolated grains and layers of coarse sand in the sedimentary record. Holocene ice margin changes have influenced the sedimentary record substantially, particularly during the mid-Holocene when the ice cap is inferred to have retreated from the catchment.

Lacustrine Sedimentary Environments in High Arctic Proglacial Bear Lake, Devon Island, Nunavut, Canada

Combined catchment, subbottom acoustic, and sedimentary studies of high arctic, proglacial Bear Lake, Devon Island, were carried out to evaluate the role lacustrine processes and Holocene catchment evolution have had on the sedimentary record. In the proximal basin, bottom deposits up to 60 m thick are generated in part by turbid underflows associated with peak meltwater flow from the Devon Island Ice Cap. These underflows produce rhythmically laminated structures that are likely varves. In shallower locations, accumulation is slower and results from homopycnal distribution of fine suspended sediment throughout the proximal basin, resulting in a simple varve couplet. The distal basin is isolated from glacial meltwater by a shallow sill, although some fine-grained detrital carbonate transported by the glacial meltwater is deposited in both basins. In most locations in the distal basin Holocene sediments are less than 10 m thick. They are composed primarily of massive clay and some carbonate interrupted by irregular graded carbonate units produced by sporadic heavy summer rainfall and sediment transport from small plateau tributaries. Eolian sedimentation is also important throughout the lake, especially when high accumulations melt through the ice in the proximal basin, producing isolated grains and layers of coarse sand in the sedimentary record. Holocene ice margin changes have influenced the sedimentary record substantially, particularly during the mid-Holocene when the ice cap is inferred to have retreated from the catchment.

Spatial and Temporal Changes in Sedimentary Processes at Proglacial Bear Lake, Devon Island, Nunavut, Canada

Lacustrine sedimentary processes are identified on an intra-annual scale at proglacial Bear Lake, Devon Island. Stage recorders, recording thermistors, sediment traps, and underflow monitoring equipment were deployed during the 1999 melt season. Episodic proximal turbidity currents were measured as positive near-bottom temperature anomalies and currents. The timing of individual positive temperature anomalies was clearly associated with diurnal peaks of discharge into the lake. During the period of 23 to 25 July, continuous underflow occurred, which preceded a large discharge event by about 24 h. Sediment traps placed throughout the lake recorded sediment accumulation rates from 16 June to 4 August. An extremely large precipitation event occurred on 29 June, when coarse, carbonate-rich sediment was deposited in front of a secondary tributary by spatially limited turbidity currents. A niveo-eolian deposit was observed on the lake ice, and sediment traps were deployed under this area. Mass accumulation rates in these traps locally overwhelmed fluvially generated sedimentation. This sediment was dominantly sand, which quickly melted through the lake ice and hastened the date of localized break-up.

Geographical variation and population structure in the White-rumped Sandpiper Calidris fuscicollis as shown by morphology, mitochondrial DNA and carbon isotope ratios.

We studied the population structure of a high arctic breeding wader bird species, the White-rumped Sandpiper Calidris fuscicollis. Breeding adults, chicks and juveniles were sampled at seven localities throughout the species' breeding range in arctic Canada in 1999. The mitochondrial control region was analysed by DNA sequencing, feathers were analysed for carbon isotope ratios (C13/C12) by isotope ratio mass spectrometry, and morphological measurements were analysed using principal component analyses, taking the effect of sex into account (identified by molecular genetic methods). In general, our results support the notion that the White-rumped Sandpiper is a monotypic species with no subspecies, and most of the morphological and genetic variation occurs within sites. Nevertheless, some differences between sites were found. Birds from the two northernmost sites (Ellesmere and Devon Islands) had relatively longer bill and wing and shorter tarsus than birds sampled further south, possibly reflecting genetic differences between populations. The carbon isotope ratios were higher at the easternmost site (Baffin Island), revealing differences in the isotope content of the food. The mtDNA sequences showed no significant differentiation between sites and no pattern of isolation-by-distance was found. Based on the mtDNA variation, the species was estimated to have a long-term effective population size of approximately 9,000 females. The species shows no clear evidence of any population expansion or decline. Our results indicate that carbon isotope ratios, and possibly also certain mtDNA haplotypes, may be useful as tools for identifying the breeding origin of White-rumped Sandpipers on migration and wintering sites.

Spatial and Temporal Changes in Sedimentary Processes at Proglacial Bear Lake, Devon Island, Nunavut, Canada

Spatial and Temporal Changes in Sedimentary Processes at Proglacial Bear Lake, Devon Island, Nunavut, Canada

Diagnostic digital echocardiography on devon island via telemedicine as a mars analog

Diagnostic digital echocardiography on devon island via telemedicine as a mars analog

Sir John Franklin's last arctic expedition: a medical disaster.

Sir John Franklin's last arctic expedition: a medical disaster.

NEW BRACHIOPOD GENERA FROM BIRD FIORD FORMATION (DEVONIAN), ARCTIC CANADA

Brachiopods are common in the lower part of the late Early to Middle Devonian Bird Fiord Formation that is a carbonate-clastic transition succession found in Arctic Canada. These brachiopods, which lived in a shallow, near-shore, marine environment, includes three new genera: Borealistrophia, Arcticastrophia, and Grinnellathyis. The strophomenid Borealistrophia, which is characterized by two pairs of straight side septa, prominent and thick socket ridges, a thick but short median septum, and a cordate ventral muscle field, is found in the Baad Fiord, Blubber Point, and Norwegian members on Bathurst, Devon, North Kent, and Ellesmere islands. The strophomenid Arcticastrophia, which is distinctive because of its stout transmuscle septa, its narrow and low medium septum, and elevated ventral muscle field, is found in the Baad Fiord Member on Bathurst and Devon islands. The athyridid Grinnellathyris, which is characterized by an imperforated cardinal plate and inverted U-shaped jugum, is found in the Baad Fiord Member on Bathurst, North Kent, and Devon islands. The similarities between Grinnellathyris and Johnsonathyris Savage, Eberlein, and Churkin, 1978, in terms of their shell size and internal structures, may indicate that the latter evolved from the former.

Impact-generated carbonate melts: evidence from the Haughton structure, Canada

Evidence is presented for the melting of dolomite-rich target rocks during formation of the 24 km diameter, 23 Ma Haughton impact structure on Devon Island in the Canadian high Arctic. Field studies and analytical scanning electron microscopy reveal that the >200 m thick crater-fill deposit, which currently covers an ∼60 km2 area in the center of the structure, comprises fragmented target rocks set within a carbonate–silicate matrix. The silicate component of the matrix consists of Si–Al–Mg-rich glass. The carbonate component is microcrystalline calcite, containing up to a few wt% Si and Al. The calcite also forms spherules and globules within the silicate glass, with which it develops microtextures indicative of liquid immiscibility. Dolomite clasts exhibit evidence of assimilation and may show calcite and rare dolomite overgrowths. Some clasts are penetrated by calcite and silicate injections. Along with the carbonate–silicate glass textures, the presence of pigeonite and spinifex-textured diopside suggests that the matrix to the crater-fill deposit was originally molten and was rapidly cooled. This indicates that the impact event that generated Haughton caused fusion of the predominantly dolomitic target rocks. It appears that the Ca–Mg component of the dolomite may have dissociated, with Mg entering the silicate melt phase, while the Ca component formed a CaCO3-dominant melt. The silicates were derived by the fusion of Lower Paleozoic sandstones, siltstones, shales and impure dolomites. Evidence for melting is corroborated by a review of theoretical and experimental work, which shows that CaCO3 melts at >10 GPa and >2000 K, instead of dissociating to release CO2. This work indicates that carbonate-rich sedimentary targets may also undergo impact melting and that the volume of CO2 released into the atmosphere during such events may be considerably less than previously estimated.

Microbiology and Vegetation of Micro-oases and Polar Desert, Haughton Impact Crater, Devon Island, Nunavut, Canada

The input of nutrients into arctic polar deserts, aided by some physical processes, can result in localized areas of high biological productivity—“micro-oases.” We examined the vegetation cover, and microbial and nematode abundance in the polar desert and in 38 micro-oases at the Haughton impact crater, Devon Island, Arctic Canada. Our sites were split between the alluvial terraces along the banks of the Haughton River and the breccia deposits resulting from the asteroid or comet impact 22 Myr ago that flank the alluvial terraces. The alluvial terraces have a vegetation cover that ranges from 2 to 11% depending on substrate and water availability with a species richness of 5 in most locations. The vegetation cover on the breccia is much lower, between 0.02 and 3% depending on water availability. The micro-oases on both substrates support between 2 and 98% cover, but they are smaller and more sparsely distributed than similar features found in the Truelove Lowland, Devon Island, and on Bathurst Island. Microbial and nematode numbers were an order of magnitude greater inside the micro-oases compared to outside. Micro-oases are often dominated by a particular species, resulting in well-defined groups of micro-oases that were separated by TWINSPAN analysis. The micro-oases at Haughton Crater provide insights into the process of colonization of a substrate resulting from an asteroid or comet impact and the unique biological characteristics of such substrates.