121-617: The Gulf Islands is a group of islands in the Salish Sea between Vancouver Island and the mainland coast of British Columbia . The name "Gulf Islands" comes from " Gulf of Georgia ", the original term used by George Vancouver in his mapping of the southern part of the archipelago and which before the San Juan Island dispute also was taken to include what have since been called the San Juan Islands . While geopolitically divided,
242-476: A domain and kingdom of single-celled microorganisms . These microbes are prokaryotes , meaning they have no cell nucleus or any other membrane-bound organelles in their cells. Archaea were initially classified as bacteria , but this classification is outdated. Archaeal cells have unique properties separating them from the other two domains of life, Bacteria and Eukaryota . The Archaea are further divided into multiple recognized phyla . Classification
363-451: A "commuting" distance to an island that has enough resources to be sustainable. The presence of an island is marked by seabirds , differences in cloud and weather patterns, as well as changes in the direction of waves. It is also possible for human populations to have gone extinct on islands, evidenced by explorers finding islands that show evidence of habitation but no life. Not all islands were or are inhabited by maritime cultures. In
484-509: A "rafting event". This phenomenon is known as oceanic dispersal . Tropical storms have the capacity to transport species over great distances. Animals like tortoises can live for weeks without food or water, and are able to survive floating on debris in the sea. One case study showed that in 1995, fifteen iguanas survived a 300 km journey to Anguilla in the Caribbean , an island which no iguana had lived on previously. They survived floating on
605-443: A complement to the existing national park reserve. In most parts of Canada , olive trees cannot thrive; the long, harsh winter and short, humid summer and spring make it difficult for olives to grow comfortably and properly, but Pender Island , Saturna Island , and Salt Spring Island have a Mediterranean style climate that permits olive production. Banana Joe Clemente was one of the first Islanders to introduce olive trees to
726-491: A continent. Oceanic islands can be formed from volcanic activity, grow into atolls from coral reefs , and form from sediment along shorelines, creating barrier islands . River islands can also form from sediment and debris in rivers. Artificial islands are those made by humans, including small rocky outcroppings built out of lagoons and large-scale land reclamation projects used for development. Islands are host to diverse plant and animal life. Oceanic islands have
847-476: A cooperative association called endosymbiosis . The engulfed bacteria and the host cell then underwent coevolution, with the bacteria evolving into either mitochondria or hydrogenosomes . Another engulfment of cyanobacterial -like organisms led to the formation of chloroplasts in algae and plants. The history of life was that of the unicellular eukaryotes, prokaryotes and archaea until about 610 million years ago when multicellular organisms began to appear in
968-426: A detailed review of 1,288 islands found that they were home to 1,189 highly-threatened vertebrate species, which was 41 percent of the global figure. Coral bleaching is expected to occur with more frequency, threatening marine ecosystems, some of which island economies are dependent on. Some islands that are low-lying may cease to exist given high enough amounts of sea level rise. Tuvalu received media attention for
1089-609: A few meters high, and are usually temporary. Changes in the flow speed, water level, and sediment content of the river may effect the rate of fluvial island formation and depletion. Permanent river islands also exist, the largest of which (that is completely inland) is Bananal Island in the Tocantins of Brazil, which has a maximum width of 55 kilometers. Lakes form for a variety of reasons, including glaciers , plate tectonics, and volcanism. Lake islands can form as part of these processes. The field of insular biogeography studies
1210-510: A form of life or organic structures that interact with living organisms. They are considered by some to be a life form, because they carry genetic material, reproduce by creating multiple copies of themselves through self-assembly, and evolve through natural selection . However they lack key characteristics such as a cellular structure generally considered necessary to count as life. Because they possess some but not all such qualities, viruses have been described as replicators and as "organisms at
1331-668: A fundamental level, marine life affects the nature of the planet, and in part, shape and protect shorelines, and some marine organisms (e.g. corals ) even help create new land via accumulated reef -building. Marine life can be roughly grouped into autotrophs and heterotrophs according to their roles within the food web : the former include photosynthetic and the much rarer chemosynthetic organisms ( chemoautotrophs ) that can convert inorganic molecules into organic compounds using energy from sunlight or exothermic oxidation , such as cyanobacteria, iron-oxidizing bacteria , algae ( seaweeds and various microalgae ) and seagrass ;
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#17328371691951452-438: A hierarchy of nested groups—similar to a family tree. However, modern research has suggested that, due to horizontal gene transfer , this "tree of life" may be more complicated than a simple branching tree since some genes have spread independently between distantly related species. Past species have also left records of their evolutionary history. Fossils, along with the comparative anatomy of present-day organisms, constitute
1573-402: A higher carrying capacity also have more genetic diversity , which promotes speciation . Oceanic islands, ones that have never been connected to shore, are only populated by life that can cross the sea. This means that any animals present on the island had to have flown there, in the case of birds or bats , were carried by such animals, or were carried in a sea current in what is known as
1694-472: A loss of almost all the infrastructure in Dominica. Sea level rise and other climate changes can reduce freshwater reserves, resulting in droughts . These risks are expected to decrease the habitability of islands, especially small ones. Beyond risks to human life, plant and animal life are threatened. It has been estimated that almost 50 percent of land species threatened by extinction live on islands. In 2017,
1815-403: A mass of uprooted trees from a storm. Plant species are thought to be able to travel great distances of ocean. New Zealand and Australia share 200 native plant species, despite being separated by 1500 km. Continental islands, islands that were at one point connected to a continent, are expected to share a common history of plant and animal life up until the point that the island broke away from
1936-832: A minimum. Some islands became host to humans due to a land bridge or a continental island splitting from the mainland. Today, up to 10% of the world's population lives on islands. Islands are popular targets for tourism due to their perceived natural beauty, isolation, and unique cultures. Islands became the target of colonization by Europeans, resulting in the majority of islands in the Pacific being put under European control. Decolonization has resulted in some but not all island nations becoming self-governing , with lasting effects related to industrialisation , invasive species , nuclear weapons testing , and tourism . Islands and island countries are threatened by climate change . Sea level rise threatens to submerge nations such as Maldives ,
2057-743: A minority. Cultural attitudes related to communal ownership of land as well as a lack of individualistic decision-making may make some island cultures less compatible with the global capitalist economy, causing these nations to experience less economic growth. Islands have long been a popular target for tourism , thanks to their unique climates, cultures, and natural beauty. However, islands may suffer from poor transportation connectivity from airplanes and boats and strains on infrastructure from tourist activity. Islands in colder climates often rely on seasonal tourists seeking to enjoy nature or local cultures, and may only be one aspect of an island's economy. In contrast, tourism on tropical islands can often make up
2178-599: A permanent caisson , a steel or concrete structure built in a closed loop and then filled with sand. Some modern islands have been constructed by pouring millions of tons of sand into the sea, such as with Pearl Island in Qatar or the Palm Islands in Dubai. These islands are usually created for real estate development , and are sold for private ownership or construction of housing. Offshore oil platforms have also been described as
2299-524: A phenomenon where new oceanic crust is formed, pushing away older crust. Islands sitting on the continental shelf may be called continental islands. Other islands, like those that make up New Zealand , are what remains of continents that shrank and sunk beneath the sea. It was estimated that Zealandia , the continent-like area of crust that New Zealand sits on, has had 93% of its original surface area submerged. Some islands are formed when coral reefs grow on volcanic islands that have submerged beneath
2420-423: A press conference publicizing the ongoing submerging of the island country. Tuvalu signed a cooperation agreement with Australia agreeing to annually allow 280 of its citizens to become permanent residents of Australia. The Marshall Islands, a country of 1,156 islands, have also been identified as a country that may be existentially threatened by rising seas. Increasing intensity of tropical storms also increases
2541-483: A priority target of conservation efforts, to prevent the extinction of these species. Despite high levels of endemism, the total species richness , the total number of unique species in a region, is lower on islands than on mainlands. The level of species richness on islands is proportional to the area of that island, a phenomenon known as the species-area relationship . This is because larger areas have more resources and thus can support more organisms. Populations with
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#17328371691952662-411: A restricted set of natural resources. However, these nations control some of the largest fisheries in the world, deposits of copper , gold , and nickel , as well as oil deposits . The natural beauty of island nations also makes them a magnet for tourism . Islands also have geopolitical value for naval bases , weapons testing , and general territorial control. One such example is French Polynesia ,
2783-468: A selection pressure for smaller animals that require less food. Having fewer predators would mean these animals did not need not be large to survive. Charles Darwin formulated the theory of natural selection through the study of island ecology. The species he observed on the Galápagos Islands , including tanager birds, contributed to his understanding of how evolution works. He first traveled to
2904-509: A specific property known as adaptive radiation . In this process, a species that arrives on a group of islands rapidly becomes more diverse over time, splitting off into new species or subspecies. A species that reaches an island ecosystem may face little competition for resources, or may find that the resources that they found in their previous habitat are not available. These factors together result in individual evolutionary branches with different means of survival. The classical example of this
3025-414: A territory that receives substantial military expenditure and aid from France. Since the first discoveries of Polynesian, Micronesian , and other islands by Westerners, these nations have been the subject of colonization. Islands were the target of Christian missionaries . These missionaries faced resistance, but found success when some local chiefs used European support to centralize power. Beginning in
3146-514: A tree that is present in Australia, New Zealand, parts of South American, and New Guinea, places that today are geographically distant. A possible explanation for this phenomenon is that these landmasses were once all part of the continent Gondwana and separated by tectonic drift. However, there are competing theories that suggest this species may have reached faraway places by way of oceanic dispersal. Species that colonize island archipelagos exhibit
3267-603: A type of island. Some atolls have been covered in concrete to create artificial islands for military purposes, such as those created by China in the South China Sea . These atolls were previously low-tide elevations, landmasses that are only above water during low tide . The United Nations Convention on the Law of the Sea indicates that these islands may not have the same legal status as a naturally occurring island, and as such may not confer
3388-507: Is Darwin's finches , a group of up to fifteen tanager species that are endemic to the Galápagos Islands. These birds evolved different beaks in order to eat different kinds of food available on the islands. The large ground finch has a large bill used to crack seeds and eat fruit. The Genovesa cactus finch prefers cacti as a food source, and has a beak adapted for removing pulp and flowers from cacti. The green warbler-finch (in
3509-596: Is a unique feature in the Solar System . Earth's hydrosphere consists chiefly of the oceans but technically includes all water surfaces in the world, including inland seas, lakes, rivers, and underground waters down to a depth of 2,000 metres (6,600 ft). The deepest underwater location is Challenger Deep of the Mariana Trench in the Pacific Ocean , having a depth of 10,900 metres (6.8 mi). Conventionally,
3630-588: Is actually a cognate of Swedish ö and German Aue , and more distantly related to Latin aqua (water). The spelling of the word was modified in the 15th century because of a false etymology caused by an association with the Old French loanword isle , which itself comes from the Latin word insula . Islands often are found in archipelagos or island chains, which are collections of islands. These chains are thought to form from volcanic hotspots , areas of
3751-529: Is difficult because the majority have not been isolated in the laboratory and have only been detected by analysis of their nucleic acids in samples from their environment. Archaea and bacteria are generally similar in size and shape, although a few archaea have very strange shapes, such as the flat and square-shaped cells of Haloquadratum walsbyi . Despite this morphological similarity to bacteria, archaea possess genes and several metabolic pathways that are more closely related to those of eukaryotes, notably
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3872-447: Is diverse and still poorly understood, such as for the role of viruses in marine ecosystems. Most marine viruses are bacteriophages , which are harmless to plants and animals, but are essential to the regulation of saltwater and freshwater ecosystems. They infect and destroy bacteria in aquatic microbial communities, and are the most important mechanism of recycling carbon in the marine environment. The organic molecules released from
3993-530: Is found elsewhere in the Solar System. Europa , one of the moons orbiting Jupiter , is slightly smaller than the Earth's Moon . There is a strong possibility a large saltwater ocean exists beneath its ice surface. It has been estimated the outer crust of solid ice is about 10–30 km (6–19 mi) thick and the liquid ocean underneath is about 100 km (60 mi) deep. This would make Europa's ocean over twice
4114-439: Is no life without water. It has been described as the universal solvent for its ability to dissolve many substances, and as the solvent of life . Water is the only common substance to exist as a solid , liquid, and gas under conditions normal to life on Earth. The Nobel Prize winner Albert Szent-Györgyi referred to water as the mater und matrix : the mother and womb of life. The abundance of surface water on Earth
4235-519: Is studied scientifically in both marine biology and in biological oceanography . By volume, oceans provide about 90% of the living space on Earth , and served as the cradle of life and vital biotic sanctuaries throughout Earth's geological history . The earliest known life forms evolved as anaerobic prokaryotes ( archaea and bacteria ) in the Archean oceans around the deep sea hydrothermal vents , before photoautotrophs appeared and allowed
4356-399: Is that the complex biochemistry that makes up life came from simpler chemical reactions. The beginning of life may have included self-replicating molecules such as RNA and the assembly of simple cells. In 2016 scientists reported a set of 355 genes from the last universal common ancestor (LUCA) of all life , including microorganisms, living on Earth . Current species are a stage in
4477-497: Is the apple snail , initially introduced to the U.S. by aquarium owners. It has since been transported by hurricanes across the Gulf Coast and neighboring islands. These species compete for resources with native animals, and some may grow so densely that they displace other forms of existing life. For hundreds of years, islands have been created through land reclamation . One of the first recorded instances of this when people of
4598-628: Is the giant tortoise of the Seychelles , though it is unknown if it grew in size before or after reaching the island. Larger animals such as the hippopotamus tend to become smaller, such as in the case of the pygmy hippopotamus . This is known as insular dwarfism . In the case of smaller animals, it has been hypothesized that animals on islands may have fewer predators and competitors, resulting in selection pressure towards larger animals. Larger animals may exhaust food resources quickly due to their size, causing malnutrition in their young, resulting in
4719-529: The Atlantic Ocean in search of an alternate route to the East Indies . These historians theorize that successful explorers were rewarded with recognition and wealth, leading others to attempt possibly dangerous expeditions to discover more islands, usually with poor results. About 10% of the world's population lives on islands. The study of the culture of islands is known as island studies . The interest in
4840-714: The Eoarchean era after a geological crust started to solidify following the earlier molten Hadean Eon. Microbial mat fossils have been found in 3.48 billion-year-old sandstone in Western Australia . Other early physical evidence of a biogenic substance is graphite in 3.7 billion-year-old metasedimentary rocks discovered in Western Greenland as well as "remains of biotic life " found in 4.1 billion-year-old rocks in Western Australia. According to one of
4961-524: The Mariana Trench , the deepest spot in the Earth's oceans. Microorganisms live inside rocks 580 m (1,900 ft) below the sea floor under 2,590 m (8,500 ft) of ocean off the coast of the northwestern United States, as well as 2,400 m (7,900 ft; 1.5 mi) beneath the seabed off Japan. The greatest known temperature at which microbial life can exist is 122 °C (252 °F) ( Methanopyrus kandleri ). In 2014, scientists confirmed
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5082-569: The Marshall Islands , and Tuvalu completely. Increases in the frequency and intensity of tropical cyclones can cause widespread destruction of infrastructure and animal habitats. Species that live exclusively on islands are some of those most threatened by extinction . An island is an area of land surrounded by water on all sides that is distinct from a continent. There is no standard of size that distinguishes islands and continents . Continents have an accepted geological definition – they are
5203-655: The Neoproterozoic , and which culminated in a large evolutionary radiation event of mostly sessile macrofaunae known as the Avalon Explosion . This was followed in the early Phanerozoic by a more prominent radiation event known as the Cambrian Explosion , where actively moving eumetazoan became prevalent. These marine life also expanded into fresh waters , where fungi and green algae that were washed ashore onto riparian areas started to take hold later during
5324-566: The Ordivician before rapidly expanding inland during the Silurian and Devonian , paving the way for terrestrial ecosystems to develop. Today, marine species range in size from the microscopic phytoplankton , which can be as small as 0.02– micrometres ; to huge cetaceans like the blue whale , which can reach 33 m (108 ft) in length. Marine microorganisms have been variously estimated as constituting about 70% or about 90% of
5445-501: The Polynesians . Many of the previous island settlements required traveling distances of less than 100 km (62 mi), whereas Polynesians may have traveled 2,000–3,200 km (1,200–2,000 mi) to settle islands such as Tahiti . They would send navigators to sail the ocean without the aid of navigational instruments to discover new islands for settlement. Between 1100 and 800 BC, Polynesians sailed East from New Guinea and
5566-814: The Solomon Islands and reached the islands that make up the modern-day Fiji and Samoa . The furthest extent of this migration would be Easter Island in the East, and New Zealand in the South, with New Zealand's first settlements between 1250 and 1300. Historians have sought to understand why some remote islands have always been uninhabited, while others, especially in the Pacific Ocean , have long been populated by humans. Generally, larger islands are more likely to be able to sustain humans and thus are more likely to have been settled. Small islands that cannot sustain populations on their own can still be habitable if they are within
5687-493: The Solomon Islands created eighty such islands by piling coral and rock in the Lau Lagoon . One traditional way of constructing islands is with the use of a revetment . Sandbags or stones are dropped with a barge into the sea to bring the land level slightly out of the water. The island area is then filled with sand or gravel, followed by a construction of this revetment to hold it together. Islands have also been constructed with
5808-795: The enzymes involved in transcription and translation . Other aspects of archaeal biochemistry are unique, such as their reliance on ether lipids in their cell membranes , such as archaeols . Archaea use more energy sources than eukaryotes: these range from organic compounds , such as sugars, to ammonia , metal ions or even hydrogen gas . Salt-tolerant archaea (the Haloarchaea ) use sunlight as an energy source, and other species of archaea fix carbon ; however, unlike plants and cyanobacteria , no known species of archaea does both. Archaea reproduce asexually by binary fission , fragmentation , or budding ; unlike bacteria and eukaryotes, no known species forms spores . Archaea are particularly numerous in
5929-414: The lithosphere where the mantle is hotter than the surrounding area. These hotspots would give rise to volcanoes whose lava would form the rock the islands are made of. For some islands, the movement of tectonic plates above stationary hotspots would form islands in a linear chain, with the islands further away from the hotspot being progressively older and more eroded , before disappearing under
6050-748: The marine biomass . A microorganism , or microbe, is a microscopic organism too small to be recognised with the naked eye. It can be single-celled or multicellular . Microorganisms are diverse and include all bacteria and archaea , most protozoa such as algae , fungi , and certain microscopic animals such as rotifers . Many macroscopic animals and plants have microscopic juvenile stages . Some microbiologists also classify viruses (and viroids ) as microorganisms, but others consider these as nonliving. Microorganisms are crucial to nutrient recycling in ecosystems as they act as decomposers . Some microorganisms are pathogenic , causing disease and even death in plants and animals. As inhabitants of
6171-415: The microbial mats to expand into shallow water marine environments . The Great Oxygenation Event of the early Proterozoic significantly altered the marine chemistry , which likely caused a widespread anaerobe extinction event but also led to the evolution of eukaryotes through symbiogenesis between surviving anaerobes and aerobes . Complex life eventually arose out of marine eukaryotes during
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#17328371691956292-496: The scientific classification changed after the discovery in the 1990s that prokaryotes consist of two very different groups of organisms that evolved from an ancient common ancestor. These evolutionary domains are called Bacteria and Archaea . The ancestors of modern bacteria were unicellular microorganisms that were the first forms of life to appear on Earth, about 4 billion years ago. For about 3 billion years, most organisms were microscopic, and bacteria and archaea were
6413-450: The sea as a natural barrier to the introduction of new species, causing the species that do reach the island to evolve in isolation. Continental islands share animal and plant life with the continent they split from. Depending on how long ago the continental island formed, the life on that island may have diverged greatly from the mainland due to natural selection . Humans have lived on and traveled between islands for thousands of years at
6534-474: The thermophilic archaea, particularly the orders Sulfolobales and Thermoproteales . Viruses are an important natural means of transferring genes between different species, which increases genetic diversity and drives evolution. It is thought that viruses played a central role in the early evolution, before the diversification of bacteria, archaea and eukaryotes, at the time of the last universal common ancestor of life on Earth. Viruses are still one of
6655-522: The 16th century, European states placed most of Oceania in under colonial administration . Pohnpei was colonized by Spain as early as 1526. It changed hands from Germany to Japan to the United States before joining the Federated States of Micronesia in 1982, maintaining a "free association" status with the U.S. Guam was a Spanish territory until 1898, and now is a unincorporated territory of
6776-614: The DNA or RNA of viruses and are a useful means of investigating how they arise. Viruses are now recognised as ancient and as having origins that pre-date the divergence of life into the three domains . But the origins of viruses in the evolutionary history of life are unclear: some may have evolved from plasmids —pieces of DNA that can move between cells—while others may have evolved from bacteria. In evolution, viruses are an important means of horizontal gene transfer , which increases genetic diversity . Opinions differ on whether viruses are
6897-658: The Gulf Islands". The division of the Gulf Islands into two groups, the Southern and Northern Gulf Islands, is relatively common. The dividing line is approximately that formed by the city of Nanaimo on Vancouver Island, and the mouth of the Fraser River on the mainland. The islands of the Discovery Islands , Howe Sound , and Fraser River delta are not considered part of the Gulf Islands. The Southern Gulf Islands are near
7018-506: The Hawaiian islands being home to irrigated fields of taro, whereas in some islands, like Tahiti, breadfruit was more widely cultivated and fermented in order to preserve it. There is archeological evidence that Canary Islanders would chew the roots of ferns for sustenance, a practice that wore heavily on their molars . These islanders would also grow barley and raised livestock such as goats . Many island nations have little land and
7139-666: The Origin of Species . The first evidence of humans colonizing islands probably occurred in the Paleolithic era, 100,000 to 200,000 years ago. Reaching the Indonesian islands of Flores and Timor would have required crossing distances of water of at least 29 km (18 mi). Some islands, such as Honshu , were probably connected to the mainland with a land bridge that allowed humans to colonize it before it became an island. The first people to colonize distant oceanic islands were
7260-767: The San Juan Islands and Gulf Islands geologically form part of the larger Gulf Archipelago. Strictly speaking, the Strait of Georgia is only the wide, open waters of the main strait between the mainland and Vancouver Island , and does not officially refer to the adjoining waters between the islands and Vancouver Island but has become a common misnomer for the entire Gulf, which includes waters such as Active Pass (between Galiano Island and Mayne Island ), Trincomali Channel (between Galiano Island and Saltspring Island ), Sansum Narrows (between Saltspring Island and Vancouver Island), and Malaspina Strait (between Texada Island and
7381-612: The Southern Gulf Islands in 1993 growing dozens from seed. In 1994/1995, planting a grove of the seed-grown olive trees around a Botchi pit on Salt Spring Island. He also distributed them to Islanders for their private gardens. Banana Joe is also responsible for introducing Musa basjoo , a hardy species of Banana plant to Salt Spring Island. Farm owner Andrew Butt planted his first olive tree in 2001 at his farm on Pender Island, using Frantoio and Leccino cultivars that he obtained from California . He uses kelp obtained from
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#17328371691957502-448: The Strait of Georgia, the Strait of Juan de Fuca , Puget Sound , and all connecting and adjoining waters. According to BC Geographical Names (BCGNIS) the name "Gulf Islands" was originally intended and commonly understood to refer to the archipelago at the southern end of the Strait of Georgia; from Gabriola Island in the north to Saturna Island in the southeast and D'Arcy Island in
7623-481: The U.S. The decolonization era saw many island states achieve independence or some form of self-governance . Nuclear weapons testing on the Marshall Islands left many atolls destroyed or uninhabitable, causing the forced displacement of people from their home islands as well as increases in cancer rates due to radiation . Colonization has resulted in a decline of observance of traditional cultural practices in places such as Hawaii, where Native Hawaiians are now
7744-527: The accumulation of oxygen in the atmosphere from photosynthesis. About 500 million years ago, plants and fungi started colonising the land. Evidence for the appearance of the first land plants occurs in the Ordovician , around 450 million years ago , in the form of fossil spores. Land plants began to diversify in the Late Silurian , from around 430 million years ago . The colonisation of
7865-694: The archaeal/eukaryotic lineage. Bacteria were also involved in the second great evolutionary divergence, that of the archaea and eukaryotes. Here, eukaryotes resulted from the entering of ancient bacteria into endosymbiotic associations with the ancestors of eukaryotic cells, which were themselves possibly related to the Archaea . This involved the engulfment by proto-eukaryotic cells of alphaproteobacterial symbionts to form either mitochondria or hydrogenosomes , which are still found in all known Eukarya. Later on, some eukaryotes that already contained mitochondria also engulfed cyanobacterial-like organisms. This led to
7986-402: The average virus is about one one-hundredth that of the average bacterium . Most viruses cannot be seen with an optical microscope so electron microscopes are used instead. Viruses are found wherever there is life and have probably existed since living cells first evolved. The origin of viruses is unclear because they do not form fossils, so molecular techniques have been used to compare
8107-406: The continent. For example, the presence of freshwater fish on an island surrounded by ocean would indicate that it once was attached to a continent, since these fish cannot traverse the ocean on their own. Over the course of time, evolution and extinction changes the nature of animal life on a continental island, but only once it splits from the mainland. An example is that of the southern beech ,
8228-594: The dead bacterial cells stimulate fresh bacterial and algal growth. Viral activity may also contribute to the biological pump , the process whereby carbon is sequestered in the deep ocean. A stream of airborne microorganisms circles the planet above weather systems but below commercial air lanes. Some peripatetic microorganisms are swept up from terrestrial dust storms, but most originate from marine microorganisms in sea spray . In 2018, scientists reported that hundreds of millions of viruses and tens of millions of bacteria are deposited daily on every square meter around
8349-450: The deep portions of Earth's crust . Bacteria also live in symbiotic and parasitic relationships with plants and animals. Once regarded as plants constituting the class Schizomycetes , bacteria are now classified as prokaryotes . Unlike cells of animals and other eukaryotes , bacterial cells do not contain a nucleus and rarely harbour membrane-bound organelles . Although the term bacteria traditionally included all prokaryotes,
8470-451: The deposition of sediment by waves . These islands erode and grow as the wind and waves shift. Barrier islands have the effect of protecting coastal areas from severe weather because they absorb some of the energy of large waves before they can reach the shore. A fluvial island is an island that forms from the erosion and sedimentation of debris in rivers; almost all rivers have some form of fluvial islands. These islands may only be
8591-426: The distances and frequency with which invasive species may be transported to islands. Floodwaters from these storms may also wash plants further inland than they would travel on their own, introducing them to new habitats. Agriculture and trade also have introduced non-native life to islands. These processes result in an introduction of invasive species to ecosystems that are especially small and fragile. One example
8712-410: The dominant forms of life. Although bacterial fossils exist, such as stromatolites , their lack of distinctive morphology prevents them from being used to examine the history of bacterial evolution, or to date the time of origin of a particular bacterial species. However, gene sequences can be used to reconstruct the bacterial phylogeny , and these studies indicate that bacteria diverged first from
8833-400: The ecological processes that take place on islands, with a focus on what factors effect the evolution , extinction , and richness of species. Scientists often study islands as an isolated model of how the process of natural selection takes place. Island ecology studies organisms on islands and their environment. It has yielded important insights for its parent field of ecology since
8954-530: The ecosystem endangered . Since then, GOERT has been working to motivate public and private restoration of the rare ecosystem and promote conservation activities. [1] The unique ecosystem of the islands has been a focal point of conservation efforts for decades. BC Parks operates a variety of provincial parks on the islands, the oldest being Mount Maxwell Provincial Park on Salt Spring Island . In 2003, Parks Canada established Gulf Islands National Park Reserve to protect ecologically important regions of
9075-399: The edge of life". Bacteriophages , often just called phages , are viruses that parasite bacteria and archaea. Marine phages parasite marine bacteria and archaea, such as cyanobacteria . They are a common and diverse group of viruses and are the most abundant biological entity in marine environments, because their hosts, bacteria, are typically the numerically dominant cellular life in
9196-506: The emergence of these first multicellular organisms, a remarkable amount of biological diversity appeared over a span of about 10 million years, in an event called the Cambrian explosion . Here, the majority of types of modern animals appeared in the fossil record, as well as unique lineages that subsequently became extinct. Various triggers for the Cambrian explosion have been proposed, including
9317-463: The evolution of these large animals, smaller organisms similar to the types that evolved early in this process continue to be highly successful and dominate the Earth, with the majority of both biomass and species being prokaryotes. Estimates on the number of Earth's current species range from 10 million to 14 million, of which about 1.2 million have been documented and over 86 percent have not yet been described. Microorganisms make up about 70% of
9438-546: The existence of microorganisms living 800 m (2,600 ft) below the ice of Antarctica . According to one researcher, "You can find microbes everywhere — they're extremely adaptable to conditions, and survive wherever they are." Viruses are small infectious agents that do not have their own metabolism and can replicate only inside the living cells of other organisms . Viruses can infect all types of life forms , from animals and plants to microorganisms , including bacteria and archaea . The linear size of
9559-468: The few areas where they differ helps shed light on when the common ancestor of these species existed. Prokaryotes inhabited the Earth from approximately 3–4 billion years ago. No obvious changes in morphology or cellular organisation occurred in these organisms over the next few billion years. The eukaryotic cells emerged between 1.6 and 2.7 billion years ago. The next major change in cell structure came when bacteria were engulfed by eukaryotic cells, in
9680-481: The formation of chloroplasts in algae and plants. There are also some algae that originated from even later endosymbiotic events. Here, eukaryotes engulfed a eukaryotic algae that developed into a "second-generation" plastid. This is known as secondary endosymbiosis . The largest known bacterium, the marine Thiomargarita namibiensis , can be visible to the naked eye and sometimes attains 0.75 mm (750 μm). The archaea (Greek for ancient ) constitute
9801-498: The habit of true warbler species) consumes spiders and insects that live on plants. Other examples of this phenomenon exist worldwide, including in Hawaii and Madagascar, and are not limited to island ecosystems. Species endemic to islands show a common evolutionary trajectory. Foster's rule (also known as the island rule), states that small mammals such as rodents evolve to become larger, known as island gigantism . One such example
9922-454: The islands as a naturalist on HMS Beagle in 1835, as part of a five-year circumnavigation of Earth. He wrote that "the different islands to a considerable extent are inhabited by a different set of beings". Through the study of the finches and other animals he realized that organisms survive by changing to adapt to their habitat. It would be over twenty years before he published his theories in On
10043-480: The land by plants was soon followed by arthropods and other animals. Insects were particularly successful and even today make up the majority of animal species. Amphibians first appeared around 364 million years ago, followed by early amniotes and birds around 155 million years ago (both from " reptile "-like lineages), mammals around 129 million years ago, homininae around 10 million years ago and modern humans around 250,000 years ago. However, despite
10164-643: The largest landmass of a particular tectonic plate . Islands can occur in any body of water, including lakes , rivers , seas . Low-tide elevations , areas of land that are not above the surface during a high tide , are generally not considered islands. Islands that have been bridged or otherwise joined to a mainland with land reclamation are sometimes considered "de-islanded", but not in every case. The word island derives from Middle English iland , from Old English igland (from ig or ieg , similarly meaning 'island' when used independently, and -land carrying its contemporary meaning. Old English ieg
10285-527: The largest environment on Earth, microbial marine systems drive changes in every global system. Microbes are responsible for virtually all the photosynthesis that occurs in the ocean, as well as the cycling of carbon , nitrogen , phosphorus , other nutrients and trace elements. Viruses [REDACTED] Bacteria [REDACTED] Archaea [REDACTED] Protists [REDACTED] Microfungi [REDACTED] Microanimals [REDACTED] Microscopic life undersea
10406-442: The largest reservoirs of unexplored genetic diversity on Earth. Bacteria constitute a large domain of prokaryotic microorganisms . Typically a few micrometres in length, bacteria have a number of shapes, ranging from spheres to rods and spirals. Bacteria were among the first life forms to appear on Earth , and are present in most of its habitats . Bacteria inhabit soil, water, acidic hot springs , radioactive waste , and
10527-604: The last remaining pockets of Garry oak ecosystems . Only about five percent of Garry oak ecosystems remain in their natural state, landing 91 of the approximately 350 species it supports on the province's list of species at risk . The unique Mediterranean characteristics of the islands' climate supports the Garry oak ecosystem. Garry oak ecosystems are home to more plant species, such as the camas , than any other terrestrial ecosystem in coastal B.C. and are one of Canada's most at-risk natural habitats . Today, Garry oak meadows exist in
10648-453: The latter include all that are not considered vertebrates . Generally, marine vertebrates are much more nektonic and metabolically demanding of oxygen and nutrients, often suffering distress or even mass dyings (a.k.a. " fish kills ") during anoxic events , while marine invertebrates are a lot more hypoxia -tolerant and exhibit a wide range of morphological and physiological modifications to survive in poorly oxygenated waters . There
10769-427: The latter include all the rest that must feed on other organisms to acquire nutrients and energy, which include animals, fungi, protists and non-photosynthetic microorganisms. Marine animals are further informally divided into marine vertebrates and marine invertebrates , both of which are polyphyletic groupings with the former including all saltwater fish , marine mammals , marine reptiles and seabirds , and
10890-460: The mainland around Powell River ). "The Gulf" refers to all such waters collectively, and to those communities and shores surrounding it. Only the term "Strait of Georgia" remains in the provincial gazette although its use as a synonym for the Gulf is unofficial, while the term Gulf of Georgia remains in current use though not in the provincial gazette. The term Salish Sea was adopted in 2010 to refer to
11011-404: The mainland, they had no need for boats. The motivation for island exploration has been the subject of research and debate. Some early historians previously argued that early island colonization was unintentional, perhaps by a raft being swept out to sea. Others compare the motivations of Polynesian and similar explorers with those of Christopher Columbus , the explorer who sailed westward over
11132-451: The major cities of Nanaimo and Victoria on Vancouver Island as well as Vancouver on the mainland. None of the islands are linked to another island by bridge, the exception being Pender Island which was artificially divided into two by a canal dug in 1903. Various proposals have been made to link one or more of the islands to another island, or with the mainland coast of the province, without success. Challenges include high capital costs,
11253-589: The majority of the local economy and built environment . These islands sometimes also require consistent foreign aid on top of tourism in order to ensure economic growth. This reliance can result in social inequality and environmental degradation . During tourism downturns, these economies struggle to make up the lost inflow of cash with other industries. Climate change threatens human development on islands due to sea level rise , more dangerous tropical cyclones , coral bleaching , and an increase in invasive species . For example, in 2017 Hurricane Maria caused
11374-633: The marine biomass. It is estimated viruses kill 20% of this biomass each day and that there are 15 times as many viruses in the oceans as there are bacteria and archaea. Viruses are the main agents responsible for the rapid destruction of harmful algal blooms , which often kill other marine life. The number of viruses in the oceans decreases further offshore and deeper into the water, where there are fewer host organisms. There are also archaeal viruses which replicate within archaea : these are double-stranded DNA viruses with unusual and sometimes unique shapes. These viruses have been studied in most detail in
11495-492: The morphological, or anatomical, record. By comparing the anatomies of both modern and extinct species, paleontologists can infer the lineages of those species. However, this approach is most successful for organisms that had hard body parts, such as shells, bones or teeth. Further, as prokaryotes such as bacteria and archaea share a limited set of common morphologies, their fossils do not provide information on their ancestry. More recently, evidence for common descent has come from
11616-402: The northern end of the Strait of Georgia , including all islands south of Savary Island , the southernmost island of the neighbouring Discovery Islands . The major Northern Gulf Islands are as follows: The islands and surrounding ocean are rich with ecologically diverse plants and sea life including Garry oaks , wild lilies, kelp beds and Orcas . The Gulf Islands are home to one of
11737-547: The oceanic temperature distribution can cause significant weather shifts, such as the El Niño-Southern Oscillation . Altogether the ocean occupies 71 percent of the world surface, averaging nearly 3.7 kilometres (2.3 mi) in depth. By volume, the ocean provides about 90 percent of the living space on the planet. The science fiction writer Arthur C. Clarke has pointed out it would be more appropriate to refer to planet Earth as planet Ocean. However, water
11858-493: The oceans in the Ediacaran period. The evolution of multicellularity occurred in multiple independent events, in organisms as diverse as sponges , brown algae , cyanobacteria , slime moulds and myxobacteria . In 2016 scientists reported that, about 800 million years ago, a minor genetic change in a single molecule called GK-PID may have allowed organisms to go from a single cell organism to one of many cells. Soon after
11979-515: The past, some societies were found to have lost their seafaring ability over time, such as the case of the Canary Islands , which were occupied by an indigenous people since the island's first discovery in the first century until being conquered by the Spanish Empire in 1496. It has been hypothesized that since the inhabitants had little incentive for trade and had little to any contact with
12100-403: The planet is divided into five separate oceans, but these oceans all connect into a single world ocean . The mass of this world ocean is 1.35 × 10 metric tons or about 1/4400 of Earth's total mass. The world ocean covers an area of 3.618 × 10 km with a mean depth of 3682 m , resulting in an estimated volume of 1.332 × 10 km . If all of Earth's crustal surface was at
12221-443: The planet. Microscopic organisms live throughout the biosphere . The mass of prokaryote microorganisms — which includes bacteria and archaea, but not the nucleated eukaryote microorganisms — may be as much as 0.8 trillion tons of carbon (of the total biosphere mass , estimated at between 1 and 4 trillion tons). Single-celled barophilic marine microbes have been found at a depth of 10,900 m (35,800 ft) in
12342-456: The presence of ecologically sensitive ecosystems, the mountainous terrain of the islands, impracticality due to the low population of the islands, and opposition from locals. Island An island or isle is a piece of land, distinct from a continent, completely surrounded by water. There are continental islands, which were formed by being split from a continent by plate tectonics , and oceanic islands, which have never been part of
12463-569: The process of evolution, with their diversity the product of a long series of speciation and extinction events. The common descent of organisms was first deduced from four simple facts about organisms: First, they have geographic distributions that cannot be explained by local adaptation. Second, the diversity of life is not a set of unique organisms, but organisms that share morphological similarities . Third, vestigial traits with no clear purpose resemble functional ancestral traits and finally, that organisms can be classified using these similarities into
12584-424: The researchers, "If life arose relatively quickly on Earth … then it could be common in the universe ." All organisms on Earth are descended from a common ancestor or ancestral gene pool . Highly energetic chemistry is thought to have produced a self-replicating molecule around 4 billion years ago, and half a billion years later the last common ancestor of all life existed. The current scientific consensus
12705-424: The salt in the ocean comes from the weathering and erosion of rocks on land. Some salts are released from volcanic activity or extracted from cool igneous rocks . The oceans are also a reservoir of dissolved atmospheric gases, which are essential for the survival of many aquatic life forms. Sea water has an important influence on the world's climate, with the oceans acting as a large heat reservoir . Shifts in
12826-428: The same elevation as a smooth sphere, the depth of the resulting world ocean would be about 2.7 kilometres (1.7 mi). About 97.5% of the water on Earth is saline ; the remaining 2.5% is fresh water . Most fresh water – about 69% – is present as ice in ice caps and glaciers . The average salinity of Earth's oceans is about 35 grams (1.2 oz) of salt per kilogram of seawater (3.5% salt). Most of
12947-673: The same legal rights. Sea life Marine life , sea life or ocean life is the collective ecological communities that encompass all aquatic animals , plants , algae , fungi , protists , single-celled microorganisms and associated viruses living in the saline water of marine habitats , either the sea water of marginal seas and oceans , or the brackish water of coastal wetlands , lagoons , estuaries and inland seas . As of 2023 , more than 242,000 marine species have been documented, and perhaps two million marine species are yet to be documented. An average of 2,332 new species per year are being described. Marine life
13068-775: The sea entirely. An example is the Hawaiian Islands , with the oldest island being 25 million years old, and the youngest, Hawaii , still being an active volcano . However, not all island chains are formed this way. Some may be formed all at once by fractures in the tectonic plates themselves, simultaneously creating multiple islands. One supporting piece of evidence is that of the Line Islands , which are all estimated to be 8 million years old, rather than being different ages. Other island chains form due to being separated from existing continents. The Japanese archipelago may have been separated from Eurasia due to seafloor spreading ,
13189-541: The sea. Generally there are about 1 million to 10 million viruses in each mL of seawater, or about ten times more double-stranded DNA viruses than there are cellular organisms, although estimates of viral abundance in seawater can vary over a wide range. Tailed bacteriophages appear to dominate marine ecosystems in number and diversity of organisms. Bacteriophages belonging to the families Corticoviridae , Inoviridae and Microviridae are also known to infect diverse marine bacteria. Microorganisms make up about 70% of
13310-616: The shallow and exposed soil of valleys , rocky foothills and southern slopes —areas that the settlers of the past 150 years have found unsuitable for agriculture or development . The Garry Oak Ecosystems Recovery Team (GOERT), a partnership of a number of governmental and non-governmental agencies that comprise 22 individuals, was established in 1999 after the delegates of the First International Garry Oak Ecosystem Symposium met in Victoria and declared
13431-526: The southeastern Gulf Islands. As a National Park Reserve , the long-term goal is to protect most of the southeastern Gulf Islands. In 2012, Parks Canada published a feasibility Study for the proposed Southern Strait of Georgia National Marine Conservation Area Reserve. The goal of the National Marine Conservation Area is to protect ecologically significant marine habitats and ensure sustainable use of marine resources. It would also serve as
13552-499: The southern end of the Strait of Georgia , forming an intricate network of waterways between them, collectively referred to as part of the Salish Sea . The Southern Gulf Islands include hundreds of islands and islets, and form part of a larger archipelago that also includes the nearby San Juan Islands of the state of Washington in the United States . The major Southern Gulf Islands are: The Northern Gulf Islands are located near
13673-419: The southwest. During the 1990s, however, the name began to be applied to all the islands in the Strait of Georgia, resulting in the introduction of the term "Southern Gulf Islands", which BCGNIS calls a misnomer, to distinguish the original "Gulf Islands" from the rest, which are sometimes called the "Northern Gulf Islands". BCGNIS further notes that Quadra Island is increasingly described as the "northernmost of
13794-461: The study of biochemical similarities between organisms. For example, all living cells use the same basic set of nucleotides and amino acids . The development of molecular genetics has revealed the record of evolution left in organisms' genomes: dating when species diverged through the molecular clock produced by mutations. For example, these DNA sequence comparisons have revealed that humans and chimpanzees share 98% of their genomes and analysing
13915-549: The study of islands is due to their unique cultures and natural environments that differ from mainland cultures. This is for a few reasons: First, the obvious political and geographic isolation from mainland cultures. Second, unique restraints on resources and ecology creating marine-focused cultures with a focus on fishing and sailing. Third, a lasting historical and political significance of islands. The Polynesian diet got most of its protein from fishing. Polynesians were known to fish close to shore, as well as in deep water. It
14036-450: The surface. When these coral islands encircle a central lagoon , the island is known as an atoll . The formation of reefs and islands related to those reefs is aided by the buildup of sediment in shallow patches of water. In some cases, tectonic movements lifting a reef out of the water by as little as 1 meter can cause sediment to accumulate and an island to form. Barrier islands are long, sandy bars that form along shorelines due to
14157-406: The surrounding straits as fertilizer and uses a pruning method that enhances the sunlight exposure on the trees. Michael Pierce and colleagues established an olive tree nursery on Saturna Island in 2009 that supplied olive trees to the region. The larger populated islands are served by BC Ferries , which operates various vehicle and passenger ferries between the Gulf Islands and to terminals near
14278-438: The time of Charles Darwin . In biology, endemism is defined as the phenomenon where species or genus is only found in a certain geographical area. Islands isolate land organisms from others with water, and isolate aquatic organisms living on them with land. Island ecosystems have the highest rates of endemism globally. This means that islands contribute heavily to global biodiversity . Areas with high lives of biodiversity are
14399-483: The total marine biomass . Marine primary producers , mainly cyanobacteria and chloroplastic algae , produce oxygen and sequester carbon via photosynthesis , which generate enormous biomass and significantly influence the atmospheric chemistry . Migratory species, such as oceanodromous and anadromous fish , also create biomass and biological energy transfer between different regions of Earth, with many serving as keystone species of various ecosystems. At
14520-524: The volume of the Earth's ocean. There has been speculation Europa's ocean could support life , and could be capable of supporting multicellular microorganisms if hydrothermal vents are active on the ocean floor. Enceladus , a small icy moon of Saturn, also has what appears to be an underground ocean which actively vents warm water from the moon's surface. The Earth is about 4.54 billion years old. The earliest undisputed evidence of life on Earth dates from at least 3.5 billion years ago, during
14641-470: Was reported that Rapa Nui people were known to fish as far as 500 km (310 mi) from shore at coral reefs. Spear , line , and net fishing were all used, to catch tuna as well as sharks and stingrays . Island cultures also cultivate native and non-native crops. Polynesians grew the native yam , taro , breadfruit , banana , coconut and other fruits and vegetables. Different island climates made different resources more important, such as
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