Insular dwarfism

Insular dwarfism

Overview
Insular dwarfism, a form of phyletic dwarfism, is the process and condition of the reduction in size of large animals – typically mammal
Mammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...

s – when their population's range is limited to a small environment, primarily islands. This natural process is distinct from the intentional creation of dwarf breeds, called dwarfing
Dwarfing
Dwarfing is a characteristic in plants and animals whereby one or more members of a breed or cultivar are significantly smaller than standard members of their species...

. This process has occurred many times throughout evolutionary history, with examples including dinosaur
Dinosaur
Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...

s, like Europasaurus
Europasaurus
Europasaurus is a basal macronarian sauropod, a form of quadrupedal herbivorous dinosaur. It lived during the Late Jurassic of northern Germany, and has been identified as an example of insular dwarfism resulting from the isolation of a sauropod population on an island within the Lower Saxony...

, and modern animals such as elephants and their relatives.
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Encyclopedia
Insular dwarfism, a form of phyletic dwarfism, is the process and condition of the reduction in size of large animals – typically mammal
Mammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...

s – when their population's range is limited to a small environment, primarily islands. This natural process is distinct from the intentional creation of dwarf breeds, called dwarfing
Dwarfing
Dwarfing is a characteristic in plants and animals whereby one or more members of a breed or cultivar are significantly smaller than standard members of their species...

. This process has occurred many times throughout evolutionary history, with examples including dinosaur
Dinosaur
Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...

s, like Europasaurus
Europasaurus
Europasaurus is a basal macronarian sauropod, a form of quadrupedal herbivorous dinosaur. It lived during the Late Jurassic of northern Germany, and has been identified as an example of insular dwarfism resulting from the isolation of a sauropod population on an island within the Lower Saxony...

, and modern animals such as elephants and their relatives. Insular dwarfism is one aspect of the more general "island rule", which posits that when mainland animals colonize islands, small species tend to evolve larger bodies, and large species tend to evolve smaller bodies.

There are several proposed explanations for the mechanism which produces such dwarfism. One is a selective process where only smaller animals trapped on the island survive, as food periodically declines to a borderline level. The smaller animals need fewer resources and smaller territories, and so are more likely to get past the break-point where population decline allows food sources to replenish enough for the survivors to flourish. Smaller size is also advantageous from a reproductive standpoint, as it entails shorter gestation period
Gestation period
For mammals the gestation period is the time in which a fetus develops, beginning with fertilization and ending at birth. The duration of this period varies between species.-Duration:...

s and generation times. In the tropics, small size should make thermoregulation
Thermoregulation
Thermoregulation is the ability of an organism to keep its body temperature within certain boundaries, even when the surrounding temperature is very different...

 easier. Among herbivores, large size confers advantages in coping with both competitors and predators, so a reduction or absence of either would facilitate dwarfing; competition appears to be the more important factor. Among carnivores, the main factor appears to be the size and availability of prey resources, and competition appears to be less important. In tiger snakes, insular dwarfism appears associated with restriction of available prey to smaller sizes than are normally taken by mainland snakes. Since prey size preference in snakes is generally proportional to body size, small snakes may be better adapted to take small prey. For both herbivores and carnivores, island size, the degree of island isolation and the size of the ancestral continental species appear not to be of major direct importance.

This process, and other "island genetics" artifacts, can occur not only on traditional islands, but also in other situations where an ecosystem is isolated from external resources and breeding. This can include caves, desert oases, isolated valleys and isolated mountains ("sky island
Sky island
Sky islands are mountains that are isolated by surrounding lowlands of a dramatically different environment, a situation which, in combination with the altitudinal zonation of ecosystems, has significant implications for natural habitats. Endemism, vertical migration, and relict populations are...

s").

There is also an inverse process, island gigantism
Island gigantism
Island gigantism or insular giantism is a biological phenomenon in which the size of animals isolated on an island increases dramatically in comparison to their mainland relatives....

, wherein small animals breeding on isolated islands lacking the predators of large land masses may become much larger than normal. An excellent example is the dodo
Dodo
The dodo was a flightless bird endemic to the Indian Ocean island of Mauritius. Related to pigeons and doves, it stood about a meter tall, weighing about , living on fruit, and nesting on the ground....

, the ancestors of which were normal-sized pigeons. There are also several species of giant rats
Papagomys
Papagomys is a genus of very large rats in the tribe Rattini of the subfamily Murinae. It contains two species, which are known only from the Indonesian island of Flores:*Flores Giant Rat Papagomys armandvillei...

, one still extant, that coexisted with both Homo floresiensis and the dwarf stegodons on Flores.

Famous examples



Among the most famous examples of insular dwarfism are:
  • Dinosaur
    Dinosaur
    Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...

    s, including the recently validated Europasaurus
    Europasaurus
    Europasaurus is a basal macronarian sauropod, a form of quadrupedal herbivorous dinosaur. It lived during the Late Jurassic of northern Germany, and has been identified as an example of insular dwarfism resulting from the isolation of a sauropod population on an island within the Lower Saxony...

    , on Mesozoic
    Mesozoic
    The Mesozoic era is an interval of geological time from about 250 million years ago to about 65 million years ago. It is often referred to as the age of reptiles because reptiles, namely dinosaurs, were the dominant terrestrial and marine vertebrates of the time...

     islands such as Haţeg Island
    Hateg Island
    Hațeg Island was a large offshore island in the Tethys Sea during the Cretaceous period. It was situated in an area corresponding to the region around modern-day Hațeg, Romania...

    , Romania
    Romania
    Romania is a country located at the crossroads of Central and Southeastern Europe, on the Lower Danube, within and outside the Carpathian arch, bordering on the Black Sea...

    . Other dwarf dinosaurs, mainly from Haţeg Island, include Magyarosaurus
    Magyarosaurus
    Magyarosaurus is a genus of dwarf sauropod dinosaur from late Cretaceous Period in what is now Romania. It is one of the smallest-known adult sauropods, measuring only six meters in length. The type species is Magyarosaurus dacus...

    , Rhabdodon
    Rhabdodon
    Rhabdodon is a genus of dinosaur that lived in Europe approximately 70 million years ago in the Late Cretaceous. It is unclear whether it was an iguanodont or a hypsilophodont, and may be a "missing link" between the two. Current evidence indicates it is an iguanodont similar to Tenontosaurus...

    , Balaur bondoc and Telmatosaurus
    Telmatosaurus
    Telmatosaurus is a genus of basal hadrosaurid dinosaur from the Late Cretaceous. It was a relatively small hadrosaur, approximately five meters long, found in what is now Romania....

    . Also, the dwarf nodosaurid
    Nodosaurus
    Nodosaurus was a genus of herbivorous ankylosaurian dinosaur from the Late Cretaceous, the fossils of which are found in North America. Two incomplete specimens have been discovered in Wyoming and Kansas, and no skulls...

     Struthiosaurus
    Struthiosaurus
    Struthiosaurus is one of the smallest known and most basal genera of nodosaurid dinosaurs, from the Late Cretaceous period of Austria, Romania and France in Europe. It was protected by body armour...

    from Europe
    Europe
    Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

    .
  • Dwarf ground sloths
    Pilosans of the Caribbean
    The mammalian order Pilosa, which includes the sloths and anteaters, includes various species from the Caribbean region. Many species of sloths are known from the Greater Antilles, all of which went extinct over the last millennia, but some sloths and anteaters survive on islands closer to the...

     in the recent natural history of Cuba
    Cuba
    The Republic of Cuba is an island nation in the Caribbean. The nation of Cuba consists of the main island of Cuba, the Isla de la Juventud, and several archipelagos. Havana is the largest city in Cuba and the country's capital. Santiago de Cuba is the second largest city...

    , Hispaniola
    Hispaniola
    Hispaniola is a major island in the Caribbean, containing the two sovereign states of the Dominican Republic and Haiti. The island is located between the islands of Cuba to the west and Puerto Rico to the east, within the hurricane belt...

    , and Puerto Rico
    Puerto Rico
    Puerto Rico , officially the Commonwealth of Puerto Rico , is an unincorporated territory of the United States, located in the northeastern Caribbean, east of the Dominican Republic and west of both the United States Virgin Islands and the British Virgin Islands.Puerto Rico comprises an...

    . (There is also a living dwarf tree sloth
    Pygmy Three-toed Sloth
    The Pygmy Three-toed Sloth is a three-toed sloth. It is endemic to Isla Escudo de Veraguas, an island off the coast of Panama, which separated from the mainland nearly 8900 years ago. The species is thought to have originated from isolation of individuals from the mainland population of Bradypus...

     on Isla Escudo de Veraguas
    Isla Escudo de Veraguas
    Isla Escudo de Veraguas is a small isolated Caribbean island of the Republic of Panama. Despite its name, it is not part of the province of Veraguas, but rather Bocas del Toro...

    .)
  • The Channel Islands Mammoth which lived on the prehistoric island of Santa Rosae
    Santa Rosae
    Santa Rosae was an ancient landmass off the coast of present-day southern California, near Ventura County and Santa Barbara County, of which the northern Channel Islands of California are remnants....

     in the California Channel Islands, and the small woolly mammoth
    Woolly mammoth
    The woolly mammoth , also called the tundra mammoth, is a species of mammoth. This animal is known from bones and frozen carcasses from northern North America and northern Eurasia with the best preserved carcasses in Siberia...

    s of Saint Paul Island off Alaska
    Alaska
    Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...

    , and Wrangel Island
    Wrangel Island
    Wrangel Island is an island in the Arctic Ocean, between the Chukchi Sea and East Siberian Sea. Wrangel Island lies astride the 180° meridian. The International Date Line is displaced eastwards at this latitude to avoid the island as well as the Chukchi Peninsula on the Russian mainland...

     north of Siberia
    Siberia
    Siberia is an extensive region constituting almost all of Northern Asia. Comprising the central and eastern portion of the Russian Federation, it was part of the Soviet Union from its beginning, as its predecessor states, the Tsardom of Russia and the Russian Empire, conquered it during the 16th...

    .
  • Dwarf elephant
    Dwarf elephant
    Dwarf elephants are prehistoric members of the order Proboscidea, that, through the process of allopatric speciation, evolved to a fraction of the size of their immediate ancestors...

    s in the recent natural history of Malta
    Malta
    Malta , officially known as the Republic of Malta , is a Southern European country consisting of an archipelago situated in the centre of the Mediterranean, south of Sicily, east of Tunisia and north of Libya, with Gibraltar to the west and Alexandria to the east.Malta covers just over in...

    , Crete
    Crete
    Crete is the largest and most populous of the Greek islands, the fifth largest island in the Mediterranean Sea, and one of the thirteen administrative regions of Greece. It forms a significant part of the economy and cultural heritage of Greece while retaining its own local cultural traits...

    , Cyprus
    Cyprus
    Cyprus , officially the Republic of Cyprus , is a Eurasian island country, member of the European Union, in the Eastern Mediterranean, east of Greece, south of Turkey, west of Syria and north of Egypt. It is the third largest island in the Mediterranean Sea.The earliest known human activity on the...

    , and Sicily
    Sicily
    Sicily is a region of Italy, and is the largest island in the Mediterranean Sea. Along with the surrounding minor islands, it constitutes an autonomous region of Italy, the Regione Autonoma Siciliana Sicily has a rich and unique culture, especially with regard to the arts, music, literature,...

    .
  • Dwarf stegodon
    Stegodon
    Stegodon , is a genus of the extinct subfamily Stegodontinae of the order Proboscidea. It was assigned to the family Elephantidae , but has also been placed in Stegodontidae . Stegodonts were present from 11.6 mya to 4,100 years ago...

    ts (elephant relatives) from the recent natural history of the Philippines
    Philippines
    The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...

    , Flores
    Flores
    Flores is one of the Lesser Sunda Islands, an island arc with an estimated area of 14,300 km² extending east from the Java island of Indonesia. The population was 1.831.000 in the 2010 census and the largest town is Maumere. Flores is Portuguese for "flowers".Flores is located east of Sumbawa...

    , Sulawesi
    Sulawesi
    Sulawesi is one of the four larger Sunda Islands of Indonesia and is situated between Borneo and the Maluku Islands. In Indonesia, only Sumatra, Borneo, and Papua are larger in territory, and only Java and Sumatra have larger Indonesian populations.- Etymology :The Portuguese were the first to...

    , Sumba
    Sumba
    Sumba is an island in eastern Indonesia, is one of the Lesser Sunda Islands, and is in the province of East Nusa Tenggara. Sumba has an area of 11,153 km², and the population was officially at 611,422 in 2005...

     and Timor
    Timor
    Timor is an island at the southern end of Maritime Southeast Asia, north of the Timor Sea. It is divided between the independent state of East Timor, and West Timor, belonging to the Indonesian province of East Nusa Tenggara. The island's surface is 30,777 square kilometres...

    .
  • A recently confirmed separate species of hominid called Homo floresiensis
    Homo floresiensis
    Homo floresiensis is a possible species, now extinct, in the genus Homo. The remains were discovered in 2003 on the island of Flores in Indonesia. Partial skeletons of nine individuals have been recovered, including one complete cranium...

    , from fossils found on Flores
    Flores
    Flores is one of the Lesser Sunda Islands, an island arc with an estimated area of 14,300 km² extending east from the Java island of Indonesia. The population was 1.831.000 in the 2010 census and the largest town is Maumere. Flores is Portuguese for "flowers".Flores is located east of Sumbawa...

     Island in Indonesia
    Indonesia
    Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...

    .
  • Small-bodied humans from Palau
    Palau
    Palau , officially the Republic of Palau , is an island nation in the Pacific Ocean, east of the Philippines and south of Tokyo. In 1978, after three decades as being part of the United Nations trusteeship, Palau chose independence instead of becoming part of the Federated States of Micronesia, a...

    , Micronesia
    Micronesia
    Micronesia is a subregion of Oceania, comprising thousands of small islands in the western Pacific Ocean. It is distinct from Melanesia to the south, and Polynesia to the east. The Philippines lie to the west, and Indonesia to the southwest....

    , similar in size to the Flores hominins (disputed).

Additional examples


Carnivora
Carnivora
The diverse order Carnivora |Latin]] carō "flesh", + vorāre "to devour") includes over 260 species of placental mammals. Its members are formally referred to as carnivorans, while the word "carnivore" can refer to any meat-eating animal...

  • Bali tiger
    Bali Tiger
    The Bali Tiger , harimau Bali in Indonesian, or referred to as samong in archaic Balinese language, was a subspecies of Tiger which was found solely on the small Indonesian island of Bali...

     †
  • Channel Island fox in California
    California
    California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...

    , United States
    United States
    The United States of America is a federal constitutional republic comprising fifty states and a federal district...

    , and the enigmatic, nearly extinct Cozumel fox
    Cozumel Fox
    The Cozumel Fox is an undescribed species of fox which is apparently close to extinction or even already extinct. It is found on the island of Cozumel, Mexico. The Cozumel Fox, which has not been scientifically described to date, is a dwarf form like the Island Fox but slightly larger, being up...

  • Cozumel raccoon
    Cozumel Raccoon
    The Cozumel raccoon , also called the pygmy raccoon, is a critically endangered species of raccoon endemic on Cozumel Island off the coast of the Yucatan Peninsula, Mexico.The pygmy raccoon goes by a variety of common names...

  • Honshū Wolf
    Honshu Wolf
    The Honshū Wolf, known in Japan as the , , or simply , is one of the two extinct subspecies of the Gray Wolf once endemic to the islands of Japan. The Honshū Wolf occupied the islands of Honshū, Shikoku, and Kyūshū in Japan. The other subspecies is the Hokkaidō Wolf, native to the island of Hokkaidō...

     † in Japan
    Japan
    Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

  • Sardinian dhole
    Sardinian Dhole
    The Sardinian Dhole Cynotherium sardous was an endemic insular canid, that occurred on the Italian island of Sardinia and the French island of Corsica . It became extinct when humans began to settle on the island.When this canid became confined to the island, it faced a menu consisting of small and...

     †
  • Zanzibar leopard
    Zanzibar Leopard
    The Zanzibar Leopard is an elusive and possibly extinct subspecies of leopard endemic to Unguja Island in the Zanzibar archipelago, part of Tanzania. Increasing conflict between people and leopards in the 20th century led to their demonization and determined attempts to exterminate them...

    , possibly extinct


Ungulate
Ungulate
Ungulates are several groups of mammals, most of which use the tips of their toes, usually hoofed, to sustain their whole body weight while moving. They make up several orders of mammals, of which six to eight survive...

s
  • Key deer
    Key Deer
    The Key Deer is an endangered deer that lives only in the Florida Keys. It is a subspecies of the White-tailed deer .-Physical description and behavior:...

     of the Florida Keys
    Florida Keys
    The Florida Keys are a coral archipelago in southeast United States. They begin at the southeastern tip of the Florida peninsula, about south of Miami, and extend in a gentle arc south-southwest and then westward to Key West, the westernmost of the inhabited islands, and on to the uninhabited Dry...

  • Extinct red deer
    Red Deer
    The red deer is one of the largest deer species. Depending on taxonomy, the red deer inhabits most of Europe, the Caucasus Mountains region, Asia Minor, parts of western Asia, and central Asia. It also inhabits the Atlas Mountains region between Morocco and Tunisia in northwestern Africa, being...

     populations in Jersey
    Jersey
    Jersey, officially the Bailiwick of Jersey is a British Crown Dependency off the coast of Normandy, France. As well as the island of Jersey itself, the bailiwick includes two groups of small islands that are no longer permanently inhabited, the Minquiers and Écréhous, and the Pierres de Lecq and...

  • Philippine Sambar
    Philippine Sambar
    The Philippine Deer , also known as the Philippine Sambar, is a vulnerable species of deer found in forest and grassland on most larger islands in the Philippines, although its range is increasingly fragmented because of habitat loss and hunting...

  • Candiacervus
    Candiacervus
    Candiacervus was a genus of deer native to Pleistocene Crete. Their most notable feature, besides their peculiar, spatula-shaped antlers, was their small stature: the smallest species, C. ropalophorus, stood about 40 cm at the shoulders when fully grown, as can be inferred from a mounted...

     ropalophorus
    †, Crete
  • Cervus astylodon †, Ryukyu Islands
    Ryukyu Islands
    The , also known as the , is a chain of islands in the western Pacific, on the eastern limit of the East China Sea and to the southwest of the island of Kyushu in Japan. From about 1829 until the mid 20th century, they were alternately called Luchu, Loochoo, or Lewchew, akin to the Mandarin...

     of Japan
  • Hoplitomeryx
    Hoplitomeryx
    The extinct five-horned prongdeer Hoplitomeryx matthei with its sabrelike upper canines lived on the former Gargano Island during the Miocene and the Early Pliocene, now a peninsula on the east coast of South Italy....

    †, the Gargano promontory (the former Gargano Island) of South Italy
  • Philippine water buffalo
    Bubalus
    Bubalus is a genus of bovines, whose English name is buffalo. Species that belong to this genus are:* Subgenus Bubalus** Water Buffalo, Bubalus bubalis*** Carabao, Bubalus bubalis carabanesis...

    , Tamaraw
    Tamaraw
    The Tamaraw or Mindoro Dwarf Buffalo is a small, hoofed mammal belonging to the family Bovidae. It is endemic to the island of Mindoro in the Philippines and is the only endemic Philippine bovine. It is believed, however, to have once also thrived on the greater island of Luzon...

    , anoa
    Anoa
    Anoa, also known as Dwarf Buffalo and Sapiutan, are a subgenus of Bubalus comprising two species native to Indonesia: the Mountain Anoa and the Lowland Anoa . Both live in undisturbed rainforest, and are essentially miniature water buffalo...

    , the extinct Bubalus cebuensis
    Bubalus cebuensis
    The Cebu tamaraw is a fossil dwarf buffalo discovered in the Philippines, and first described in 2006.-Anatomy and morphology:...

    † and other dwarf bovid
    Bovid
    A bovid is any of almost 140 species of cloven-hoofed ruminant mammal at least the males of which bear characteristic unbranching horns covered in a permanent sheath of keratin....

    s from Southeast Asia
  • The strange, tiny Balearic Islands
    Balearic Islands
    The Balearic Islands are an archipelago of Spain in the western Mediterranean Sea, near the eastern coast of the Iberian Peninsula.The four largest islands are: Majorca, Minorca, Ibiza and Formentera. The archipelago forms an autonomous community and a province of Spain with Palma as the capital...

     cave goat (Myotragus balearicus
    Myotragus balearicus
    Myotragus balearicus , also known as the Balearic Islands Cave Goat, a species of the subfamily Caprinae which lived on the islands of Majorca and Minorca until its extinction around 5,000 years ago...

    ) † in Majorca and Minorca
    Minorca
    Min Orca or Menorca is one of the Balearic Islands located in the Mediterranean Sea belonging to Spain. It takes its name from being smaller than the nearby island of Majorca....

     and its close relative Nesogoral †, from Sardinia
    Sardinia
    Sardinia is the second-largest island in the Mediterranean Sea . It is an autonomous region of Italy, and the nearest land masses are the French island of Corsica, the Italian Peninsula, Sicily, Tunisia and the Spanish Balearic Islands.The name Sardinia is from the pre-Roman noun *sard[],...

     which became extinct after human settlement
  • Several extinct species of dwarf hippopotamus from the Pleistocene of Mediterranean islands (such as Hippopotamus minor) † and Madagascar
    Madagascar
    The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...



Birds
  • King Island Emu
    King Island Emu
    The King Island Emu or Black Emu is an extinct sub-species of emu which occurred on King Island between mainland Australia and Tasmania. It is known from 19th century descriptions of live birds, as well as subfossil bones and one museum specimen...

     and Kangaroo Island Emu
    Kangaroo Island Emu
    Kangaroo Island Emu or Dwarf Emu is an extinct member of the bird family Casuariidae. It was restricted to Kangaroo Island, South Australia, which was known as Ile Decrés by the members of the Baudin expedition. It differed from the mainland Emu mainly in its smaller size...

    , both extinct


Snakes
  • Tiger snakes of Roxby Island, South Australia
    South Australia
    South Australia is a state of Australia in the southern central part of the country. It covers some of the most arid parts of the continent; with a total land area of , it is the fourth largest of Australia's six states and two territories.South Australia shares borders with all of the mainland...


See also


  • Island gigantism
    Island gigantism
    Island gigantism or insular giantism is a biological phenomenon in which the size of animals isolated on an island increases dramatically in comparison to their mainland relatives....

  • Foster's rule
    Foster's rule
    Foster's rule is a principle in evolutionary biology stating that members of a species get smaller or bigger depending on the resources available in the environment. This is the core of the study of island biogeography. For example, it is known that pygmy mammoths evolved from normal mammoths on...

  • Deep-sea gigantism
    Deep-sea gigantism
    In zoology, deep-sea gigantism, also known as abyssal gigantism, is the tendency for species of crustaceans, invertebrates and other deep-sea-dwelling animals to display a larger size than their shallow-water counterparts...

  • Pleistocene extinctions
  • Baron Franz Nopcsa

External links