rekordy: Insular dwarfism

Evidence: 100 • authority: 72

Insular dwarfism, a form of phyletic dwarfism, is the process and condition of large animals evolving or having a reduced body size 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. This process has occurred many times throughout evolutionary history, with examples including various species of dwarf elephants that evolved during the Pleistocene epoch, as well as more ancient examples, such as the dinosaurs Europasaurus and Magyarosaurus. This process, and other "island genetics" artifacts, can occur not only on islands, but also in other situations where an ecos…

Evidence: 42 • authority: 88

Genetics of Genome-Wide Recombination Rate Evolution in Mice from an Isolated Island. Abstract Recombination rate is a heritable quantitative trait that evolves despite the fundamentally conserved role that recombination plays in meiosis. Differences in recombination rate can alter the landscape of the genome and the genetic diversity of populations. Yet our understanding of the genetic basis of recombination rate evolution in nature remains limited. We used wild house mice (Mus musculus domesticus) from Gough Island (GI), which diverged recently from their mainland counterparts, to characterize the genetics of recombination rate evolution. We quantified genome-wide autosomal recombination…

Evidence: 36 • authority: 92

Genetic Structure and Signs of Local Adaptation in Icelandic Brown Trout Populations.. Loss of anadromy in Salmonids frequently follows postglacial colonization and habitat change, a process driven by selective pressures where benefits of residency outweigh migration costs. At the end of the last Ice Age ca . 10,000 years ago, anadromous brown trout arrived in Iceland and invaded newly formed habitats. Some populations became isolated in headwaters early after the ice retreated, presumably accelerating local adaptation and the evolution of residency. In this study, we assessed the genetic relatedness and diversity of brown trout on a countrywide scale to decipher the number of unique popula…

Evidence: 36 • authority: 92

Genomic structural variation rescues a classic biological invader from a population bottleneck.. Invasion genetics presents a classic paradox: How do species successfully spread despite severe population bottlenecks? The brown treesnake ( Boiga irregularis ) in Guam represents a notable example of this phenomenon, having been introduced with only a handful of individuals. We show that the population endured an extreme bottleneck, with roughly half of the genome exhibiting runs of homozygosity, comparable to species of conservation concern. Despite this, we uncovered extensive diversity in the form of nearly 19,000 genomic structural variants, which affect almost eight times more of the geno…

Evidence: — • authority: 72

Birds are vertebrate animals constituting the class Aves, characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweight skeleton. They are warm-blooded, live worldwide, and range in size from the 5.5 cm (2.2 in) bee hummingbird to the 2.8 m (9 ft 2 in) common ostrich. There are over 11,000 living species of birds, classified in 44 orders. More than half of the world's bird species are passerine or "perching" birds. Nearly all birds have wings whose development varies according to the life style of each species. Wings, which are modified forelimbs, gave birds the ability to fly, although further…

Evidence: — • authority: 72

Forest management is a branch of forestry concerned with overall administrative, legal, economic, and social aspects, as well as scientific and technical aspects, such as silviculture, forest protection, and regulation. This includes management for timber, aesthetics, recreation, urban values, water, wildlife, inland and nearshore fisheries, wood products, plant genetic resources, and other forest resource values. Management objectives can be for conservation, utilisation, or a mixture of the two. Techniques include timber extraction, planting and replanting of different species, building and maintenance of roads and pathways through forests, and preventing fire. Forest Management plays an…

Evidence: — • authority: 72

A landrace is a domesticated, locally adapted, often traditional variety of a species of an animal, plant or fungus that has developed over time, through adaptation to its natural and cultural environment of agriculture and pastoralism, and due to isolation from other populations of the species. Landraces are distinct from cultivars and from standard breeds. A significant proportion of farmers around the world grow landrace crops, and most plant landraces are associated with traditional agricultural systems. Landraces of many crops have probably been grown for millennia. Increasing reliance upon modern plant cultivars that are bred to be uniform has led to a reduction in biodiversity, becau…

Evidence: — • authority: 72

Habitat fragmentation is the emergence of discontinuities (fragmentation) in an organism's preferred environment (habitat), causing population fragmentation and ecosystem decay. Causes of habitat fragmentation include geological processes that slowly alter the layout of the physical environment (suspected of being one of the major causes of speciation), and human activity such as land conversion, which can alter the environment much faster and causes the population fluctuation of many species. More specifically, habitat fragmentation is a process by which large and contiguous habitats get divided into smaller, isolated patches of habitats.

Evidence: — • authority: 72

Axel Heiberg Island is an uninhabited island in the Qikiqtaaluk Region, Nunavut, Canada. Located in the Arctic Ocean, it is the 34th largest island in the world and Canada's ninth largest island. According to the United States Geological Survey, Esri, and the United Nations Environment Programme - World Conservation Monitoring Centre it has an area of 42,276.97 km2 (16,323.23 sq mi). It is named after Axel Heiberg. One of the larger members of the Arctic Archipelago, it is also a member of the Sverdrup Islands and Queen Elizabeth Islands. It is known for its unusual fossil forests, which date from the Eocene period. Owing to the lack of mineralization in many of the forest specimens, the tr…

Evidence: — • authority: 72

The Guanches were the indigenous inhabitants of the Canary Islands, located in the Atlantic Ocean some 100 kilometres (60 mi) to the west of modern Morocco and the North African coast. The islanders spoke the Guanche language, which is believed to have been related to the Berber languages of mainland North Africa. The language became extinct in the 17th century, several generations after the completion of the conquest of the Canary Islands by the Catholic Monarchs of Spain. It is believed that the Guanches may have arrived at the archipelago some time in the first millennium BC. The Guanches were the only indigenous people known to have lived in the Macaronesian archipelago region off the c…

Evidence: — • authority: 80

Australian External Territories (Ashmore and Cartier Islands, Christmas Island, Cocos [Keeling] Islands, Norfolk Island)

Evidence: — • authority: 80

Stone artifacts from the Keppel Islands : the use of stone in an island economy