Why Do Animals On Islands Become So GIGANTIC?
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3 سال پیش
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#IslandGigantism
#IslandGigantism #Galapagos
Video on why animals on islands become so big known as Island Gigantism, founded by Bristol Foster.
Sources:
https://blog.uwgb.edu/biodiversity/20...
https://www.pnas.org/content/116/36/1...
https://en.wikipedia.org/wiki/Insular...
https://www.worldatlas.com/articles/w...
https://www.ncbi.nlm.nih.gov/pmc/arti...
Videos used: The truth about the Dodo
This video is about Bristol Foster's Foster rule which was Island Gigantism. Galapogus turtle, Koala lemur, Loris, Dodo, Moa, Extinct animals, Prehitoric animals, Island animals. Animals and Wildlife channel. Interesting information. First video on this. Amazing information. Unique and exclusive animal and wildlife information. Trees proved our understanding into why animals on islands can grow so much larger. Large size provides a number of evolutionary advantages to species. Bigger animals can choose from a larger array of food items. Large predators can choose small or large prey. Bigger animals can produce more offspring and provide each with more food and better protect themselves and their offspring. It is not known whether this is an isolated individual or representative of a new population, perhaps associated with the Cat Island Chain restoration. NAS biology professor and spider expert Michael Draney noted that “Spiders often grow to larger sizes in urban areas thanks to favorable sites for building webs, especially near lights.” However he did add that “This individual is quite a bit larger than the average, though.” Draney, whose specialty are dwarf spiders, shook his head as he considered both the photo and his past advice to area arachnophobes. “Throughout my career,” he said, “I’ve tried to reassure people that spiders in Wisconsin are nothing to worry about. He looked apprehensively out his office window as he added, “All that has changed now.”
Island gigantism is one concept of the island rule which was first inferred in 1964 in the journal Nature by J. Bristol Foster. Foster published a paper titled “Evolution of Mammals on Island," after undertaking a survey of 116 island-living species and comparing them to their mainland relatives. The study revealed some interesting observations such as rodents lean towards gigantism while lagomorphs, carnivores, and artiodactyls (deer and hippos) tend towards dwarfism. In summary, large species decrease in size when food is limited while small species grow big where there is no significant predation pressure. Foster's ideas pioneered the study of the phenomenon which has been advanced upon by other biogeographers over time
The first reason is the absence of large mammalian carnivore predators. Islands tend to
discourage the settlement of such mammals due to difficulties in over-water dispersal and inefficient range. Large birds, small carnivores,
and reptiles take the place of predators but are inefficient since they are less advanced than other carnivores such as lions. Small sizes render herbivores less v
ulnerable to predation since they can hide or escape easily. The absence of predators relaxes the predation pressure and allows them to grow bigger. Some animals, as seen in the case of
island tortoises, may grow big to reduce vulnerability
to food resources. Larger size enables them to survive for extended intervals without food or water or to travel longer distances in search of the resources. Territorialism has been
suggested to be a possible cause as well. Species which are territorial tend towards larger size as an advantage to better defend their territories. Thus, island gigantism is facilitated by
the dismissal of constraints on the size of small animals as it pertains to competition and predation
The giant tortoises of the Galapagos, Seychelles and Mascarene islands represent some of the most conspicuous examples of island gigantism. These species, which fall at the upper end of the size scale for extant chelonians (turtles and tortoises), are thought to have achieved their large size as a consequence of relaxed predation pressure, competitive release, or as an adaptation to increased environmental fluctuations on islands [1].
Island gigantism, or insular gigantism, is a biological phenomenon in which the size of an animal species isolated on an island increases dramatically in comparison to its mainland relatives. Island gigantism is one aspect of the more general "island effect" or "Foster's rule", which posits that when mainland animals colonize islands, small species tend to evolve larger bodies, and large species tend to evolve smaller bodies (insular dwarfism). Following the arrival of humans
Video on why animals on islands become so big known as Island Gigantism, founded by Bristol Foster.
Sources:
https://blog.uwgb.edu/biodiversity/20...
https://www.pnas.org/content/116/36/1...
https://en.wikipedia.org/wiki/Insular...
https://www.worldatlas.com/articles/w...
https://www.ncbi.nlm.nih.gov/pmc/arti...
Videos used: The truth about the Dodo
This video is about Bristol Foster's Foster rule which was Island Gigantism. Galapogus turtle, Koala lemur, Loris, Dodo, Moa, Extinct animals, Prehitoric animals, Island animals. Animals and Wildlife channel. Interesting information. First video on this. Amazing information. Unique and exclusive animal and wildlife information. Trees proved our understanding into why animals on islands can grow so much larger. Large size provides a number of evolutionary advantages to species. Bigger animals can choose from a larger array of food items. Large predators can choose small or large prey. Bigger animals can produce more offspring and provide each with more food and better protect themselves and their offspring. It is not known whether this is an isolated individual or representative of a new population, perhaps associated with the Cat Island Chain restoration. NAS biology professor and spider expert Michael Draney noted that “Spiders often grow to larger sizes in urban areas thanks to favorable sites for building webs, especially near lights.” However he did add that “This individual is quite a bit larger than the average, though.” Draney, whose specialty are dwarf spiders, shook his head as he considered both the photo and his past advice to area arachnophobes. “Throughout my career,” he said, “I’ve tried to reassure people that spiders in Wisconsin are nothing to worry about. He looked apprehensively out his office window as he added, “All that has changed now.”
Island gigantism is one concept of the island rule which was first inferred in 1964 in the journal Nature by J. Bristol Foster. Foster published a paper titled “Evolution of Mammals on Island," after undertaking a survey of 116 island-living species and comparing them to their mainland relatives. The study revealed some interesting observations such as rodents lean towards gigantism while lagomorphs, carnivores, and artiodactyls (deer and hippos) tend towards dwarfism. In summary, large species decrease in size when food is limited while small species grow big where there is no significant predation pressure. Foster's ideas pioneered the study of the phenomenon which has been advanced upon by other biogeographers over time
The first reason is the absence of large mammalian carnivore predators. Islands tend to
discourage the settlement of such mammals due to difficulties in over-water dispersal and inefficient range. Large birds, small carnivores,
and reptiles take the place of predators but are inefficient since they are less advanced than other carnivores such as lions. Small sizes render herbivores less v
ulnerable to predation since they can hide or escape easily. The absence of predators relaxes the predation pressure and allows them to grow bigger. Some animals, as seen in the case of
island tortoises, may grow big to reduce vulnerability
to food resources. Larger size enables them to survive for extended intervals without food or water or to travel longer distances in search of the resources. Territorialism has been
suggested to be a possible cause as well. Species which are territorial tend towards larger size as an advantage to better defend their territories. Thus, island gigantism is facilitated by
the dismissal of constraints on the size of small animals as it pertains to competition and predation
The giant tortoises of the Galapagos, Seychelles and Mascarene islands represent some of the most conspicuous examples of island gigantism. These species, which fall at the upper end of the size scale for extant chelonians (turtles and tortoises), are thought to have achieved their large size as a consequence of relaxed predation pressure, competitive release, or as an adaptation to increased environmental fluctuations on islands [1].
Island gigantism, or insular gigantism, is a biological phenomenon in which the size of an animal species isolated on an island increases dramatically in comparison to its mainland relatives. Island gigantism is one aspect of the more general "island effect" or "Foster's rule", which posits that when mainland animals colonize islands, small species tend to evolve larger bodies, and large species tend to evolve smaller bodies (insular dwarfism). Following the arrival of humans
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