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Sanford's Sea Eagle
Sanford's sea eagle (''Haliaeetus sanfordi''), also known as Sanford's fish eagle or the Solomon eagle, is a sea eagle endemic to the Solomon Islands archipelago. Taxonomy Sanford's sea eagle was discovered by and named after Dr Leonard C. Sanford, a trustee for the American Museum of Natural History. The first description was by Ernst Mayr in 1935. The "sea eagle" name is used to distinguish the species of the genus ''Haliaeetus'' from the closely related ''Ichthyophaga'' true fish eagles. The species was described in 1935 by Ernst Mayr who noticed that earlier observers had overlooked it, thinking it was a juvenile of the white-bellied sea eagle. It forms a superspecies with the white-bellied sea eagle. As in other sea eagle species pairs, the other taxon is white-headed. These two are genetically very close, it seems; their lineages separated not longer than 1 million years ago, probably only in the Middle Pleistocene, a few 100,000 years ago. Both share a dark bill, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ernst Mayr
Ernst Walter Mayr (; 5 July 1904 – 3 February 2005) was one of the 20th century's leading evolutionary biologists. He was also a renowned taxonomist, tropical explorer, ornithologist, philosopher of biology, and historian of science. His work contributed to the conceptual revolution that led to the modern evolutionary synthesis of Mendelian genetics, systematics, and Darwinian evolution, and to the development of the biological species concept. Although Charles Darwin and others posited that multiple species could evolve from a single common ancestor, the mechanism by which this occurred was not understood, creating the '' species problem''. Ernst Mayr approached the problem with a new definition for species. In his book '' Systematics and the Origin of Species'' (1942) he wrote that a species is not just a group of morphologically similar individuals, but a group that can breed only among themselves, excluding all others. When populations within a species become is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Predator
Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill the host) and parasitoidism (which always does, eventually). It is distinct from scavenging on dead prey, though many predators also scavenge; it overlaps with herbivory, as seed predators and destructive frugivores are predators. Predators may actively search for or pursue prey or wait for it, often concealed. When prey is detected, the predator assesses whether to attack it. This may involve ambush or pursuit predation, sometimes after stalking the prey. If the attack is successful, the predator kills the prey, removes any inedible parts like the shell or spines, and eats it. Predators are adapted and often highly specialized for hunting, with acute senses such as vision, hearing, or smell. Many predatory animals, both vertebrate an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hybrid (biology)
In biology, a hybrid is the offspring resulting from combining the qualities of two organisms of different breeds, varieties, species or genera through sexual reproduction. Hybrids are not always intermediates between their parents (such as in blending inheritance), but can show hybrid vigor, sometimes growing larger or taller than either parent. The concept of a hybrid is interpreted differently in animal and plant breeding, where there is interest in the individual parentage. In genetics, attention is focused on the numbers of chromosomes. In taxonomy, a key question is how closely related the parent species are. Species are reproductively isolated by strong barriers to hybridisation, which include genetic and morphological differences, differing times of fertility, mating behaviors and cues, and physiological rejection of sperm cells or the developing embryo. Some act before fertilization and others after it. Similar barriers exist in plants, with differences in flowering t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Introgression
Introgression, also known as introgressive hybridization, in genetics is the transfer of genetic material from one species into the gene pool of another by the repeated backcrossing of an interspecific hybrid with one of its parent species. Introgression is a long-term process, even when artificial; it may take many hybrid generations before significant backcrossing occurs. This process is distinct from most forms of gene flow in that it occurs between two populations of different species, rather than two populations of the same species. Introgression also differs from simple hybridization. Simple hybridization results in a relatively even mixture; gene and allele frequencies in the first generation will be a uniform mix of two parental species, such as that observed in mules. Introgression, on the other hand, results in a complex, highly variable mixture of genes, and may only involve a minimal percentage of the donor genome. Definition Introgression or introgressive hybridi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Northern Common Cuscus
The northern common cuscus (''Phalanger orientalis''), also known as the gray cuscus, is a species of marsupial in the family Phalangeridae native to northern New Guinea and adjacent smaller islands, but is now also found in the Bismarck Archipelago, southeast and central Moluccas, the Solomons, and Timor, where it is believed to have been introduced in prehistoric times from New Guinea. It was formerly considered conspecific with the allopatric '' P. intercastellanus'' and '' P. mimicus''. It is hunted for human consumption in New Guinea. Names It is known as ''laku ita'' in the Naueti language or ''meda'' in the Tetum Terik Tetum language of Timor-Leste. Habitat The northern common cuscus normally inhabits disturbed habitats. These would include secondary forest, plantations, and gardens. This species is also found in primary tropical forests.Leary, T., Singadan, R., Menzies, J., Helgen, K., Wright, D., Allison, A., Hamilton, S., Salas, L. & Dickman, C. 2008. Phalanger ori ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canopy (biology)
In biology, the canopy is the aboveground portion of a plant cropping or crop, formed by the collection of individual plant crowns. In forest ecology, canopy also refers to the upper layer or habitat zone, formed by mature tree crowns and including other biological organisms (epiphytes, lianas, arboreal animals, etc.). The communities that inhabit the canopy layer are thought to be involved in maintaining forest diversity, resilience, and functioning. Sometimes the term canopy is used to refer to the extent of the outer layer of leaves of an individual tree or group of trees. Shade trees normally have a dense canopy that blocks light from lower growing plants. Observation Early observations of canopies were made from the ground using binoculars or by examining fallen material. Researchers would sometimes erroneously rely on extrapolation by using more reachable samples taken from the understory. In some cases, they would use unconventional methods such as chairs sus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rainforest
Rainforests are characterized by a closed and continuous tree canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforest can be classified as tropical rainforest or temperate rainforest, but other types have been described. Estimates vary from 40% to 75% of all biotic species being indigenous to the rainforests. There may be many millions of species of plants, insects and microorganisms still undiscovered in tropical rainforests. Tropical rainforests have been called the "jewels of the Earth" and the " world's largest pharmacy", because over one quarter of natural medicines have been discovered there. Rainforests as well as endemic rainforest species are rapidly disappearing due to deforestation, the resulting habitat loss and pollution of the atmosphere. Definition Rainforest are characterized by a closed and continuous tree canopy, high humidity, the presence of moisture-dependent vegetation, a moist layer of le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megabat
Megabats constitute the family Pteropodidae of the order Chiroptera ( bats). They are also called fruit bats, Old World fruit bats, or—especially the genera ''Acerodon'' and '' Pteropus''— flying foxes. They are the only member of the superfamily Pteropodoidea, which is one of two superfamilies in the suborder Yinpterochiroptera. Internal divisions of Pteropodidae have varied since subfamilies were first proposed in 1917. From three subfamilies in the 1917 classification, six are now recognized, along with various tribes. As of 2018, 197 species of megabat had been described. The leading theory of the evolution of megabats has been determined primarily by genetic data, as the fossil record for this family is the most fragmented of all bats. They likely evolved in Australasia, with the common ancestor of all living pteropodids existing approximately 31 million years ago. Many of their lineages probably originated in Melanesia, then dispersed over time to mainland Asia, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea Snake
Sea snakes, or coral reef snakes, are elapid snakes that inhabit marine environments for most or all of their lives. They belong to two subfamilies, Hydrophiinae and Laticaudinae. Hydrophiinae also includes Australasian terrestrial snakes, whereas Laticaudinae only includes the sea kraits (''Laticauda''), of which three species are found exclusively in freshwater. If these three freshwater species are excluded, there are 69 species of sea snakes divided between seven genera. Most sea snakes are venomous, except the genus ''Emydocephalus'', which feeds almost exclusively on fish eggs. Sea snakes are extensively adapted to a fully aquatic life and are unable to move on land, except for the sea kraits, which have limited land movement. They are found in warm coastal waters from the Indian Ocean to the Pacific and are closely related to venomous terrestrial snakes in Australia. All sea snakes have paddle-like tails and many have laterally compressed bodies that give them an e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tortoises
Tortoises () are reptiles of the family Testudinidae of the order Testudines (Latin: ''tortoise''). Like other turtles, tortoises have a turtle shell, shell to protect from predation and other threats. The shell in tortoises is generally hard, and like other members of the suborder Cryptodira, they retract their necks and heads directly backward into the shell to protect them. Tortoises can vary in size with some species, such as the Galápagos tortoise, Galápagos giant tortoise, growing to more than in length, whereas others like the Chersobius signatus, Speckled cape tortoise have shells that measure only long. Several lineages of tortoises Giant tortoise, have independently evolved very large body sizes in excess of 100 kg, including the Galápagos tortoise, Galapagos giant tortoise and the Aldabra giant tortoise. They are usually Diurnality, diurnal animals with tendencies to be crepuscular depending on the ambient temperatures. They are generally reclusive animals. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crab
Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" (abdomen) ( el, βραχύς , translit=brachys = short, / = tail), usually hidden entirely under the thorax. They live in all the world's oceans, in freshwater, and on land, are generally covered with a thick exoskeleton, and have a single pair of pincers. They first appeared during the Jurassic Period. Description Crabs are generally covered with a thick exoskeleton, composed primarily of highly mineralized chitin, and armed with a pair of chelae (claws). Crabs vary in size from the pea crab, a few millimeters wide, to the Japanese spider crab, with a leg span up to . Several other groups of crustaceans with similar appearances – such as king crabs and porcelain crabs – are not true crabs, but have evolved features similar to true crabs through a process known as carcinisation. Environment Crabs are found in all of the world's oceans, as well as in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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