|
Evolutionary Anachronism
Evolutionary anachronism is a concept in evolutionary biology named by Connie C. Barlow in her book, ''The Ghosts of Evolution'' (2000). It refers to attributes of living species that are best explained as a result of having been favorably selected in the past due to coevolution with other biological species that have since become extinct. When this context is removed, the natural attributes appear as unexplained energy investments by the living organism, with no apparent benefit, and perhaps are prejudicial to the continued reproduction of the surviving species. The general theory was formulated by Costa Rican-based American botanist Daniel Janzen and University of Arizona-based geologist Paul S. Martin (a prominent defender of the overkill hypothesis to explain the Quaternary extinction event) in a ''Science'' article published in 1982, titled ''Neotropical Anachronisms: The fruit the gomphotheres ate.'' Previously, in 1977, Stanley Temple had proposed a similar idea to expla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ginkgo
''Ginkgo'' is a genus of non-flowering seed plants. The scientific name is also used as the English name. The order to which it belongs, Ginkgoales, first appeared in the Permian, 270 million years ago, and is now the only living genus within the order. The rate of evolution within the genus has been slow, and almost all its species had become extinct by the end of the Pliocene. The sole surviving species, ''Ginkgo biloba'' is only found in the wild in China, but is cultivated around the world. The relationships between ginkgos and other groups of plants are not fully resolved. Prehistory The ginkgo (''Ginkgo biloba'') is a living fossil, with fossils similar to the modern plant dating back to the Permian, 270 million years ago. The closest living relatives of the clade are the cycads, which share with the extant ''G. biloba'' the characteristic of motile sperm. The ginkgo and cycad lineages are thought to have an extremely ancient divergence dating to the early Ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paul Schultz Martin
Paul Schultz Martin (born in Allentown, Pennsylvania, 1928 - died in Tucson, Arizona September 13, 2010Mari N. Jensen. '. University of Arizona. Retrieved 2010-09-17. ) was an American geoscientist at the University of Arizona who developed the theory that the Pleistocene extinction of large mammals worldwide was caused by overhunting by humans. Martin's work bridged the fields of ecology, anthropology, geosciences, and paleontology. In 1953, Martin received his bachelor's degree in zoology from Cornell University. In 1953 and 1956 he completed his master's and doctorate programs at the University of Michigan and then proceeded with postdoctoral research at the Yale University and the University of Montreal. Martin's early interest embraced ornithology and herpetology and he conducted extensive fieldwork from 1948 to 1953 in Tamaulipas, Mexico. He published biogeographys on the birds of the Sierra de Tamaulipas and the herpetofauna of the Gómez Farias (= El Cielo) region o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Avocado
The avocado (''Persea americana'') is a medium-sized, evergreen tree in the laurel family (Lauraceae). It is native to the Americas and was first domesticated by Mesoamerican tribes more than 5,000 years ago. Then as now it was prized for its large and unusually oily fruit. The tree likely originated in the highlands bridging south-central Mexico and Guatemala. Its fruit, sometimes also referred to as an alligator or avocado pear, is botanically a large berry containing a single large seed. Avocado trees are partially self-pollinating, and are often propagated through grafting to maintain consistent fruit output. Avocados are presently cultivated in the tropical and Mediterranean climates of many countries. Mexico is the world's leading producer of avocados as of 2020, supplying nearly 30% of the global harvest in that year. The fruit of domestic varieties have smooth, buttery, golden-green flesh when ripe. Depending on the cultivar, avocados have green, brown, purplish, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vestigiality
Vestigiality is the retention, during the process of evolution, of genetically determined structures or attributes that have lost some or all of the ancestral function in a given species. Assessment of the vestigiality must generally rely on comparison with homologous features in related species. The emergence of vestigiality occurs by normal evolutionary processes, typically by loss of function of a feature that is no longer subject to positive selection pressures when it loses its value in a changing environment. The feature may be selected against more urgently when its function becomes definitively harmful, but if the lack of the feature provides no advantage, and its presence provides no disadvantage, the feature may not be phased out by natural selection and persist across species. Examples of vestigial structures (also called degenerate, atrophied, or rudimentary organs) are the loss of functional wings in island-dwelling birds; the human vomeronasal organ; and the hi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megaherbivores
Megaherbivores (Greek μέγας megas "large" and Latin ''herbivora'' "herbivore") are large terrestrial herbivores that can exceed in weight. This polyphyletic group of megafauna includes elephants, rhinos, hippos, and giraffes. The largest bovids ( gaurs and American bisons) occasionally reach a weight of , but they are generally not considered to be megaherbivores. There are nine extant species of megaherbivores living in Africa and Asia. The African bush elephant is the largest extant species with bulls reaching a height of up to and a maximum weight of . All megaherbivores are keystone species in their environment. Their ecological role is to change the vegetative structure through feeding behavior, and seed dispersal. Megaherbivores like most large mammals are ''K-''selected species. They are characterized by their large size, invulnerability to predators, their impact on vegetation and their dietary tolerance. Megaherbivores have been around for over 300 million years ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seed Dispersal
In Spermatophyte plants, seed dispersal is the movement, spread or transport of seeds away from the parent plant. Plants have limited mobility and rely upon a variety of dispersal vectors to transport their seeds, including both abiotic vectors, such as the wind, and living ( biotic) vectors such as birds. Seeds can be dispersed away from the parent plant individually or collectively, as well as dispersed in both space and time. The patterns of seed dispersal are determined in large part by the dispersal mechanism and this has important implications for the demographic and genetic structure of plant populations, as well as migration patterns and species interactions. There are five main modes of seed dispersal: gravity, wind, ballistic, water, and by animals. Some plants are serotinous and only disperse their seeds in response to an environmental stimulus. These modes are typically inferred based on adaptations, such as wings or fleshy fruit. However, this simplified view may ignor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dodo
The dodo (''Raphus cucullatus'') is an extinct flightless bird that was endemic to the island of Mauritius, which is east of Madagascar in the Indian Ocean. The dodo's closest genetic relative was the also-extinct Rodrigues solitaire. The two formed the subfamily Raphinae, a clade of extinct flightless birds that were a part of the family which includes pigeons and doves. The closest living relative of the dodo is the Nicobar pigeon. A white dodo was once thought to have existed on the nearby island of Réunion, but it is now believed that this assumption was merely confusion based on the also-extinct Réunion ibis and paintings of white dodos. Subfossil remains show the dodo was about tall and may have weighed in the wild. The dodo's appearance in life is evidenced only by drawings, paintings, and written accounts from the 17th century. Since these portraits vary considerably, and since only some of the illustrations are known to have been drawn from live specimens, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tambalacoque
''Sideroxylon grandiflorum'', known as tambalacoque or dodo tree, is a long-lived mesocaul tree in the sapote family Sapotaceae, superfiially resembling the unrelated Plumeria, but the Dodo Tree's flowers and fruit are cauliflorous. endemic to Mauritius. It is valued for its timber. The ''Sideroxylon grandiflorum'' fruit is analogous to the peach. They are both termed drupes because both have a hard endocarp, or pit, surrounding the seed, History In 1973, it was thought that this species was dying out. There were supposedly only 13 specimens left, all estimated to be about 300 years old. The true age could not be determined because tambalacoque has no growth rings. Stanley Temple hypothesized that the dodo, which became extinct in the 17th century, ate tambalacoque fruits, and only by passing through the digestive tract of the dodo could the seeds germinate. Temple (1977) force-fed seventeen tambalacoque fruits to wild turkeys. Seven of the fruits were crushed by the bird's gi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endemism
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, the Cape sugarbird is found exclusively in southwestern South Africa and is therefore said to be ''endemic'' to that particular part of the world. An endemic species can be also be referred to as an ''endemism'' or in scientific literature as an ''endemite''. For example '' Cytisus aeolicus'' is an endemite of the Italian flora. '' Adzharia renschi'' was once believed to be an endemite of the Caucasus, but it was later discovered to be a non-indigenous species from South America belonging to a different genus. The extreme opposite of an endemic species is one with a cosmopolitan distribution, having a global or widespread range. A rare alternative term for a species that is endemic is "precinctive", which applies to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mauritius
Mauritius ( ; french: Maurice, link=no ; mfe, label=Mauritian Creole, Moris ), officially the Republic of Mauritius, is an island nation in the Indian Ocean about off the southeast coast of the African continent, east of Madagascar. It includes the main island (also called Mauritius), as well as Rodrigues, Agaléga and St. Brandon. The islands of Mauritius and Rodrigues, along with nearby Réunion (a French overseas department), are part of the Mascarene Islands. The main island of Mauritius, where most of the population is concentrated, hosts the capital and largest city, Port Louis. The country spans and has an exclusive economic zone covering . Arab sailors were the first to discover the uninhabited island, around 975, and they called it ''Dina Arobi''. The earliest discovery was in 1507 by Portuguese sailors, who otherwise took little interest in the islands. The Dutch took possession in 1598, establishing a succession of short-lived settlements over a period of about ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stanley Temple
Stanley A. "Stan" Temple is an American avian ecologist and wildlife biologist. He is the Beers-Bascom Professor in Conservation, Professor of Wildlife Ecology and Professor of Environmental Studies at the University of Wisconsin–Madison. At Cornell University he graduated in 1968 with a B.S. in biological sciences, in 1970 with an M.S. in ecology, and in 1972 with a Ph.D. in ecology and evolutionary biology. Professor Temple has made important contributions to the study of peregrine falcons, whooping cranes, trumpeter swans, Andean condors, hook-billed kites, Mauritius kestrels, Seychelles kestrels, Puerto Rican amazons, Mauritius parakeets, tooth-billed pigeons, Hawaiian crows, loggerhead shrikes, and dickcissels. He has also worked on the responses of wildlife to habitat fragmentation, human impacts on wildlife populations and the ecology of avian predator Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gomphothere
Gomphotheres are any members of the diverse, extinct taxonomic family Gomphotheriidae. Gomphotheres were elephant-like proboscideans, but do not belong to the family Elephantidae. They were widespread across Afro-Eurasia and North America during the Miocene and Pliocene epochs and dispersed into South America during the Pleistocene following the Great American Interchange. Gomphotheriidae in its broadest sense is probably paraphyletic with respect to Elephantidae, which contains modern elephants. While most famous forms such as ''Gomphotherium'' had long lower jaws with tusks, which is the ancestral condition for the group, after these forms became extinct, the surviving gomphotheres had short jaws with either vestigial or no lower tusks (brevirostrine), looking very similar to modern elephants, an example of parallel evolution. By the end of the Early Pleistocene, gomphotheres became extinct in Afro-Eurasia, with the last two genera, ''Cuvieronius'' persisting in southern North ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
_(16485955207).jpg "Click for more on -> Megaherbivores")
.jpg "Click for more on -> Endemism")