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Daphne Major Finch
The Daphne Major finches are a group of Darwin's finches that inhabit Daphne Major island of the Galápagos. The common cactus finch (''Geospiza scandens'') and the medium ground finch (''G. fortis'') are the main species; while the large ground finch (''G. magnirostris'') and the Española cactus finch (''G. conirostris'') are regular immigrants. Most extensively studied by Peter and Rosemary Grant of Princeton University since 1973, the birds are one of the sources of the understanding of bird behaviour, adaptation, and evolution. Since the early 1980s, it has been observed that a population of finches on Daphne Major, named the Big Bird lineage, has started to develop into what will likely become a distinct species. These birds are currently still considered as hybrids of the Española cactus finch (''G. conirostris'') and the medium ground finch, but the breeding of the offspring exclusively among themselves gave rise to a new lineage which are reproductively isolated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Large Ground Finch (4229035966)
The large ground finch (''Geospiza magnirostris'') is a species of bird. One of Darwin's finches, it is now placed in the family Thraupidae and was formerly in the Emberizidae. It is endemic 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 else ... to the Galapagos Islands, and is found in the arid zone of most of the archipelago, though it is absent from the southeastern islands ( Floreana, Española, San Cristóbal, and Santa Fé). It is the largest species of Darwin's finch both in total size and size of beak. It has a large, short beak for cracking nuts to get food. Gallery File:Large ground finch (4229044630).jpg, left, Large ground finch File:Geospiza magnirostris.jpg, left, One of Darwin's finches. Charles and Chatham Islands, Galapagos Archipelago. References Geospiza ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Darwin's Finches
Darwin's finches (also known as the Galápagos finches) are a group of about 18 species of passerine birds. They are well known for their remarkable diversity in beak form and function. They are often classified as the subfamily Geospizinae or tribe Geospizini. They belong to the tanager family and are not closely related to the true finches. The closest known relative of the Galápagos finches is the South American '' Tiaris obscurus''. They were first collected when the second voyage of the ''Beagle'' visited the Galápagos Islands, with Charles Darwin on board as a gentleman naturalist. Apart from the Cocos finch, which is from Cocos Island, the others are found only on the Galápagos Islands. The term "Darwin's finches" was first applied by Percy Lowe in 1936, and popularised in 1947 by David Lack in his book ''Darwin's Finches''. Lack based his analysis on the large collection of museum specimens collected by the 1905–06 Galápagos expedition of the California Academy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daphne Major
Daphne Major is a volcanic island just north of Santa Cruz Island and just west of the Baltra Airport in the Archipelago of Colón, commonly known as the Galápagos Islands. It consists of a tuff crater, devoid of trees, whose rim rises above the sea. Though easily accessible to most visitors to the Galápagos, the national park service has highly restricted visits to this island, and it is primarily used for scientific research. An intensive study of Darwin's finches was conducted here by biologists Peter and Rosemary Grant over a period of 20 years. They examined the behaviour and life cycles of finches, demonstrating the role of natural selection in producing biological evolution. Their efforts were documented in the Pulitzer Prize–winning book ''The Beak of the Finch''. Daphne is home to a variety of other birds including Galápagos martins, blue-footed booby, Nazca booby, short-eared owls, red-billed tropicbirds and magnificent frigatebirds. References *B. Rosemary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Common Cactus Finch
The common cactus finch or small cactus finch (''Geospiza scandens'') is a species of bird in the Darwin's finch group of the tanager family Thraupidae. It is endemic to the Galapagos Islands, where it is found on most islands, with the notable exception of Fernandina, Española, Genovesa, Darwin and Wolf. Most of these islands are inhabited by its close relative, the Española cactus finch. Its natural habitats are dry scrubland and woodland. It is usually closely associated with the cactus '' Opuntia''. Taxonomy The common cactus finch is one of nine species in the genus ''Geospiza ''Geospiza'' is a genus of bird in the tanager family Thraupidae. All species in the genus are endemic to the Galápagos Islands. Together with related genera, they are collectively known as Darwin's finches. Although in the past, they were class ...'', part of a group of closely related species known as Darwin's finches.Swash and Stills 2005, p. 100. There are four recognized subspecies: *'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medium Ground Finch
The medium ground finch (''Geospiza fortis'') is a species of bird in the family Thraupidae. It is endemic to the Galapagos Islands. Its primary natural habitat is tropical shrubland. One of Darwin's finches, the species was the first which scientists have observed evolving in real-time. The population of medium ground finches has been experiencing inbreeding depression due to small population numbers. Inbreeding depression occurs when there is a decrease in fitness due to individuals mating with genetic relatives. Typically, this leads to a loss of genetic diversity and a reduction in heterozygosity. Description Like the other members of its genus, the medium ground finch is strongly sexually dimorphic; the female's plumage is brown and streaky, while male's is solid black, with white tips to the undertail coverts. The bird measures in length—which falls between the lengths of the small and large ground finches. The bill of this species is quite variable in size, though the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Large Ground Finch
The large ground finch (''Geospiza magnirostris'') is a species of bird. One of Darwin's finches, it is now placed in the family Thraupidae and was formerly in the Emberizidae. It is endemic 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 else ... to the Galapagos Islands, and is found in the arid zone of most of the archipelago, though it is absent from the southeastern islands ( Floreana, Española, San Cristóbal, and Santa Fé). It is the largest species of Darwin's finch both in total size and size of beak. It has a large, short beak for cracking nuts to get food. Gallery File:Large ground finch (4229044630).jpg, left, Large ground finch File:Geospiza magnirostris.jpg, left, One of Darwin's finches. Charles and Chatham Islands, Galapagos Archipelago. References Geospiza ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Española Cactus Finch
The Española cactus finch (''Geospiza conirostris''), is a species of bird in the tanager family Thraupidae. It is one of Darwin's finches, and is endemic to the Galápagos islands, where it is restricted to Española, Genovesa, and the Darwin and Wolf Islands. This rather dark bird resembles the smaller and finer-beaked common cactus finch, but the two species do not co-inhabit any island. Its natural habitat is dry shrubland and it is commonly seen on the ground. Its main food source is the cactus '' Opuntia''. Taxonomy The Española cactus finch is one of Darwin's finches, a group of closely related birds that evolved on the Galápagos Islands. The group is related to the ''Tiaris'' grassquits, which are found in South America and the Caribbean. An ancestral relative of those grassquits arrived on the Galápagos Islands some 2–3 million years ago, and the Española cactus finch is one of the species that evolved from that ancestor.Grant & Grant (2008), p. 25. From a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peter And Rosemary Grant
Peter Raymond Grant (born October 26, 1936) and Barbara Rosemary Grant (born October 8, 1936) are a British married couple who are evolutionary biologists at Princeton University. Each currently holds the position of emeritus professor. They are known for their work with Darwin's finches on Daphne Major, one of the Galápagos Islands. Since 1973, the Grants have spent six months of every year capturing, tagging, and taking blood samples from finches on the island. They have worked to show that natural selection can be seen within a single lifetime, or even within a couple of years. Charles Darwin originally thought that natural selection was a long, drawn out process but the Grants have shown that these changes in populations can happen very quickly. In 1994, they were awarded the Leidy Award from the Academy of Natural Sciences of Philadelphia. The Grants were the subject of the book '' The Beak of the Finch: A Story of Evolution in Our Time'' by Jonathan Weiner, which won ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Princeton University
Princeton University is a private university, private research university in Princeton, New Jersey. Founded in 1746 in Elizabeth, New Jersey, Elizabeth as the College of New Jersey, Princeton is the List of Colonial Colleges, fourth-oldest institution of higher education in the United States and one of the nine colonial colleges chartered before the American Revolution. It is one of the highest-ranked universities in the world. The institution moved to Newark, New Jersey, Newark in 1747, and then to the current site nine years later. It officially became a university in 1896 and was subsequently renamed Princeton University. It is a member of the Ivy League. The university is governed by the Trustees of Princeton University and has an endowment of $37.7 billion, the largest List of colleges and universities in the United States by endowment, endowment per student in the United States. Princeton provides undergraduate education, undergraduate and graduate education, graduate in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Big Bird (bird)
Big Bird, also known as the Big Bird lineage, is one of the species of Darwin's finches that is exclusively present on Daphne Major of the Galápagos islands. It originated from a mixed-breed (hybrid) of the Española cactus finch (''Geospiza conirostris'') and the medium ground finch (''Geospiza fortis'') that immigrated to Daphne Major in 1981. It resembles the medium ground finch but is relatively larger, hence, the name. The original Big Bird bred with a female medium ground finch and the offspring tend to breed only with their own family members, thereby giving rise to reproductive isolation and undergoing speciation. Discovered by the research team of Peter and Rosemary Grant, the formation of Big Birds as a distinct species is considered as an instance of observed speciation and as a process of evolution by natural selection Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of ev ... [...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 tim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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