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Mexican Wolf
The Mexican wolf (''Canis lupus baileyi''), also known as the lobo,; nah, Cuetlāchcoyōtl is a subspecies of gray wolf native to southeastern Arizona and southern New Mexico in the United States, and northern Mexico; it also previously ranged into western Texas. It is the smallest of North America's gray wolves, and is similar to the Great Plains wolf (''C. l. nubilus''), though it is distinguished by its smaller, narrower skull and its darker pelt, which is yellowish-gray and heavily clouded with black over the back and tail.Bailey, V. (1932), Mammals of New Mexico. U.S. Department of Agriculture, Bureau of Biological Survey. North American Fauna No. 53. Washington, D.C. Pages 303-308. Its ancestors were likely the first gray wolves to enter North America after the extinction of the Beringian wolf, as indicated by its southern range and basal physical and genetic characteristics. Though once held in high regard in Pre-Columbian Mexico, it is the most endangered gray wolf s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sevilleta National Wildlife Refuge
The Sevilleta National Wildlife Refuge is a protected area of New Mexico managed by the United States Fish and Wildlife Service as part of the National Wildlife Refuge System. It is located in the Chihuahuan Desert, 20 miles north of Socorro, New Mexico. The Rio Salado and the Rio Grande flow through the refuge. History The area that is now the Sevilleta National Wildlife Refuge was inhabited by the Piro Pueblo prior to Spanish arrival in 1598 in what is now the southwestern part of the United States. El Camino Real de Tierra Adentro, which passed through the area, was the main transportation route from Santa Fe, New Mexico to Mexico City, Mexico. In 1680, Governor Antonio de Otermin of Santa Fe retreated through the area to El Paso during the Pueblo Revolt. By this time, the Piro Pueblo, as well as many other Pueblos, were already abandoned due to Spaniard encroachment. After the Piro were gone, the Spanish built a military post called "New Sevilla" on the site. This post ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Academies Of Sciences, Engineering, And Medicine
The National Academies of Sciences, Engineering, and Medicine (also known as NASEM or the National Academies) are the collective scientific national academy of the United States. The name is used interchangeably in two senses: (1) as an umbrella term for its three quasi-independent honorific member organizations the National Academy of Sciences (NAS), the National Academy of Engineering (NAE), and the National Academy of Medicine (NAM); and (2) as the brand for studies and reports issued by the operating arm of the three academies, the National Research Council (NRC). The NRC was first formed in 1916 as an activity of the NAS. Now jointly governed by all three academies, the NRC produces some 200 publications annually which are published by the National Academies Press. The reports produced by the National Academies have been characterized as reflective of scientific consensus. History The US National Academy of Sciences was created by an Act of Incorporation dated March 3 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laurentide Ice Sheet
The Laurentide Ice Sheet was a massive sheet of ice that covered millions of square miles, including most of Canada and a large portion of the Northern United States, multiple times during the Quaternary glacial epochs, from 2.58 million years ago to the present. The last advance covered most of northern North America between c. 95,000 and c. 20,000 years before the present day and, among other geomorphological effects, gouged out the five Great Lakes and the hosts of smaller lakes of the Canadian Shield. These lakes extend from the eastern Northwest Territories, through most of northern Canada, and the upper Midwestern United States (Minnesota, Wisconsin, and Michigan) to the Finger Lakes, through Lake Champlain and Lake George areas of New York, across the northern Appalachians into and through all of New England and Nova Scotia. At times, the ice sheet's southern margin included the present-day sites of coastal towns of the Northeastern United States, and cities suc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dire Wolf
The dire wolf (''Aenocyon dirus'' ) is an extinct canine. It is one of the most famous prehistoric carnivores in North America, along with its extinct competitor ''Smilodon''. The dire wolf lived in the Americas and eastern Asia during the Late Pleistocene and Early Holocene epochs (125,000–9,500 years ago). The species was named in 1858, four years after the first specimen had been found. Two subspecies are recognized: ''Aenocyon dirus guildayi'' and ''Aenocyon dirus dirus''. The largest collection of its fossils has been obtained from the Rancho La Brea Tar Pits in Los Angeles. Dire wolf remains have been found across a broad range of habitats including the plains, grasslands, and some forested mountain areas of North America, the arid savanna of South America, and the steppes of eastern Asia. The sites range in elevation from sea level to . Dire wolf fossils have rarely been found north of 42°N latitude; there have been only five unconfirmed reports above this latitude. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vancouver Island Wolf
The Vancouver Coastal sea wolf or Vancouver coastal island wolf (''Canis lupus crassodon'') is a subspecies of grey wolf, endemic to Great Bear Rainforest and northern Vancouver Island within the Pacific Northwest Coast of North America. It lives in packs of about five to twenty. These coastal wolves are popularly known as sea wolves. In some coastal regions, the main food source is fish, making up 90 percent of their diet, with salmon accounting for nearly a quarter of that. They also forage on barnacles, clams, herring eggs, seals, river otters, and whale carcasses. These wolves will also commonly feed on deer and small mammals. Description Sea wolves of the Great Bear Rainforest are fast, powerful distance swimmers and move stealthily in the water, their backs and bodies submerged and with only their eyes, ears and snouts peeking above the surface. There are packs living on the big island off the coast, which is from Bella Bella, and there is no way for wolves to get the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phylogenetic Tree
A phylogenetic tree (also phylogeny or evolutionary tree Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA.) is a branching diagram or a tree showing the evolutionary relationships among various biological species or other entities based upon similarities and differences in their physical or genetic characteristics. All life on Earth is part of a single phylogenetic tree, indicating common ancestry. In a ''rooted'' phylogenetic tree, each node with descendants represents the inferred most recent common ancestor of those descendants, and the edge lengths in some trees may be interpreted as time estimates. Each node is called a taxonomic unit. Internal nodes are generally called hypothetical taxonomic units, as they cannot be directly observed. Trees are useful in fields of biology such as bioinformatics, systematics, and phylogenetics. ''Unrooted'' trees illustrate only the relatedness of the leaf nodes and do not require the ancestral root to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clade
A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, the equivalent Latin term ''cladus'' (plural ''cladi'') is often used in taxonomical literature. The common ancestor may be an individual, a population, or a species (extinct or extant). Clades are nested, one in another, as each branch in turn splits into smaller branches. These splits reflect evolutionary history as populations diverged and evolved independently. Clades are termed monophyletic (Greek: "one clan") groups. Over the last few decades, the cladistic approach has revolutionized biological classification and revealed surprising evolutionary relationships among organisms. Increasingly, taxonomists try to avoid naming taxa that are not clades; that is, taxa that are not monophyletic. Some of the relationships between org ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Southern Rocky Mountain Wolf
The southern Rocky Mountain wolf (''Canis lupus youngi'') is an extinct subspecies of gray wolf which was once distributed over southeastern Idaho, southwestern Wyoming, northeastern Nevada, Utah, western and central Colorado, northwestern Arizona (but north of the Grand Canyon), and northwestern New Mexico. It was a light-colored, medium-sized subspecies closely resembling the Great Plains wolf (''C. l. nubilus''), though larger, with more blackish-buff hairs on the back. This wolf was extirpated by 1935. Wolves of the subspecies ''Canis lupus occidentalis'' have now been reestablished in Idaho and Wyoming. Taxonomy This wolf is recognized as a subspecies of ''Canis lupus'' in the taxonomic authority ''Mammal Species of the World'' (2005). A 2005 study compared the mitochondrial DNA sequences of modern wolves with those from 34 specimens dated between 1856 and 1915. The historic population was found to possess twice the genetic diversity of modern wolves, which suggests that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetic Diversity
Genetic diversity is the total number of genetic characteristics in the genetic makeup of a species, it ranges widely from the number of species to differences within species and can be attributed to the span of survival for a species. It is distinguished from '' genetic variability'', which describes the tendency of genetic characteristics to vary. Genetic diversity serves as a way for populations to adapt to changing environments. With more variation, it is more likely that some individuals in a population will possess variations of alleles that are suited for the environment. Those individuals are more likely to survive to produce offspring bearing that allele. The population will continue for more generations because of the success of these individuals. The academic field of population genetics includes several hypotheses and theories regarding genetic diversity. The neutral theory of evolution proposes that diversity is the result of the accumulation of neutral substitutio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DNA Sequences
A nucleic acid sequence is a succession of bases signified by a series of a set of five different letters that indicate the order of nucleotides forming alleles within a DNA (using GACT) or RNA (GACU) molecule. By convention, sequences are usually presented from the 5' end to the 3' end. For DNA, the sense strand is used. Because nucleic acids are normally linear (unbranched) polymers, specifying the sequence is equivalent to defining the covalent structure of the entire molecule. For this reason, the nucleic acid sequence is also termed the primary structure. The sequence has capacity to represent information. Biological deoxyribonucleic acid represents the information which directs the functions of an organism. Nucleic acids also have a secondary structure and tertiary structure. Primary structure is sometimes mistakenly referred to as ''primary sequence''. Conversely, there is no parallel concept of secondary or tertiary sequence. Nucleotides Nucleic acids consis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mitochondrial DNA
Mitochondrial DNA (mtDNA or mDNA) is the DNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, such as adenosine triphosphate (ATP). Mitochondrial DNA is only a small portion of the DNA in a eukaryotic cell; most of the DNA can be found in the cell nucleus and, in plants and algae, also in plastids such as chloroplasts. Human mitochondrial DNA was the first significant part of the human genome to be sequenced. This sequencing revealed that the human mtDNA includes 16,569 base pairs and encodes 13 proteins. Since animal mtDNA evolves faster than nuclear genetic markers, it represents a mainstay of phylogenetics and evolutionary biology. It also permits an examination of the relatedness of populations, and so has become important in anthropology and biogeography. Origin Nuclear and mitochondrial DNA are thought to be of separate evolutionary origin, with the mtDNA being derive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genes
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a basic unit of heredity and the molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protein-coding genes and noncoding genes. During gene expression, the DNA is first copied into RNA. The RNA can be directly functional or be the intermediate template for a protein that performs a function. The transmission of genes to an organism's offspring is the basis of the inheritance of phenotypic traits. These genes make up different DNA sequences called genotypes. Genotypes along with environmental and developmental factors determine what the phenotypes will be. Most biological traits are under the influence of polygenes (many different genes) as well as gene ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
