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Nabeul Tortoise
The Tunisian tortoise or Nabeul tortoise (''Testudo graeca nabeulensis'') is a subspecies of Greek tortoises. It was originally described as a new species in 1990, and even placed in a distinct genus. The spur-thighed or "Greek" tortoises are usually collectively referred to as ''Testudo graeca'', but this covers a wide variety of subspecies that have very different ecological and morphological characteristics and appear to comprise at least three phylogenetic lineages.van der Kuyl, Antoinette C.; Ballasina, Donato L. Ph. & Zorgdrager, Fokla (2005): Mitochondrial haplotype diversity in the tortoise species ''Testudo graeca'' from North Africa and the Middle East. '' BMC Evol. Biol.'' 5: 29. (HTML/PDF fulltext + supplementary material) As its name implies, it is found in Tunisia and nearby Algeria. Description and ecology The Tunisian tortoise is a relatively small tortoise. The adult males usually have carapaces that seldom exceed 13 cm (about 4.5 in), whilst the adult f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Furculachelys
''Testudo'', the Mediterranean tortoises, are a genus of tortoises found in North Africa, Western Asia, and Europe. Several species are under threat in the wild, mainly from habitat destruction. Background They are small tortoises, ranging in length from 7.0 to 35 cm and in weight from 0.7 to 7.0 kg. Systematics The systematics and Taxonomy (biology), taxonomy of ''Testudo'' is notoriously problematic. Highfield and Martin commented: Synonymies on ''Testudo'' are notoriously difficult to compile with any degree of accuracy. The status of species referred has undergone a great many changes, each change introducing an additional level of complexity and making bibliographic research on the taxa extremely difficult. Most early and not a few later checklists contain a very high proportion of entirely spurious entries, and a considerable number of described species are now considered invalid – either because they are homonyms, non-binomial or for some other reason. Since ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semiarid
A semi-arid climate, semi-desert climate, or steppe climate is a dry climate sub-type. It is located on regions that receive precipitation below potential evapotranspiration, but not as low as a desert climate. There are different kinds of semi-arid climates, depending on variables such as temperature, and they give rise to different biomes. Defining attributes of semi-arid climates A more precise definition is given by the Köppen climate classification, which treats steppe climates (''BSk'' and ''BSh'') as intermediates between desert climates (BW) and humid climates (A, C, D) in ecological characteristics and agricultural potential. Semi-arid climates tend to support short, thorny or scrubby vegetation and are usually dominated by either grasses or shrubs as it usually can't support forests. To determine if a location has a semi-arid climate, the precipitation threshold must first be determined. The method used to find the precipitation threshold (in millimeters): *multiply by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scientific Name
In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin grammatical forms, although they can be based on words from other languages. Such a name is called a binomial name (which may be shortened to just "binomial"), a binomen, name or a scientific name; more informally it is also historically called a Latin name. The first part of the name – the '' generic name'' – identifies the genus to which the species belongs, whereas the second part – the specific name or specific epithet – distinguishes the species within the genus. For example, modern humans belong to the genus ''Homo'' and within this genus to the species ''Homo sapiens''. ''Tyrannosaurus rex'' is likely the most widely known binomial. The ''formal'' introduction of this system of naming species is credit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maghreb
The Maghreb (; ar, الْمَغْرِب, al-Maghrib, lit=the west), also known as the Arab Maghreb ( ar, المغرب العربي) and Northwest Africa, is the western part of North Africa and the Arab world. The region includes Algeria, Libya, Mauritania (also considered part of West Africa), Morocco, and Tunisia. The Maghreb also includes the disputed territory of Western Sahara (controlled mostly by Morocco and partly by the Sahrawi Arab Democratic Republic) and the Spanish cities Ceuta and Melilla.Article 143. As of 2018, the region had a population of over 100 million people. Through the 18th and 19th centuries, English sources often referred to the region as the Barbary Coast or the Barbary States, a term derived from the demonym of the Berbers. Sometimes, the region is referred to as the Land of the Atlas, referring to the Atlas Mountains, which are located within it. The Maghreb is usually defined as encompassing much of the northern part of Africa, including ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haplotype
A haplotype ( haploid genotype) is a group of alleles in an organism that are inherited together from a single parent. Many organisms contain genetic material ( DNA) which is inherited from two parents. Normally these organisms have their DNA organized in two sets of pairwise similar chromosomes. The offspring gets one chromosome in each pair from each parent. A set of pairs of chromosomes is called diploid and a set of only one half of each pair is called haploid. The haploid genotype (haplotype) is a genotype that considers the singular chromosomes rather than the pairs of chromosomes. It can be all the chromosomes from one of the parents or a minor part of a chromosome, for example a sequence of 9000 base pairs. However, there are other uses of this term. First, it is used to mean a collection of specific alleles (that is, specific DNA sequences) in a cluster of tightly linked genes on a chromosome that are likely to be inherited together—that is, they are likely to be con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
12S RRNA
Mitochondrially encoded 12S ribosomal RNA (often abbreviated as 12S or 12S rRNA), also known as Mitochondrial-derived peptide MOTS-c or Mitochondrial open reading frame of the 12S rRNA-c is the SSU rRNA of the mitochondrial ribosome. In humans, 12S is encoded by the ''MT-RNR1'' gene and is 959 nucleotides long. MT-RNR1 is one of the 37 genes contained in animal mitochondria genomes. Their 2 rRNA, 22 tRNA and 13 mRNA genes are very useful in phylogenetic studies, in particular the 12S and 16S rRNAs. The 12S rRNA is the mitochondrial homologue of the prokaryotic 16S and eukaryotic nuclear 18S ribosomal RNAs. Mutations in the MT-RNR1 gene may be associated with hearing loss. Structure The ''MT-RNR1'' gene is located on the p arm of the mitochondrial DNA at position 12 and it spans 953 base pairs. Function The ''MT-RNR1'' gene encodes for a protein responsible for regulating insulin sensitivity and metabolic homeostasis. The protein acts as an inhibitor of the folate cycle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MtDNA
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 derived from t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paraphyletic
In taxonomy (general), taxonomy, a group is paraphyletic if it consists of the group's most recent common ancestor, last common ancestor and most of its descendants, excluding a few Monophyly, monophyletic subgroups. The group is said to be paraphyletic ''with respect to'' the excluded subgroups. In contrast, a monophyletic group (a clade) includes a common ancestor and ''all'' of its descendants. The terms are commonly used in phylogenetics (a subfield of biology) and in the tree model of historical linguistics. Paraphyletic groups are identified by a combination of Synapomorphy and apomorphy, synapomorphies and symplesiomorphy, symplesiomorphies. If many subgroups are missing from the named group, it is said to be polyparaphyletic. The term was coined by Willi Hennig to apply to well-known taxa like Reptilia (reptiles) which, as commonly named and traditionally defined, is paraphyletic with respect to mammals and birds. Reptilia contains the last common ancestor of reptiles a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lumpers And Splitters
Lumpers and splitters are opposing factions in any discipline that has to place individual examples into rigorously defined categories. The lumper–splitter problem occurs when there is the desire to create classifications and assign examples to them, for example schools of literature, biological taxa and so on. A "lumper" is a person who assigns examples broadly, assuming that differences are not as important as signature similarities. A "splitter" is one who makes precise definitions, and creates new categories to classify samples that differ in key ways. Origin of the terms The earliest known use of these terms was by Charles Darwin, in a letter to Joseph Dalton Hooker in 1857: ''It is good to have hair-splitters & lumpers''. They were introduced more widely by George G. Simpson in his 1945 work ''The Principles of Classification and a Classification of Mammals''. As he put it: A later use can be found in the title of a 1969 paper "On lumpers and splitters ..." by the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Russian Tortoise
The Russian tortoise (''Testudo horsfieldii''), also commonly known as the Afghan tortoise, the Central Asian tortoise, Horsfield's tortoise, four-clawed tortoise, and the (Russian) steppe tortoise, is a threatened species of tortoise in the family Testudinidae. The species is endemic to Central Asia. Human activities in its native habitat contribute to its threatened status. Etymology Both the specific name, ''horsfieldii'', and the common name "Horsfield's tortoise" are in honor of the American naturalist Thomas Horsfield. Systematics This species is traditionally placed in '' Testudo''. Due to distinctly different morphological characteristics, the monotypic genus ''Agrionemys'' was proposed for it in 1966, and was accepted for several decades, although not unanimously. DNA sequence analysis generally concurred, but not too robustly so. However, in 2021, it was again reclassified in ''Testudo'' by the Turtle Taxonomy Working Group and the Reptile Database, with ''Agrionem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Testudo (genus)
''Testudo'', the Mediterranean tortoises, are a genus of tortoises found in North Africa, Western Asia, and Europe. Several species are under threat in the wild, mainly from habitat destruction. Background They are small tortoises, ranging in length from 7.0 to 35 cm and in weight from 0.7 to 7.0 kg. Systematics The systematics and taxonomy of ''Testudo'' is notoriously problematic. Highfield and Martin commented: Synonymies on ''Testudo'' are notoriously difficult to compile with any degree of accuracy. The status of species referred has undergone a great many changes, each change introducing an additional level of complexity and making bibliographic research on the taxa extremely difficult. Most early and not a few later checklists contain a very high proportion of entirely spurious entries, and a considerable number of described species are now considered invalid – either because they are homonyms, non-binomial or for some other reason. Since then, DNA sequence ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polymorphism (biology)
In biology, polymorphism is the occurrence of two or more clearly different morphs or forms, also referred to as alternative ''phenotypes'', in the population of a species. To be classified as such, morphs must occupy the same habitat at the same time and belong to a panmictic population (one with random mating). Ford E.B. 1965. ''Genetic polymorphism''. Faber & Faber, London. Put simply, polymorphism is when there are two or more possibilities of a trait on a gene. For example, there is more than one possible trait in terms of a jaguar's skin colouring; they can be light morph or dark morph. Due to having more than one possible variation for this gene, it is termed 'polymorphism'. However, if the jaguar has only one possible trait for that gene, it would be termed "monomorphic". For example, if there was only one possible skin colour that a jaguar could have, it would be termed monomorphic. The term polyphenism can be used to clarify that the different forms arise from the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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