Ecological speciationEcological speciation is a form of speciation arising from reproductive isolation that occurs due to an ecological factor that reduces or eliminates gene flow between two populations of a species. Ecological factors can include changes in the environmental conditions in which a species experiences, such as behavioral changes involving predation, predator avoidance, pollinator attraction, and foraging; as well as changes in mate choice due to sexual selection or communication systems.
Animal husbandryAnimal husbandry is the branch of agriculture concerned with animals that are raised for meat, fibre, milk, or other products. It includes day-to-day care, selective breeding, and the raising of livestock. Husbandry has a long history, starting with the Neolithic Revolution when animals were first domesticated, from around 13,000 BC onwards, predating farming of the first crops. By the time of early civilisations such as ancient Egypt, cattle, sheep, goats, and pigs were being raised on farms.
NeolithicThe Neolithic or New Stone Age (from Greek νέος 'new' and λίθος 'stone') is an archaeological period, the final division of the Stone Age in Europe, Asia and Africa. It saw the Neolithic Revolution, a wide-ranging set of developments that appear to have arisen independently in several parts of the world. This "Neolithic package" included the introduction of farming, domestication of animals, and change from a hunter-gatherer lifestyle to one of settlement. The term 'Neolithic' was coined by Sir John Lubbock in 1865 as a refinement of the three-age system.
Human genetic variationHuman genetic variation is the genetic differences in and among populations. There may be multiple variants of any given gene in the human population (alleles), a situation called polymorphism. No two humans are genetically identical. Even monozygotic twins (who develop from one zygote) have infrequent genetic differences due to mutations occurring during development and gene copy-number variation. Differences between individuals, even closely related individuals, are the key to techniques such as genetic fingerprinting.
Molecular phylogeneticsMolecular phylogenetics (məˈlɛkjᵿlər_ˌfaɪloʊdʒəˈnɛtɪks,_mɒ-,_moʊ-) is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to determine the processes by which diversity among species has been achieved. The result of a molecular phylogenetic analysis is expressed in a phylogenetic tree.
GoatThe goat or domestic goat (Capra hircus) is a domesticated species of goat-antelope typically kept as livestock. It was domesticated from the wild goat (C. aegagrus) of Southwest Asia and Eastern Europe. The goat is a member of the animal family Bovidae and the tribe Caprini, meaning it is closely related to the sheep. There are over 300 distinct breeds of goat. It is one of the oldest domesticated species of animal, according to archaeological evidence that its earliest domestication occurred in Iran at 10,000 calibrated calendar years ago.
Academic degreeAn academic degree is a qualification awarded to a student upon successful completion of a course of study in higher education, usually at a college or university. These institutions often offer degrees at various levels, usually divided into undergraduate and postgraduate degrees. The most common undergraduate degree is the bachelor's degree, although some educational systems offer lower level undergraduate degrees such as associate and foundation degrees. Common postgraduate degrees include master's degrees and doctorates.
Associate degreeAn associate degree or associate's degree is an undergraduate degree awarded after a course of post-secondary study lasting two to three years. It is a level of academic qualification above a high school diploma and below a bachelor's degree. The first associate degrees were awarded in the UK (where they are no longer awarded) in 1873 before spreading to the US in 1898. In the United States, the associate degree may allow transfer into the third year of a bachelor's degree.
Fertile CrescentThe Fertile Crescent (الهلال الخصيب, הסהר הפורה) is a crescent-shaped region in the Middle East, spanning modern-day Iraq, Syria, Lebanon, Israel, Palestine and Jordan, together with the northern region of Kuwait, southeastern region of Turkey and the western portion of Iran. Some authors also include Cyprus and Northern Egypt. The Fertile Crescent is believed to be the very first region where settled farming emerged as people started the process of clearance and modification of natural vegetation to grow newly domesticated plants as crops.
Molecular clockThe molecular clock is a figurative term for a technique that uses the mutation rate of biomolecules to deduce the time in prehistory when two or more life forms diverged. The biomolecular data used for such calculations are usually nucleotide sequences for DNA, RNA, or amino acid sequences for proteins. The benchmarks for determining the mutation rate are often fossil or archaeological dates. The molecular clock was first tested in 1962 on the hemoglobin protein variants of various animals, and is commonly used in molecular evolution to estimate times of speciation or radiation.
