Unicellular organismA unicellular organism, also known as a single-celled organism, is an organism that consists of a single cell, unlike a multicellular organism that consists of multiple cells. Organisms fall into two general categories: prokaryotic organisms and eukaryotic organisms. Most prokaryotes are unicellular and are classified into bacteria and archaea. Many eukaryotes are multicellular, but some are unicellular such as protozoa, unicellular algae, and unicellular fungi.
Model organismA model organism (often shortened to model) is a non-human species that is extensively studied to understand particular biological phenomena, with the expectation that discoveries made in the model organism will provide insight into the workings of other organisms. Model organisms are widely used to research human disease when human experimentation would be unfeasible or unethical. This strategy is made possible by the common descent of all living organisms, and the conservation of metabolic and developmental pathways and genetic material over the course of evolution.
EukaryoteThe eukaryotes constitute the domain of Eukaryota (juːˈkærioʊts,_-əts), organisms whose cells have a nucleus. All animals, plants, fungi, and many unicellular organisms are eukaryotes. They constitute a major group of life forms, alongside the two groups of prokaryotes, the Bacteria and the Archaea. Eukaryotes represent a small minority of the number of organisms, but due to their generally much larger size, their collective global biomass is much larger than that of prokaryotes.
History of evolutionary thoughtEvolutionary thought, the recognition that species change over time and the perceived understanding of how such processes work, has roots in antiquity—in the ideas of the ancient Greeks, Romans, Chinese, Church Fathers as well as in medieval Islamic science.
Tree of life (biology)The tree of life or universal tree of life is a metaphor, model and research tool used to explore the evolution of life and describe the relationships between organisms, both living and extinct, as described in a famous passage in Charles Darwin's On the Origin of Species (1859). The affinities of all the beings of the same class have sometimes been represented by a great tree. I believe this simile largely speaks the truth. Tree diagrams originated in the medieval era to represent genealogical relationships.
Genetically modified organismA genetically modified organism (GMO) is any organism whose genetic material has been altered using genetic engineering techniques. The exact definition of a genetically modified organism and what constitutes genetic engineering varies, with the most common being an organism altered in a way that "does not occur naturally by mating and/or natural recombination". A wide variety of organisms have been genetically modified (GM), from animals to plants and microorganisms.
Ancestry.comAncestry.com LLC is an American genealogy company based in Lehi, Utah. The largest for-profit genealogy company in the world, it operates a network of genealogical, historical records, and related genetic genealogy websites. In November 2018, the company said to have provided access to approximately 10 billion historical records, to have 3 million paying subscribers, and to have sold 18 million DNA kits to customers. By 2022, this number had risen to 30 billion records according to the company.
FlagellumA flagellum (fləˈdʒɛləm; : flagella) (Latin for 'whip' or 'scourge') is a hairlike appendage that protrudes from certain plant and animal sperm cells, and from a wide range of microorganisms to provide motility. Many protists with flagella are known as flagellates. A microorganism may have from one to many flagella. A gram-negative bacterium Helicobacter pylori for example uses its multiple flagella to propel itself through the mucus lining to reach the stomach epithelium, where it may cause a gastric ulcer to develop.
Fission (biology)Fission, in biology, is the division of a single entity into two or more parts and the regeneration of those parts to separate entities resembling the original. The object experiencing fission is usually a cell, but the term may also refer to how organisms, bodies, populations, or species split into discrete parts. The fission may be binary fission, in which a single organism produces two parts, or multiple fission, in which a single entity produces multiple parts. Organisms in the domains of Archaea and Bacteria reproduce with binary fission.
Evolutionary origin of religionThe evolutionary origin of religion and religious behavior is a field of study related to evolutionary psychology, the origin of language and mythology, and cross-cultural comparison of the anthropology of religion. Some subjects of interest include Neolithic religion, evidence for spirituality or cultic behavior in the Upper Paleolithic, and similarities in great ape behavior. Religious behavior in animals Humanity's closest living relatives are common chimpanzees and bonobos.
