Deep homologyIn evolutionary developmental biology, the concept of deep homology is used to describe cases where growth and differentiation processes are governed by genetic mechanisms that are homologous and deeply conserved across a wide range of species. In 1822, the French zoologist Étienne Geoffroy Saint-Hilaire dissected a crayfish, discovering that its body is organised like a vertebrate's, but inverted belly to back (dorsoventrally): I just found that all the soft organs, that is to say, the principal organs of life are found in crustaceans, and so in insects, in the same order, in the same relationships and with the same arrangement as their analogues in the high vertebrate animals .
Generation of AnimalsThe Generation of Animals (or On the Generation of Animals; Greek: Περὶ ζῴων γενέσεως (Peri Zoion Geneseos); Latin: De Generatione Animalium) is one of the biological works of the Corpus Aristotelicum, the collection of texts traditionally attributed to Aristotle (384 – 322BC). The work provides an account of animal reproduction, gestation and heredity. Generation of Animals consists of five books, which are themselves split into varying numbers of chapters. Most editions of this work categorise it with Bekker numbers.
Science in classical antiquityScience in classical antiquity encompasses inquiries into the workings of the world or universe aimed at both practical goals (e.g., establishing a reliable calendar or determining how to cure a variety of illnesses) as well as more abstract investigations belonging to natural philosophy. Classical antiquity is traditionally defined as the period between 8th century BC and the 6th century AD, and the ideas regarding nature that were theorized during this period were not limited to science but included myths as well as religion.
Four causesThe four causes or four explanations are, in Aristotelian thought, four fundamental types of answer to the question "why?", in analysis of change or movement in nature: the material, the formal, the efficient, and the final. Aristotle wrote that "we do not have knowledge of a thing until we have grasped its why, that is to say, its cause." While there are cases in which classifying a "cause" is difficult, or in which "causes" might merge, Aristotle held that his four "causes" provided an analytical scheme of general applicability.
Teleology in biologyTeleology in biology is the use of the language of goal-directedness in accounts of evolutionary adaptation, which some biologists and philosophers of science find problematic. The term teleonomy has also been proposed. Before Darwin, organisms were seen as existing because God had designed and created them; their features such as eyes were taken by natural theology to have been made to enable them to carry out their functions, such as seeing.
Tinbergen's four questionsTinbergen's four questions, named after 20th century biologist Nikolaas Tinbergen, are complementary categories of explanations for animal behaviour. These are also commonly referred to as levels of analysis. It suggests that an integrative understanding of behaviour must include ultimate (evolutionary) explanations, in particular: behavioural adaptive functions phylogenetic history; and the proximate explanations underlying physiological mechanisms ontogenetic/developmental history.
Crane (bird)Cranes are a family, the Gruidae, of large, long-legged, and long-necked birds in the group Gruiformes. The 15 species of cranes are placed in three genera, Antigone, Balearica, and Grus. Unlike the similar-looking but unrelated herons, cranes fly with necks outstretched, not pulled back. Cranes live on most continents, with the exception of Antarctica and South America. They are opportunistic feeders that change their diets according to the season and their own nutrient requirements.
Function (biology)In evolutionary biology, function is the reason some object or process occurred in a system that evolved through natural selection. That reason is typically that it achieves some result, such as that chlorophyll helps to capture the energy of sunlight in photosynthesis. Hence, the organism that contains it is more likely to survive and reproduce, in other words the function increases the organism's fitness. A characteristic that assists in evolution is called an adaptation; other characteristics may be non-functional spandrels, though these in turn may later be co-opted by evolution to serve new functions.
History of AnimalsHistory of Animals (Τῶν περὶ τὰ ζῷα ἱστοριῶν, Ton peri ta zoia historion, "Inquiries on Animals"; Historia Animalium, "History of Animals") is one of the major texts on biology by the ancient Greek philosopher Aristotle, who had studied at Plato's Academy in Athens. It was written in the fourth century BC; Aristotle died in 322 BC. Generally seen as a pioneering work of zoology, Aristotle frames his text by explaining that he is investigating the what (the existing facts about animals) prior to establishing the why (the causes of these characteristics).
ZoologyZoology (zoʊˈɒlədʒi) is the scientific study of animals. Its studies include the structure, embryology, classification, habits, and distribution of all animals, both living and extinct, and how they interact with their ecosystems. Zoology is one of the primary branches of biology. The term is derived from Ancient Greek ζῷον, ('animal'), and λόγος, logos ('knowledge', 'study'). Although humans have always been interested in the natural history of the animals they saw around them, and used this knowledge to domesticate certain species, the formal study of zoology can be said to have originated with Aristotle.
