General Zoology

• Zoology, also known as animal science, is a field of biological sciences that deals with animals.
• Zoology studies about the morphological, anatomical and physiological characteristics of animals, from their microscopic to their macroscopic structures.
• Zoology also includes the evolutionary, taxonomical and ecological perspectives on animal life.
• Animals are multicellular, eukaryotic, lack cell walls and are heterotrophs.
• Species is the basic unit of classification, a group of populations that can interbreed and as a consequence gene either actually or potentially exchanged, referred to as biological species concept.
• Allopatric speciation happens if there are geographic barriers such as a mountain range or river between subpopulations, preventing mating success due to adaptations to different environments or genetic drift.
• Sympatric speciation happens within a single population, where speciation refers to a process when two groups of identical species lived in identical geographical areas, they evolve in such a way that they could no longer interbreed.
• Parapatric speciation happens within demes or small, local populations, where members experience different selection pressures in a deme.
• Speciation is the formation of new species, where interbreeding is avoided between subpopulations, resulting in reproductive isolation or non-occurrence of gene flow.
• There are an estimated 1.5 million+ animals, with 3 million undescribed, and they are classified into 35 current Phyla.
• Phylum Arthropoda contains 1.2 million+ named species.
• Mammals represent only about 5,000 named species.
• Structural Zoology includes fields such as Morphology, Anatomy, Histology, and Cytology.
• Developmental Zoology includes fields such as Embryology, Ontogeny, and Genetics.
• Antoine Van Leeuwenhoek devoted his lifetime towards observing new undiscovered areas of biology under the microscope during the 1600s and 1700s.
• Robert Hooke was a renowned innovator who had improved the compound microscope and observed what he called, "little boxes or cells", marking the birth of what we understand as cells.
• Pierre Belon noted several anatomical similarities between the human skeleton and that of a bird.
• Conrad Gesner contributed to the 16th century progression of zoology and produced a five-volume bibliography of his knowledge of plants and animals entitled, History Animalum.
• Pierre Belon's contributions led others to build upon comparative anatomy for various species, as well as explore more unknowns about the animal world.
• Magnus paid attention to both terrestrial and aquatic animals.
• Magnus, a Swedish naturalist, wrote 22 books on animals and humans, categorizing them based on their physiological capabilities.
• Edward Topsell was a famous natural historian who published Historie of Four-Footed Beastes and Historie of Serpents in 1607 and 1608, respectively.
• Magnus observed that the lobster and sea locust had similar movements, which were quite opposite of that of the squids, octopuses, and cuttlefishes or also known as the cephalopods.
• Pierre Belon published La nature et diversité des poissons in 1551, containing many illustrations of his observations of fishes, marine mammals, and birds.
• Functional Zoology includes fields such as Animal Physiology and Animal Behavior/Ethology.
• The Cro-Magnons, who replaced the Neanderthals long ago, used etching and cave sketches to document some of the earliest known pictures of the animals they encountered.
• Albertus Magnus, also known as Albert the Great (1193 - 1280), was one of the only natural philosophers of the late Middle Ages that gave the present-day historians an in-depth view of recorded observations during this time period.
• The medieval science era served as an important time period for the field of science.
• In his work, he collected all the known facts about approximately 500 animals, and devised the first known classification system.
• These carvings are found in various places from different individuals.
• Aristotle's System includes animals with blood, four-footed animals, animals that bear their young, animals that lay eggs, birds, fish, and animals without blood, mollusks, crabs, insects.
• Aristotle created his History of Animals that zoology became a science.
• There are two main distinctions of the medieval time period that the study of zoology has influenced: the observation and experimentation that led to information based on natural philosophy, and the use of mythology and folklore to describe natural history.
• Albert the Great's translated version of "On animals, a medieval summa zoology" is a continuation of Aristotle's keen observation and detailed work, also known as De Animalibus.
• Albertus Magnus cited particular animals according to their genus to each of their own lifestyles, their dwelling places, and their motion.
• During the Stone Age from 18,000 BC to 18,000 BC, there were several examples of deer reproduction in parietal art.
• Systematic/Taxonomy includes fields such as Protozoology, Entomology, Conchology, Malacology, Herpetology, Ornithology, Ichthyology, Helminthology, and Medical Zoology.
• Distributional Zoology includes fields such as Zoogeography, Ecology, and Historical Zoology.
• Crossing Over among the homologous chromosomes: Crossing over, as related to genetics and genomics, refers to the exchange of DNA between paired homologous chromosomes (one from each parent) that occurs during the development of egg and sperm cells (meiosis)
• Hardy - Weinberg Theorem: Allele frequencies remain constant (or at equilibrium) over generations in the absence of distressing factors.