Animals, behavior, anatomy, physiology, evolution, ecology, biodiversity, vertebrates, invertebrates, and animal science

Zoology

Zoology studies animals, explaining their bodies, behavior, evolution, classification, ecological roles, and relationships with humans and other life.

Core focus
Zoology studies animal diversity, anatomy, physiology, behavior, development, evolution, and ecology.
Animal kingdom
Animals are multicellular organisms that usually obtain energy by eating other organisms or organic material.
Human relevance
Zoology supports conservation, medicine, agriculture, veterinary science, pest management, and understanding human origins.
Zoology studies animal bodies, behavior, adaptation, diversity, and ecological roles.View image in OpenStax Biology 2e

What zoology studies

Zoology is the scientific study of animals. It asks how animals are built, how they move, feed, sense, reproduce, develop, behave, and adapt to their environments. The field ranges from microscopic animals in soil and water to insects, corals, fish, birds, reptiles, mammals, and extinct species known from fossils.

Animal bodies

Animal bodies vary enormously, but zoologists often compare shared problems: getting energy, exchanging gases, moving materials internally, sensing the environment, avoiding harm, and reproducing. Body plans can include symmetry, tissues, organs, digestive cavities, skeletons, limbs, nervous systems, and specialized surfaces for breathing or feeding.

Diversity and classification

Animal classification organizes species by shared ancestry and traits. Invertebrates make up most animal diversity and include sponges, cnidarians, worms, mollusks, arthropods, and many other groups. Vertebrates include fishes, amphibians, reptiles, birds, and mammals. Modern taxonomy uses anatomy, development, behavior, fossils, and DNA evidence.

Behavior

Animal behavior includes feeding, migration, mating, communication, cooperation, play, parental care, aggression, navigation, and learning. Some behaviors are strongly shaped by inherited neural programs, while others depend on experience. Ethology and behavioral ecology connect behavior to survival, reproduction, social life, and environmental pressures.

Evolution and adaptation

Animals have evolved through mutation, natural selection, genetic drift, gene flow, and changing environments. Adaptations can be anatomical, physiological, behavioral, or developmental. Wings, venom, camouflage, echolocation, social colonies, warm-bloodedness, and complex eyes are examples of animal traits that evolved in specific ecological contexts.

Animals in ecosystems

Animals shape ecosystems as predators, prey, grazers, pollinators, seed dispersers, parasites, scavengers, ecosystem engineers, and nutrient recyclers. A single animal species can affect plant growth, soil structure, disease dynamics, or food-web stability. Zoology therefore overlaps deeply with ecology and conservation biology.

Zoology and people

People depend on animal knowledge in many ways. Zoology informs wildlife management, fisheries, livestock care, pollinator protection, disease research, animal welfare, laboratory models, and the control of invasive species and pests. It also helps explain human biology because humans are animals with evolutionary relatives and shared cellular systems.

Why it matters

Zoology helps people understand the living world as a network of bodies, behaviors, lineages, and relationships. It gives conservationists evidence for protecting habitats and species, gives medicine models for disease and development, and gives society a clearer view of how closely human life is tied to animal life around us.