Applied Science
Material Type:
Rice University
Provider Set:
OpenStax College
  • Abiotic
  • Aboveground Biomass
  • Abyssal Zone
  • Algal Bloom
  • Aphotic Zone
  • Aquatic Biome
  • Aquatic Environment
  • Aquatic Influence
  • Arctic Tundra
  • Atmospheric Carbon Dioxide
  • Benthic Realm
  • Biogeography
  • Biome
  • Biosphere
  • Biotic
  • Boreal Forest
  • Canopy
  • Channel
  • Chaparral
  • Clathrate
  • Climate
  • Climate Change
  • Community Ecology
  • Conspecific
  • Coral Reef
  • Cryptofauna
  • Ecological Research
  • Ecological Study
  • Ecologist
  • Ecology
  • Ecology Study
  • Ecosystem
  • Ecosystem Ecology
  • Ecosystem Service
  • Emergent Vegetation
  • Endemic
  • Energy Source
  • Estuaries
  • Estuary
  • Fall Turnover
  • Fall and Spring Turnover
  • Freshwater Biome
  • Geological Climate Change
  • Global Climate
  • Global Climate Change
  • Global Warming
  • Greenhouse Effect
  • Greenhouse Gas
  • Haze-effect Cooling
  • Heterospecific
  • Industrial Revolution
  • Inorganic Nutrient
  • Interdisciplinary Ecology
  • Intertidal Zone
  • Lake
  • Marine Biome
  • Milankovitch Cycle
  • Mutualism
  • Neritic Zone
  • Net Primary Productivity
  • Ocean Upwelling
  • Oceanic Zone
  • Organismal Ecology
  • Pelagic Realm
  • Permafrost
  • Photic Zone
  • Planktivore
  • Pond
  • Population Ecology
  • Predator
  • Present Climate Change
  • River
  • Sargassum
  • Soil
  • Solar Intensity
  • Source Water
  • Spring Turnover
  • Stream
  • Subtropical Desert
  • Temperate Forest
  • Temperate Grassland
  • Temperature
  • Terrestrial Biome
  • Terrestrial Environment
  • Terrestrial Influence
  • Thermocline
  • Tropical Wet Forest
  • Water
  • Weather
  • Wetland
    Creative Commons Attribution


     Photo (a) shows a deer tick on a leaf. The tick has a brown oval body with a smaller, round oval toward the front. The head and legs are black. Photo (b) shows an arm with a red, circular rash enclosed in a ring-like rash. Photo (c) shows a brown mouse with a white belly and legs and large, round ears.
    The (a) deer tick carries the bacterium that produces Lyme disease in humans, often evident in (b) a symptomatic bull’s eye rash. The (c) white-footed mouse is one well-known host to deer ticks carrying the Lyme disease bacterium. (credit a: modification of work by Scott Bauer, USDA ARS; credit b: modification of work by James Gathany, CDC; credit c: modification of work by Rob Ireton)

    Why study ecology? Perhaps you are interested in learning about the natural world and how living things have adapted to the physical conditions of their environment. Or, perhaps you’re a future physician seeking to understand the connection between your patients' health and their environment.

    Humans are a part of the ecological landscape, and human health is one important part of human interaction with our physical and living environment. Lyme disease, for instance, serves as one modern-day example of the connection between our health and the natural world (Figure). More formally known as Lyme borreliosis, Lyme disease is a bacterial infection that can be transmitted to humans when they are bitten by the deer tick (Ixodes scapularis in the eastern U.S., and Ixodes pacificus along the Pacific coast). Deer ticks are the primary vectors (a vector is an organism that transmits a pathogen) for this disease. However, not all ticks carry the pathogen, and not all deer ticks carry the bacteria that will cause Lyme disease in humans. Also, the ticks I. scapularis and pacificus can have other hosts besides deer. In fact, it turns out that the probability of infection depends on the type of host upon which the tick develops: a higher proportion of ticks that live on white-footed mice carry the bacterium than do ticks that live on deer. Knowledge about the environments and population densities in which the host species is abundant would help a physician or an epidemiologist better understand how Lyme disease is transmitted and how its incidence could be reduced.