Zoology Lec. Module 3 PDF

**ZOOL 1 -- General Zoology** **Chapter 3. Ecology: Preserving The Animal Kingdom Animals and Their Abiotic Environment**  - **Ecology** **The study of the relationships between organisms and their environment and to other orga...

**ZOOL 1 -- General Zoology** **Chapter 3. Ecology: Preserving The Animal Kingdom Animals and Their Abiotic Environment**  - **Ecology** **The study of the relationships between organisms and their environment and to other organisms. It is the study of the interactions of an animal with its habitat, which includes all living (biotic) and nonliving (abiotic) characteristics of the area in which the animal lives** - **Physiological ecologists \-- who study abiotic influences have found that animals live within a certain range of values, called the [tolerance range], for any environmental factor.** - ***\*At either limit of the tolerance range, one or more essential functions cease. A certain range of values within the tolerance range, called the range of optimum, defines the conditions under which an animal is most successful.*** - **Taxis** - **Taxis are a form of [movement behavior] that involves movement towards or away from a stimulus.** **For example, a response to light is called Phototaxis.** - **Positive Phototaxis** - **Negative Phototaxis** **Energy** - **Animals obtain energy from the food they consume, using that energy to maintain body temperature and perform other metabolic functions.** - **An accounting of an animal's total energy intake and a description of how that energy is used and lost is an energy budget.** **1.Heterotroph** - **An organism that consumes other organisms in a food chain.** - **Heterotrophs are unable to produce organic substances from inorganic ones.** **2. Autotroph** - **Organisms (e.g., plants, algae, and some protists) carry on photosynthesis or other carbon-fixing activities that supply their food source.** **Temperature** - **Temperature influences the rates of chemical reactions in animal cells (metabolic rate) and affects the animal's overall activity.** - **"warm-blooded animals"** - **Control body temperatures using metabolically produced heat.** - **Constitute [birds and mammals] of the animal kingdom. However, [some fish] are also endothermic.** - **A type of clinically induced hypothermia is used to lower a structure\'s or the entire body\'s metabolic rate.** - **Controlled hypothermia can take the form of daily torpor, hibernation, and aestivation.** 1. **Daily Torpor** - **A time of decreased metabolism and lowered body temperature that may occur daily in bats, hummingbirds,** - **Some other small birds and mammals must feed almost constantly when they are active.** - **A [time of decreased metabolism and lowered body temperature] that may last for weeks or months.** - **During hibernation, [an animal's metabolic rate drops, heart and respiratory rates fall, and the set point of its thermoregulatory center usually drops to near environmental temperature]** - **A period of inactivity in some animals that must withstand extended periods of heat and drying.** - **It generally does not eat or drink and emerges again after moisture returns.** - **Aestivation is common in [many invertebrates, reptiles, and amphibians]** - **These are so-called "cold-blooded animals" that is, any animal whose regulation of body temperature depends on external sources, such as sunlight or a heated rock surface.** - **Animals like amphibians and non-avian reptiles are ectothermic.** - **A state of sluggishness, inactivity, or torpor exhibited by reptiles (such as snakes or lizards) during winter or extended periods of low temperature.** - **Uncontrolled hypothermia in ectotherms which may cause freezing of animals and can die during very harsh winters because body temperature is not regulated metabolically** - **Population** - **groups of individuals of the same species that occupy a given area at the same time and have unique attributes** - **Biotic characteristics of a habitat include interactions that occur within an individual's own species. examples of biotic characteristics include how populations grow and how growth is regulated, food availability, and competition for that food, and numerous other interactions between species that are the result of shared evolutionary histories.** - **Survivorship - change in populations over time because of birth, death, and dispersal. survivorship characterizes a population regarding the chances of survival of an individual in the population** - **Exponential Growth - potential for a population to increase in numbers of individuals. The population increases by the same ratio per unit time.** - **Environmental Resistance - the constraints that climate, food, space, and other environmental factors.** - **Carrying Capacity - the population size that a particular environment can support.** - **Logistic Population Growth - growth curves that assume a sigmoid.** - **Population Regulation -- the conditions that an animal must meet to survive are unique for every species.** - **Population Density** - **Density-Independent Factor - influences the number of animals in a population without regard to the number of individuals per unit space (density).** - **Density Independent Factor - more severe when population density is high than they are at other densities. Animals often use territorial behavior, song, and scent marking to tell others to look elsewhere for reproductive space.** - **Herbivory and Predation** - **Animals that feed on plants by cropping portions of the plant, but usually not killing the plant** - **Interspecific Competition** - **Competitive Exclusion Principle** - **Some of the best examples of adaptations arising through coevolution come from two different species living in continuing, intimate associations** 1. **Parasitism - a common form of symbiosis in which one organism lives in or on a second organism, called a host.** 2. **Commensalism -- a symbiotic relationship in which one member of the relationship benefits and the second is neither helped nor harmed.** 3. **Mutualism -- a symbiotic relationship that benefits both members.** **Ecological Community** - **A group or association of populations of two or more different species occupying the same geographical area at the same time, these organisms interact with one another and with their physical environment in complex and dynamic ways** **The Ecological Niche --** - **Describes how an individual organism fits into an ecosystem. Each species occupies a niche in the community, and it includes the type of food it eats, where it lives, where it reproduces and its relationship with other species.** **Community Stability** - **Ability of a particular species to resist or recover from disturbances and maintain its essential structure and functions over time.** - **helps ecosystems recover from disturbances and grow richer in diversity over time.** **Seral Community** - **Early stages of geological succession** - **Characterized by rapid changes in species composition** - **Low community stability. These community often susceptible to disturbances such fire or human intervention** - **Low biodiversity: Seral communities tend to have fewer species as pioneer species are adapted to colonize disturbed areas.** **Climax Community** - **Final stage of ecological succession.** - **Characterized by relatively stable species composition and structure.** - **Higher community stability: Climax communities are more resilient to disturbances due to the mature, well-adapted species present.** - **Higher biodiversity: Climax communities typically have higher species diversity as they provide stable niches for a wider range of species.** **Trophic Structure of the Ecosystem** - **Energy is a constant resource in ecosystems, as it supports all organisms\' activities and once it leaves, it cannot be reused.** - **Energy typically enters ecosystems through sunlight and is absorbed by organic compounds in living tissues.** - **The total amount of energy converted into living tissues in each area per unit of time.** - **It supports all organisms within an ecosystem** - **The total mass of all organisms in an ecosystem** - **The sequence of organisms through which energy moves in an ecosystem** - **Complexly interconnected food chains, that involve many kinds of organisms** - **The feeding level of an organism in an ecosystem** - **break down dead organisms and feces by digesting organic matter extracellularly and absorbing the products of digestion** - **The increase in concentration of a substance in the tissues of organisms at higher levels of food webs** - ***Example: Novel organic compounds, called persistent organic pollutants (POPs), such as mercury, cannot be broken down biologically because evolution has not had time to build enzyme systems to process them.*** - **The cycling of elements between reservoirs of inorganic compounds and living matter in an ecosystem** - **Nutrients with gaseous cycles require that the nutrient be captured as a gas and incorporated into living tissues.** - **Barry Commoner (1917-2012)** - **Father of the Environmental Movement** - **Earth's problems -- ecological degradation, social injustice, and economic and national security -- are all interconnected no permanent environmental solutions exist without social change** **Human Population Growth** - **The root of virtually all environmental problems** - **Earth\'s ecosystem has a carrying capacity, and human populations should stabilize when it reaches this capacity; otherwise, war, famine, or disease will take care of the problem.** - **Environmentalists argue that the current 7.6 billion people are too many, as Earth\'s carrying capacity depends on the desired standard of living and equal resource distribution.** - **The proportion of a population that is in pre - reproductive, reproductive, and post - reproductive classes.** - **The Earth has approximately 1.9 hectares of productive resources (crop, grazing, forest, and fishing) per person** - **The United States uses 9.5 hectares of productive resources, while Western Europeans use half, and Mozambican uses less than 0.5 hectares.** - **North America and Western Europe, comprising 12% of the global population, account for 60% of global consumption.** - **Southern Asia and sub-Saharan Africa comprise 33% of the global population and consume 3.2% of the world\'s goods and services.** - **The International Union for Conservation of Nature's (IUCN) survey of 48,000 species revealed that 46% are in extinction risk categories, ranging from extinct to near threatened.** - **Diverse ecosystems safeguard water and soil resources, promote nutrient cycling, and provide biological resources like food, medicines, and novel genomes, benefiting both ecosystems and human populations.** - **Habitat Loss** - **Annually, approximately 32 million hectares of tropical rain forests are being deforested.** - **Tropical rain forests, covering only 7% of the Earth\'s land surface, are home to over 50% of the world\'s species.** - **Tropical rain forests offer innovative medicines, foods, climate control by absorbing CO2 from the atmosphere, and protect delicate soil and water resources.**