SAT II Biology Episode 2 Part 2 potx

Chapter 8 BEHAVIOR AND ECOLOGY OVERVIEW The two areas included in this chapter take an even broader view of living things.. ANIMAL BEHAVIOR This is an area not specifically covered in an

Chapter 8 BEHAVIOR AND ECOLOGY

OVERVIEW

The two areas included in this chapter take an even broader view of living things Starting with animal behavior, we explore the way that animals interact with their environment as an individual behavioral matter, and specifically how they learn and react to their surround-ings Following this, we outline what we know about how animals communicate, move, feed, and interact socially Finally, we look at circadian rhythms The second section is involved with an even broader view than the individual behaviors covered in the first section Taking a worldview, we outline what the student may be tested on, beginning with the relationships between members of a population and their involvement with other species at a community level We outline the different kinds of communities within the biosphere and, by including the abiotic factors, we study the interac-tions between the biosphere, the hydrosphere, the lithosphere, and the atmosphere on this planet in different regions and climes called biomes From there, a worldview, literally, is outlined in summing up the relationships of all living things to each other and the planet and the changes they—living things and the planet—undergo

ANIMAL BEHAVIOR

This is an area not specifically covered in any of the other areas in this book, but it actually brings together several factors in describing the way life expresses itself, given the interaction of all those other factors In addition to learning, the areas covered alternately relate to the individual, groups, and their interactions Some of the areas covered involve the study of influences outside the individual; others involve those that “come with the package.” The argument persists as

to whether nature or nurture dominates life Do we come with a prepackaged set of formative influences, or do the environment and our response to it shape everything?

LEARNING

This is usually defined as acquiring information or a behavior that was not previously a part of the organism and tends to be brought about

by experience We now know that behavior has a genetic component

with other individuals An example is the case of reproductive success or survival fitness Evolution and natural selection are seen to enhance these genetically conferred traits

Conditioning

Conditioning is defined as exhibiting a behavior as a result of a response to a particular set of conditions, known or unknown, usually called a stimulus Care should be taken not to “run around in circles” on the matter of stimulus/response A stimulus is anything that results in activity; a response is the result produced

A Classical

Classical conditioning, or associative behavior, is of course, given in Pavlov’s classical “salivating dog” experiment and is taken as respond-ing to a substitute stimulus rather than the original or expected stimulus

B Operant

Operant conditioning is more of a trial-and-error kind of conditioning The closer an individual gets to the desired response with positive reinforcement, the more the individual will repeat the response This occurs in animal training, but it can also be seen in an animal that spends initial energy on revisiting a feeding site that has yielded success in the recent past

Imprinting

This behavior is an example of one that appears to involve a “critical period.” It occurs only if the right stimulus occurs during a particular time Examples would be salmon returning to the precise site of their birth or, as in Lorenz’s studies, with goslings

Habituation

Habituation involves a behavior in which unproductive results are soon disregarded, and the stimulus that causes them is also disre-garded eventually

Insight

Without any previous experience with a situation, an animal performs

a successful behavior, most likely influenced by previous behaviors

Observational

Individuals copy the behavior of another without having previously experienced the stimulus that produces that behavior

Behaviors, or the potential for them, that already exist inside the individual are called innate

Fixed action pattern

These follow a regular, unwavering pattern that is initiated by a specific stimulus and carried out even in the absence of the ability to complete the original intent

Instinct

Instinct is the classic innate behavior that has no other explanation other than that it is inherited One such behavior appears to deal with time and is known as circadian rhythm Internal clocks or cycles appear in part to have a genetic basis to an organism’s interaction between the environment and chemical promoters in the individual

MOVEMENT

Animals have particular ways in which they move Three specific ways have been identified, and they involve very specific actions according to the organisms and the environment in which they reside

Kinesis

Kinesis is a random change in speed and/or direction of an organism

in response to a stimulus It will, for example, speed up in an unfavorable environment and slow down in a favorable one

Taxis

Taxis is a very specific, directed response to a stimulus, in the direction of the stimulus if it is favorable and away from the stimulus

if it is unfavorable

Group

Group movement, better known as migration, is the wholesale movement of animals that is usually brought on by seasonal influ-ences, in particular the availability of food

COMMUNICATION

Communication is usually observed within a species to recognize one’s own kind for mating, for social behavior, or for the avoidance

of a nearby predator

Chemical communication uses pheromones, which trigger a response when smelled or, in some cases, when eaten In the case of bees, the workers eat a pheromone, and it prevents them from developing reproductive ability

Visual

Visual communication is usually observed during courtship or aggressive behavior when defending territory or establishing pecking order In some, visual displays by males are releasers for reproductive behavior in females

Auditory

Auditory communication may be for definition of territory; for species recognition, as in the case of a mating behavior; or for alerting

behavior, as when a predator is nearby

Tactile

Tactile communication is a common behavior in bonding, infant care, and mating In bees, it is even used to locate successful food sources

FEEDING

Feeding behaviors that organize the search for food have been observed and appear to impact the survival of the species and have, therefore, great impact and importance for the individual, even as the individual may relate to a group

Groups

Groups of individuals have evolved several successful means of feeding or finding food

A Herds

Herds use this kind of group behavior when feeding as a means of defending against predators by shielding each other, when attempting

to avoid a predator by becoming hidden from view, or simply by being alert to the presence of a predator A member on one end of the herd may not be aware of a predator approaching the other end

of the herd

B Packs

Packs engage in group hunting, which is most often observed when smaller species attack a larger one

Search image

Animals will seek food based on the success previously experienced

or on images they possess, however limited, of the target previously experienced A measure of habituation obviously contributes to the success of this feeding behavior

SOCIAL

Individuals behave in two different settings: in a group or on their own Eventually, they will make contact with other organisms within their species or outside their species The most successful interac-tions survive, as do the individuals or the groups that exhibit them

Agonistic

Agonistic behavior is aggressive/submissive behavior that actually has great survival value, since it is most often quite ritualized and,

therefore, actually reduces negative aspects of aggression

Dominance

Dominance establishes hierarchies, or “pecking order,” and also minimizes conflict within the group

Territoriality

Territoriality is a behavior that ensures a food supply, a place for reproductive activities, and successful rearing of infants

Altruistic

Altruism is seemingly unselfish behavior that is not beneficial to, or may be harmful to, an individual but that actually increases the fitness

of the group by ensuring survival of the species and parental genes

ECOLOGY

The word ecology comes from the root ecce, meaning home or place.

If, in several instances, we have talked about the big picture, this is the biggest of all All of the material discussed so far culminates in the study of our environment or ecology, the study of “this place.”

BIOSPHERE

The biosphere is the realm of living things, along with the hydro-sphere, lithohydro-sphere, and atmohydro-sphere, that make up our world

The Earth

The earth includes the four “spheres” and the ways in which they interact

Major Biomes

Under the influence of latitude or elevation and various abiotic, nonliving factors, the earth is divided into large areas known as biomes, areas of distinctly different living things Beginning with the most inhospitable, because it is the coldest, we begin at the “top” of the world While reference will be made only to latitude as we progress toward the equator, one can also find similar conditions when descending a mountain

A Tundra

The northernmost biome is tundra, which contains rapidly maturing plants, a permanent layer of ice under the soil, and mostly small homeotherms

B Taiga

Taiga is less forbidding It nonetheless has long cold winters; larger plants, such as stunted conifers, exist; and there are more large animals

C Temperate deciduous forests

Temperate deciduous forests contain larger trees that lose their leaves

in dry—usually winter—seasons, proliferate heterotrophs and autotrophs, and have warm summers and colder winters

D Grasslands

Grasslands feature hot summers, cold winters, unpredictable rainfall, mostly grassy autotrophs, and a fairly wide variety of wildlife

E Deserts

Deserts contain drought-resistant plants, low rainfall, a very dry climate, small homeotherms, and proliferate reptilia

F Tropical rain forests

The tropical rain forests are the most proliferate of all biomes for living things, containing high rainfall and temperatures and poor soil

ECOSYSTEM

An ecosystem is smaller than a biome and is most often a self-contained area, such as a lake or a tidal pool

Abiotic factors

Abiotic factors are nonliving factors that include air, water, topogra-phy, geology, and sun The interactions of these include things like temperature, humidity, wind, and erosion

Biotic factors

Biotic factors are living things in an ecosystem and the way they interact

A Producers

Autotrophs are known as producers since, in the presence of the ultimate source of energy—the sun—they provide most of the biomass

B Consumers

As the name suggests, these consume biomass but are not capable of producing or using sunlight directly to create a food source, as the autotrophs are Consumers are usually divided into at least primary consumers, whose primary source of nutrition is producers, and secondary consumers, whose primary source of nutrition is another consumer

1 Herbivore—designed to metabolize producers exclusively

2 Carnivore—designed to metabolize other consumers exclusively

3 Omnivore—designed to metabolize both producers and

consum-ers

C Decomposers

At some point, the complex molecules that living things construct from their nutrients must be broken down lest the environment run out of raw materials that some organisms need to carry on life This is the role of the decomposers

FUNCTIONING

The biotic world functions at several levels, which are outlined here

Food chain

The food chain consists of a linear interaction between organisms in which the starting point is usually a plant, which is consumed by the next organism, which is consumed by the next organism, and so on, until the chain ends It can be portrayed vertically in what is called a food pyramid that more accurately portrays the amount of biomass at each level in the chain (called a trophic level)

Food web

The food web is several food chains interacting For example, a mouse might not just eat corn; it might also eat nuts or grains

Community

A community is a group of populations living in the same area

A Habitat

A habitat is the place where organisms usually live

B Niche

A niche consists of all the living and nonliving sources that contribute

to an animal’s survival—or, more accurately, a species survival—as a result of successful achieving of equilibrium with these factors by the animal (species) A niche is an organism’s “job,” or what it does in an ecosystem

C Biodiversity

Biodiversity is the variety of living things, their ecological functions, and the variety of genes they contain

SYMBIOSIS

Symbiosis refers to relationships where animals are in proximity to each other and interact as a result Literally, it means “living to-gether.”

Camouflage

Camouflage is the successful concealment from view of an organism, usually from its predator

Commensalism

Commensalism is an interaction between organisms where one benefits and the other is not harmed or benefited

Mimicry

Mimicry is similar to camouflage in that a protective appearance has evolved, but this might be displayed rather than concealed, since it might resemble a predator of an attacker or, at the very least, a more aggressive or distasteful organism than the attacker planned on encountering

Unlike commensalism, both organisms benefit in mutualistic interac-tion

Parasitism

Parasitism must strike a delicate balance between the parasite and the organism off of which it lives, mainly the host The parasite-host relationship is one in which one organism is helped; the other—the host—is harmed but not killed

Predator/Prey

The killing of the prey benefits the predator

POPULATION STUDIES

This very important area of science is applied primarily to the study

of human populations, although the principles relate to all lines of living things Generally, the areas of study seek to determine the nature of the population, particularly its health or equilibrium with the environment

Size

The number (N) of individuals in a population

Density

N per unit of volume—not area since some organisms occupy a three-dimensional cross-section of the niche

Dispersion

How the population is distributed

Age structure

The N of each age group, diagrammed along a vertical line that separates male and female members of the population on either side, results in specific shapes that can be interpreted as population trends

Mortality

Mortality is the survival of individuals throughout their lifetime

Growth

Two organisms and their life strategies emerge from our studies of populations Their growth is the result of these strategies as they impact the environment, and vice versa The r-selected species have a lifestyle of rapid invasion, rapid increase—from birth rates that

involve many small offspring that mature quickly—and rapid decline

On the other hand, K-selected species’ numbers remain at the carrying capacity and have few, relatively large offspring who require much care

A Biotic potential

Maximum growth rate of a population under ideal conditions for all the factors just discussed, always, however, tempered by environmen-tal resistance