Lecture Power Point to accompany Inquiry into Life

Lecture Power. Point to accompany Inquiry into Life Twelfth Edition Sylvia S. Mader Chapter 32 Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display.

32. 1 Nature versus Nurture: Genetic Influences • Behavior – Any action that can be observed and described – Genes, to a degree, control behavior

32. 1 Nature versus Nurture: Genetic Influences • Experiments with Lovebirds, Snakes, and Snails – Lovebird Nesting Behavior • Fischer lovebirds, Agapornis fischeri, cut strips from leaves and carry them to their nest site • Peach-face lovebirds, Agapornis roseicollis, also cut strips but tuck them into their rump feather and carry them that way • Hybrid lovebirds exhibit intermediate behavior. They cut strips and try to tuck them into feathers, but are unsuccessful • These studies support the hypothesis that behavior has a genetic basis.

Nest Building Behavior in Lovebirds

32. 1 Nature versus Nurture: Genetic Influences • Experiments with Lovebirds, Snakes, and Snails – Garter Snake Experiments • Genetic role in food preference – Inland populations of garter snakes are aquatic and feed in the water on fish and frogs – Coastal populations are terrestrial and feed on slugs – In the laboratory, inland snakes refused slugs, while coastal snakes readily accepted them » Hybrid snakes exhibited intermediate acceptance of slugs as food • This study suggests a genetic basis for feeding preference

Feeding Behavior in Garter Snakes

32. 1 Nature versus Nurture: Genetic Influences • Experiments with Lovebirds, Snakes, and Snails – Garter Snake Experiments • Determined that sensory receptors are specific for prey – Researchers presented baby snakes with slug extract on cotton swabs and then counted the number of tongue flicks » Coastal snakes had a higher number of tongue flicks than inland snakes » Apparently, coastal snakes have many receptors on their tongues for taste and smell of slugs, inland snakes do not • A genetic difference between the two populations results in a physiological difference in nervous systems.

32. 1 Nature versus Nurture: Genetic Influences • Experiments with Lovebirds, Snakes, and Snails – Snail experiments • Show role of endocrine system in behavior • ELH- egg-laying hormone was isolated in Aplysia snails • ELH controls all aspects of egg laying behavior – After mating, snail pulls egg string with mouth, winds it in a loose ball, and attaches it to an object – When given ELH, snail exhibits all behaviors even without mating

32. 1 Nature versus Nurture: Genetic Influences • Experiments with Humans – Twin Studies • Look at characteristics of twins raised apart • Many share common preferences in food, activity patterns, and mate selection

32. 2 Nature versus Nurture: Environmental Influences • Environmental influences also affect behavior • Fixed Action Patterns (FAP): specific behaviors elicited by a sign stimulus • Learning: A durable change in behavior brought about by experience

32. 2 Nature versus Nurture: Environmental Influences • Learning in Birds

32. 2 Nature versus Nurture: Environmental Influences • Learning in Birds – Imprinting: a simple form of learning • Young birds follow the first moving object they see – Sensitive period: time during which imprinting may occur • Social interactions between parent and offspring during the sensitive period are important – Young birds are sensitive to parents vocalization even before hatching

32. 2 Nature versus Nurture: Environmental Influences • Learning in Birds – Song Learning • White-crowned sparrows: species-specific song with different dialects; experiments show learning plays a role • Birds that heard no songs: sang an undeveloped song as adults • Birds that heard species song: sang in that dialect as long as tape was played during a sensitive period • Birds that had adult tutor: sang the tutor’s song even if a different species and no matter when tutoring began

32. 2 Nature versus Nurture: Environmental Influences • Associative Learning – A change in behavior that involves an association between two events. – Classical Conditioning • The presentation of two different types of stimuli at the same time causes an animal to form an association between them. – Operant Conditioning • A stimulus-response connection is strengthened

Classical Conditioning

32. 2 Nature versus Nurture: Environmental Influences • Associative Learning – Operant Conditioning • Training an animal by rewarding it

32. 3 Adaptive Mating Behavior • Sexual Selection: adaptive changes that increase ability to attract a mate • Biological Fitness: ability to produce surviving offspring

32. 3 Adaptive Mating Behavior • Female Choice – Female animals produce few eggs, choosing a mate is a serious consideration. – Two Hypotheses: • Good Genes Hypothesis: females choose mates on basis of traits that improve survival • Run-away Hypothesis: females choose mates in bases of traits that improve appearance

32. 3 Adaptive Mating Behavior • Female Choice – The plumage of the male Raggiana birds of paradise may signal health and vigor to the females.

32. 3 Adaptive Mating Behavior • Male Competition – Males can produce many offspring because continuously produce sperm in large numbers – Less time and energy invested in reproduction – Males compete to inseminate as many females as possible

32. 3 Adaptive Mating Behavior • Male Competition – Cost / Benefits • Baboons have dominance hierarchies. Dominant males mate more often than subordinates. Yet the dominant male is more likely to be in fights, therefore increasing the chance of injury. • Males red deer stags compete for a harem of a particular territory. The harem master is large and powerful with little body fat. Little body fat increases the chance of starvation if food is scarce.

A Male Baboon Displaying Full Threat

Competition Between Male Red Deer

32. 3 Adaptive Mating Behavior • Mating in Humans – Human Males Compete • Women invest more time and energy in a child biologically – Nine month pregnancy and then lactation • Men only need to contribute sperm during sex act • Result: men are more available for reproduction than women – Because more men are available, they must compete • Humans are dimorphic: men are larger and stronger likely as result of past selection by females – Males pay a price. The average life span is seven years less than females.

32. 3 Adaptive Mating Behavior • Mating in Humans – Females Choose • In one study, the ability to achieve financial success was found to be the most preferred trait by females • Other studies have shown that facial body symmetry is important – Men Also Have a Choice • Men prefer youthfulness and attractiveness in females, signs that their partner can provide them with children. • By choosing younger women, older men can increase their fitness.

32. 4 Sociobiology and Animal Behavior • Sociobiology applies the principles of evolutionary biology to the study of social behavior in animals. • Hypothesis: Living in a society has a greater reproductive benefit than reproductive cost.

32. 4 Sociobiology and Animal Behavior • Benefits of Group Living – Helps an animal avoid predators, rear offspring, and find food. • Disadvantages to Group Living – Competition among members of the group for resources and exposes group members to illnesses and parasites.

32. 4 Sociobiology and Animal Behavior • Sociobiology and Human Culture – Humans live in organized societies. – The culture of a human society involves a wide spectrum of customs. – The earliest organized societies may have been the “hunters-gatherers. ” – A predatory lifestyle likely encouraged the evolution of intelligence and the development of language.

32. 4 Sociobiology and Animal Behavior • Altruisms versus Self-Interest – Altruism includes behaviors that sacrifice the individual for the benefit of the group – Inclusive fitness of an individual includes personal reproductive success as well as that of relatives • Measured by how many genes individual contributes to next generation • Helpers at the Nest – Minimal short-term reproductive sacrifice made to maximize future reproductive potential – Helper contributes to survival of kin

Inclusive Fitness

32. 5 Animal Communication • Communication: An action by a sender that influences the behavior of the receiver – Chemical Communication: Pheromones • Powerful chemical signals passed in low concentration • May be released into the air or used in territory marking – Auditory Communication • Very rapid and can be modified for specific situations – Visual Communication • Most used by diurnal species-must be able to be seen • Plumage, courtship “dances”, aggressive displays, etc. – Tactile Communication • Occurs when one individual touches another

Use of a Pheromone (Chemical Communication)

A Chimpanzee with a Researcher (Auditory Communication)

Visual Communication

Communication Among Bees (Tactile Communication)