A] INTRODUCTION

•  Adaptation - a structural, physiological, or behavioral trait possessed by an organism which allows it to survive and reproduce in the environment in which it lives.
•   structural - deals with shape of parts of organism (internal & external)
•   physiological - deals with the chemical reactions that occur within an     organism
•   behavioral - deals with the actual actions of organisms

• Radial symmetry - an arrangement of the body parts of an organism like pieces of a pie around an imaginary central axis.  Any slice passing longitudinally through a radially symmetrical organism’s central axis divides it into mirror-image halves

•  Bilateral symmetry - an arrangement of body parts such that an organism can be divided equally by a single cut passing  longitudinally through it.  A bilaterally symmetrical organism has a mirror-image right and left sides.

• Cryptic coloration - coloration which blends an organism into its environment    (camouflage)
•  most common adaptation of organisms
•  used by both predators and prey

•  Aposematic coloration - bright, flashy coloration which advertises the animal’s presence to the world but often means that the animal has an unpleasant odor or taste

•  Mimicry - animals which look very much like other species which have a successful defense against predators.
•  Batesian mimicry - a type of mimicry in which a palatable species mimics an unpalatable one
•  for this type of mimicry to be effective, the mimic must be considerably less abundant than the species it copies.
•  Mullerian mimicry - a type of mimicry in which two unpalatable species that    inhabit the same community mimic each other
• presumably, both gain an adaptive advantage beyond their own defenses because predators will learn more quickly to avoid any prey with this appearance

• Herbivores - animals which get their energy by eating plants
• Carnivores - animals which get their energy by eating other animals
• Omnivores - animals which eat both plants and animals
• By observing the teeth arrangement in skulls of mammals, it can be seen that the herbivores differ from those that eat meat (the carnivores and omnivores) - there is a distinct gap in herbivore teeth between the front incisors and the rear molars, while meat-eaters have teeth that sit side-by-side, without such a gap

• Models of 7 different skulls related to human ancestory/evolution are on display and 4 categories for comparing these skulls are examined
• Brain size (as determined from cranial capacity)
• Teeth
• Foramen magnum (the opening in the skull through which the spinal cord passes) - the location of this part of the skull gives an indication of whether the animal tends to walk on all 4 limbs (quadripedal) or if the animal tends to walk on its hind limbs (bipedal)
• Muscle size (in particular, the muscles involved with chewing or jaw closure) (as determined by the space formed by the zygomatic arch)

• Homologous - structures that are similar because of common ancestry (common evolutionary orgins)
• Analogous - similar in function
• Homologous vs. analogous structures involved with flight
• wings of birds, bats, and arms of humans are homologous (same basic bone structure; due to common evolutionary origins)
• wings of birds and insects are analagous (both used for flight) but they are not homologous (from common evolutionary origins)
• the arms of humans and the wings of bats are homologous, but not analagous

• Instinct - inborn behaviors coded in the DNA of an organism
• Positive phototaxis - instinctive movement towards a source of light
• Negative phototaxis - instinctive movement away from a source of light
• Isopods are affected by both light and moisture.  They also move to dark areas and they also move to moist areas (neither dry nor wet).  They do this instinctively (an inborn behavior)

• Hissing of cockroach as a type of behavioral defense against predators
• Other behavioral mechanisms insects use as a defense against predators (actions taken by the organisms, not structures); for example:
•  running fast
•  hiding in cracks and crevices
•  only coming out in the dark
•  flying away

• Examples of communication
•  hissing at a predator
•  sending a signal that an animal is ready to mate
•  telling others where there is a good source of food
•  The honeybee dance - as a communication technique
• scout honeybees which find a new food source perform a ritualized dance inside the hive to communicate to the other bees the direction and distance to the new food source (highly accurate)

• Species - a population or group of populations that can interbreed and produce fertile offspring under natural conditions
• Symbiotic interaction - an interaction between two species in which one species lives in or on another species
• Parasitism - a type of symbiosis where one species (the parasite) benefits while the other species (the host) is harmed
•  ectoparasite - external parasite
•  internal parasite - parasite which lives within its host
•  social parasite - parasite which uses another species’ behavior to complete its own life cycle
• Mutualism - type of symbiosis where both species benefit from the relationship
• Commensalism - type of symbiosis where one organism benefits and the other is neither harmed nor helped
• few cases of absolute commensalism probably exist
• example of birds feeding on insects flushed by grazing cattle (in textbook)