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Lecture

Bio lab 1 notes Sep 27 2009

by OC4

Department
Biology
Course Code
BIO120H1
Professor
Ingrid L.Stefanovic

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Bio lab no. 1
Insects are arthopods animals with joined legs.
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reproducing is called an adaptation t can be a physical characteristics or a behaviour.
Noun t trait, verb t adapt to certain environment
Mechanism fro process of adaption t natural selection
Mutation and recombination create the new traits and new combination of traits.
Fintess t the ability to survive and reproduce
Natural selection results from the variation of individuals in the number of surviving offsprings they
contribute to the next generation.
If the higher fitness traits are heritable t these traits will present a larger proption in next generation.
Natural selection and inheritance are repeated every generation
Evolution: the process tchange over generations in the proportion of individuals with a certain trait.
Not all traits are adaptations: some differences are neutral.
Genetic drift and gene flow also change genetics, but they may result in random varitation, so may not
be adaptation.
Phylogeny: evolutionary history and realtionships
Few hypothesis: two types t viability and competition for mates
Adaptations for viability:
Viability selection: natural selection arising from variation in viability.
Camouflage t organisms may benefit by physically resembling their environment, making them less
vicible to predators.
Feeding t some organisms have adapted to particular diets by evolving specialized mothparts. Eg. Jaws
for biting and tearing, tubes for piercing and sucking, and long tongues for lapping up nectar from
flowers
Life in water t organisms living in water have special adaptation. often have bodies and legs specially-
shaped to facilitate lcomotion in theis aquatic enironment.
Adaptation for competing for mates:
Sexual selection: natural selection raised from variable mating success.
Sexual selection results from the difference between males and females t secondary sexual
characteristics t such a difference is called the sexual dimorphism.
Two principal mechanisms for sexual selection t intra-sexual competition and mate choice.
Intra-sexual competition: male-male competition, some male possess adaptation for fighting, such as
anlters, horns, mandibles or tusks .
Mate choice: some species, female and /or males are choosy. Mate choice is thought to increase the
fitness of the chooser by enabling it to mate with healthy individuals t many organisms adapt to the
preference of their opposite gender.
Diversity: the varitation of life on earth.
Specimens in the experiment:
1.Butterflies t order lepidoptera, Preyde by birds
Undergo prefound change in body form, behaviour, and life style, a process know as complete
metamorphosis.
Egges t larvae (feed on vegetables) t pupa t adults (feed on nectar of flowers)
2.Waterstriders t living on the surface flim of water t order Hemiptera
Fine hairs cover the underbody and the water-proof feet and light body weight aiding these insects to
move over water.
Females choose thies mates by engaing in pre-mating struggles which only some males can overcome
Have tubular sucking mouthparts
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