BIOL10004 Lecture Notes - Lecture 21: Frogfish, Oecophylla Smaragdina, Coevolution
28 Jun 2018
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LECTURE 21 – DIVERSITY
Biological Diversity
• diversity between species
• diversity within species
o phenotypic variation – morphology, development, behaviour
o genotypic variation – genes an organism inherits
§ may be visible à i.e. has the gene but not observed phenotypically
• diversity is a product of evolutionary processes
• Four evolutionary forces that contribute to generating & maintaining diversity
Mutation à Occurs at random, may be disadvantageous, neutral or advantageous
• Diverse population = higher chance of survival if there was an infection
• i.e. cloned potatoes will all become infected & die out
• Agriculturally, clones = cheaper but vulnerable to diseases
Migration à Movement of genes between population (gene flow)
• Gene flow introduce or reintroduce genes to different parts of population
• Increases genetic variation
• Less gene flow à more likely the two population will evolve into separate species
• Biological concept of race à sub-population due to geographic boundaries whereby there’s a high degree of
genetic differentiation
o However, humans = most genetically homogenous species
o Race = cultural intervention
Drift à random to the genetic makeup of a population
• Doesn’t produce adaptations
• Associated with small population size
• Bottleneck vs found effects
• Many Amish people have specific syndrome b/c of limited gene flow (no exchange)
Selection
• Evolution by natural selection
o Variation exist, the traits are heritable, the trait affects fitness
o Consequences: genes for more advantageous trait increase in frequency
• Using insecticides, antibiotics etc à resistance develops
• Refugia as a means of controlling pests
Selection acts on individuals, not species
• Abiotic environment (non-living) à temperature, water abundance, water salinity
