Unit review

• Adaptation


  A structure, behaviors or physiological process that helps an organism survive and reproduce in a particular environment
• Adaptation Examples


  • Camouflage
  • Hibernation
  • Physical Features (sharp talons, excellent vision, thick fur, thorns, being poisonous)
  • Mimicry
  • Reproductive features (flowers, horns, lion's roar)
• Variation


  Differences between individuals, which may be structural, functional or physiological
• Selective advantage


  A genetic advantage of one organism over its competitors
• Artificial selection


  Humans have selectively bred various plants and animals for thousands of years
• Selective breeding


  The crossing of desired traits from plants or animals to produce offspring that have one or several of the favoured characteristics
• Inbreeding


  The process by which breeding is limited to a number of desirable phenotypes, for example purebred dogs
• Hybridization


  The mating of two different parents to produce offspring with desirable characteristics of both parents
• Natural selection


  The "Mechanism" by which Evolution occurs - certain traits will increase the chances of an individual's survival and reproduction, and are more likely to be passed on to the next generation
• Genetic diversity


  The biological variation that occurs within species, making it possible for species to adapt when the environment changes
• Monoculture


  Most farmers over large parcels of land have the same variety of species all genetically similar to each other
• Mutations


  Random change in structure of DNA, sometimes beneficial for survival
• Gene flow


  Immigration and Emigration in an area can change the "allele frequencies"
• Genetic drift


  When a population size is very small, chance events can have large effects on allele frequencies
• Founder's effect


  When a small group of individuals establish a new population, they establish a new allele frequency than the original population
• Bottleneck effect


  When a huge natural disaster occurs and kills off a whole group of individuals, the small group of survivors has a very low probability of having the same allele frequency as the original population
• Stabilizing selection


  In periods where there is not significant environmental change, the traits that have allowed that organism to survive in previous generations continue to be favored traits
• Directional selection


  Selection favors individuals with more extreme variation of traits, shifting the next generation in a different direction
• Disruptive selection


  Selection favors two or more variations of a trait that differ from the current population average

  
• Sexual selection


  Selection favors traits that enhance reproductive success, often leading to males and females of a species evolving quite different appearances and behaviors
• Speciation


  The formation of an entirely new species
• Divergent evolution


  Two or more species can evolve from a common ancestor due to disruptive selection or genetic drift
• Convergent evolution


  Two species that do not share a common ancestor develop very similar structural or behavioral features because they experience similar selective forces
• Coevolution


  Two species interact closely and can affect each other's evolution
• The Roman Catholic church believes and accepts the theory of evolution as there is more than enough information supporting the theory
• Evolution is the process of changes that occur within a species it does not explain how life begin
• Humans are a close relative to monkeys/chimps but we have not evolved from them
• Evolution has no direction, therefore organisms can go from simple to complex or complex to simple
• Adaptation


  A physical or behavioral feature of an animal that helps them better survive in their environment
• How adaptations develop


  By the process of natural selection, the nature of the species gradually changes to become adapted to the niche
• If a species becomes very well adapted to its environment, and if the environment does not change, species can exist for a very long time before they become extinct
• The peppered moth had 3 color variations - grayish, whitish with black dots, and black
• Before the black color variation was extremely rare, the color statistic had begun to change 50 years later, with the black peppered moth being more common in urban areas
• This statistic changed due to the fact that these moths were more active during the night, and the black peppered moths survived better by camouflage in darker areas of London
• Later on when England began to fix their environmentally damaging habits, lighter trees began to grow again, reducing the black peppered moth's population to its original numbers
• The process of evolution is too slow to be observed directly in a human lifetime, except for bacteria & viruses who because of their short life span are able to evolve and develop resistance to antibiotics
• Humans have been using artificial selection for many thousands of years to breed animals and plants with desirable traits
• The benefit of artificial selection is that it allows humans to increase the speed of evolution to meet their needs and produce organisms with preferred traits
• Artificial selection has long been used in agriculture to produce animals and crops with desirable traits, such as the meats, fruits and vegetables we have today
• Artificial Selection is a type of Biotechnology, which is the use of technology and organisms to produce useful products, and has a huge impact on humans and our survival