Evolution

• Darwin set off on the 'H.M.S. Beagle' in 1831 with who?

  Captain Robert Fitz Roy
• What was Darwins role on the H.M.S Beagle


  To collect, observe, and record specimens of rocks, plants, and animals.
• On his journey he found that similar organisms to those in Europe living in completely different habitats. This lead to what conclusion?

  His initial belief in the immutability of species (the idea that each species of organisms does not and cannot change) was incorrect.
• Darwin spent a lot of his trip studying Galapagos finches, what did he learn about them?


  The finches all had different beaks (based on the environment) that allowed them to have a survival advantage for its habitat
• What were Darwins (2) final conclusions after his journey?


  1.A species separated in location, over time, could

  diverge and become adapted to different habitats

  and eventually become a separate species.

  
  

  2.Evolution acts upon species through a process

  called natural selection
• Darwin received a letter from a fellow scientist named _______________ , disclosing similar thoughts about natural selection. This lead him to publish his book called _______________ in _____________.

  1. Alfred Wallace

  2. Origin of Species

  3. 1859
• What are homologous features? (think house)

  Features that are similar in structure but different in function (whale flippers /human arms)
• What are analogous features?

  Features similar in function but different in structure (bird wings, bat wings, bee wings)
• What was Darwins conclusion about homologous and analogous features?

  Organisms with homologous features likely

  shared a more recent common ancestor while

  those with analogous features did not
• What are vestigial features?

  Features useful to ancestors, but not useful to the modern organism that has them (wisdom teeth, appendix)

  
  

  Remember vasectomy and vestigial are similar words, vasectomy makes the balls useless.
• What was Darwins conclusion on vestigial features?

  Non functioning features lead to his belief that the features were an example of a species evolutionary past, and a species common ancestor.
• Members of the same species compete with each

  other for __________________.

  Survival
• Charles Darwins belief is that survival is not _______________.

  Random
• What is natural selection?

  The process whereby organisms better adapted to their environment tend to survive and produce more offspring
• What are the 5 steps in the process of natural selection?

  1. Selective pressure

  2. Fitness

  3. Reproduction (if an organism survives it will reproduce)

  4. Successful genes inherited in the next generation

  5. Change in the gene pool (over time)
• What is selective pressure? What are the 4 selective preassures?

  An evolutionary force that causes a particular phenotype to be more favorable in certain environmental conditions.

  These pressures include: (think HFCP - hogs frogs cogs progs)

  - habitat

  - food

  - competition

  - predators
• What does 'fitness' mean in evolution?

  Phenotype is an advantage = survival

  Phenotype is a disadvantage = death
• Natural selection acts on ______________ but its consequences occur in _____________

  individuals, populations
• Natural selection acts on existing ____________

  traits
• Natural Selection acts on phenotypes but evolution consists of change in ________________.

  genotypes
• Natural Selection is directed and purposeful according to the _________________.

  environment
• Describe what pattern of selection Stabilizing Selection is?

  Individuals with most common phenotypes favoured by the environment

  
• Describe what pattern of selection Directional Selection is?

  Individuals with more extreme variations of a trait are favoured by the environment

  
• Describe what pattern of selection Disruptive Selection is?

  Individuals with variations at opposite extremes of the trait are favoured by the environment.

  
• What are the 6 types of evolutionary mechanisms? (Hand)

  - natural selection

  - genetic drift

  - mutation

  - sexual selection

  - gene flow

  - artificial selection

  
• What is genetic drift? - describe both.

  Bottleneck effect: When a severe event / natural disaster results in a drastic reduction in population numbers. The small sample of organisms may survive to establish a new population

  
  

  Founders effect: When a few individuals from a large population leave to establish a new population elsewhere
• What is gene flow?

  When organisms migrate, leaving a population and joining another. This alters the allele frequencies of both populations.
• What is a gene mutation?

  Any change in genotype other than by genetic recombination (sex)
• What is sexual selection?

  Organisms with certain inherited traits are more likely to obtain mates than others (Sexual dimorphism and social behaviour can both be sexual selection pressure)
• What is artificial selection? What can this lead to?

  Intentional breeding of domestic plants and animals to produce certain traits - this can lead to a reduced genetic variability within the population
• What are morphological adaptations? What are the 3 kinds of morphological adaptations?

  A structure of the organism that enhances the survivability and hence reproductive success of an individual

  1) Camouflage

  2) Aposematic colouration (advertising yourself as poisonous or bad tasting)

  3) mimicry (an organism matching a dangerous species)
• What are physiological adaptations? - give an example.

  Processes inside an organisms body that increase its chance of survival (poison ivy, gills of fish, snake venom)
• What are behavioural adaptions?

  An action that an organism takes that significantly Adaptations

  increases its survival and/or reproductive success

  relative to other members of the population.
• What kinds of behavioural adaptations are there? (4)

  1) Related to the environment

  2) related to food

  3) protection of young/group

  4) related to mating
• What are behavioural adaptations related to food?

  - using tools

  - hunting in groups

  - obtaining food by deception

  - Food selectivity

  - protection of food
• What are behavioural adaptations related to protecting young and others in a group?

  - harassing/mobbing

  - decoy and deception

  - Living in groups (safety in numbers)

  - warnings of unpleasantness
• What is intrasexual selection? What does this include?

  Males compete directly with males for the rights to reproduce

  This includes sperm warfare, combat, and Infanticide.

  
  

  Intra - intrafere with a male for a mate
• What is intersexual selection?


  Males do not directly control access to females or resources and therefore must advertise for mates.

  
  

  Inter - interesting characteristics attracts mates
• What is sexual dimorphism?


  When males display colours to attract mate
• What is courtship behaviour?

  When a male performs a behaviour to attract a mate.