Evolutionary thinking/ forms of speciation


Lesson 2: evolutionary thinking
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This lesson contains 20 slides, with interactive quizzes and text slides.

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Lesson 2: evolutionary thinking

Slide 1 - Slide

In a certain population, disruptive selection is occurring. In this population, which is most likely to survive?
organisms with average traits
organisms with extreme traits
organisms that sexually select
organisms that are small

Slide 2 - Quiz

Effect natural selection on phenotype distribution

Slide 3 - Slide

Cheetahs nearly became extinct but recovery efforts managed to save them. Now, most cheetahs are genetically identical. This is due to:
gene flow
the bottleneck effect
selective migration
random mating

Slide 4 - Quiz

Members of different species do not normally produce offspring due to:
differing courtship rituals
varying breeding times
gamete incompatibility
all of these

Slide 5 - Quiz

Who is afraid of snakes (or spiders) and why?

Slide 6 - Mind map

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Five processes that lead to evolution
  1. Small population/genetic drift: chance will start to play a role
  2. Non-random mating/sexual selection
  3. Mutation
  4. Gene flow: immigration and emigration 
  5. Natural selection 

Slide 13 - Slide

Properly describing natural selection
  1. There is genetic variation in the population caused by mutations
  2. Some individuals have a higher chance of survival due to an advantage/adaptation(describe the advantage)
  3. The better adapted individuals will reproduce more (higher fitness) 
  4. The genes of the better adapted individuals will therefore become more common in the population

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1. part of a population becomes separated from the rest of the species.
2. adaptation to different environmental conditions.
3. reproductive isolation. As long as the two groups interbreed they share the same gene pool and remain the same species.

Slide 15 - Slide

Forms of speciation
Allopatric speciation: reproductive isolation is caused by a geographical barrier

Sympatric speciation: there is no geographical barrier, but something else stopping them from reproducing, for example temporal, behavioral or habitat isolation

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Slide 18 - Link

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Slide 20 - Slide