Students will be able to:
One of the biggest difficulties I encountered as a teacher teaching the Evolution unit is getting students away from the Lamarck theory of evolution: that evolution occurs due to the inheritance of acquired characteristics. For example, giraffes have long necks due to stretching of their necks to reach leaves in trees; the long neck acquired characteristic is passed on to future generations of offspring.
It is therefore important to show students that evolution occurs through natural selection of beneficial traits created through genetic variation within a population. This activity also introduces students to the theory of punctuated equilibrium, which is that evolution occurs faster when the environment surrounding the organism is rapidly changing.
The setup of the classroom is flexible and up to the teacher, but one option is to have students work in pairs at their desks, and set up one area in the center of the table with a number of “food sources” for the tests. Ensure that the food sources are located relatively equidistant to where the students are sitting.
Part 1: Competition for Resources
Part 2: Changing Environment
Part 3: Introducing Genetic Variation
Part 4: Observing Natural Selection
Backwards design a suitable diet for the finch from the structure of the beak.
“The Beaks of Finches,” New York State Education Department.
New York State Living Environment Standards
3.1f Species evolve over time. Evolution is the consequence of the interactions of (1) the potential for a species to increase its numbers, (2) the genetic variability of offspring due to mutation and recombination of genes, (3) a finite supply of the resources required for life, and (4) the ensuing selection by the environment of those offspring better able to survive and leave offspring.
3.1g Some characteristics give individuals an advantage over others in surviving and reproducing, and the advantaged offspring, in turn, are more likely than others to survive and reproduce. The proportion of individuals that have advantageous characteristics will increase.
October 23, 2011 - 4:05pm
San Angelo, Texas, United States
May 27, 2014 - 9:59am
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