Natural Selction

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Natural Selection In The Population of Seeds

Question:
How does the environment affect the types of individuals surviving and reproducing over a period of time (generations)?

Background Information:
When looking at this experiment, we can see that it has a direct relationship with natural selection. To better understand the theory of natural selection and other theories that relate to natural selection, like Darwinism, I did background research on these subjects. To start to look at natural selection, the first place I started was with Charles Darwin. Charles Darwin is famous for his book “On The Origin of Species”, in which he explained his theory of natural selection and evolution. Darwin first developed his theory of natural selection when on a visit to the Galapagos Islands in the Eastern Pacific ocean. The Galapagos Islands have several species of finches, all with different sized beaks. When Darwin was there he realized that the different finches beaks’ were related to their diets. He concluded that when the South American finches reached the Islands, they had to adapt to different conditions over generations. These adaptations allowed them to get enough food to survive. This theory of one ancestral species diverging into multiple descendent species was groundbreaking at the time and was the basis for the theory of natural selection. Nature had selected the best-adapted varieties to survive and reproduce amongst the finches, giving them different beaks to fir their different eating needs, like getting nectar from flowers or eating hard seeds. This theory of natural selection can be directly related to our experiment of shaking the seeds. Each of the pans has different-sized holes, some being larger and others smaller. Each of these pans represents a separate environment to which the seeds will have to adapt. The theory of natural section leads me to believe that the pinto bean being the largest bean of the group, would have the best chance to survive and reproduce, as it was least likely to fall through the holes in the pan by virtue of its size.

Hypothesis:
The pinto bean will have the largest population after five generations.

Materials:

5 different types of seeds
Pan with 6 holes (approximately the same size)

Experimental Design:
1. Obtain a small loaf pan punched with 6 holes in the bottom. 2. To create the initial seed populations, select 5 seeds of each type available. 3. Place this population of 25 seeds in the pan.

4. Shake the pan 15 times and note which beans fall through the holes. You will probably get the best results if you shake the bowl from side to side similar to the motion you use just before you throw dice. 5. Record accurate numbers of each type of seed that falls as well as those remaining in the pan. The ones that fall through the holes are considered dead while the seeds remaining in the pan are considered the first generation and will be sued to represent the “parents” for the next generation. Only seeds that survive reproduce. So, for each of the seeds that remain in the pan, add another one of the same type to indicate that the seeds reproduced. 6. Repeat the same procedure with the population from the first generation. Shake the pan 15 times. Count and record the number of seeds remaining in the pan. 7. Repeat for a total of 5 generations.

Seed Population Totals For Generations in Pan #1

Generation |Start |1 |1 |2 |2 |3 |3 |4 |4 |5 |5 | |Seed Type | |#left |doubled |#left |doubled |#left |doubled |#left |doubled |#left |doubled | |Rice |5 |0 | | | | | | | | | | |Lentil |5 |3 |6 |0 | | | | | | | | |White |5 |2 |4 |3 |6 |12 |10 |20 | | | | |Pinto |5 |2 |4 |4 |8 |6 |12 |10 |20 |14 |28 | |Popcorn |5 | | | | | | | | | | | |

Seed Population Totals For Generations in Pan #2 Generation |Start |1 |1 |2 |2 |3 |3 |4 |4 |5 |5 | |Seed Type | |#left |doubled |#left |doubled...
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