Medium Ground Finch CER by SYDNEY SHRUM https://padlet.com/sydneyshrum24/m1mb8h8lpsy2 Made with wonder en-us 2020-02-04 16:27:37 UTC 2025-12-07 17:48:28 UTC hello@padlet.com Natural Selection caused the change in the finches beak in 1976-1978 on Daphne Major. sydneyshrum24 https://padlet.com/sydneyshrum24/m1mb8h8lpsy2/wish/440392205 2020-02-04 16:34:40 UTC https://padlet.com/sydneyshrum24/m1mb8h8lpsy2/wish/440392205 In 1976 the rainfall was 130mm. In 1977 a drought occurred and the amount of rainfall decreased to 20mm. In 1988 it then increased back up to 540mm. This shows that there was a drought in 1977 because the rainfall decreased by 110mm. sydneyshrum24 https://padlet.com/sydneyshrum24/m1mb8h8lpsy2/wish/440393409 2020-02-04 16:35:53 UTC https://padlet.com/sydneyshrum24/m1mb8h8lpsy2/wish/440393409 2- In 1976 the average population was 751. It then decreased to an average of 388.16 in 1977. In 1978 it decreased again to 228.16. This shows that the drought caused the population to decrease because they didn't have the easy to eat Portulaca seed because it could not reproduce with no water. sydneyshrum24 https://padlet.com/sydneyshrum24/m1mb8h8lpsy2/wish/442220065 2020-02-07 15:56:37 UTC https://padlet.com/sydneyshrum24/m1mb8h8lpsy2/wish/442220065 1- In 1976 the average seed abundance for the Portulaca seed was 11.3. In 1978 the average seed abundance decreased to .45 and even went to 0 in some months. The average seed abundance for teh Tribulus seed in 1976 was 10.5. In 1978 the average seed abundance decreased to 5.083. This proves that the Tribulus seed was the only one left. sydneyshrum24 https://padlet.com/sydneyshrum24/m1mb8h8lpsy2/wish/442223480 Portulaca seed- soft easy to eat
Tribulus seed- hard difficult to eat]]> 2020-02-07 16:00:55 UTC https://padlet.com/sydneyshrum24/m1mb8h8lpsy2/wish/442223480 3- The average beak depth increased from about 9.6 to 10.5 from 1976-1978. The average beak length also increased from about 10.7-11.6. We see this change of the beak because the birds had to adapt to the hard not easy to each Tribulus seeds. sydneyshrum24 https://padlet.com/sydneyshrum24/m1mb8h8lpsy2/wish/442227947 2020-02-07 16:06:47 UTC https://padlet.com/sydneyshrum24/m1mb8h8lpsy2/wish/442227947 Natural selection caused the change in the finches beak. Because of the little rain we saw in 1977 it caused the food abundance to decrease (the plants had no water to reproduce). The Portulaca seed or the easy to eat soft seed population was very low and even sparked to zero. The finches were then only left with the Tribulus seed or the hard, difficult to eat seed. The finches beaks were not meant for this seed so many of the birds died, this is why we saw a decrease in population. Since the birds beaks were not meant for the Tribulus seed the birds had to adapt to the only food left, and the only way to do that was by the length and depth of the beak to increase. The change in the beak size was ultimately a result of natural selection. Natural selection is when a trait variation affects the survival or reproduction and is passed on to the next generation. The drought triggered the change in the beak which was a result of natural selection because it will affect the offspring and the next generations. sydneyshrum24 https://padlet.com/sydneyshrum24/m1mb8h8lpsy2/wish/442231115 2020-02-07 16:10:55 UTC https://padlet.com/sydneyshrum24/m1mb8h8lpsy2/wish/442231115 Portulaca seed sydneyshrum24 https://padlet.com/sydneyshrum24/m1mb8h8lpsy2/wish/442239287 2020-02-07 16:22:56 UTC https://padlet.com/sydneyshrum24/m1mb8h8lpsy2/wish/442239287 Tribulus seed sydneyshrum24 https://padlet.com/sydneyshrum24/m1mb8h8lpsy2/wish/442239485 2020-02-07 16:23:15 UTC https://padlet.com/sydneyshrum24/m1mb8h8lpsy2/wish/442239485 Finches beak change sydneyshrum24 https://padlet.com/sydneyshrum24/m1mb8h8lpsy2/wish/442241296 2020-02-07 16:26:03 UTC https://padlet.com/sydneyshrum24/m1mb8h8lpsy2/wish/442241296 Average Rainfall sydneyshrum24 https://padlet.com/sydneyshrum24/m1mb8h8lpsy2/wish/443395971 2020-02-10 23:33:25 UTC https://padlet.com/sydneyshrum24/m1mb8h8lpsy2/wish/443395971