Introduction 1.0:
Biogeography is the study of life in certain spaces and time, which includes the process of how life got there. Due to this complex and broad study, biogeography unifies many sciences such as biology, ecology, geology, meteorology, climatology, and genetics. Although naturalists such as Alfred Russell Wallace set down the basic principles for biogeography, it was not considered as a formal study until the 1960’s when theories on plate tectonics and continental drift was an accepted theory (Holsinger, 2012). In studying biogeography, one sees the importance of biodiversity and the significance in keeping a balance in the ecological cycle.
Hamecha-Daniels, [Narjess]. (n.d.). The Importance of Biodiversity. [Pinterest Post]. Pinterest. Retrieved February 23,2021, https://www.pinterest.com/pin/531776668495445787/
1.1: Island Biogeography
Biogeography can be broken up into subcategories as most academic subjects can. Scientists who study island biogeography, study isolated spaces and their species. The most well-known studies of island biodiversity are from the data collected by Charles Darwin in the Galapagos islands and Alfred Russell Wallace’s work in the Malay Archipelago. Naturalists and scientists have concluded that the survival of a species and the richness of biodiversity depends on the size of the island and the distance from the mainland. The amount of space matters, as to how many species it can hold and occupy. The distance will determine how many species can actually reach the island from the mainland (Quantumwombat, 2015).
2.0 Data Collection and Analysis:
To test these theories and observations, multiple trials were done using the Virtual Biology Lab Island Biogeography Simulator (Jones et al., 2016). Here are some of the recordings categorized by variations of factors that would in real life contribute to the number of diverse species on an island.
Image representing the baseline of the simulation. No manipulation has been done. (Jones et al., 2016)
2.1 Manipulation 1- No Manipulation (Baseline):
In the first trial conducted, the default perimeters were kept in place. Both islands were identical in variables. Distance at 10km from mainland, migration rate 2, island size 256km, and mortality rate .05. Two separate trials were done with close to similar results. The current number of species on island 1&2 through the first trial were at 8 and in the second trial, number of species on island 1 was at 8 while island 2 had two more arriving at 10 species. Average amount of species on island 1 was at 8.2 and island 2 at 8.4. On the second trial run, average amount of species on island 1 was at 8.4 and island 2 8.3. The top most abundant species on island 1 was species 1&5 and island two had species 3&6. The second trial produced species 4&9 for island 1 and species 1&10 for island 2. The island total on the first island was 15 and in the second trial 11. For island 2 total, first trial came up with 17 and second trial 15.
2.2 Distance Manipulation:
The second manipulation data was changed to have the second island further out at 270(km), keeping the first island at the initial distance of 10(km). The size remained the same as in manipulation 1. Trial 1’s current number of species for island 1 was 10 and 9 for island 2. In the second trial, island 1 had 9 and island 2 had 8. The average number of species for island 1 in the first trial was 7.3 and 6.9 for the second trial. Island 2 had 7.7 for the first trial and 6.5 for the second trial. The distance seemed to create a diverse species for both the islands even though the second island was further out. In trial 1, island 1’s top species were 1,2, & 10. The second island had species 4,9, &10. In the second trial, island 1 contained 6 &10 as the top abundant species and on island 2 it was species 2,3, & 8. It was difficult to say whether distance made an impact between the two. The island total for island 1 was 20 and in the second trial 17. For island 2, the first trial data showed the island total of 15, and on the second trial 18.
2.3 Size Manipulation:
On the 3rd manipulation, the size on the second island was altered. The size was shrunk down to 64 (km). Other measurements of the two islands remained the same as in manipulation 1. Surprisingly the second island seemed to flourish in species and diversity more than island 1, even though the island was now smaller. The current number of species data for island 1 was 2 and island 2 had 8 during the first trial. In the second trial, island 1 had 0 and island 2 had 8. The average number of species for island 1 was .9 and island 2 had 7.3 during the first trial. In the second trial island 1 had .9 and island 2 had 5.8. The top abundant species on island one was species 1&10 and in the second trial there were 0. On island 2, the most abundant species were species 2,3,4,7 & 8 on the first trial and species 2,3,5, &6 on the second trial. On the first trial for island 1, the island total was 2 and a significant 14 for island 2. On the second trial, island 1 had 0 and island 2 had 12. You can see the huge difference in the chart below.
Bar graph for manipulation 2.3 Size, created in excel by data that was collected.
2.4 Size plus Distance Manipulation:
To further investigate the diversity from the size manipulation data, both islands were reduced to 64(km) and this time the first island was measured further out from the mainland at 410(Km). The current number of species for island 1 showed 1, island 2 had 0. In trial 2, island 1 had 2 and island 2 had 0. For the first trial, the average number species on island 1 was 1.2 and island 2 .9. In the second trial, island 1 had 1.2 and island 2 had .5. The most abundant species on island 1 was species 4 and island 2, 0. The second trial, island 1 was species 1 &6, and island 2, 0. Island 1 had an island total of species of 2 for both trial 1 and 2. Island 2 had a total number of 0 for both trials.
2.5 Migration and Mortality Manipulation:
The last manipulation, the variables were kept the same as the 4th manipulation of distance and size. The mortality rate which had been at .05 for all past previous trials, was then decreased to .02. The migration variable was at 2, then pushed up to 10. The current number of species at that time for island 1 was 9, island 2 had 9 as well. In trial 2, island 1 6, and island 2 at 8. The average number of species for trial 1 showed 8.3 for island 1, and 7.5 for island 2. In the second trial, the first island had 6.6 & second island 7.1. The top abundant species for island 1 was species 6,7,8, &5 in trial 1, and trial 2, species 4,5,6, &10. On island 2 the diversity was extremely rich among the species. The 1st trial it had species 1,5,6,8,9, &10. The 2nd trial had so many, species 1,2,3,4,6,7,9 &10. The island total for island 1 was 26 first trial, 10 2nd trial. Island 2 had a total number of 17 for the 1st trial and 9 for the 2nd trial.
An image of the 5th manipulation of the two islands on 2.5 Migration and Mortality. (Jones et al., 2016)
3.0 Discussion:
As was mentioned above in the introduction, scientists who studied island biogeography came up with theories with size and distance. It was difficult to see the data matching the theory on size when in manipulation 3, the size manipulation showed an increase of diversity and animals on island 2 when the variable was reduced in size. You can see this visibly in the 2.3 bar graph. The size did matter when distance was altered to have the islands further out from the mainland, at a decent size of 256(km). The number of species and diversity was high despite the distance, and this seems attributed to the larger size. When size was reduced and island variables were changed to a longer distance from the island, the island total and diversity of species decreased dramatically. Now, regardless if the size of island is smaller and further out from the mainland, if the migration is strong and mortality rate is low, the data showed the island will succeed in creating a rich diversity and a high totality rate. The data demonstrated proved the theory that a larger sized island and an island closer to the mainland will have a thriving environment of species. To have a low mortality rate, an island must be large enough to allow a species to spread. To increase migration, the distance between the island and mainland needs to be closer.
4.0 References:
Hamecha-Daniels, [Narjess]. (n.d.). The Importance of Biodiversity. [Pinterest Post]. Pinterest. Retrieved February 23,2021, https://www.pinterest.com/pin/531776668495445787/
Holsinger, John R. (2012). Overview of Biogeography. Science Direct. https://www.sciencedirect.com/topics/earth-and-planetary-sciences/biogeography
Jones, T. C., Hiatt, A. C., Emma, T., Mains, A. R., Kiser, K., & Ford, D. (2016). Virtual biology lab [Computer software]. East Tennessee State University. http://virtualbiologylab.org/ModelsHTML5/IslandBiogeography/IslandBiogeography.html
Quantumwombat. (2015, November 13). Theory of Island Biography [Video]. YouTube.
Three Comparisons
ReplyDelete1. We both had manipulations that yielded more species on an island we manipulated to be smaller (in your case) or farther (in my case). The reason for either is unknown because it is the opposite of what the research we used in the introduction explained is likely to happen.
2. We both used an illustration in our introduction to help visually explain biodiversity
3. We both related our findings to the information used in our introductions to help support the data we collected.
Three Contrasts
1. Our distance manipulation was different in that your island 2 that was moved further produced less species than island 1 which did not move distance. For an unknown reason in my experiment, my further island produced more species than the unmoved island.
2. Migration and Mortality differed in our experiments in that you decreased the mortality rate and significantly increased the migration rate. This difference showed a strong increase in your species diversity on island 2 compared to only 3 most abundant species in my trial.
3. My size manipulation produced less species on the smaller island compared to your smaller island producing more species.
-Gabriella Tijerina
Crystal,
ReplyDeleteNice job on your report!
Comparisons:
1. We both chose a tropical habitat.
2. We both received similar-ish data on our current number of species throughout the first manipulation exercise.
3. In the discussion, we both associated our data with the theory of island biogeography. It is clearly interconnected with your results.
Contrasts:
1. You provided much more visuals than I did in my report- in hindsight, I wish I would have done the same. It just adds a nice illustration as I was reviewing your data.
2. We both chose tropical habitat type, however, your type of species was arthropods and I chose mammals. I could conclude that this probably made all the difference when comparing our data because I have much higher numbers in all variables than your finding for the most part. Since we had chosen the same habitat, this leads me to believe the type of species was the cause of this.
3. According to your size and distance manipulation round, your island 1 was extremely further out than mine. In your 2.4 paragraph, you mentioned moving island 1 further out to 410 km in which I set mine at 210 km. This is a huge difference and I can see that in the comparison of our data.
I enjoyed your report!
Thank you Erika! :)
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