Seal the Deal

For our second unit of our fall STEAM class called Population, we learned about how to group populations and samples of populations of things or animals. For the FE that we went on this unit, we went to the Field Museum, to learn more about organisms and how they've evolved and changed over the millions of years that life has existed here on Earth. For this Action Project, we were tasked with researching an organsim, then changing something about the environment that it lives in and imagining how it might evolve to adapt to those changes. Below is my project, which is on the Harbor Seal.

The scientific name for my organsim is Phoca vitulina. It's more commonly known as the Harbor seal. Phoca vitulina are found in coastal waters of the northern Atlantic and Pacific Oceans, and the Baltic and North Seas. They usually thrive in colder habitats (such as Alaska), but have been observed to go as far south as Baja California, Mexico.

https://www.oceansoffun.org/pinniped_species/44

Because they live in these cold environments, Harbor Seals have developed specific traits to keep themselves warm. A thick layer of blubber insulates the harbor seal, reducing heat loss. The blubber of a Northern Pacific Harbor Seal during winter may account for 27% to 30% of its total body mass. Blubber also streamlines the body and functions as an energy reserve from which the harbor seal can draw energy during periods of fasting. A harbor seal's hair provides no insulation. When hauled out onto land, blood vessels dialate, allowing heat to be released into the nearby environment. The most important sense of a harbor seal is touch via whiskers.

Specimen 1:

“Harbor Seals Hang out on Glacier Ice - GeoSpace.” Magma Cum Laude, 17 Dec. 2015, blogs.agu.org/geospace/2015/12/17/12288/.

Specimen 2

https://en.wikipedia.org/wiki/Harbor_seal#/media/File:Common_Seal_Phoca_vitulina.jpg

Specimen 3

https://commons.wikimedia.org/wiki/File:Harbor_seals_(Phoca_vitulina)_at_Magdalen_fjord,_Svalbard_(3).jpg

Specimen 4

https://commons.wikimedia.org/wiki/File:Harbor_Seal_(Phoca_vitulina).jpg

Specimen 5

https://ptes.org/get-informed/facts-figures/common-harbour-seal/

Specimen 6

http://glacierhub.org/wp-content/uploads/2018/03/35852221312_12faae983c_o-e1520952771199.jpg

Specimen 7

http://www.pbase.com/image/136568395

Specimen 8

https://dissolve.com/stock-photo/Harbor-Seal-Phoca-Vitulina-Near-Sankin-Island-Ikatan-Bay-royalty-free-image/101-D869-24-784

Specimen 9

https://hilltromper.com/article/harbor-seal

We also had to find the similarities and differences our animals have with a living relative. In my case, I chose to compare and contrast my Harbor Seal with Sea Lions.

Both seals and sea lions, together with the walrus, are pinnipeds, which means "fin footed" in Latin. Similar-looking, easy for your average person to mistake a sea lion for a harbor seal, or vice versa. Both often come to shore to periodically rest and bask in the sun, and once a year, to mate. Both have blubber just under their skin, to keep them warm in cold environments.

Sea lions are noisy, barking quite a lot. Seals are quieter, vocalizing via soft grunts. Seals spend more time in the water than sea lions and it’s fairly common for seals to lead much more solitary lives, only meeting up with other seals to meet and mate. Sea lions have external ears, while seals do not. Seals instead have little holes in their head for ears. Sea lions are able to “walk” on land using their flippers. Seals can’t do this, and instead have to crawl on their bellies, wriggling to get around.

https://en.wikipedia.org/wiki/File:California_sea_lion_in_La_Jolla_(70568).jpg

On top of that, we also had to compare and contrast our animal to an extinct relative of theirs. In my case, I found Puijila darwini, an ancient ancestor of the modern seal.

To be honest, the two aren’t very similar, and there’s limited info on Puijila darwini, as only one of them has been discovered. Its skull and teeth are similar to that of a seals’. It’s the earliest discovered ancestor of the seal family yet found. Both have fur covering their bodies. Both live(d) in cool, temperate climates near the Arctic.

Unlike seals, Puijila darwini doesn’t have flippers. It had webbed feet instead. Puijila darwini is actually more otter-like than seal-like. However its skull and teeth indicate that it is, in fact, a seal. Puijila darwini was only semi-aquatic, instead of being fully aquatic like seals. Puijila darwini is also somewhat genetically related to ursids (bears) and mustelidae (weasels and otters). It’s a transitional fossil that provides info on how the seal family returned to the seas.

Puijila darwini skeleton.

https://en.wikipedia.org/wiki/Puijila#/media/File:Puijila_darwini_(fossil).jpg

Puijila darwini restoration (or what it may have looked like).

https://en.wikipedia.org/wiki/Puijila#/media/File:Puijila.jpg

The environmental change that I came up with is that sea temperatures have risen by 2 degrees, forcing the seals to adapt or overheat due to warmer waters. I have 9 specimens, and I had to choose three of them that would live on through this change to the seals' environment.

Specimen 1 (see above for corresponding images for each specimen):
Lower metabolic rate
They won’t need their higher metabolic rate anymore because of the warmer waters.

Specimen 8:
Less body mass
Since they would have less blubber and a lower metabolic rate, they wouldn’t need as much body mass and therefore be slimmer than they were before climate change.

Specimen 7:
Blubber depth reduction
Since they will most likely switch to somewhat warmer environments when their resting ice melts, they won’t need their blubber as much because of that. On the downside, this would cause them to have less reserve energy.

WH, Future Seal, 2018.

The seal would become thinner, since it would have no need for some of its blubber anymore because of the rising sea temperatures. It would also probably have to have stronger fins, as the rising tides alongside global warming would mean more space for predators to wait. The seals would also lose hair, since they wouldn't really need it.

Here are my calculations for the central tendencies. Central tendencies show all of the numbers in a data set. Here, I am measuring the weight of adult male harbor seals, in kilograms. They usually weigh between 30 and 100 kilograms, or from 66 to 220 pounds.

All male seals, weight in kilograms.
Seal 1: 75 kg
Seal 2: 50 kg
Seal 3: 80 kg
Seal 4: 100 kg
Seal 5: 50 kg
Seal 6: 60 kg
Seal 7: 90 kg
Seal 8: 65 kg
Seal 9: 55 kg

Maximum: 100
Minimum: 45
Range: 100 - 45 = 55
Mode (most occurring number): 50

Mean: 50 + 50 + 55 + 60 + 65 + 75 + 80 + 90 + 100 = 625
625 / 9 = 69.44. So, 69.44 is the average weight between all the seals in the group.

Median (middle number): 50 50 55 60 65 75 80 90 100. 65 is the median.

1QR (median of the first half): 55
3QR (median of the second half): 80
IQR (range of the 1QR and the 3QR): 80 - 55 = 25

I used a box-and-whisker plot to also show this information, as seen below.

WH, Box-And-Whisker Plot, 2018

Standard deviation is a tool that is used in statistics to show variation in a set. To find standard deviation, you have to use the median from the previous step. My process is shown below.

WH, Standard Deviation Table, 2018

This is a combination, because the order in which they are selected does not matter, compared to a permutation, where it does matter. The equations for permutation and combination are nPr and nCr, respectively. Below is the math that shows how many possible ways I could have combined my three seals out of the 9 I had.

WH, Calculations, 2018

In conclusion, this project was like an interesting add-on to our previous Action Project. It took me quite a while to finish, and got somewhat annoying to do at times, but I pulled through, and I'd like to think I did a pretty good job on it.

Works Cited:

Northern Fur Seal Printout- EnchantedLearning.com, enchantedlearning.com/subjects/mammals/pinniped/Northernfurseal.shtml.

“Harbor Seal.” Oceans of Fun, www.oceansoffun.org/pinniped_species/44.

NOAA. “Harbor Seal.” NOAA Fisheries, www.fisheries.noaa.gov/species/harbor-seal.

“Sea Temperature Rise -- Pristine Seas.” National Geographic, 25 Aug. 2015, www.nationalgeographic.com/environment/oceans/critical-issues-sea-temperature-rise/.

SeaWorld Parks & Entertainment. “Adaptations.” Animals: Explore. Discover. Connect., seaworld.org/en/animal-info/animal-infobooks/harbor-seal/adaptations.

SeaWorld Parks & Entertainment. “Adaptations.” Animals: Explore. Discover. Connect., seaworld.org/en/animal-info/animal-infobooks/harbor-seal/adaptations.