Download (Island). When mentioning islands most people think of land

"It is not the strongest or the most intelligent who will survive but
those who can best manage change”- Charles Darwin. Island
Geography has revealed the evolutionary process through
colonization and isolation (Overview). There are fossils that date
back 300 million years, providing a record of life at that time. Using
these fossils is one way the theory of Island Geography is studied.
Throughout this paper I will reveal the history, theories, and various
concepts of Island Geography.
History
Biogeography dates back to the eighteenth century; starting
with Georges-Louis Leclerc, Comte de Buffon. He was one of the
first to question 2,000 years of the churches belief system. Unlike his
colleagues, Buffon refused to accept catastrophe stories, such as
the biblical flood. Sea fossils and sedimentation of rock beds
indicate the continents were once submerged under water.
Reemergence of them had no explanation. Buffon was an
advocate of real causes and insisted these changes occurred
naturally through subsidence and earthquakes.
He was mostly involved with biological and zoological
problems, along with key information on quadrupeds, birds, and
minerals. He believed the best method was having “the complete
description and exact history of each thing in particular” (ibid. p.
14B), (Buffon).
“The history of one animal should be… that of the entire
species of that particular animal; it ought to include their
procreation, gestation period, the time of birth, number of
offspring, the care given by the mother and father, their
education, their instincts, their habitats, their diet, the manner
in which they procure food, their habits, their wiles, their
hunting methods” [ibid., 16A–B] (Buffon).
Melissa Gantt
Bio 111 D6
Page 1
One of the most well-known studies of
Island Geography is the Galapagos Islands.
From the shoreline of the equator it can take
up to 600 miles to reach the cluster of islands.
Because of this factor they were isolated for
millions of years, creating homes for the rarest
forms of plants and animals on the planet.
Even now their geography is constantly
changing because of the frequent volcanic
activity and erosion on the Islands.
It is said that the abundance of rare
and unique life forms had Darwin in awe.
Soon enough these incredible species
created a breakthrough in his work. The way
these creatures were able to flourish with
such an unforgiving environment peaked
curiosity; helping pave the path to Darwin’s
Theory of Evolution and Natural Selection as
we know it today.
Many initial arrivals came to the island at its lowest. There were
no mates to be greeted, no plants to be fed on, and not even soil to
put down roots
(Biological).
Over millions of
year’s natural
occurrences
helped
populate the
island, bringing
birds through
storms, seals
and penguins
through
currents and
carrying seeds
across
continents (G.
islands).
Melissa Gantt
Bio 111 D6
Page 2
These original species could live off of what seemed to be
nothing; even plants were growing out of lava. They basically
survived to die; to feed the flora for the next vegetarian generation.
Darwin’s interest in the island put his Theory of Natural Selection into
motion.
Discovery
Darwin’s Theory of Natural Selection was based on what is
called “Darwin’s Finches.” Originally, species were thought to be
static, meaning they were thought to have no evolutionary
capabilities. However, this was proven wrong by mutations in DNA.
The useful genes connected to survival or breeding, help a species
produce more offspring that have the same advanced gene, which
will be passed down. The ones that can adapt and change will
survive.
Originally Darwin thought in the view of “centers of creation”
he completely ignored transmutation of species. When voyaging
on The Beagle they found different types of species on every island
they stopped on, including 3 species of mockingbirds. Finches were
also found but ignored at this point.
Darwin sent his findings of birds to ornithologist expert John
Gould. He discovered that the birds thought to be black birds and
finches were in fact 12 species of ground finches. Every island
Darwin visited had not just a variety of mockingbirds but completely
different species per island. Gould found 26 species of birds, way
more than Darwin anticipated, and 25 of the 26 were new and
distinct species only found near the South American continent
(Darwin’s). At this time the acting governor, Nicholas Lawson
informed Darwin about the differences in Galapagos Tortoises and
he became intrigued.
Melissa Gantt
Bio 111 D6
Page 3
One of the tortoises’ most unique evolutionary traits occurred
because of a rice rat infestation. They ate all the food on the island
and eventually tortoises evolved to be able to go without food or
water for up to a year. This amazing trait indirectly led to their
downfall. Buccaneers, whalers and fur sealers heard about these
giant tortoises and wanted to store them on their ships for fresh
meat, exploiting their adaptation (Watson).
These traits made Darwin wonder about the stability of
species; eventually leading to Darwin’s acceptance of
transmutation of species idea. These species were similar from island
to island but perfectly adapted to their environment forcing him to
question the origin of the islands inhabitants (Biological).
The Galapagos Islands had an enormous impact on Darwin
and the world of science. This is the reason for the Charles Darwin
Research Station established at Puerto Ayora, Santa Cruz Island,
Galapagos in 1964 (History). The enclosure allows people to come
face to face with the giant tortoises Darwin himself studied, along
with an “internationally-recognized herbarium containing the largest
Galapagos plant collection in the world” (History).
The stations main goal is conserving life on the Islands.
Unfortunately, in 2012 the last surviving Pinta Tortoise, Lonesome
George, passed away. Originally they tried mating him, but nothing
ever came from it. “[The Charles Darwin Foundation provides]
unique scientific solutions to protect the Islands Galapagos. [Their]
work continues to make the biggest impacts at local, national and
international levels” (History).
Melissa Gantt
Bio 111 D6
Page 4
Types of Island Geography
“An "island" is any area of suitable habitat surrounded by an
expanse of unsuitable habitat” (Island). When mentioning islands
most people think of land surrounded by water. However, there are
many types of untraditional islands. Some organisms are able to live
on mountain tops while others are restricted to the valleys. An island
for one organism may not be suitable for another.
The volcanic island, Surtsey also known as the island of fire, has
made it possible for scientists to study the evolution of plants and
animals naturally. It was named after the Norse mythological figure,
Sutur, because he was said to carry a sword of fire. There is no more
volcanic activity feeding this island, meaning the peak of the island
is set at 508 ft. above sea level. Due to porous scoria (very porous
volcanic rock); 3 acres of land disappear every year.
When the island first came about Scientists seized their
opportunity to see just how long it would take for life to form on this
new and untouched land. Within the same year a searocket was
found growing on the shoreline. These plants most likely came by
sea from the island Heimaey, which is 11 miles away (Kuschk). Birds
started colonizing on the island instead of just using it as a stop
during migration, so vegetation started to flourish. Birds are thought
to be 75% responsible for all seed dispersal.
There is now grassland 25 acres long that can be seen from
satellite due to gulls colonizing in a specific area. So far, 69 species
of plants have been documented on Surtsey and 32 have become
entrenched, meaning they’ll always be on the island (Kuschk).
Melissa Gantt
Bio 111 D6
Page 5
Insects have been on Surtsey since the beginning; starting with
flying bugs, then spiders and so on. They came in contact with this
new land mass via drift wood, dead carcasses that washed up; and
by grass and soil that broke off from other land masses and floated
to its shore. Not
only are birds a
main occupier,
seals have
been using the
island since
1983 for
breeding
grounds.
The
colonization is
still happening
with chestnut
worms and
slugs, found in
1990, which
helps fertilize
the soil. The
significance
and
evolutionary
possibilities of
this island led to
a ban on all non-science related visitation.
During mid-1970, someone improperly discarded their bowel
movement and a tomato plant took root (Kuschk). Another incident
occurred when boys from the neighboring island Heimaey planted
potatoes. Both of these foreign plants were removed. This way
nothing is growing there due to human interference.
Melissa Gantt
Bio 111 D6
Page 6
Surtsey is giving us a great look at evolution in the process.
From the beginning in 1963, it was created from a volcanic erpution.
Birds started landing on the island during migration and dropped off
seeds. Eventually, a group of gulls colonized and there is now 25
acres covered in grass. This means birds, inclement weather, and
ocean tides all made this new, untouched land habitable; naturally.
There was very minimal human interference and this island is thriving
with plants and wildlife.
The lead scientist on the island, Borgthor Magnusson, was just
11 years old when he saw the volcano erupt. He stated, “this
opportunity to follow the colonization of a new site on earth right
from its formation – from the time when it was a pile of ash until now,
with many hundreds, even thousands of plant species and animals,
to be able to follow that is very, very rare” (Blask).
There is, however, a possibility of seeing this phenomenon
again. A volcanic eruption is currently causing a new island. They
are uncertain if the eruption in the Pacific will last long enough to
create a sustainable island. It is only 650 ft. wide and 980 long as of
lately. Unfortunately, the opportunity to study evolution at this
potential island is being overlooked by territory disputes between
China and Japan.
Melissa Gantt
Bio 111 D6
Page 7
Mountains can be considered islands because they have a
wide range of habitats for different species. The Rocky Mountains is
a great example of this, because they range in western North
America, from far north Canada down to southeastern New Mexico.
This creates many temperatures and rainfall types. There is a mixture
of habitats in the Rockies. They consist of alpine, subalpine, and
boreal throughout the Northern Rockies (Ecology). Coniferous
forests are located throughout the range which, “contain the
highest level of biomass and are notable for their trees” (Ecology).
There are also wetlands and prairies where the Rockies meet the
plains.
This mountain range holds a huge variety of wildlife; so much
so that ecologists divided it into life zones. They figure this out by
seeing where trees are supported and species that define traits and
characteristics of the environment, known as indicator species
(Ecology).
“Piñon pine and juniper are common in the southern Rockies,
while they give way to firs, pines, and spruces further north.
Beyond the timber line (the altitude above which trees cannot
grow), mountain goats and bighorn sheep browse in alpine
meadows. The forests downslope are home to bears, deer,
elk, hares, minks, cougars, porcupines, squirrels, and other
woodland creatures. The rivers of the region are rich with fish
such as rainbow trout and grayling. Within the Rocky
Mountains lies the Continental Divide, which separates the
waters that flow to the Pacific Ocean from those which will
flow into the Atlantic . . .” (Rocky).
Just looking at the flora and fauna living in each zone provides
Darwin’s theory with proof of colonization and isolation. Not only
are there places where trees will or will not grow, but there are
places where different animals are unable to live. Most likely the
squirrel would have died off if they lived high in the alpines.
However, they either would have adapted to their environment or
migrated down to the valleys to find a more suitable one.
Melissa Gantt
Bio 111 D6
Page 8
Why does the bighorn sheep choose to live on the mountain
tops? They have to have rough hooves just to get the right amount
of traction to maneuver on the side of a mountain. Some study
suggests bighorns could have possibly adapted to the mountain
tops to avoid predators such as coyotes, but these are still just
theories. We weren’t around when these species settled and fully
adapted to their habitat.
Now that we are established, permanent human settlement in
the Rocky’s is forcing species to decline. Gray wolves and grizzly
bears were completely eliminated from the United States and are
only returning because of conservation measures in affect.
Humans have become a main reason for a decline in what
once was a thriving species. Because of these actions we are now
considered a super predator. Human beings have forced evolution
to occur because of a continuous population and just out of pure
ignorance. “[The] Bighorn Sheep is one of the many species
documented as getting smaller, on average” (Britt). This has forced
body size and reproduction ability to occur 300 times faster than
what’s naturally acceptable.
One reason larger species are dying off is because of trophy
hunters, people that kill to boast and keep horns as evidence.
Basically animals are being killed for their traits and features. Once
again, like with the Pinta Tortoise, people are exposing these species
adaptation and killing them off. Unfortunately, it’s not for food this
time around, but just for a status in the hunting community. This is
why Surtsey Island is so important. Not only are we experiencing
evolution first hand, but there is a ban on anyone setting foot on the
island other than scientists to prevent unnecessary change. Surtsey
is allowing us to study the evolutionary changes from the beginning,
starting with nothing but a volcanic eruption.
Melissa Gantt
Bio 111 D6
Page 9
We now have a habitable environment consisting of birds,
plants, seals and recently discovered slugs and earthworms.
Everything that has occurred on this island is happening through
nature. The seeds that washed up were quite large, capable of
floating and can tolerate salty water, which is how they were able
to make landfall and germinate. Woolly Willow, Dwarf Willow, and
Tea-Level Willows are now all established on the island, because
these species have tufts of hair making it easier to be dispersed long
distances through wind (Ólafsson).
Birds also played a major role in creating an adaptable
environment. Originally the island was used just during migration.
Once Scurvy grass appeared where the gulls rested it made more
sense for these gulls to colonize there. Hopefully, Surtsey will
continue to grow and with the right protection measures we will see
natural selection occur on this island and get some real answer
about evolution as we know it.
“A total of 300 different species of invertebrates have been
found on Surtsey, and approximately half of them have become
permanently established” (Ólafsson). Flying insects are the most
obvious of species. One of interest is the Ceutorrhyncus insularis, a
very small snout beetle that feeds on scurvy grass and is an
extremely rare species on a global scale.
Melissa Gantt
Bio 111 D6
Page 10
A look at Island Geography forming
Melissa Gantt
Bio 111 D6
Page 11
A very interesting island that has been mistaken for a continent
before is Greenland. It is known for being the world’s largest island.
One main reason it is considered an Island is because it sits on North
America’s tectonic plate and is not geologically separated from
Canada, the U.S., and Mexico. It is mostly covered by an ice sheet,
making two-thirds of the land subject to permafrost. This island is
very important when it comes to climate change. It will be able to
raise sea levels dramatically if it were to melt via global warming.
Interestingly enough all cities in Greenland are built on the coast.
That is the only places where there is no ice formed.
Greenland was first discovered by Erik the Red who was exiled
from Iceland for 3 years for committing murder. He named this
island Groenland, which translates into “green land.” There were
rumors he named it this to attract more settlers to the area, thinking
people would be willing to travel if the name sounded appealing.
Being very persuasive he was able to get 25 fleet ships to
follow him back to this “green land.” There were women, children,
and domestic animals on board. Only 14 ships made it to their
destination. They then separated into 2 colonies, known as the east
and west settlements. This icy land actually restricts all human
activity to the coasts.
25000 BC is thought to be the year humans first set foot on the
island. However, when the Icelandic Vikings settled on the land it
looked to be uninhabited. They took settlement along the
southwestern coast. “Excavations have shown that the fjords at that
time were surrounded by forests of 4-to 6-metre-tall birch trees and
by hills covered with grass and willow brush” (History of). However, it
is thought that when the Norse landed they cleared out the trees for
fuel and building material, and allowed their goats to graze during
winter and summer, clearing out much of the grass originally there.
Melissa Gantt
Bio 111 D6
Page 12
During the 14th and 15th centuries the “Little Ice Age” began.
The Inuit, better known as Eskimos in the U.S., survived icy weather
and the “Little Ice Age” period. However, the Norse settlements
were disappearing so fast that Denmark-Norway still claimed
sovereignty on the land (History of). The climate survival was very
difficult. However, this led to one culture in particular being able to
succeed as other groups died out. The Inuit were the only people
inhabiting Greenland for several centuries.
The ice-free areas benefited a few cold tolerant species to
survive the Ice Age. Other than that, it can be assumed that all life
was exterminated and current species invaded Greenland after the
Ice Age ended. As of now Greenland’s population is 89% Inuit and
11% Danish (Upton).
The majority of Greenland’s plant species originated from
Europe. However, their national flower, Niviarsiaq, meaning “young
lady”, is commonly found in North America. The fauna such as
reindeer, polar bears, and artic fox can be found living on
Greenland and other land. There are not many unique animal
species to the island due to the extermination of animals during the
Ice Age.
There are 10 unique vascular plants found nowhere else but in
Greenland, including








East Greenland Saxifrage
Greenland Alkali Grass
Porsild’s Alkali Grass
Greenland Fescue
Greenland Blue-eyed Grass
Greenland Pondweed
Two Pussy Toes
15 endemic micro species of hawkweed.
Melissa Gantt
Bio 111 D6
Page 13
“The evolution of
vascular tissue allowed for
an early dominance of
these plants on land. It
gives them the ability to
transport water and
dissolved minerals through
specialized strands of
elongated cells that run
from the plant root to the
tips of the leaves”
(Vascular). Just like the
first plants that came on
land.
There is also a flatworm, and a comb jelly from Umanak Fjord
that is native to Greenland. These are two marine invertebrates
considered to represent families known only from Greenland
(Greenland). Adaptation to cold and drought are main factors in
the distribution of species.
The Greenland shark is a one of a kind animal that can be
found throughout the northern Pacific Ocean at great depths. It is
one of the only fish that prefer artic to subarctic temperature
ranging from -2 and 7 degrees Celsius at all times. During winter
they can be found around the surface and near the edge of ice
flows. Their skin
color can range
from brown to a
violet.
These sharks
can be up to 21
feet in length, but
have ironically
small fins. There
dorsal fin is equal in
size, sits on the
middle of the sharks
trunk and is
spineless (Rogers).
Melissa Gantt
Bio 111 D6
Page 14
Another interesting fact about these historic sharks is their eyes.
They have spiracles on the tops and bottoms which allow them to
breathe when buried in sand or laying on the bottom of the floor.
However, most of these sharks are blind due to parasites living off
their eyes.
They use to be hunted down for their liver in Greenland,
Norway, and Iceland, but that is no longer practiced. Inuit hunters
do eat the shark but it is not a delicacy due to the cold water they
live in and the fact the meat is poisonous when raw. Unlike the
Bighorn Sheep and the Pinta Tortoise, hunters are not putting these
sharks into extinction. Unfortunately many other shark species aren’t
as lucky.
Conclusion
Charles Darwin once said, "in the struggle for survival, the fittest
win out at the expense of their rivals because they succeed in
adapting themselves best to their environment." Reflecting back on
my research of Island Geography I saw this quote being fulfilled time
and time again.
Just look at the Galapagos Islands, the initial arrivals served
only one purpose; to die so they could feed the flora for the next
generation. Slowly but surely this Island came to have over 25 new
species of finches along with Pinta Tortoises that were able to adapt
after the rat infestation. If not for humans who knows how the Pinta
Tortoise could have evolved.
Even now Surtsey Island is showing us evolution from the
beginning, starting with a pile of ash to becoming colonized by gulls
who helped scurvy grass grow over 25 acres of land. This will give us
a look at natural selection, with very minimal human interference.
Birds, weather, ocean tides, natural selection, and even mutation
can form and create colonization on an island. Looking at the huge
variety of species and geography of these islands shows why Darwin
was so intrigued by the Galapagos and its finches.
Melissa Gantt
Bio 111 D6
Page 15
Island Geography can be found all over the world from the
peaks and valleys of mountains to the depths of the Pacific Ocean.
Species are constantly adapting and evolving to geographical and
ecological changes. The same species of finches might have
adapted different features if they were located on Greenland or
could have died off to make way for the fittest of the species.
Natural Selection and Evolution are able to be noted by looking at
the various “islands” I mentioned throughout this paper. Darwin was
lucky enough to stumble across many types of species of finches
that adapted to best benefit them. We are once again able to see
these evolutionary traits in motion all thanks to Surtsey Island.
Eventually we will start seeing positive mutations in DNA and
hundreds of thousands of flora and fauna will continue to flourish.
Melissa Gantt
Bio 111 D6
Page 16
Works Cited
“Biological Evolution of the Galapagos.” Galapagosislands.com. Web. 25
Nov 2013.
Blask, Sara. “Iceland’s New Island is an Exclusive Club—for Scientists
Only.”Csmonitor.com. 24 Oct 2008. Web. 28 Nov 2013.
Britt, Robert Roy. “Super-Predators: Humans Force Rapid Evolution of
Animals.” Livescience.com. 12 Jan 2009. Web 2 Dec 2013.
“Buffon, Georges-Louis Leclerc, Comte De." Complete Dictionary of
Scientific Biography. 2008. Encyclopedia.com. 26 Nov. 2013.
“Darwin’s Finches.” Avibushistoriae.com. Wikipedia. Web. 25 Nov 2013.
“Ecology of the Rocky Mountains.” En.wikipedia.org. Wikipedia. Web. 1
Dec 2013.
“Greenland.” Intreasures.com. Living National Treasures. Web. 4 Dec 2013.
“History and Achievements.” Darwinfoundation.org. Charles Darwin
Foundation. Web. 27 Nov 2013.
“History of Greenland.” En.wikipedia.org. Wikipedia. Web 5 Dec 2013.
“Island Biogeography.” En.wikipedia.org. Wikipedia. Web. 28 Nov 2013.
Kuschk. “Surtsey: Evolution of an Island.” Basementgeographer.com. 28
May 2012. Web. 1 Dec 2013.
Ólafsson, Erling. “Colonization on the Island.” Surtsey.is. Surtsey: The Surtsey
Research Island. 6 May 2007. Web. 3 Dec 2013.
“Overview.” Islandbiogeography.org. National Science Foundation. Web.
26 Nov 2013.
“Rocky Mountains.” World-geography.org. World-Geography. 7 July 2010.
Web. 1 Dec 2013
Melissa Gantt
Bio 111 D6
Page 17
Rogers, Mike. “The Greenland Shark.” Sharksider.com. Shark Sider. Web. 5
Dec 2013.
Upton, Emily. “Why Greenland is an Island and Australia is a Continent.”
TodayIfoundout.com. Today I Found Out: Feed your Brain. 15 April
2013. Web. 5 Dec 2013
“Vascular Plants.” Newworldencyclopedia.org. New World Encyclopedia.
Web. 4 Dec 2013.
Watson; Oxford, Pete, and Graham. “Human Discovery: Charles Darwin.”
Galapagos.org. 2009. Print. Web. 24 Nov 2013.
Melissa Gantt
Bio 111 D6
Page 18