Introduction:
Throughout the time of the existence of planet Earth, extinction has occurred. “In the past
3.5 billion years the estimated four billion that have grown and changed with our Earth, about
99% of them have disappeared” (Barnosky et al. 2011). This is just showing how common
extinction is on our planet. Even though this is a very normal incident, this process is happening
much faster than in previous years (Withgott and Brennan 2011: 290). Right now, our planet is
going through the sixth mass extinction (Withgott and Brennan 2011: 289). Earth is losing its
animals much faster in the past but some people do not realize this. According to many sources
people are actually even the reason for the loss these species. Because this could possibly be
humans fault we clearly need to know what the cause is and how to fix it. Animal extinction is a
topic that absolutely needs to be looked at more closely due to the controversy surrounded
around the topic.
In the following paper, I will be analyzing multiple sources on the topic of animal
extinction and topics that relate to animal extinction such as biodiversity. Through many reliable
sources I can safely say that animal extinction is occurring much quicker than before and
because of this we need to figure out why this is happening and what will happen because of it. I
will be hoping to further investigate through these journal articles where animal extinction is
occurring. This is important to learn because animals need our help because not everyone sees
them or treats them the way that should be, which they see as just an object on this Earth that we
should use. I am aiming to learn about the causes of the extinctions of these animals; there are a
couple different theories behind it. This could be very important for us to know because there
might be ways that we can help to prevent us from losing these animals forever. Finally the last
item that needs to be looked at is what this means for our world, if anything at all.
Extinction Information:
First of all, there have been five mass extinctions. Since there were whip outs of over
fifty percent of the animal population there are now periods in time that separate these extinction
events. The first was the Ordovician which occurred 440 million years ago the cause is unknown,
the types of life that were most affected where marine organisms and it is unknown about
terrestrial organisms (Withgott and Brennan, 2011: 288). This was just the first of five
extinction periods that have already occurred. The names of the others are the Devonian which
happened 370 million years ago, Permo-Triassic around 250 million years ago, End-Triassic
which occurred 202 million years ago, the last one was the Cretaceous- Tertiary period which
was approximately 65 million years ago (Withgott and Brennan, 2011: 288). We are now in the
next one, the sixth massive extinction which is currently unnamed. Extinction is a normal cycle
of our planet but the problem with this most recent extinction is that it occurring much quicker
than before (Barnosky, 2011). How do we know that it is happening faster than before? The
important thing to know about extinction is how it is calculated. There are two parts, rate and
magnitude; which means how fast are these animals disappearing and how many species are
vanishing (Barnoksy, 2011). These two things are how it is calculated to how fast the extinction
of the world’s animals will be. There are a few variables that can increase the calculation. The
ideal scenario for extinction involves our climate, atmosphere, and high-intensity ecological
stressors (Barnosky, 2011). An ecological stressor could be a lack of land for the animals or lack
of food. These things have been piling up due to the climate changes and it is soon to create, if
not already, the perfect storm for extinction.
Where is it happening:
It seems to be that animal extinction is happening everywhere. It is even happening here
at home in North America. Freshwater fish have the highest extinction rate of all vertebrates in
the twentieth century (Burkhead, 2012). Most people are not aware of this information. There are
multiple events like oil spills that drastically affect the lives of marine life. With the BP oil spill,
that spill still plays a role in the aquatic lifestyle now. It seems that occurring to this particular
article they have evidence that shows that many animals are also going extinct. According to
Burkhead (2012), the species duration of extinctions per million species per year is 11,997 of
freshwater fish, 203 amphibians, 44 reptiles, 27 birds, and 113 mammals. This seems to only
continue to grow over time. In this article it states that fish are extremely important to finding
information about the environment because water is such an important part of environment, and
these creatures live in it (Burkhead, 2012). Another study talks about how many large animals
are missing in the tropics (Fritz, 2009). This seems to be a trend because there was also a study
that spoke about the rising extinction rate in the tropics. Endemic species may be more prone to
extinction because this is the only place they live, which means they may not be able to adapt to
changes as easily (Vamosi and Vamosi, 2008). They also claimed that when they were doing
their research that the information they found was that the odds of threatened animals are reduces
when these animals live on the mainland they found nothing with islands (Vamosi and Vamosi,
2008). These finds seem to be showing that it may be happening in the multiple areas of our
world not just in a certain country or climate.
Why it is occurring:
The overall view of the articles that I collected showed that humans are the reason for the
extinction of animals. The first article discussed how poaching is not only killing animals but
also stresses the female African elephant population out (Gobush, K.S. et al, 2008). They studied
this by their fecal glucocorticoid. The negative impacts were a decrease in reproductively which
could have been a side effect of the stress (Gobush, K.S. et al, 2008). The elephants that had
long-term negative impacts from poaching had a correlation found between old, related
matriarchs and the female elephants (Gobush, K.S. et al, 2008). Poaching doesn’t just affect
elephants but tigers.
The next source says that tigers actually have less ability to recover after population
declines (Chapron, 2008). They said the most important thing to increase the rate of these
animals is to have a vast variety of fertile female tigers (Chapron, 2008). Poaching is just a small
part of the problem though. According to Chapron (2008), not only are poaches the problem but
also the lack of environment for these animals is causing them to o extinct. These animals are in
habitats are losing more area all the time. They are having less space to live and hunt (Chapron,
2008). The animals that these lions hunt are also decreasing because of the human encroachment
(Chapron, 2008). Obviously this can be detrimental to these tigers because there is a decrease of
land and a lack of small animals to feed off of, this decreases the ability for these tigers to
survive.
Then according to Burkhead (2012), this study focused on the human causes of extinction
of the fish. They also agree that loss of habitat is a reason that humans are the purpose for the
extinction of these fish while people are also introducing nonindigenous fish to the environment
(Burkhead, 2012). According to these studies humans are the reason for their extinction because
we are taking them and using them for our own purposes. Griffen and Drake (2008), also agree
that environmental factors influence the extinction of animals. Because these animals are being
affected by the climate changes they are being forced to migrate which is also causing them to be
killed along their journey (Planet Earth, 2006). The other reason is because we are damaging
these animals living environments.
Why does it matter:
Not only does it seem to be our fault for this but there are also reasons to why it matters
that these animals are disappearing. Biodiversity was brought up in multiple articles so I decided
to further examine biodiversity. Burkhead (2012), stated this, “Declining biodiversity and
increasing rates of extinction are fundamentally important metrics of natural resource status and
are the subjects of intensive investigation.” Because of that statement it seemed necessary for me
to look more into this subject to relate it to extinction. An article that I read was discussing the
loss of biodiversity. Because people in developed countries are unconcerned with nature and
more with their own lives they do not think biodiversity is something that they need to worry
about (KeChung and Byrne 2006). According KeChung and Byrne (2006), “…biodiversity
determines the structure and function of ecosystems and, conversely, that ecosystem structure
and function determine patterns of biodiversity”.
Conclusion:
Overall, through the research I have found, it seems that human impacts are the major
reason for the animal extinction occurring currently. There are multiple reasons because it is
humans. Water pollution seems to be a problem with extinction. People are causing this pollution
in multiple ways. Poaching is another problem when these endangered animals are being killed
for their hides. The sixth massive extinction is still happening right now so we cannot be too sure
about the cause. From multiple sources extinction is not only happening in the tropics or places
with endemic animals but it is happening all throughout the globe. Clearly it is happening to the
freshwater fish of North America. The research to me all seemed very solid. I didn’t find too
many differences in my research. It also seemed very similar to what I had learned in this class
along with my own previous knowledge. This topic it important to all people because of
biodiversity and how it affects the Earth and everyone involved. Even though the information
that I found seems to be trustworthy there still needs to be more research. We need more research
so that we can be sure why this is happening and if it really is caused by humans. But obviously
animal extinction is occurring and fast. People need to help out and there are many ways to do
that. If we lose these animals, they are gone and forever.
Bibliography
Barnosky, A. D., Matzke, N., Tomiya, S., Wogan, G. U., Swartz, B., Quental, T. B., & ... Ferrer,
E. A. (2011). Has the Earth's sixth mass extinction already arrived?. Nature, 471(7336),
51-57. doi:10.1038/nature09678
Burkhead, N. M. (2012). Extinction Rates in North American Freshwater Fishes, 1900-2010.
Bioscience, 62(9), 798. doi:10.1525/bio.2012.62.9.5
Fritz, S. A., Bininda-Emonds, O. P., & Purvis, A. (2009). Geographical variation in predictors of
mammalian extinction risk: big is bad, but only in the tropics. Ecology Letters, 12(6),
538-549. doi:10.1111/j.1461-0248.2009.01307.x
Griffen, B. D., & Drake, J. M. (2008). A review of extinction in experimental populations.
Journal Of Animal Ecology, 77(6), 1274-1287. doi:10.1111/j.1365-2656.2008.01426.x
Gobush, K.S., Mutayobya, B.M. Wasser, S.K. (2008). Long-Term Impacts of Poaching on
Relatedness, Stress Physiology, and Reproductive Output of Adult Female African
Elephants. 22(6), 1590-1599.
Ke Chung, K., & Byrne, L. B. (2006). Biodiversity loss and the taxonomic bottleneck: emerging
biodiversity science. Ecological Research, 21(6), 794-810. doi:10.1007/s11284-0060035-7
Planet Earth: The Future: Saving Species (2006). Composer. George Fenton. Perf. Simon
Poland, David Attenborough ,and Martyn Colbeck. N.p.
Rajvanshi, A., Brownlie, S., Slootweg, R., & Arora, R. (2011). Maximizing benefits for
biodiversity: the potential of enhancement strategies in impact assessment. Impact
Assessment & Project Appraisal (Beech Tree Publishing), 29(3), 181-193.
doi:10.3152/146155111X12959673796245
Vamosi, J. C., & Vamosi, S. M. (2008). Extinction Risk Escalates in the Tropics. Plos ONE,
3(12), 1-6. doi:10.1371/journal.pone.0003886
Withgott, Jay and Brennan, Scott (2011). Environment: The Science Behind the Stories, 280289.