Summer Unit 02: Taxonomy, The Classification Of Life

Class Notes

 

Scientists, like most humans, have an obsession for naming things. Since there are millions of different kinds of life forms on Earth, giving each one a unique name is no small task. The branch of Biology that studies methods for classifying species and determining their proper name is "taxonomy." In this section you will explore the history of taxonomy, some of its working principles, and learn the characteristics of the basic groups of living organisms now recognized by biologists.

Learning Objectives: Successful students will be able to ...

• describe the contribution of Carl Linnaeus to the development of modern binomial nomenclature used by taxonomists today.
• list and give examples of the basic "rules" of taxonomy including the 6 major kingdoms of organisms, the three domains, and the standard hierarchy of taxonomic classification.
• properly use and apply the vocabulary terms prokaryote, eukaryote, unicellular, multicellular, heterotroph, and autotroph. 
• interpret a simple cladogram to determine evolutionary relationships among species, identify characteristics of common descent and derived characteristics. 

Lesson One: Carl Linnaeus.

Efforts to classify organisms goes far back to ancient times, but the beginnings of the modern science of taxonomy is usually credited to Carl Linnaeus. For an introduction to his life and work follow the link to the University of California Museum of Paleontology. Like most scientist his contributions built on the work of his predecessors. Pay attention to his role in bringing a systematic and practical methods to the classification of organisms. 

Homework, Due 14 July. Write a short paragraph describing (in your own words) how the contribution of Linnaeus to the science of taxonomy was built upon the work of other scientists. Explain what Linnaeus borrowed from others and what was his unique and important contribution. Email your paragraph to me using your Fontbonne Academy account. 

Lesson Two: Modern Taxonomy and Systematics.

The single most important theory in Biology that ties together all of the various sub-fields of the science is the theory of evolution. Since the introduction of the theory of evolution by Charles Darwin and Alfred Wallace in the 1850's, taxonomy has moved beyond the simple naming of organisms to incorporate the evolutionary relationships among species (or their phylogeny) into a broader discipline called systematics. Go to the Online Biology Textbook. 

Use figures 1 and 2 to learn the hierarchical levels use by Linnaeus and taxonomists today to classify organisms into large broad groups (kingdoms) and then further subdivide them into smaller and smaller (and more narrowly defined) groups down to the species level. Be aware that the two smallest groups the Genus and Species are used to form the unique binomial name for each kind of organism (the species). The modern implication of this approach is that the smaller subgroups represent organisms that are more closely related than those in the broader groups. Appreciate that most biologists today recognize six kingdoms, dividing the Monera into the Archaebacteria and the Eubacteria. Learn the names of the levels of classification, don't worry about memorizing the scientific names the rose and warbler.

Homework, Due 21 July. The top photo to the right is of a black widow spider and a velvet ant below that. The bottom image is of a diatom. For each of these, find and list the taxonomic levels to which they belong from their Domain down to their species (for the diatom, go here for some hints). For each level, state the characteristics of that level that qualify each organism for membership to that level (autotrophic, multicellular, etc.). Email me the results of your research using your Fontbonne Academy account.

 

Photograph of spider and velvet ant from 

http://www.victorianvilla.com/sims-mitchell/local/nature/niche/165.htm

Image of Diatom from Kent Simmons

Lesson Three: Cladistics And The Six Kingdoms.

Using the same page in the Online Biology Textbook, read the sections on Constructing Phylogenetic Trees, Nomenclature, and The Kingdoms of Life. Be aware that cladisitics is simply a technique to constructing phylogenetic relationships among species (simple in theory, not practice). Use diagrams 3, 4, and 6 to compare the traditional (Linnaeus) and the cladistic approach to the classification of reptiles and their evolutionary relationship to birds and mammals. Pay particular attention to the use of shared derived characteristics in cladistic analysis versus shared similarities in the traditional approach. Be able to use this example of the classification of reptiles in an essay question.

Figure 7 is a particularly good example of a cladogram. It demonstrates how you can use these diagrams to visualize the evolutionary relationships among various species. The time line gives an estimate of the "age" of a species and the linear distances between species is proportional to their evolutionary affinity to one another. 

Be able to state the rules of nomenclature and give examples. Be able to name the 6 kingdoms now recognized by biologist and group them into the 3 domains. Be able to give examples of organisms belong to each kingdom and know which kingdoms contain organisms which are heterotrophic or autotrophic (or both), are multicellular or unicellular (or both), and are prokaryotic or eukaryotic (no "boths"). Be able to define all these terms and give examples (see figure 8).

Homework, Due 28 July. Use the cladogram represented by figure 7 on the Online Biology Textbook and answer the following questions. Post your answers in the comment section at the bottom of this page. Feel free to comment on the responses of your classmates.

1. Which panda, the Giant or Lessor, is the "older" species? Explain your answer.
2. The geographic distribution of species (biogeography) is often used to test hypotheses about the evolutionary relationship among them. Look up some facts about the Sun Bear. Does its biogeography and that of the Giant Panda make sense in relation to their position on the cladogram? Explain your answer.
3. Now answer the same question using the Spectacled Bear and the Giant Panda. 

Photo of Pandas from ChinaPictures.org

Comments

[Erin N.]

1. The cladogram represented in figure 7 displays the evolutionary relationships among a number of species, especially that of two pandas, the Lessor and the Giant. Not only is it a visual of common ancestries and convergent evolutions, but this cladogram also conveys an estimated “age” of the species represented by proportional linear distances between each one. From this knowledge, one can come to the conclusion that the Lessor Panda is the “older” species of the two pandas. In the cladogram, the racoon clade, in which the Lessor Panda is included, came into existence almost 75 million years ago. The bear clade, however, where the Giant Panda can be found, surfaced an estimated 25 million years ago. Furthermore, the comparison of “age” can be represented by the lines that connect the two species to the cladogram. The linear distance of the Lessor Panda is longer than that of the Giant Panda, indicating the Lessor Panda is the “older” species.

2. I found Maretta’s idea of a venn diagram very useful in determining the biogeography between the Giant panda and the Sun Bear. On the cladogram, the Sun Bear is represented as a much later, evolutionized species of the Giant panda. Both are part of the bear clade. Traditionally, the Sun Bear would be classified as a descendant of the Giant panda. Cladistically, they are both part of a larger taxon. Research has shown that the Sun Bear is found primilarily in the tropical rainforests of Southeast Asia, Myanmar, Vietnam, and Southern China. The Giant panda is known to inhabit areas along the Tibetan Plateau, and currently six mountain ranges in South Central China. Prehistorically, however, fossils indicate that the Giant panda ranged from Northern Myanmar to Northern Vietnam. In fact, the warming climate may have forced the Giant pandas into a higher altitude, where cooler habitats could be found. It is possible that, around this time, the Sun Bear species developed; bears that could adapt to the warmer climate of tropical rainforests. Another factor11 is the encroaching of humans in the bears’ habitats. Deforestation and similar activity could have driven the species away from their geographic origins. Overall, the similar prehistoric and present geographic distribution of these two species indicate their evolutionary relationships, and thus reinforces their relationship to a common ancestor as shown in the cladogram.

3. The positions of the Spectacled Bear and the Giant Panda in the cladogram suggests that these two species are more closely related to each other than the Sun Bear and the Giant Panda. The biogeography, however, implies otherwise. While the Giant Panda is found in the Tibetan Plateau and South Central China, the Spectacled Bear lives halfway across the globe, in South America. This immense geographical distribution would, biogeographically, indicate that the relationship between the Spectacled Bear and the Giant Panda is a weak one. However, as Maretta and Julia pointed out and I agree with, a cladogram stresses a variety of shared derived characters when uniting species under a common ancestor, characteristics that go beyond biogeography. A traditional classification would separate the two species because of this dissimilarity, similar to how the birds and mammals were concluded to have evolved from the reptile because of their common primitive character (the amniotic egg) and unique derived characters (the feathers of a bird and hair of a mammal). When classified cladistically, however, the hair and feathers of the mammal and bird would not be present since they are only part of a specific group in the lineage. The amniotic egg would unite the three species under a common ancestor. The location of the Spectacled Bear and the Giant Panda is not a factor in the cladogram because it is only unique to each species. The purpose of the cladogram is to link species under a common ancestor, and the data used in this classification is primarily found in derived characters, and then followed by the evolution of other characters, such as location. Although the biogeography of the Spectacled Bear and the Giant Panda does not reinforce their relationship on the cladogram, the presence of corresponding derived characters is what gives the cladogram validity in joining them in the bear clade under a common ancestor. While biogeography is a useful process of connecting a variety of species, it is not the only nor the most dominant method in cladistics.

Sources:
http://wwww.carnivoraforum.com/index.cgi?board=interspecific&action=display&thread=3740
http://animals.nationalgeographic.com/animals/mammals/spectacled-bear/
http://en.wikipedia.org/wiki/Giant_panda
http://en.wikipedia.org/wiki/Spectacled_bear
http://library.sandiegozoo.org/factsheets/giant_panda/panda.htm
http://en.wikipedia.org/wiki/Sun_bear

[Kathleen (KJ) M.]

1. According to Figure 7, the Lesser Panda is the “older” species. The image implies that the two have an unnamed common ancestor that dates back 100 million years ago. From this common ancestor, the lineage splits roughly 90 millions years ago into dogs and bear-like creatures. Following the bear lineage, it once again splits approximately 75 million years ago into the ancestor of the giant panda, the spectacled bear, the sun bear, and the brown bear, and the ancestor of the lesser panda and the raccoon. Following the lineage of the lesser panda and the raccoon, the two species formed from their ancestor approximately 70 million years ago whereas the giant panda is formed from the common ancestor of the spectacled bear, sun bear, and brown bear 30 million years ago. Therefore, the lesser panda is approximately 40 million years older than the Giant Panda.
2. The Giant Panda is native to central-western and southwestern China while the Sun Bear is native to southeastern China, eastern India, and Indonesia. Biogeographically, a common ancestor seems likely for these two bears due to their close proximity as well as their biological makeup.
3. As said before, the Giant Panda is native to central-western and southwestern China. Therefore, it is difficult to understand its relation to the Spectacled Bear, which is native of western South America. However, these two bears have a common ancestor from 20 million years ago, which had developed from an ancestor 100 million years ago, a point during which the continents of the world were splitting up from one super-continent called Pangea. It is possible that this common ancestor had migrated from Eurasian area of the continent, across the African continent, to the South American area of the continent during this time (although these ancestors would have been very early mammals and it would not be until 65 millions years ago that mammals experienced a rapid growth in population; besides, the journey would cover most of what land mass there was to cover then, thus making this theory a far-fetched guess at best). There is also the possibility that the Spectacled Bear first formed in Asia 20 million years ago and migrated up through Beringia 18,000 years ago and down to South America or perhaps it developed from North American species that had traveled Beringia. Although these hypotheses seem doubtful and it is still unclear how the Spectacled Bear ended up in South America, the Giant Panda and the Spectacled Bear could have a common ancestor due to their biological makeup and similarities in function and habit. Their differences in biogeography do not support the cladogram, but they do not refute it either.

http://animals.nationalgeographic.com/animals/mammals/sun-bear/
http://nationalzoo.si.edu/Animals/GiantPandas/PandaFacts/default.cfm
http://bss.sfsu.edu/holzman/courses/spring99projects/panda.htm
http://animals.nationalgeographic.com/animals/mammals/spectacled-bear/
http://jan.ucc.nau.edu/~rcb7/Mio.jpg
http://www.windows2universe.org/earth/geology/hist_cenozoic.html
http://geology.com/pangea.htm
http://library.thinkquest.org/27130/eng/2.htm

[Cindy T.]

Hello Mr. Birch. I don't know why my answers didn't get posted but my reply to Maretta's comment did. They were on the page last night. After posting my answers, I clicked on "the Post another message" button to post my comment. I'm posting my answers again so I'm sorry if they appear twice.

1.) After analyzing Figure 7, I have concluded that out of the two species, the lesser panda is older than the giant panda. Figure 7 is a cladogram that illustrates how different species are all related through one common ancestor. Each of the listed species evolved from that common ancestor and stepped off the evolutionary track at different points in time. The lesser panda and the panda share another secondary ancestor, which would explain why they share a few similar traits. However, the lesser panda and the raccoon share a tertiary ancestor while the giant panda shares a tertiary ancestor with the brown bear, sun bear, and spectacled bear. For this reason, the lesser panda is more similar to the raccoon than to the giant panda. Also, because of their tertiary ancestors, the lesser panda is an older species than the giant panda. The lesser panda’s tertiary ancestor evolved from the primary common ancestor earlier than the giant panda’s. The lesser panda’s ancestor developed as a unique species about 80 million years ago. The giant panda’s ancestor developed about 20 million years ago. This makes the lesser panda about 60 million years older than the giant panda.

2.) The sun bear’s and the giant panda’s biogeographies are in accordance with their positions on the cladogram. The cladogram illustrates the sun bear and the giant panda sharing a tertiary ancestor. They evolved from that ancestor rather quickly when compared to other species on the cladogram. They also share similar traits such as size and average lifespan. Sun bears can be found in various regions of Southeast Asia and southern China. Giant pandas can be found in southwest China, near the Tibetan plateau. Both of these bears reside in Asia but more specifically in southern China. It is possible that their tertiary common ancestor lived in this area and then the sun bear and giant panda evolved into their separate species. Their movement to different areas of the continent could be explained through a number of different reasons. As Maretta said, it could be that hunting and poaching caused these animals to move from their previous habitats or perhaps it is because of deforestation that is destroying the habitats.

3.) In the case of the giant panda and the spectacled bear, their biogeographies do not make sense with their cladograph. They are even more related to each other than the giant panda is to the sun bear. This is because the giant panda and the spectacled bear are direct descendents of their tertiary common ancestor while the sun bear has a quaternary ancestor before finally becoming a unique species. However, they are extremely distant to one another in terms of geography. As stated above, the giant panda is found in southern China. The bespectacled bear, however, lives in the Andean region of South America. It is strange how such related species can live so far apart. Referring to Alyssa’s answer, while Asia being connected to South America at one point in time is a good possible explanation, I must “bust” this explanation. After further research on Pangaea, connected landmasses and the like, I have concluded that South Africa and Asia never came into contact with one another. That is because the African continent was in between them at all times when Pangaea was dividing.

Sources:
http://nationalzoo.si.edu/Animals/GiantPandas/PandaFacts/default.cfm
http://animals.nationalgeographic.com/animals/mammals/giant-panda/
http://animals.nationalgeographic.com/animals/mammals/sun-bear/
http://www.honoluluzoo.org/sun_bear.htm
http://animals.nationalgeographic.com/animals/mammals/spectacled-bear/
http://geology.com/pangea.htm

[Emma B]

1. The Lesser Panda is the older of the two pandas. The Lesser Panda and raccoon “split” from each other about 70 million years ago and the defined themselves as two separate species. The Giant Panda distinguished itself as a unique species about 30 million years ago. The Giant Panda originated from the same animal as the Lesser Panda but distinguished itself 40 million years after the Lesser Panda was identified. The cladistic analysis also reveals other species that originated from the common ancestor of the Giant and Lesser Panda. The dog was a distinguished species before over 80 million years ago. Then the raccoon and the Lesser Panda. 30 million years ago was when the Giant Panda, the Spectacle Bear, Sun Bear, and Brown Bear were identified as specific species.
2. The Sun Bear and the Giant Panda both live in regions of Asia. The Sun Bear lives from southern China to eastern India and some live in Indonesia. The Giant panda habitats the mountain ranges of China. The geographical location of these two species relates to the fact that they are descendants from the same species. When the two species split they needed to develop individually in different habitats. The Sun Bear, as previously said, most likely moved further south allowing this species. This transition of habitat allowed the Sun Bears to grow and develop as their own species. The similarities in the geographical locations correspond to the cladogram and the animals’ relationship to one another.
3. The Spectacled Bear and the Giant Panda do not share geographical characteristics. Unlike the Sun Bear, the Spectacled Bear lives in the Andean jungles in western South America. The Spectacled bear is the only bear residing in South America. The geographical locations of these two related species are not similar. Like said above, the geographical location of two related species is not the only factor in cladistic analysis. The similarities in their behaviors and appearances are also contributors. The geographical habitats of the Spectacled Bear and the Giant panda do not correspond with the cladogram therefore not making geography an essential factor when determining the evolution of animals.

http://animals.nationalgeographic.com/animals/mammals/sun-bear/http://animals.nationalgeographic.com/animals/mammals/giant-panda/
http://animals.nationalgeographic.com/animals/mammals/spectacled-bear/

[Cindy T.]

Also, to comment on Maretta’s comment on Alyssa’s answer, it IS interesting to think about how everyone is connected. I once read that the ancestors of the human race lived in the present-day African landmass when Pangaea existed. When the land split apart, the humans traveled to different parts of the lands. I also read that Native Americans originated from Russia and Asia. They then traveled to the North American continents through a land bridge that once connected Russia and Asia. Isn’t that interesting? I wonder if anyone else when they were younger wondered why South America and Africa seemed to fit each other like two puzzle pieces.

[Tammy C.]

1. Compared to the Giant Panda, the Lessor Panda is the older species. This was determined by looking at the cladogram in Figure 7. The cladogram shows that about 90 million years ago ancient specie evolved into two different species, one of the being the dog. The other organism is the common ancestor of the Giant Panda and the Lessor Panda. The Giant Panda does not evolve until few species later which is about 22 million years ago. While the Lessor Panda evolves much earlier at about 75 million years ago, making the specie of the Lessor Panda about 53 million years older than the Giant Panda.

2. Giant Pandas live in mountain ranges in central China in the Sichuan, Shaanxi, and Gansu provinces. The Sun bears live a little farther south in Southeast Asia regions. Sun bears are found in the countries of Burma, Laos, Cambodia, Viet Nam, Thailand, Malaysia, Borneo, and Sumatra. A few are still found in Bangladesh. The two bears are found in the same continent and area and they are sort of close to each. The two bears come from the same common ancestor show a reason for the two species to be living relatively close to one another but not together. Their ancestor evolved about 22 million years ago into the Giant Panda and into another ancient bear. That bear later evolved into two other bear species. One of the species evolved into the Sun bear about 18 million years ago. This explains the move in location, some difference in looks, while to the two bears still share bear qualities and live in nearby countries.

3. Andean or Spectacled Bears live in the Andes range and outlying mountains in South America. They are found in the countries of Venezuela and Bolivia, and a few are reported in Panama and Argentina. The Giant Pandas live on the other side of the world in central China. Giant Pandas and Andean bears share a closer ancestor and are more closely related than pandas and the Sun bears, even though they are on a completely different continent. Their common ancestor evolved into a giant panda and bear specie about 22 million years ago. Those bear specie evolved into the Andean Bear about 20 million years ago. The Andean bear or its ancestor must have found a way to cross the ocean by a possible land bridge in order to be able to be living in South America. The Andean bear could have gained its characteristics when it adapted to the Andes mountain range.

Sources:
http://nationalzoo.si.edu/Animals/GiantPandas/PandaFacts/default.cfm
http://nationalzoo.si.edu/Publications/ZooGoer/1999/2/fact-sunbear.cfm
http://nationalzoo.si.edu/Animals/Amazonia/Facts/fact-spectacled.cfm

[Christine C]

1. Figure 7 uses a tree diagram to show a cladalistic analysis between the relationship and evolving species. Using the diagram, we can determine whether the lesser and Giant Panda is the older species. According to the diagram, the Lesser Panda is the older of the two. The diagram shows how some animals evolved over millions of years. By interpreting the figure, we can conclude that the lesser Panda distinguished itself about 75 million years ago. The Giant Panda does not “branch off” or distinguish itself until about 50 million years later. Therefore, the diagram shows that the lesser Panda is the older species.

2. The Sun bear lives in the lowland forests of Southeast Asia. They inhabit areas in Southern China and even as far down as Indonesia. The Giant Panda generally lives in Central and Southwest China. Using this information, we can analyze the evolution and how the biogeography of these animals relates to their position on the cladogram. Both of the bears live in Asia, commonly in Southern China. As Maretta pointed out, this is a common central point. Therefore, we can use both the biogeography and support from the cladogram to determine that the two bears had evolved from a common ancestor. They had evolved closely to one another in time, which would make since due to their closeness in habitats.

3. The Spectacled bear and Giant Panda are distinguished most closely on the cladogram given in figure 7. The two species evolved about 2-5 million years apart. The Sun bear and Giant Panda were also close on the cladogram and had similar biogeographies. It is interesting that when I looked it up, the biogeography of the spectacled bear is very different from the Giant Panda, and yet closer on the diagram. The Spectacled Bear live smainly in SOuth America while the Giant Panda is mainly in Asia. However, if we refer back to the textbook, we can recall that the cladalistic approach is based not on similarities but based on the presence of shared derived characters. It may have been common enviornment r lifestyle that linked the two closely, rather than biogeography. The relationship between the spectacled Bear and Giant Panda are shown by their closeness on the cladogram. Unlike the previous relationship between the sun bear and giant panda, the biogeography of these species does not help to support the diagram given.

Sources:
http://animals.nationalgeographic.com/animals/mammals/sun-bear/
http://animals.nationalgeographic.com/animals/mammals/giant-panda/
http://animals.nationalgeographic.com/animals/mammals/spectacled-bear/

[Callie C.]

1.) The Lesser Panda is the “older” species. The cladogram illustrates that the species displayed all came from a common source just over 90 million years ago. The cladogram also shows that the Lesser Panda split from the raccoon clade about 70 million years ago, making the “age” of the Lesser panda 70 million years old. The Giant Panda split from the bear clade about 25 million years ago, making the “age” of the Giant Panda 25 million years old. Based on these facts, the Lesser Panda is about 45 million years older than the Giant Panda.

2.) The biogeographies of the Sun Bear and the Giant Panda certainly do make sense in relation to the bears’ positions on the cladogram. On the cladogram, the two species are only separated on the cladogram by one other species, the Spectacled Bear. The Sun Bear lives in Southeast Asia in areas from southern China to eastern India and Indonesia. The Giant Panda lives mountainous regions of central China. It is quite possible that the close geographic proximity of the two species is due to the common ancestor that they share. Based on the cladogram, the Giant Panda separated from the ancestor just under 30 million years ago and the Sun Bear did so just under 20 years ago. Such a span of time would allow the species to migrate from whatever location they originated, but perhaps keep them in closer proximity.

3.) The case of comparing the biogeographies of the Spectacled Bear and the Giant Panda is quite different than comparing those of the Sun Bear and the Giant Panda. Contrary to the latter, the case of the Spectacled Bear and the Giant Panda shows that the two species live in completely different areas of the world. The Spectacled Bear lives in the Andean jungles of western South America, with Giant Pandas living in mountainous regions of central China. The two species are right next to each other on the cladogram. In relation to the position of the bears on the cladogram, their biogeographies do not make as much sense as in the case of the Giant Panda and the Sun Bear. Although their biogeographies do not make as much sense, there is always the possibility of extreme migrations to explain the large distance between the two species. There is also the possibility of similar characteristics, such as solitary nature and mountain living, to show why the two species are so close on the cladogram. Strictly biogeographically speaking, though, the relationship between the geographies and the close proximities of the bears on the cladogram does not make very much sense.

Sources:
http://animals.nationalgeographic.com/animals/mammals/sun-bear/
http://animals.nationalgeographic.com/animals/mammals/giant-panda/
http://animals.nationalgeographic.com/animals/mammals/spectacled-bear/

[Maretta M.]

I thought that Alyssa's idea about how the Giant panda and the Spectacled bear ended up so far apart was a very interesting theory. When I was researching the animals, I was interested in how two very similar animals could end up so far away from one another. It made me think about how interconnected life on Earth is, even though geographically we are all separated.

[Rebecca S]

1. Figure 7 in the online biology text pages is a cladistic analysis that demonstrates the relationships between different bears and also their relationship to raccoons. The cladistic analysis shows these relationships by starting at a common ancestor and showing at which point in history each separate species evolved from that common ancestor and then formed its own clade. From the diagram, it can be inferred that the Lesser Panda is an older species than panda than the Great Panda. The common ancestor of both of these kinds of pandas dates back to more than 100 million years ago. However, the Great Panda species branched off of its ancestors much later than the Lesser panda. Both the Lesser Panda and what has proven to be its close relative, the raccoon, evolved from their comment ancestor approximately 72 million years ago. The Great Panda however, as shown by the cladistic analysis, did not evolve from its common ancestor until about 23 million years ago, therefore making the Lesser Panda an ‘older’ species than the Great Panda.

2. The biogeography of the Sun Bear and the Giant Panda does in fact make sense in respect to the data shown by the cladistic analysis. Within a small period of time from each other, they branched off of a common ancestor that had already evolved greatly over the years. This is supported by their biogeography because they both reside in some common areas, but they also can both live in areas not occupied by the other species. I thought Maretta’s idea of comparing the situation to a Venn diagram was accurate. There are certain zones in Asia that are shared by both species but there are some that each respective species doesn’t have to share with the other. Both species occupy areas in Southeast Asia. The Sun Bear can also be found in Vietnam, Thailand, Malaysia, and other islands in the area. The Giant Panda can be found in more mountainous areas such as central China. The eventual geographic separation of the Sun Bear and the Giant Panda can be accredited to many things, whether it is natural such as weather or forced by humans with poaching. The biogeography appears to be relative to the data shown by the cladistic analysis.

3. Unlike the Sun Bear and the Giant Panda, the Spectacled Bear and the Giant Panda do not have positions on the cladogram supported by their geographic distribution. The Spectacled Bear and the Giant Panda are relatively close to each other on the cladogram, only being separated by a couple of extremely small clades. The Spectacled Bear can be found in South America, especially around the regions with the Andes Mountains and Venezuela. The Giant Panda, however, as stated above can be found in central China but also in mountainous areas. The traits that allow both animals to have the desire to live in mountainous areas can be accredited to their closeness on the chart of their cladistic analysis. However, what does not make sense is their geographic distance from one another. The geographic distance between the Giant Panda and the Spectacled Bear is not supported by what is shown in the cladogram.

Sources:
http://nationalzoo.si.edu/Publications/ZooGoer/1999/2/fact-sunbear.cfm

http://nationalzoo.si.edu/Animals/GiantPandas/PandaFacts/default.cfm

http://nationalzoo.si.edu/Animals/Amazonia/Facts/fact-spectacled.cfm

[Eliza M.]

1) In looking at the cladogram, a tree diagram used to show the relationships between different animals, it indicates that the Lessor Panda is the “older” species in comparison to the Giant Panda. The line for the Lessor Panda extends back much farther than the line for the Giant Panda. According to the time line along the bottom of the cladogram, the Lessor Panda species is about 75 million years old while the Giant Panda species is only about 30 million years old. The branch that splits off into the Lessor Panda species and the raccoon species occurs much farther back on the cladogram than the branch that splits into the Giant Panda and the Spectacled Bear and in this way, the Lessor Panda is older than the Giant Panda.
2) The Sun Bear can be found in Southeast Asia, Southern China, Bangladesh, Thailand, Cambodia, Vietnam, Malaysia and Sumatra along with other various areas. The Giant Panda is commonly found in central and southwestern China. These animals’ biogeography is similar as both animals can be found in Asia and more specifically in southern China. These similarities are an attestation to hypotheses that these two species also have a similar evolutionary relationship. This makes sense in relation to the position of the two animals on the cladogram. The Sun Bear and Giant Panda are connected by a common node, or branch, and therefore support their similarities in biogeography.
The common ancestor of these two bears most likely resided in this area or an area close to it and as the two evolved into their own separate species, they moved to their own location in close vicinity of one another. This move could have been due to a number of factors including a natural migration process or threats to their lifestyle.
3) The Spectacled Bear can be found in northern and western South America, eastern Panama, Western Venezuela, Columbia, Ecuador, Peru, and Argentina. The Spectacled Bear’s biogeography is not similar to the Giant Panda’s and in this way does not support the positions of both animals on the cladogram. The Spectacled Bear and Giant Panda are next to each other on the cladogram and it can be assumed that the two animals have a similar evolutionary history. Their biogeography, however, does not support this assumption.
A cladogram is not based solely on biogeography, however, and has a lot to do with shared characteristics and derivation from a common ancestor. The geographic distance between these seemingly alike animals could have been due to a number of causes including necessary migration because of threat or environmental and biological needs. Cladistically speaking, however, the proximity between these two animals in figure 7 has more to do with their shared characteristics than their location on the globe.

Links used:
http://animals.nationalgeographic.com/animals/mammals/sun-bear/
http://arktofile.net/pages/bear_spec.html
http://nationalzoo.si.edu/Animals/GiantPandas/PandaFacts/default.cfm
http://www.globio.org/glossopedia/article.aspx?art_id=1

[Alyssa J.]

1. The Lesser panda is the older species. By looking at the cladogram in the textbook, I could determine that the Lesser panda species’ origin can be found about 75 million years ago and the Giant panda species can be traced back about 30 million years ago, According to the chart, the Lesser panda species was around almost 45 million years before the Giant Panda. The graph shows that while both the giant panda and lesser panda came from the same species up until about 78 million years ago, when that species divided in two, one being more like a raccoon and the other like a bear. Then approximately 75 million years ago, the raccoon-type species divided into what is today known as the Lesser panda and the Raccoon. The Giant panda remained part of the general bear-type species until the about 30 million years ago, where it divided off and became the Giant panda species found today,

2. The Sun Bear is typically found in Southeast Asia, from southern China to eastern India and Indonesia. The Giant panda is found in mountain ranges in central China. They both reside in Asia. Their geographic locations are relatively close to one another. As they evolved into two separate species from a common one, the bears most likely moved, which makes sense as the species would need its own space to grow and develop, or as Julia suggested, humans hunting and poaching may have forced the two species apart from each other. The ancestor of these bears can most likely be traced back to the area somewhere around central and southern China, which is the area most common to both species. The biogeographies of the Sun Bear and the Giant Panda make sense in relation to their positions on the cladogram.

3. As stated above, the Giant panda lives in central China, while the Spectacled Bear lives in the Andean jungles in South America. The Spectacled Bear is also known to be the only bear located in South America. Considering the common ancestry of the two bears, it is difficult to see the connection because of the diversity of their locations. If the two bears did evolve from the same common ancestor, one of them would have to have crossed an ocean in order to live on two separate continents which are in no way connected by a land mass. So unless the theory that each continent was at one point connected and the two species developed and found their individual environment during this period, it is difficult to see how the bears could share a common ancestor and be located where they currently live. However, considering the cladogram does not give absolute facts or show how the species moved when they evolved, it is not possible to give a definite answer on if they are linked and how they ended up where they are today, Based solely on the cladogram, however, it does not make much sense their positions on the cladogram compared to their biogeographies.

Sources:
http://animals.nationalgeographic.com/animals/mammals/sun-bear/
http://nationalzoo.si.edu/Animals/GiantPandas/PandaFacts/default.cfm
http://animals.nationalgeographic.com/animals/mammals/spectacled-bear/

[Julia B.]

One more source:
http://animals.nationalgeographic.com/animals/mammals/sun-bear/

[Julia B.]

1. Based on figure 7, the Lesser Panda is an “older” species than the Giant Panda. All the species found on the cladogram share an ancestor dating back almost one-hundred million years ago. Over time, evolution occured and groups separated and became unique species. The Lesser Panda appears to have “distinguished” itself as a unique species over seventy million years ago, at which point it “split” from the raccoon species. The Giant Panda, on the other hand, distinguished itself just over twenty million years ago. At that time it became a species unique from a group of bears including the Brown Bear, Sun Bear, and Speckled Bear. According to this cladogram, the Lesser Panda is approximately fifty million years “older” than the Giant Panda.

2. According to National Geographic, the geographical range of the Sun Bear species is in Southeast Asia, stretching from east India through southern China and south to Indonesia. Also according to NatGeo, the Giant Panda is found relatively nearby, a bit north of the Sun Bear range in mountainous areas of central China. (Maps can be found at these links:http://images.nationalgeographic.com/wpf/media-live/graphic/map-giant-panda-160-20056-cb1273172001.gif and http://images.nationalgeographic.com/wpf/media-live/graphic/map-sunbear-cb1285018191.gif ) This geographic proximity agrees with their proximity on the cladogram, where the two species are separated by only one species (the Spectacled Bear) and a few million years. It is possible that the shared ancestor of these species resided in China/ Southeastern Asia, and that the Sun Bear and Giant Panda established themselves nearby. Their separation is possibly a result of both natural migration and forced migration as a result of danger (ie poaching) or deforestation. As it appears on the cladogram that the species are closely related, it makes sense that their biogeography would parallel this relationship.

3. The Giant Panda, as detailed previously, is found on the mountains of central China. According to National Geographic, the Spectacled Bear is found across the Pacific Ocean on another continent entirely: South America. (See map: http://images.nationalgeographic.com/wpf/media-live/graphic/map-spectacledBear-cb1285018188.gif ) Specifically, the species resides in the Andean jungles. It is also the ONLY bear species found on the continent. According to the cladogram in figure 7, the two species are very evolutionarily close. However, they are found on different sides of the planet. This information would not immediately appear to support their closeness on the cladogram. It is, however, important to recall that a cladistic approach does not so much consider similarities but shared derived characteristics. In a cladistic evaluation, the fact of their geographic spread is irrelevant next to their many shared characteristics, which may include their solitary nature, preference of life in the mountains, and biological makeup. In this case, the biogeographic data may not support the placement of the Giant Panda and Spectacled Bear in the cladogram but hardly disproves it.

Sources:
http://animals.nationalgeographic.com/animals/mammals
http://animals.nationalgeographic.com/animals/mammals/giant-panda/?source=A-to-Z
http://animals.nationalgeographic.com/animals/mammals/spectacled-bear/?source=A-to-Z
http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookDivers_class.html

[Maretta M.]

1. The Lesser Panda is the older species. I determined this by interpreting the diagram. Figure 7 illustrates the evolution of several species. While all of these species are related in that they originated from a common source, each species has unique traits that link it more closely to one type of animal than another. In this diagram, we can see that the Lesser Panda is more closely related to raccoons, while the Giant panda is more closely related to bears. The reason for these similarities lies in the evolution of the species. At one point there was a single species. Then, about 90 million years ago, this species evolved into two new species the dog and another species that was not named in this figure. Then, about 15 million years later, this species gave way to two new species. One of these new species would give way to the Lesser Panda and the raccoon approximately 72 million years ago. The other species, which would eventually yield the Giant panda, would not evolve into a new species until approximately 23 million years ago, 49 million years after the evolution of the Lesser panda!

2. Yes, the biogeography of the Giant panda and the Sun bear make sense. These two species both live in Asia. However, in a shape similar to a Venn Diagram, there is an area where these species coexist, namely Southern China. (However, due to human developments the Sun Bear is rapidly becoming extinct in Southern China.) There are also two other regions where only one of these animals exists, one above Southern China and the other below Southern China. If these areas were shaded on a map, it would be easy to see that there was a central shared habitat where both animals lived, as well as a region above where the Giant Panda lived (Northern and Central China) and a region below where the Sun Bear lived (Southeast Asia). From this biogeography it can be hypothesized that these two animals share a common ancestor who likely lived in Southern China. As the years progressed, these two creatures migrated from this central point. This is supported by the recent migration of Sun Bears from Southern China. Due to both deforestation and hunting, there are fewer and fewer Sun bears in South China. As a result, many bears have moved farther south, below China, Today the Sun bear can be found throughout Southeast Asia in placed such as Burma, Laos, Cambodia, Vietnam, Thailand, peninsular Malaysia, and on the islands of Borneo and Sumatra. In this way, the two species have moved farther and farther apart from the area they once shared. This supports the diagram’s statement that these animals share a common ancestor.

3. Unlike the biological distribution of the previous two animals, the Spectacled bear and the Giant panda live quite far apart. As previously written, the Giant Panda lives in Southern, Central, and parts of Northern China. In contrast, the Spectacled bear is the only bear to live in South America. These bears live mainly in the Andes Mountain range from Venezuela to Argentina. However, this does not necessarily disprove the cladogram in figure 7. Cladistic classification looks at shared derived characteristics and not at the overall similarities of a group of organisms. (online textbook 4). While the Giant panda and the Spectacled bear may live on two separate continents, blood-protein tests and new molecular-genetic analysis have indicated that these species are related through a common ancestor. In this way, the cladogram does not look at where the animals live currently, but how they are linked to a shared ancestor. While biogeography can help support a hypothesis it does not necessarily disprove one either.

Sources:
http://www.carnivoreconservation.org/files/thesis/augeri_2005_phd.pdf
http://nationalzoo.si.edu/Publications/ZooGoer/1999/2/fact-sunbear.cfm
http://nationalzoo.si.edu/Animals/GiantPandas/default.cfm
http://nationalzoo.si.edu/Animals/Amazonia/Facts/fact-spectacled.cfm
http://www.bearplanet.org/pandabear.shtml