A Case Study of the Vestigial Appendix

You wake up one morning with a slight dull pain in your abdomen. You rest your hands on your stomach pressing down around your belly button. The pain increases slightly and you notice that it worsens as you move your hands over your belly towards the right side of your hip. You brush it off as a case of indigestion from the leftover meatloaf and potatoes your roommate threw together the night before, and you head off to your university classes. By the end of the day, your stomach pain and bloating has worsened. To make matters worse, you feel weak because you could not get yourself to eat at all during the day. You have to go to one last class, however, you are feeling very nauseous and starting to perspire. You run to the bathroom and hope that no one heard you vomiting as you hovered over the Porcelain toilet. At this point, you realize that you feel too awful for this to be an ordinary occurrence and you phone your roommate to take you to the hospital.

After a long night of tests in the emergency room, the doctor informs you that you have appendicitis. You will have to have surgery to remove your appendix because there is a possibility that you could die if it bursts. All you manage to extract from the conversation with the doctor is the possibility that you could die and that you have some sort of reference section at the end of your intestine. Your mind is racing and you are confused from the spike in fever. Thankfully, the nurse comes in and explains to you what is occurring in detail.

Your appendix is a small pouch-like structure attached to the beginning of your large intestine (1). The actual cause of appendicitis is not known, however, it is commonly believed that the bacterial infection is a result of trapped fecal matter in the appendix (2). The infected appendix can worsen and abscess, exploding inside your peritoneal cavity (where your intestines are located) (3). The bacteria spread throughout, causing multiple organ failure and killing the patient (4).


You are worried at this point and are thinking that your life might be drastically affected by the loss of a digestive structure, but you need the appendectomy to survive. The nurse ensures you that most patients do not notice any difference in digestion after an appendectomy since your appendix is a redundant structure (5). The appendix is a vestigial organ; meaning the original function was lost with human evolution (6). It was originally thought to be the organ responsible for digesting cellulose, as seen in other herbivorous primates sharing commons ancestors with humans (7).

All experts in the medical community do not share the opinion that the appendix is a vestigial structure. Others believe that the appendix has an immunological function as an organ where antibodies are produced (8). This theory does not have strong supporting evidence, as the appendix would less likely become infected if it were a center for antibody production. Another theory suggests that the appendix is used to store necessary intestinal bacteria (9). Although the appendix may contain important bacteria, patients fail to notice a difference in digestion without an appendix (10). This indicates that the appendix cannot have a substantial role in the digestive system and, therefore, is a structure lacking true function.

Knowing the current information puts your mind at rest and you feel relieved that shortly you will have the source of your pain removed without long term consequences. You are informed that they are ready to take you in for surgery. As you are rolled into the operating room, you whisper into the nurse’s ear one last request. You want to keep your appendix. Here is a picture of what you grew so close to and could not part with:

Your Appendix

You Tube Video:
Surgical Appendectomy (caution graphic details):
http://www.youtube.com/watch?v=0FuqMI2dKmo

References:
1) http://en.wikipedia.org/wiki/Vermiform_appendix
2) http://www.netdoctor.co.uk/diseases/facts/appendictitis.htm
3) http://www.medterms.com/script/main/art.asp?articlekey=2311
4) http://en.wikipedia.org/wiki/Septic_shock
5) http://digestive.niddk.nih.gov/ddiseases/pubs/appendicitis/
6) http://en.wikipedia.org/wiki/Vestigial
7) http://www.talkorigins.org/faqs/vestiges/appendix.html
8) http://wiki.cotch.net/index.php/The_human_
appendix_is_functional,_not_vestigial
9) http://en.wikipedia.org/wiki/Vermiform_appendix
10) http://digestive.niddk.nih.gov/ddiseases/pubs/appendicitis/

Pictures:
http://www.medicinenet.com/appendicitis/article.htm
http://www.flickr.com/photo_zoom.gne?id=384615215&size=m
http://www.healthbolt.net/2007/10/08/appendix/

On Angiosperms

By Andrea Macdonald

"It must have been around seven am when a small shrew like creature stumbled out of its dark burrow and peered near-sightedly at the first flower, and decided it wasn’t dangerous. "
This is a line from the poem “in the early Cretaceous” by Al Purdy. The poem goes on to fancifully describe the proliferation of flowering plants during the Cretaceous. Reading the poem one can’t help but wonder what it was really like during the Cretaceous, how did those first few flowers come to be? How rapidly did they develop into a dominant form of flora and what made them so successful?
At the beginning of the Cretaceous the earth was warm and wet. There were no glaciers at the poles and the continents were grouped closely together. Dinosaurs and gymnosperms were the dominant fauna and flora. By the end, the continents had dispersed, dinosaurs had nearly become extinct, mammals were on the rise, and angiosperms had replaced gymnosperms as the dominant plant life.

So what came first, the Carpel or the ovary? That is, how did angiosperms evolve from gymnosperms? The main difference is in the reproductive tissues. Gymnosperm ovules occur on sporophylls, that is, open leaves. Angiosperms differ in that they have many different tissues surrounding the ovule; there is the ovary which is at the base of the carpel, there are the stamens, the petals, and the sepals. It is believed that these structures all evolved from leaves. Once upon a time a sporophyll began to curl around the ovules until it became fused and a carpel was formed from the fused leaf. That shrew could have stumbled out and seen a whorl of leaves with shortened internodes before he noticed the first flower. This bundle of leaves with a rolled leaf surrounding an ovule might have initially been an evolutionary advantage because the seed was better protected from the elements and/or seed eating fauna by the group of leaves.
The Amborella supports the fused sporophyll theory. Amborella is believed to be the most primitive flower that still exists today (based on molecular data). The Amborella has a carpel that is not fused but is held together by secretions, a possible evolutionary step leading to the fused carpel.
Somehow this bundle of leaves became attractive to insects and from there, more and more attractive and colourful species emerged in order to be more attractive to pollinators. (Some wind pollinated angiosperms did not develop these bright colours.) Most gymnosperms rely on wind to disperse their seeds, while angiosperms take advantage of a symbiotic relationship with insects and birds (possibly their most important evolutionary advantage) , in which the animal is rewarded with a nectar for dispersing the genetic info (pollen) of the flower. How the first bee ancestor became attracted to flowers is a mystery, but it is generally accepted that the success of angiosperms is closely related to their relationship with insects and birds.
By the early cretaceous wasps and moths had evolved and during the cretaceous winged dinosaurs and some birds were becoming successful species. Perhaps this was a disadvantage for the gymnosperms, which keep there maturing seeds up high possibly as a way to keep them safe from herbivores. Angiosperms on the other hand took advantage of flying creatures not only to aid in pollination but also to help in seed dispersal. Many angiosperms produce seeds that are meant to travel through the digestive system of an animal before they are meant to germinate. Angiosperms are the main food source of mammals and we have evolved and diversified simultaneously since the mid Cretaceous through the process of co evolution.
One example of this co evolution is how insects aided in the speciation of angiosperms. Insects provide an alternative method of pollination to wind. They allow for wide dispersal of genetic material which leads to more opportunities for mixture of genetic material. Because one bee may visit many different flowers, pollen obtained containing a mutation would be dispersed widely. The plants resulting from fertilization by the mutant pollen may produce mutated flowers which might not attract the original pollinating species and so the newly mutated species would not be cross pollinated with the parent species. This creates the sexual isolation necessary for speciation. The short lifecycle of angiosperms also allowed them to speciate rapidly. More variety of species means greater chance for species to be suited to difficult environments.
Fossil evidence of flowering plants suggests that they were first successful in environments where it was difficult for gymnosperms to survive. Riverbanks and areas that experienced unstable environments were dominated by angiosperms millions of years before they began to compete with gymnosperms for space in more stable areas. Their short lifecycle also aided in this success. Angiosperms can go from a seed to a mature adult in a matter of weeks or months whereas gymnosperms take over a year to develop a seed. Angiosperms also developed a more efficient form of vascular tissue which would have helped. In addition to the same xylem and trachieds of gymnosperms they also have vascular vessels for transporting water up the stalk.
Interestingly, Amborella does not include these vascular vessels suggesting it diverged from the other angiosperms prior to this development.

Fused leaves, rapid speciation, symbiotic relationships with birds and insects, suitability to harsh climates; these are some of the main ideas about how and why angiosperms evolved. There are entire books and university courses devoted to this topic I found out in my research. Darwin referred to the appearance of angiosperms in the fossil record as “an abominable mystery.” So many years later much of the mystery remains, a vast deal of research has been done and the theories proliferate like dandelions.
As Al Purdy wrote, “no one can ever know what it was like, that first time on Primordial Earth/ when bees went mad with pollen fever and seeds drifted away from home on little white parachutes without a word to their parents/ no one can ever know, not even when someone is given the gift of a single rose and behind that rose are the ancestors of all roses and all flowers and all spring times for a 100 million years of summer, and in her eyes an echo of the first tenderness…”

References:
Biology sixth edition, Authors: Neil A. Campbell, Jane B. Reece. Copyright 2002, Benjamin Cummings
The Historical Atlas of the Earth, Authors: Stephen J. Gould, Roger Osbourne, Donald Tarling. Copyright 1996, Henry Holt and Company.

Angiosperm Origins and Evolution
Copyright © May, 2001by: Sebastian Molnar
http://www.geocities.com/we_evolve/Plants/angiosperm.html

Angiosperms
Flowering PlantsPam Soltis, Doug Soltis, and Christine Edwards
http://www.tolweb.org/Angiosperms

Sixth Sense

Many of us have experienced an urge to do something based on nothing other then a feeling. Whether it be to call a friend and learn that their father died, or to go back into a room just in time to find the dog about to eat your dinner. This feeling is often referred to as a sixth sense, or Extra-Sensory Perception (ESP). In 1999 researchers at Harvard University were examining a specialized organ in the nose called the vomeronasal organ (VNO). Many debate whether the organ still functions (in humans) and if so, whether it influences our behavior. While their research was marginally based on pheromones it got me thinking what other signals humans may be able to sense. In animals, the VNO contains many nerve cells and with the extensive abilities of nerves, the types of signals and number of signals available for them to receive could be limitless.

In modern day research there are many types of ESP, such as Clairvoyance, Precognitions, and Telepathy. But even in ancient times, before the study of ESP, many civilizations recorded having similar experiences. It is my opinion that people are experiencing ESP or a sixth sense more often, and that as we evolve we will learn to acknowledge and refine this skills more.

Photo Reference:
http://www.flickr.com/photos/daz71/90964236/
Research Reference:
http://www.hno.harvard.edu/gazette/1999/05.20/sixth.sense.html
http://en.wikipedia.org/wiki/Extra_sensory_perception

Megan Dick

Everyone Should Go Visit the Bug Zoo!

The Bug Zoo is located at 631 Courtney Street in Victoria BC. I have already visited the bug zoo a couple times this year, and it never fails to amaze me. There is an incredible array of arthropods, including spiders, insects, scorpions, and myriapods ( millipedes and centipedes). The Bug Zoo is very reasonably priced, and there are special rates for students. I highly recommend visiting the zoo. For those of you who can't make it I am going to share some of the pictures I took while I was at the zoo, and talk about each of them.

This is a Hercules Beetle. It spends a large portion of its lifecycle as a larva. "A larva is a sexually immature form of an animal that is morphologically distinct from the adult stage, usually eats different food, and may even have a different habitat than the adult... Animal larvae eventually undergo metamorphosis, a resurgence of development that transforms the animal into an adult. (Campbell N.A., Reece J. B., 2005)." The larva tunnel through wood, eating rotting wood as they go. The adults get there nutrition from decaying fruit, as you can see in the picture here.



This is one of my favourite insects! It is the praying mantis and belongs to the order Mantodea. They use their color to camouflage into their surroundings. This may help while hunting prey, and may also be benificial from hiding from preditors. Males beware before heading too close to the cage though, the females like to devour their partners after mating. First the female bites off the head of the male while they are still mating, then she begins on the rest of the body. The wings are the only evidence that there had once been a male in the cage.




No these aren't sticks! These are actually stick insects. It is incredible how much they look like their surroundings. Natural selection has caused them to develop stick like features that aid in their survival. They have even developed stick like tendencies! They sway in the wind, hang around with other branches and leaves, and even have a plant-like smell (although this could be attributed to their diet)!


This is a leaf insect. As you can see it very convincingly looks like a leaf. This camouflage provides a great deal of protection from its own predators, but sometimes other bugs and animals will accidentally mistake it for leaf and take a bite out of it. Ouch! As the leaf bugs age, they also get yellow spots, turn brown, and develop jagged edges, making them look less tasty to animals and other neighboring bugs that may have mistaken them for a meal earlier on in their lives.

You'll never guess which insect this guy is kissing. A COCKROACHE!!! I know most of you said "Ew," but Cochroaches are actually very clean when it comes to bugs. They are constantly cleaning and grooming themselves. There are approximately 4,000 species of Cochroaches. Something interesting about them is that Cochroaches, like other insects, do not have a centralized brain that controls their entire body, instead they have clumps of nerves called ganglia that carry out functions. In the coachroache has 3 ganglia in the front of the head to form the brain, and 3 in the back of the head that control the mouth and the antenna. There are 11 more ganglia distributed throughout the body of the cochroach, 3 in the thorax, and eight in the abdomen. These ganglia control the roach's legs, wings and other body parts. Because all of the ganglia operate independently of one another they are still able to carry out their functions even if say the head is removed from the abdomen, until oxygen or nutrients stops the ganglia from functioning.

Some extras:

Current Exhibits List
(animals on display will change over time)

1. Australian Stick Insects 2. Shaking Leaf Insects 3. Katydids/Orchid Mantis 4. Thorny Devils/Giant Stag Beetle 5. Giant Long legged Bush Cricket 6. Dragon Headed Crickets 7. Diving Beetles/Whirlygig beetles 8. Birdeating Tarantula - "Pinkie" 9. Suntiger & Indian Ornamental Tarantulas 10. Atlas Beetle/Frog Beetles 11. Desert Beetles/Velvet ants 12. Mix Sticks - 7 species of walking sticks in one tank, including the world's longest walking stick 13. Giant African Millepedes 14. Giant Peruvian Centipede 15. Black Widow 16. Brown Recluse 17. Hobo spider 18. Wolf spider 19. Mexican Red leg Tarantula 20. Whiptail Scorpion (Uropygid) 21. Tailess whiptail scorpion (Amblylipigid) 22. Bark scorpion 23. Stripe tail scorpion 24. Emperor scorpion 25. Asian Forest scorpion 26. Giant Brazilian Roaches 27. Madagascar Hissing Cockroaches 28. Dead Leaf Mantis/Hercules beetle 29. Ghost Mantis 30. Jungle Nymphs/Titan Stag beetle 31. Assassin Bugs 32. Leafcutter Ant Colony - Amazing!! http://www.bugzoo.bc.ca/groups.htm


Sources:
http://www.bristolzoo.org.uk/learning/animals/invertebrates/hercules-beetle
http://www.nytimes.com/2006/09/05/science/05cann.html?_r=1&n=Top/News/Science/Topics/Insects&oref=slogin
http://en.wikipedia.org/wiki/Praying_mantis
http://www.bugzoo.bc.ca/groups.htm
http://www.geocities.com/CapeCanaveral/Hangar/2437/roaches.html
Campbell, N. A., & Reece, J. B. (2005). Biology seventh edition. An introducduction to animal diversity ( pp. 627). San Fransisco: Benjamin Cummings.

The Effects of Climate Change on Lyme Disease

Currently, Lyme disease is not a nationally reportable disease in Canada; however, this may soon change. The increased effects of global warming are creating an environment favorable to disease bearing ticks, even in typically cooler countries such as Canada. Lyme disease is typically transmitted by ticks carrying the infectious spiral bacteria. These ticks are highly sensitive to temperature change and are unable to survive in cold environments. For this reason, cases of lyme disease are usually reported in southern Manitoba, Ontario and BC where temperatures are milder.
Unfortunately, with global warming comes increased humidity and shorter winters, leading to a more hospitable climate for ticks and their hosts. Short winters mean a longer season for tick activity, allowing them to infect an increased number of hosts. Recent studies have shown that globally, tick activity is not only prolonged but is shifting further north geographically. Incidences of lyme disease have been reported in mountainous regions of Europe as well as Canada.
Within Canada, rates of lyme disease are expected to increase at quite a shocking rate. By the 2020s, the northern range limit of the disease is expected to shift a minimum of 200 kms. The range is only likely to increase exponentially from there. Currently, the Public Health Agency of Canada is researching just how dramatically global warming will affect disease rates in the country. It appears; however, that the spread of lyme disease is inevitable on a global scale.

References:
http://www.phac-aspc.gc.ca/id-mi/lyme-fs_e.html#8
http://www.sfgate.com/cgi-bin/article.cgi?file=/c/a/2007/04/17/MNGFCP9UL41.DTL

Preserving Biodiversity

After searching through websites on evolution and diversity, I came across the article, “How Stream Diversity is Used to Monitor the Health of Our Rivers” by Karen Markwort. The article is about how small invertebrates, such as mayfly nymphs and caddisfly larvae are collected from rivers to monitor the state of the waterway. I found it interesting that even though society has become reliant on technology, we can still use biological resources to keep our rivers healthy. As Dr Richard Norris, project leader for the CRCFE, states, “there are several advantages in using biological techniques to monitor water quality: it's fast and can be conducted by almost anyone without expensive technical equipment.”
A second article I came across is about the Rideau River Biodiversity project. The river has been under research for how to perverse the river’s great biodiversity. The Small invertebrates are essential to the well being of the river’s ecosystem. Aquatic and terrestrial animals provide food and resources and plants provide clean air and filter air. The project was started with the goal to record information on the river’s biodiversity. The researchers of the project have found that the Rideau River provides all of this for Earth’s survival and needs to be preserved.

References:

http://nature.ca/rideau/g/g1-e.html

http://www.environment.gov.au/biodiversity/publications/articles/biolink9.html#1

Frontiers of animal discovery

One of the most exciting aspects of the study of biology must be the discovery of new species of animal. There are hundreds, maybe thousands of new species of bacteria and insects discovered every year, and not to take away from the diligent researchers making these discoveries, but the discovery of a new animal is especially unique. At first, it seems incredible that an undiscovered species can exist when you consider the population of the earth, and the geographic penetration of populations of humans into every land area of the plant. But on the other hand, consider that these "new discoveries" are not necessarily new to humankind- only new to the scientists that make publications and keep records. Aboriginal societies in the remote areas where new species are found likely not only to know about the species but have names for them. Take for example the new monkey species discovered in the African country Tanzania named the highland mangabey (Lophocebus kipunji). The locals were already aware of the monkey, and called it kipunji. In fact, it was through interviewing the local tribes that scientists first learned of its existence. Does this make the discovery any less exciting? Not at all. In fact, the process of sleuthing amongst old-world tribes to obtain clues towards finding new species makes it all the more interesting and exciting.

The island of Borneo in Indonesia is often in the news due to the high numbers of new species discovered there. If you aspire to go into a career discovering new species, this may be a good place to start. There were 52 new species of plant and animal discovered there in 2006, and researchers say many more are yet to be discovered. Many of the new animal species are fish, and there are also new frogs, lizards and even a new species of cat similar to a clouded leopard (see image). If you are interested in discovering new marine species, then the island of New Guinea may be the best place. There have been dozens of new coral, shrimp and fish species discovered in the waters surrounding the Indonesian part of the island in recent years.

Sadly, many of the new species found on Borneo and elsewhere may not be around for long. Not surprisingly, most new species are endemic to the regions they are found, meaning that they are found only in those regions. Unlike Canada where natural ecosystems are effectively protected by government programs and enforcement (yeah, right) the governments of other places in the world do not have the resources to enforce this level of protection. In Borneo, the rainforests are under threat of land clearing for rubber plantations.

There was a discussion on this blog in October about the issue of naming a new species and the traditional right of a biologist making the discovery to do so. Although most discussion members were disgusted that the naming of a species should be carried out by auction, I would like to point out that there can be a positive outcome of auctioning the right to name a new species. If the money raised was put back into the biologist's work to discover or protect a new species, it can be a good thing. It is difficult for biologists to raise funds for research endeavours to find new species, and given the benefit to the species that can be realized by human awareness of their existence, it shouldn’t be such a concern that it is named after some rich guy’s wife. On the other hand, Lophocebus microsoftus or Lophocebus cocacola doesn’t give me a nice feeling.

Image Source:
http://www.msnbc.msn.com/id/17619064/

New species of monkey in Tanzania:
http://news.nationalgeographic.com/news/2005/05/0519_050519_newmonkey.html

New species in Borneo:
http://www.msnbc.msn.com/id/16270956/

New marine species:
http://www.msnbc.msn.com/id/14834763/

Naming of new species by auction:
http://darwinslegacy.blogspot.com/2007/09/nomenclature-or-moneyclature.html