Lecture 3/2/11

*** Several questions and interesting comments were made during lecture and here is a couple of responses.

Question 1:  Check out a sea slug…

          – Interestingly, I found an entire website devoted to sea slugs. I thought it was shocking that there was a “forum” to discuss everything about sea slugs. (http://www.seaslugforum.net/general.htm) I would suggest checking out the site because there are details upon details about sea slugs… however, here are a few tidbits that were especially interesting.   

                ORDER CEPHALASPIDEA

  •           The order includes upto 77 families and many subfamilies and underneath these families and subfamilies include 100’s, possible 1000’s of species, making for a very diverse phylogeny.
  •           Some sea slugs are edible. (Yum!) According to the website listed above, most sea slugs are considered mollusks and so some seafood recipes call for a sea slug, specifically the species of a sea cucumber (not to be confused with a regular cucumber, which goes really well in salads) However most are poisonous.
  •           Sea slugs are important in lab testing due to their simple  nervous system (brain) and they have very very large nerve cells which allows for easy mapping.

—–This sea slug website included this quote, which I included because it relates to out ecology unit, and I think relating things in science allows for a better appreciation of everything.        “To understanding life histories and population survival therefore, we have to understand not just the life cycle and biology of one species, but the life cycle and biology of its food, its predators and many physical aspects of the environment.”  (http://www.seaslugforum.net/find/popfluc)

(http://scientopia.org/blogs/proflikesubstance/2010/09/12/solar-sea-slugs-part-animal-part-plant-or-not/)
(http://www.dailymail.co.uk/news/article-518372/Sea-colour-The-amazing-photographs-captured-amateur-photographer-underwater.html)

 

Question 2: What is a little ice age?

             – The information I found about little ice ages were about the historical “little” ice age that occurred in medival times. According to the Environmental History Resouce website (http://www.eh-resources.org/timeline/timeline_lia.html), the Little Ice Age occurred between 1300 and 1870 in Europe and involved extremely hard winters and overall harsh climates in otherwise habitable human environments. Causes could have been a particular way the sun was hitting the Earth at the time called: “Mauder Minimum” and a “coincidence of low sunspot activity.” (Huh?) The graph below shows how years corresponded with the sunspot observations and we can conclude that we have a higher rate of sunspot in present day times, so a conclusion could be that we may enjoy a more stable, more habitable climate. (Though, observe some recent extreme peaks, which leads me to believe that pollution leading to global warming may not be the only explanation to global climate increases. Not that I believe pollution is acceptable behavior to our lovely Earth.)

Maunder Minimum 

  

Question 3: What areas are relic species found?

          – We know from discussion in class that most relic species are found in remote areas like islands, an example being an anteater in Australia. However, I couldn’t find any further information and maybe the next person to blog might be more successful in finding more information on relic species.

 

Question 4: What benefits and effects does an ecosystem engineer have on an organism? 

  •            According to the website, The Encyclopedia of Earth, (http://www.eoearth.org/article/Ecosystem_engineer) the zebra mussel increases water filtration which allows for increased visualization deeper into a body of water which may cause increase predation from predators and also an increase in algea growth.
  •           Another example is the caterpillar and while it creates its own shelter, it may be creating a shelter for another organism.
  •          Most of us appreciate the beaver as a very common ecosystem engineer. The beaver creates dams, which stills water. Unmoving water creates a great environment for other species such as insects, algea and other organisms.
  •           Corals impact ocean life, in the sense that that are protecting other organisms for large waves and also providing shelters and environments for ocean life.

 

*** Things to keep in mind for the upcoming quiz:

 

  1. Know the Density graph

Density Dependent Factors

        

          2.      Characteristics of R/K Species

R/K Species Characterization

 

          3.        Typical Trends in Succession 

*** Soils – increase in nutrients, increase in soil depth, increase in organic matter and development of soil horizons.

*** Inorganic nutrients – the pool of inorganic nutrients decreases in the soil and increases within the plants

                §Early successional vegetation depends upon abiotic sources of nutrients – mineral soil
               §Late successional vegetation acquires nutrients from organic sources – decomposed organisms
***Vegetation sequence – from annual to perennial herbs to woody plants (not necessarily shrubs to trees)
***Species diversity – increases from simple communities of early succession to richer communities.
               §Diversity increases through time on xeric & intermediate sites
                §Diversity on mesic sites is maximized in early stages, then decreases from late stages to climax.
***Niche breadth – decreases from early to late stage, organisms become more specialized

***Productivity – the total biomass of the site increases from early to late successional stages

          4.   And also keep in mind the differences between food and nutrients.

*** Food has energy stored in it (Carbon) and nutrienst lacks energy needed to sustain an organism.

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Contest! Can you answer this question?

In class we talked about why some gases are more potent as greenhouse gases on a per molecule basis than other gases.  For example, nitrous oxide is 300 times more effective than carbon dioxide as a greenhouse gas.  Using knowledge about chemistry, explain why this is the case.  The first person to post a correct answer will win a fabulous prize in class.  You can look for the answer on the web, in a text, in the brain of your chemistry tutor or professor etc.

 

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los plantas

From 1958 to 2010  alone, the [CO2] (<– means concentration of carbon dioxide in case you didn’t know) in the atmosphere increased from 315ppm (parts per million) to 378 ppm. It currently raises at a rate of about 3.5% per year and in order to return to the level of pre-industrial [CO2] about 70% of the atmosphere’s air would need to be scrubbed down clean to remove all of the CO2 in that air.

 

If you’re interested in stem cells, and want to know some basics, check it out:

http://stemcells.nih.gov/info/basics/basics1.asp

 

 

Female cones exist on the top of the tree, while males are on the bottom to encourage cross breeding.

Pinus silvestris seed and cones

 

 

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Volcanoes and Climate; The Size of Dinosaurs; Human Microbiota: Bacteria Within the Human Body; Titan arum: the art of smell

Volcanoes and Climate:

Volcanoes can cause long or short-term effects on the global climate. Dust particles and ash usually have little effect on the global climate unless the dust is able to reach the upper-dryer atmosphere, in which case the global cooling will occur over large amounts of the earth’s surface. The major cause of global cooling after the eruption of a giant volcano is caused mainly by the release of sulfur dioxide and other sulfur compounds into the stratosphere (upper atmosphere). These compounds will mix with the limited water in the stratosphere to form droplets and after months or years these droplets will fall to the earth. While these sulfur hazes are in the upper atmosphere, they reflect a great deal of light resulting in global cooling. Other gases that are released by one of these volcanoes such as water and carbon dioxide affects the global climate little due to the water condensing out of the atmosphere quickly and the carbon dioxide dissolving in the ocean and being absorbed by these plants in a short amount of time. Also, these two gases are found abundantly in the atmosphere, so the addition of these by even large volcanoes into the atmosphere will not affect their numbers dramatically. However, after a long period of time (thousands or millions of years) of volcanic activity, increasing levels of carbon dioxide in the atmosphere can cause drastic global warming.

The Size of Dinosaurs:

The debate about how dinosaurs came to be so large usually comes down to the question: were dinosaurs warm-blooded or cold-blooded? Paleontologist Brian McNab from the University of Florida believe the they were neither. “When you’re that big, you can’t cool off rapidly like a small lizard will,” said McNab. “You have a large volume, and you have comparatively small surface area. And so if you’re warm, you’re going to stay warm, unless something unforeseen happens.” McNab believes that these huge dinosaurs were homeothermic, somewhere in between cold-blooded and warm-blooded. These dinosaurs would probably not use all of their energy to metabolize for warmth because there were no grasses, and although other plants were in plentiful amounts, they were probably not enough. These huge animals probably used the energy they received from these plants to grow very large to keep their body at a relatively stable temperature.

Human Microbiota: Bacteria Within the Human Body:

The human microbiota consists of bacteria, archaebacteria and even some fungi. Some of these organisms perform useful tasks, but most have little to no beneficial or harmful effect. In a sense, they are just along for the ride. Estimates about numbers of bacteria within and on the human body range from 1000-2000 species, while the amount of species of archaebacteria known in the human body are but a fraction of the number of species of bacteria that live, grow, feed, reproduce and die within us. Also in few numbers are the fungi, the main species of fungi having been found within the human body consisting mainly of yeasts.

Fun fact: 60% of the dry mass of excrement is bacteria.

Your Plant Smell Like Meat: Titan arum:

Found in the rain forests of Sumatra, the Titan arum or Amorphophallus titanum. This plant is best known as its pungent, rotten meat smell. It also boasts the largest unbranched inflorescence of any flowering plant in the world.

Fun fact: In 1939, the Titan arum was named the official flower of the Bronx in New York City, however this prestigious title was transferred to the day lily in 2009.

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February 7, 2011

Hello dear class,

As you know, I am the blogger for this morning’s class period and have some rather interesting things to share with you. After the broad range of things we discussed today, the things I must incorporate in the blog might seem rather random, so bear with me.

First, we talked about the beginnings of the universe, the Earth, and of life on Earth. The question was brought up about whether or not a final decision had been made regarding Pluto’s planet status. In my research, I discovered that the International Astronomical Union has officially demoted Pluto from a planet to a dwarf planet. They made the decision nearly five years ago and still stand to their words. Many still like to foster the debate however. If you want to read more in depth about it, here’s a link to an article CNN posted:

http://articles.cnn.com/2009-08-24/tech/pluto.dwarf.planet_1_pluto-day-iau-international-astronomical-union?_s=PM:TECH

Another question was posed, when talking about the universe and Earth’s beginnings, about “that other planet that hit the Earth and caused the moon to form.” After some research, I have found some intriguing information about the supposed origin of the moon. This hypothesis one of our peers mentioned is actually referred to as “The Giant Impact Hypothesis.” Two senior scientists from the Planetary Science Institute first suggested it in 1975. It states that during Earth’s formation one of the other newly forming planets bumped into it, knocking a fraction of debris into orbit around the Earth. This debris supposedly aggregated to later form the moon. If this particularly interests you, I left a link below with much more information:

http://www.psi.edu/projects/moon/moon.html

After a quick refocus onto our home planet, we got into talking about the Earth’s development and composition. Since some students have not had the privilege of seeing magma flow, and our Earth is composed of it, I took the initiative to show you all this awesome YouTube video:

Then, the class period began to dive into some hypotheses about life’s beginnings on Earth. It is said by many that life began here between 3.5 and 4 billion years ago. Those who follow this theory follow a string of hypotheses that can be outlined in four stages:

1)    Nucleotides and amino acids arise

2)    They come together to make DNA, RNA and proteins

3)   Membranes enclose the DNA, RNA, proteins, and other polymers

4)   Polymers enclosed in membranes evolved cellular properties

In talking about the origin of organic molecules, many questions were posed. One of the main hypotheses about the organic molecules’ origin is called the Deep Sea Vent Hypothesis. Some scientists propose that the H2S being emitted would be a great source of energy for the earliest forms of life, through the oxidizing of hydrogen sulfide bonds. In fact, some bacteria get their energy this way. Below, you can see some pictures of interesting organisms that find their homes in or near deep sea vents (including that worm everyone was so interested in).

 

 

http://www.marinebio.net/marinescience/04benthon/dsvents.htm

We left off by finishing our talk on the origin of organic molecules and starting in on the geological changes of the Earth. We will get deeper on this topic next class.

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Ligers and Tigons Oh My!

02.02.2011

Class Events:

1. Quiz 1 (Over Ch. 23-25)

2. Discussion of Speciation

  • Anagenesis
  • Cladogenesis
  • Allopathic Speciation
  • Pace of Speciation (Gradual vs. Punctuated Equilibrium)

3. Discussion of Developmental Biology

  • Hox Genes
  • Allometeric Growth

Points of Interest:

1. Is a Tigon big or not?

In general, a tigon is a hybrid cross between a male tiger and a female lion. Tigons generally do not exceed the size of their parent species due to the fact that they inherit growth inhibitory genes from the mother lion. While they are usually smaller in size compared to their parents, all signs rule out any chance of dwarfism or miniaturization. An average tigon weighs around 400lbs.

The Tigon

 
2. Can a Liger produce viable offspring?
  
For those who are unaware, a liger is a hybrid cross between a male lion and a female tiger. Ligers (and Tigons) can only exist in captivity because the two species never overlap in the wild. Compared to tigons, ligers are massive in size and, when fully developed, tower over both parent species. While this is a fuzzy topic for most zoologists, it is said that female ligers and tigons are fertile but the males of both variations are sterile. This inhibits further generations of ligers and tiogns. All ligers and tigons must be created using the original lions and tigers. 

The Liger

   

 
 
 

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Behavioral Epigenetics Article from Science Magazine

Here is the Epigenetics Article.

Behavioral Epigenetics

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