Tuesday, October 30, 2007

Ethology and Isopods

Ethology
-
- The study of behavior in animals














Ethology is a combination of laboratory and field science

Behavior - the way in which a person, organism, or group responds to a specific set
of conditions
Innate - relating to qualities that a person or animal is born with. coming directly from
the mind rather than being acquired by experience or external sources
Automatic, fixed behavior. Despite difference in habitat, all individuals exhibit the
same behavior usually triggered by a stimulus.
Fixed Action Patterns (FAP)- Sequence of behaviors essentially unchangeable and
usually conducted to completion once started
Sign Stimulus - a release that triggers FAP

Learned - acquired information or skills through experience.
Modified from experience. Triggered by an experience and it varies.
(Behavior is a part of phenotype)
Pioneers
Karl Von Frisch

He studied the senses of bees, identified their mechanisms of communication and showed their sensitivity to ultraviolet and polarized light. His work was based on the study of the sensory perceptions of the honey bee and was one of the first who translated the meaning of the waggle dance The theory was disputed by other scientists and greeted with skepticism at the time. Only recently was it definitively proved to be an accurate theoretical analysis
Waggle Dance - figure-eight dance of the honeybee dance demonstrates the will to share with their hive mates the information about the direction and distance to patches of flowers yielding nectar or pollen, or both, and to water sources. Thus the waggle dance is a mechanism whereby successful foragers can recruit other bees in their colony to good locations for collecting various resources.






Niko Tinbergen

Well known for work with birds as well as developing the four questions to be asked when observing the behavior of an animal/species:
Proximate Questions

1. What are the stimuli that elicit the response, and how has it been modified by recent learning?
2. How does the behaviour change with age, and what early experiences are necessary for the behaviour to be shown?

Ultimate Mechanisms

3. How does the behaviour compare with similar behaviour in related species, and how might it have arisen through the process of phylogeny?
4. How does the behaviour impact on the animal's chances of survival and reproduction?
Konrad Lorenz
Lorenz studied instinctive behavior in animals, especially in grey lag geese and jackdaws. Working with geese, he rediscovered the principle of imprinting in the behavior of nidifugous birds.
One result of these studies was that Lorenz "realised that an overpowering increase in the drives of feeding as well as of copulation and a waning of more differentiated social instincts is characteristic of very many domestic animals."
Imprinting - a form of rapid learning very early in an animal's social development that results in strong behavioral patterns of attraction to members of its own species, especially parents.
Imprinting was first described by Konrad Lorenz in 1937 when he trained young ducks and geese to follow him and regard him as their mother.

Isopods:



Iso is Greek for "similar or equal." Pod means "foot." Both sides have the same number of legs.

Arthropod: One of the most diverse orders of crustaceans, with many species living in all environments, but are most common in shallow marine waters. Unlike most crustaceans, isopods are successful on land, although their greatest diversity remains in the deep sea.

Appearance: Isopods have three main body parts; the head, thorax, and the abdomen. They have one prominent pair of antennae which are used to search and taste and smell food and have a second pair which are not seen. and seven pairs of legs. Isopods have seven separate appendages on the thorax and paired appendages at the end of the abdomen called uropods. Isopods vary in colour from dark gray to white, with and without pattern.

Behavior: Some species roll up into a ball when disturbed. Eggs (up to 100) are held in broad pouch on female. Juveniles look like adults and are soon liberated from pouch. Molting is in two stages. First the back half molts, then two to three days later, the front half molts. Coloration of both halves may be different at this time. Many species are fast walkers, but can be easily observed when held in the palm of the hand.

Habitat: Isopods breathe with gills, so they are restricted to areas with high humidity, under
rocks or logs, in leaf litter or in crevices. Some species are nocturnal.



Some Videos:
Isopods:

Waggle Dance:

http://youtube.com/watch?v=-7ijI-g4jHg

Tomorrows Sherpa is Marc

Monday, October 29, 2007

Earth's biomes



Earth's biomes consist of tropical forest, savanna, desert, polar and high mountain ice, chaparral, temperate grassland, temperate deciduous forest, coniferous forest, and tundra.










Environmental Factors



There are different factors effecting each environment. These factors are both biotic ( caused by living components such as animals and plants) and abiotic (non-living chemical and physical factors caused by temperature, light, water, and nutrients.)



Marine : This is the largest biome in the world and covers approximately 70% of the earth. There are three zones in the Marine Biome. These are the intertidal, coral reef, and benthos zones. The benthos is the only biome not built on sunlight.



Tropical Rainforest: Tropical rainforests are located around the equator, have much precipitation, are always warm and have many plants and animals. Also, tropical rainforests have thin soil.



Savanna: Savannas are also located around the equator. Their precipitation is seasonal (having both a dry season and a wet season), temperature is always warm. Savannas are fire-adapted, have drought tolerated plants, the animals are herbivores, and savannas have fertile soil. There is less moisture, and a lower biodiversity than in the rainforest.



Desert: Deserts are located at around 30* N & S latitude. The temperature varies daily and seasonally between extreme heat and cold. Deserts have sparse vegetation and animals, and are drought tolerant. Organisms living in deserts are cacti, reptiles, insects, rodents and birds. Deserts have high energy and no moisture.



Temperate Grassland: Temperate Grasslands are located at mid-latitudes and mid-continent. Precipitation is seasonal (there is both a dry and wet season), the temperature is hot summers and cold winters. Temperate grassland has prairie grasses, is fire adapted, has drought tolerant plants, many herbivores, and deep fertile soil. It has less insolation and its seasons restrict biodiversity.



Temperate Deciduous Forest: Located mid-latitude and in the northern hemisphere. They have adequate precipitation (summer rains and winter snow). The temperature is moderate warm in the summer and cool in the winter. Temperate Deciduous forests contain many mammals, insects, deciduous trees and fertile soils. These areas are very diverse.



Coniferous Forest (Taiga): These are located at high latitudes and in the northern hemisphere. Precipitation is adequate to dry and temperature is cool year round. Many conifers are present, along with a diversity of mammals, birds, and insects. The trees have needles leaves.



Arctic Tundra: Located in the arctic at high latitudes (northern hemisphere). It is a very dry region and is cold year round. There is permafrost, lichens & mosses, migrating animals, and resident herbivores. Herds of animals move across tundras during the season to get to another community. The tundra has low energy and water and can not support a bid biodiversity.



Alpine Tundra: This tundra is located at high elevations and at all latitudes. It is a dry region and is cold all year round. Characteristics also include permafrost, lichens & mosses, grasses, and has migrating animals and resident herbivores. There is low moisture.



Earth and What is Happening



Impact of ecology as a science: Ecology provides a scientific context for evaluating environmental issues.



Rachel Carson published a book Silent Spring in 1962 which warned of pesticides such as DDT and their effects on non-target organisms. DDT is a problem, because although it has no harmful effects on humans, it does hurt other organisms such as birds. Once DDT is in the food chain it stays forever. This is a picture of what DDT can do to birds eggs:








Barry Commoners Laws of Ecology:


>Everything is connected to everything else.


>Everything must go somewhere


>there is no such place as "away"


>Nature knows best.


>There is no such thing as a free lunch.





These are Barry Commoner's Laws of Ununtended Consequence. Pretty much he means hat, garbage is never gone because it has to go somewhere in the ecosystem when thrown away. Also everything has an effect on the ecosystem, whether it be a benefit or not.





Acid Precipitation:


Acid precipitation puts nitrogen oxides and sulfur dioxide in the air. The causes of acid precipitation is power plants, industry, and transportation because they burn fuels such as coal. Wind brings acid rain from certain regions to others, because in areas with many factories, tall pipes are made to "get rid of the bad air" and then the wind blows that to other areas. Many things have been ruined by acid, such as statues. Acid rain leeches minerals from the environment causing both ecological and economic damage.





Biomagnification:


>Energy Pyramid: tocins concentrate as they move up the food chain. THere have been ecological problems occurring with where manufacturing companies dump their waste. General Electric, for example, was once manufacturing on the Hudson River and dropped PCBs in the sediment near where striped bass reproduce. This causes the striped bass to have high levels of PCBs.





Global Warming:


There is a direct relationship between the increasement of carbon dioxide and temperature which can support the belief of Global Warming. Global warming is believed to be anthropogenic ( human caused), and raises the temperature which in turn is increasing the rate at which the polar ice caps are melting and raising the coastline which can and will eventually destroy major cities which are situated on coastlines. Some believe that global warming is not a problem, and others acknowledge it but do nothing because of economic factors. Many wealthy politicians have ties in the oil industry and if they promoted burning less fossil fuels then they would also lose money.




During warmer seasons CO2 levels in the atmosphere are lower because plants are photosynthesizing and turning CO2 into glucose. One way to help the environment would be to plant more plants, because it would help decrease CO2 levels more.


Ozone Depletion:

The ozone layer protects from UV rays from the sun and also contains CFCs which are coolants. Over the years, the O3 layer in the ozone has been breaking down into O2. There has been the biggest decrease in ozone over antarctica. Several precautions and changes have been taken to help decrease the depletion, and they have proven successful. There is both bad ozone and good ozone. Smog is bad ozone which is caused by pollution.


Deforestation:

Humans are cutting down forests to build houses, or to have more farmland, and grazing land for animals. Doing so destroys the habitat, which decreases biodiversity and also accounts for a loss of stability in the environment.Cutting down the trees, decreases the energy supple for the herbivores which in turn decreases the available energy for predators, and then the community cannot support the top predator, who will then die off.

Loss of Diversity:

There are three levels of biodiversity. The first level is genetic diversity and causes inbreeding within shrinking populations. The second level is community diversity which is a mix of species, and the environment can not support as much with loss of diversity. The third level is ecosystem diversity which accounts for different habitats across landscape. All biodiversity is decreased by human acticity.

Fragmented Habitats make for loss of habitat, loss of food resources for higher levels on the food chain, loss of biodiversity, and loss of stability.

http://www.youtube.com/watch?v=EDIP71Lviys

http://www.youtube.com/watch?v=kMckwcwvb50

Tomorrow's Sherpa is Shannah =]

Thursday, October 25, 2007

Community Ecology: Part III

HEY HEY..... PERIODS 8 & 9, LISTEN UP...

Today's lesson was on ECOLOGICAL SUCCESSION... and it's outcomes.




What is ecological succession??? Well it is a "sequence of community changes."
Yeah... but what does that mean . It means that the ecology of a community changes to maintain the balance and success. It is the transition in species composition over time (may be years or even decades). Species composition refers to the contribution of plant species in a certain area. Most of the time this is caused by a disturbance in the area.

There are two types of ecological succession: Primary succession and Secondary succession.




Primary Succession
Primary Succession begins on plain lifeless land without soil...
What happens next...
1. Bacteria moves in and by definition of what they do, they turn the dirt into soil. Land with nutrient and land able to support some sort of living matter besides bacteria.
2. Lichen and mosses move in and begin to grow. They use the nutrient from the soil to support themselves.
3. Grasses are then able to move in by the seeds that come in from adjacent communities.

















Wednesday, October 24, 2007

Community Ecology: Part DUEX.

predation drives evolution:
basically - as predators become better at locating and subduing pray, their pray over time develops adaptations to elude and defend themselves. Pray can have adaptations such as horns, speed, muscle or coloration. Plants who are pray can develop spines, toxins or thorns.
There are many different types of defense mechanisms such as camouflage (cryptic coloration), Aposematic coloration, Batesian mimicry and Mullerian mimicry.



Cryptic coloration is when an organism's phenotype resembles or is even identical to its surroundings. This is used to make themselves harder to find by predators.




Aposematic coloration is another form of defense mechanisms. Aposematic means (in Ms.Foglia's terms) that an animal is saying " don't eat me , don't eat me." An organisms doesnt want to be eaten not only so they, obviously, survive and also because they are poisonus or just taste horrible. Most of the time animals have the colors black, red, orange and yellow to show predators that they shouldn't be eaten.


Batesian mimicry is when a creature is harmful and another animal that mimic's it is not harmful. The animal that is mimicing the harmful animal has an advantage because predators will stay away from it to not take a chance of getting sick or dying. An example is of the green parrot snake and the hawkmoth larvae. These two animals also have convergent evolution meaning they have the same solution to the same problem.



Mullerian mimicry is when all of the organisms that look the same are "nasty" ( meaning they're poisonus or taste bad). With this type of mimicry predators may evolve an innate avoidance of any animal or organism that looks like or is the harmful one.






Coevolution in Community:
there are three different types of coevolution in a community: Predator- prey relationships, Parasite-host relationships, and flower & pollinator relationship. This involves long term evolutionary adjustments between species.


characterizing a community:
every community has a structure made up of three diffferent parts: Species diversity ( how many different species are present, composition ( dominant or most abundant species, species with the largest biomass)( biomass is if you took an entire species and dried them out and weighed them), and a keystone species ( which plays a key role and has a strong effect on coposition of the community)


species diversity:
GREATER DIVERSITY = GREATER STABILITY
greater biodiverstiy offers more food resources, more habitat and more resilience in the face of enviornmental change.

keystone species:
they have an influential ecological role and can increase the diversity of a habitat.
keystone species can effect the community in two ways : they can increase nutrients from the bottom of the food chain up, or start at the top and can control herbavore devistation going down the food chain.


good night guys. hope this was helpfull!!!! oh and sherpa for tomorrow night is KIM!

Monday, October 22, 2007

Community Ecology

Community Ecology

A community is all the organisms that live together in one place. Community Ecology is the study of interactions among all populations in a common enviornment.








Inside o community there are niches. A niche is the role a organism has in the community. Weather its a producer preditor or decomposer. There can't be more than one species in each niche. If there was both would out compete each other and the niche wouldnt work. In class today we saw the barnicles. The bigger ones pushed out the smaller ones. This is because there can't be more than one species in one niche at the same time. Basically one niche equals one species. AN example of this is Lions and Tigers.




Because there can't be members of the same species int he same niche some spiecies have devloped mmicrohabitats. This reduces competition between species. To do this the habititat is divied up into layers. In each layer a different member of the same species rains as king preditor.

Interspecific Interactions
Symbiotic interactions aren't always beneficial. Sometimes it may benefit you and sometimes you get owned. A few exapmles of symbiotic interaction are competition predation/parasitism, mutalism and commensalism. Competition doesn't benefit anyone (-/-). Eventually there is competitive exclusion, this is when one species takes over. Next theres predation/parasitism. THis benefits one animal (-/+). Someone gets food and someone gets eaten.

Next there is Mutualism. In mutalism both organisms recive benefits (+/+). An example of this are lichens, algaes and fungi.
Last there is commensalism. In commensalism one organism benefits and there is no effect on the other (+/0). AN exaple of this are barnacles on whales.
That's basically what we did in class today. Tomarows shurpa will be nicole. ^_^

Sunday, October 21, 2007

Population Growth

Hey Period 8+9, this is what Friday’s lesson was all about:

Basically what we were learning dealt with growth of populations on Earth and the effect population growths have on our planet. First, we dealt with what is called the Logistic rate of growth in which we learned that population, which can grow exponentially cannot always continue to grow because it is impossible. For example, if you refer back to the graph (which showed exponential growth) on the PowerPoint slide from Friday, (K) is the variable that stands for the Carrying Capacity of nature, while the other variable is (N), which stands for the number of individuals in a population. As one variable approaches the other, preferably (N) to (K) the effects of natural controls put its foot down and tries to alter this course. Without any natural control, the population would keep growing at an exponential rate and go over (K)’s limit. This would be an enormous problem in nature and on the ecosystem because the resources of that area are sure to run out do to its constant usage from the large population. Luckily nature always takes action in some way or form.



Now, going back to Carrying Capacity. (K) is the maximum size of a population that nature is able to support without reducing the quality or degrading the habitat. The Carrying Capacity can be altered with changes in resources of an environment. Again going back to the graph from PowerPoint, we see that the plankton population, after an exponential growth, decreases at a certain point because the organism overshot the Carrying Capacity. Now before, I said that changes in the resources in the environment varies the Carrying Capacity. One such example is the population cycles or Predator – Prey interactions. Referring back to the slide with the Snowshoe Hare and the Lynx, years that Hare populations are high (probably a warmer winter where grass is an available food source), the lynx population also high.

Next we learned about Human Population growth on Earth. For example the slide that dealt with the population growth of humans shows that advances of science, technology and industry are what led to an increase in the human population after the Bubonic Plague in the 1400’s. Also, in 2005, there are over 6 Billion people on Earth and that 82 Million people are being born each year. China and India having enormous populations, (1.3 Million People and 1.1 Million People). Could Humans be reaching Carrying Capacity? I truly believe so.

So what has been causing this sharp population increase? Well, countries that are still developing seem to have a higher fertility rate than that of developed countries (90% of births are in these developing countries). Also that the populations in these developing countries can either have a high, medium or low fertility rate in the future. Low fertility would be a better idea that having a medium or high fertility because we really don’t know what (K) is for the Human race, maybe 10 Million, maybe 15. A major factor that could aid in a better future for the world would be the education and income of people. If people were more educated and had more money problems like this wouldn’t happen. This could ultimately effect fertility rates and lead to a much lower population scenario in the years to come, benefiting Planet Earth.

Humans leave an ecological footprint. I feel that Humans are over-consuming resources on Earth and that we are destroying it as well. In the slide referring to Ecological footprints, the US uses so much land to support its population while India, whose population is much larger uses lesser land. The World is located on the deficit rather than the benefit side of its ecological footprint (which is a very bad thing people!), as well as our own nation because more wastes are being created from the consumption of resources such as land and water.

In the end, that’s pretty much all we learned on Friday. I think the Human race is heading onto a rough patch in the future. The Sherpa for Monday night will be Tom, (Your Welcome Tom). So that’s it, alright guys, Goodnight.
P.S, Sorry if its too Short or there arent enough pictures and such, I couldnt really find anything that could help illustrate the lesson. Sorry! :-)

Thursday, October 18, 2007

More Ecology...

Age Structure

Certain populations throughout the world have different growth rates within cohorts. In nations with a lack of medicine or education such as Kenya, there is too much reproduction occuring between 10-15 year old's. Because younger people are reproducing more than older people, the population size between 0-10 year old children is very large and steadily decreases as they age. In other nations such as Italy, there is a much lower population rate in younger peoples making their population size relatively steady throughout ages. Population sizes are a major effect on environments everywhere. In nations such as China overpopulation has had a negative effect on their nation and ability to survive.



Survivorship Curves

There are three types of strategies used by different species that help them survive. Type 1 includes humans and is when a species thrives in population size up and till the post-reproductive stage. Humans continue to live and reproduce successfully until they are past the age of reproduction then begin to die off. Type 2 includes Hydra's and is when there is a constant production and mortality rate throughtout the species. Year by year the population sizes remain the same and they continue to die off and reproduce consistently until death. Type 3 which includes Oysters has a very high mortality rate in the early stages of life. In Oysters, almost 99% of their population dies off before they can even reach a reproductive state. The survivors however, live a long life after their survival and must reproduce a lot. They cannot donate much energy or time to each individual offspring because 99% of them will die off so they will reproduce as much as possible then walk away. As an example, after the salmon are born they travel downstream to grow and develop. Once they become of age to reproduce they must swim all the way back upstream. This is of great cost to the parent salmon which is why once they arrive upstream, they reproduce as much as possible to get as much out of their journey as they can. This process not only affects animals but plants as well. The sunflower is an annual plant that only flowers one season. The flower cannot miss this season or else it could be fatal to the survival of it's next generation so they must strike while the iron is hot !




Reproductive Strategies

There are also reproductive strategies that can affect the population size in different species. If a species is K-selected, they have a late reproduction age and fewer offspring. They have less time in their lives to reproduce so they must take time to make sure the few offspring they create survive easily. Examples of this are primates and plants like coconuts.



Weedy plants such as dandelions produce many seeds and can grow very rapidly unlike the palms tree. In dandelions it is known that some out of it's many offspring will surivive and make more plants. With the palm tree, they produce a moderate number of very large seeds. Their large endosperm provides nutrients for the embryo. This process ensures that a larger portion of their small offspring with survive and succeed.

Population Growth

Change in population = Births - Deaths

dN/dt=riN

By using this formula, scientist's can presume the average number of offspring each couple had to of had in order for the population to grow from it's original size to it's present size. If every pair has two offspring, they are merely replacing themselves in the environment and not adding or taking away any numbers. But by only having less than two or more than two offspring you are changing the population and adding or taking away certain numbers from the species.

N= How many you start with. (specifically females being they are the ones that reproduce.)

r= The rate of growth, specifically how many offspring each couple had

ri= The intrinsic rate or how many offspring does your species generally make over time

t= Time

d = rate of change

Regulation of population size/ Introduced species

When certain species are endangered or introduced to a new environment, they can be protected and allow to reproduce exponentially. This is when there is no boundaries or limits set on the amount of offspring allowed to be produced. There are limiting factors that make population necessary to be regulated as well. Density dependant factors consist of competion for food and nesting sights and disease. Density independant factors consist of certain abiotic things like sunlight, rainfall and other sources of necessities. These are uncontrollable but still play a major role in the survival of a species in an environment.

When a species is introducted to a new environment it can greatly affect this new area. As an example, when European ships docked in North American shorelines, they brought along Zebra mussels. These mussels reproduce sporadically thus taking over entire shorelines. The fish who once used to lay their eggs on those shorelines are now in dire need to find a new ground to reproduce. Also, Purple Loosetrife which is a large flower that reproduces very rapidly and efficiently has taken over certain wetlands. These wetlands which were once home to all kinds of species is now infested with these purple loosestrife and these species which once lived there can no longer survive.


Wednesday, October 17, 2007

Some More on Ecology

Hey guys, today we learned more about ecology. We learned that organisms interact with the enviornment, and face both biotic and abiotic factors. Biotic environment would be food, competitors and the predators.
Abiotic environment would include sunlight temperature water and soil. (Don't forget nutrients cycle while sunlight is always being input into the environment.) Populations are groups of individuals that are the same species at the same location.
Populations have all different ranges (how much area they live across), pattern spacing (how in the ecosystem the population is spread out), and sizes. When it come to the range they have geographical limitations.
Prey, predators, temperature, and water all act as boundaries for the range of populations. The boundaries sometimes allow for change, so the range can expand or contract. Endangered species are endangered due to limitations on range and their habitats.

There are three types of population spacing for populations. There's clumped ex: schools of fish or packs of wolves. Clumped spacing is the most commom and is an evolutionary advantage because it provides protection. There is uniform ex: birds. Uniform spacing can occur due to direct interaction with other individuals within a species, and it can involve an individual being territorial.
Also there is random spaccing ex: plants in a forest. For population size there are two factors that increase size and two that decrease the size. Birth and Immigration both increase population size, and to balance it out death and emigration decrease the size. Growth rate is looked at with three factors in mind. One is the ratio of male to female. The second is at what age females are able to reproduce. Also lastly, age structure. Factors that can control the growth and decline of populations are involved in demography. Scientists gather information on the populations and create statistics based upon their information. They can also use the information to create survivorship curves. Also scientists keep track of the number of individuals of each age group.



Tomorrow's sherpa will be Kelly S.

Tuesday, October 16, 2007

Ecosystems

This was the Lesson for Monday and Tuesday!!!

So far we have talked about the three Domains and the different Kingdoms. These encompassed living organisms and their populations. Now we are jumping into the part of the world which includes both the biotic and abiotic factors. An
Ecosystem is all the organisms in a community plus the abiotic factors. Ecosystems need three processes to occur in order to to be self-sustaining:

  1. Capture of energy

  2. Transfer of Energy

  3. Cycle of Nutrients

There are Two Inputs in an ecosystem which are necessary. They are:

  1. Energy
  2. Nutrients
There is a constant source of energy that life of earth gets and that source is the sun. Sunlight is needed in order for there to be life. Energy flows through an ecosystem. Energy is lost through each trophic level. Producers have the greatest amount of energy and primary consumers receive less energy, then seconday consumers get a lesser amount and so on.

Nutrients on the other hand cycle through a system. There are a limited amount of nutrients on this earth and they are recycled because according to the first law of thermodynamics matter can neither be created nor destroyed. Both nutrients and energy go through a series of trophic levels. In general the nutrients are in an abiotic reservoir of some kind. They then are made available to producers, which then goes to consumers. Decomposers are the key to recycling most nutrients. They take the stored nutrients and put them back into the ecosystem to circulate the process. There are various elements that can be cycled. A couple important cycles are the carbon cycle, nitrogen cycle, phosphorus cycle, and the water cycle.


Carbon Cycle:



The Carbon cycle is the most known and famous cycle because of its importance. Organisms on earth are carbon based so carbon is essential for life. Carbon is found in the atmosphere and is made usable by the process of photosynthesis. Producers take carbon and in the process of photosynthesis make it usable to the rest of the biotic community. Carbon is returned back into the atmosphere with respiration as animals exhale it out as a byproduct of respiration. Carbon can also be returned into the atmosphere when humans burn fossil fuels which are the deposition of dead material.


Nitrogen Cycle:


The Nitrogen cycle is different in that nitrogen is mostly found in an unusable form. The triple bond of N2 prevents most processes from breaking down the compound. Bacteria are the only ones that can break down nitrogen into a usable form. Nitrogen-fixing bacteria make nitrogen available in the soil which consumers eat where nitrogen is then return to the soil with either decomposition or excretion. Denitrifying bacteria are the only ones that can return nitrogen back into the atmosphere. The nitrogen cycle is important because nitrogen is included in the base pairs of DNA as they are called nitrogen bases. Nitrogen also is important for the production of amino acids which code for proteins which enzymes are. Enzymes take part in many processes.


Phosphorus Cycle:

Phosphorus is found in rocks and minerals, usually igneous rock. Phosphates are leeched by water and are available in the water or soluble soil which are then absorbed by plants. Phosphorus cannot be returned to the abiotic reservoir but decomposers cycle the phosphorus. Sugar phosphates line DNA and phosphates are included in Adenosine Triphosphate.


Water Cycle:

The reservoir for water is usually the ocean, lakes, groundwater, or water vapor in the atmosphere. Precipitation transfers water from the atmosphere to the ground. Evaporation transfers some water from the ground to the atmosphere but transpiration does most of the job. Transpiration is the evaporation of water from plants as water escapes the stomates. The stickiness of water which causes one molecule of water to pull another molecule up a plant is called transpirational pull.

Deforestation has been breaking the water cycle. Groundwater is not transpired to the atmosphere, so precipitation is not created. This has led to desertification. Deforestation has caused nitrate levels in runoff to increase by 600% as shown by studies done in the Hubbard Brook forest region. There are people out there in the world trying to make a difference. The Greenbelt Movement in Kenya has been influenced by Wangari Maathai who has restored sustainable ecosystems and has won a Nobel Peace prize in 2004.















Deforestation in Eastern Angola




Deforestation in Middle Land, ParĂ¡ Brazil








Wangari Maathai planting a tree at the Outspan Hotel, Nyeri, Kenya, to mark the launch of her autobiography, Unbowed


Deforestation Video:




Ecological Pyramid and Trophic Structure:


Food webs are linked into food webs because there is a complex connecting system of producers, preys, and predators. Depending on what a species eats or its niche, it can weave into the web at different levels. All levels are connected by decomposers who put the dead matter back into the cycle. The length of a food chain is limited by inefficiency of energy transfer. Energy is always lost at each level. in various processes. 50% of energy is passed the organism and is given off as waste. 33% of energy goes to cellular respiration and the rest of the 17% goes to growth. The loss of energy at each level creates an ecological pyramid in both energy amount and population size. The bottom of the pyramid has a lot of energy so it can hold a greater population while the top has very little energy so it can hold only a small population.

Review:

  1. Energy flows through a system

  2. Nutrients cycle through a system
  3. Both energy and nutrients are needed to support an Ecosystem

More Information on Hubbard Brook Research go to: http://www.hubbardbrook.org/


More Info on the Grenbelt Movement go to: http://www.greenbeltmovement.org/

Tomorrow's Sherpa will be Kristen

Sunday, October 14, 2007

Yep, Its the Animal Kingdom


Hey Period 8 and 9! This was what Friday’s lesson was on:

The Animal Kingdom is the final kingdom of the Eukarya Domain along with the Protists, Plants and Fungi. What makes the Animals special from the other 3 Kingdom's you ask? Well first of Animals are Heterotrophs, in which the ingestion of other organisms is need in order for nutrients to be obtained. Secondly Animals have extreme complex bodies and their cells do not contain a cell wall, which allows for active movement to take place. Thirdly, Animals partake in Sexual Reproduction in which 2 organisms male and female mate with each other (Cool! just like these Turtles!). There is no alternation of generations nor are there Haploid Gametophytes. Animals stay Diploid for most of their life cycle with the exception of gamete production in which the Gametes, namely an Egg and Sperm are haploid.

Now, all animals came from one Ancestral Protist. From the Eukaryotes came the Animals and the first step of Animal Evolution wass Multicellularity. From there the Porifera group of more commonly known as sponges became apparent. Porifera's were primitive animals. They are invertebrate animals or have no back bone or spinal cord. Sponges were primitive because they lacked any distinct tissues organ but had specialized cells in them and were the only animals without organization. Porifera obtained its food by the process of Endocytosis or infolded its cell membranes like and Amoeba. Sponges have no symmetry what so ever.

Along with the appearance of Porifera's, step 2 came about in evolution by branching off of mulitcellularity and the introduction of tissues. Next came the Cnidarian’s or the Jellyfishes, Hydra, Sea Anemone and Corals. The Cnidarian group contained Tissues but no organs and had not one but two cell layers, outside and in, and Cnidaria's like the Porifera's are invertebrates in which they have no spinal cord. They are predators because the Hydra, Sea Anemone and Jellyfishes contain stinging cells on their tentacles surrounding their gut openings and had extracellular digestion in which enzymes are released into the gut cavity, break down the meal and spit the waste out the way it came in (Ew, that must smell horrific) . Cnidarian’s are radically symmetrical in which if the organism was cut in half in any direction the opposing half would be exactly the same. (I Do Not recommend being stung but one of these creatures apparently they are not a very good thing and happen to be extremely painful and annoying, thanks Tom)





Step 3 came about in Animal evolution with the branching off of Bilateral Symmetric organisms and the introduction of the Platyhelminthes otherwise known as the Flatworms! (Gross creatures). Once again these organisms are invertebrates. Tapeworms and Planaria are examples of Flatworms. Flatworms are mostly parasitic creatures and don’t need to digest food just absorb it. They are also bilaterally symmetrical meaning they have a mouth and an anus. To be bilaterally symmetrical allows for a high level of specialization within parts of the body of an organism, which is a MAJOR advantage. On the next step of Animal evolution was the branching off of organisms that contained body cavities in which the outside world was separated from the inside one. These newfound organisms are called the Nematoda group or the Roundworms (once again gross!). Like their flatworm cousin they are bilaterally symmetrical (have mouth and anus) and contain a complex and well-developed digestive system. Like their flatworm cousin they are also parasitic organisms for example the Hookworm or the Nematodes. (I hope to never experience these creatures, ever).
* This next stop is much more complicated! As there are 2 different branches created leading to different groups of different qualities.

The 1st branch is the Segmentation branch and the 2nd the Endoskeleton branch each branch having its own separate mini-branches. So lets talk about branch #1. Branch 1 which is Segmentation contains three mini-branches, Mini-Branch #1 being the Mollusca group (Mollusks). Clams, Snails and Squids are part of this group. Once again they are invertebrate animals and are bilaterally symmetrical (there are few exceptions of course). Most of these organisms have soft bodies being protected by hard shells. These organisms have a true Coelem or an internal digestive cavity separated from everything else. This is an advantage because when bilateral organisms eat they could be eating other harmful things and separating that from your body can help lots! Mini-Branch #2 is the Annelida group. These are the Segmented worms such as the earthworms, fan worms and the leeches. They are, like Mollusks, bilaterally symmetrical and contain a true coelem or internal digestive tract. However the segments on each organism are not specialized to serve a purpose. They are also invertebrates. The Final Min-Branch, #3, is the Arthropoda group. These are such organisms as the spiders (Yuck!), insects and crustaceans (lobsters and crabs).
Arthropods happen to be the most successful animal phylum because there are more of them than any other animal on Earth. Yes, they are bilaterally symmetrical and are invertebrates. Arthropods are segmented creatures therefore making jointed appendages possible. Also they have an exoskeleton made of Chitin + Proteins. That’s the hard shell you have to crack through when you’re at Red Lobster treating yourself to a nice expensive meal. (Unfortunately I’m too cheap to spend my money on dinner). In the Arthropod group there are the Arachnids, containing 8 legs and 2 body parts (Spiders, Ticks and Scorpions)
, the Crustaceans, containing Gills, and 2 pairs of antennae (Crabs, Lobsters, Barnacles and Shrimp),
and finally the Insects, containing 6 legs and 3 body parts (You should know what an insect is). Well that’s the Segmented Branch of phylum’s. On to Branch # 2! Yay! Branch #2 (Almost Done!) which is the Endoskeleton groups contains only 2 mini-branches. Mini-Branch # 1 are the Echinodermatas most commonly known as the Starfishes, Sea Urchins and Sea Cucumbers.

These creatures are different from others because they are no longer bilaterally symmetrical, they are radially symmetrically. Remember what that is? Well in other words if this organism was cut in half in any direction the opposing side would be exactly the same or symmetrical. Echinodermata's also have spiny exoskeletons. Finally! Here we are! The final min-branch, #2, are the Chordates otherwise known as the Vertebrates, in which each organism contains a spinal cord or back bone unlike invertebrates do. Vertebrates also contain and internal bony skeleton and have a skull that encases the brain and have a backbone encased in a spinal column. There are many different kinds of vertebrates for example fish, reptiles, amphibians, birds and mammals (<---- cool us!).
Our first examples of Vertebrates are Fish (Trout, Sharks and Salmon). Fish appeared over 450 MYA on Earth.

Fish happen to have a bony and cartilaginous skeleton, scales, fins and jaws equipped to their bodies. Fish have gills in order to perform gas exchange under the water. Fish are different from so vertebrates because they only have a two-chambered heart meaning a singled loop of blood being circulated throughout its body. This quality is given a name. It is called being Ectothermic in which the blood of the organism is the same as the outside of the organism (Temperature-wise). Fishes partake in external reproduction in which fertilization takes place outside of the body in the water (the embryo also develops in the water in a aquatic egg casing (Think Finding Nemo).

*Fishes evolved into land creatures called Tetrapods meaning four limbs. An example of this so-called transition organism is Tiktaalik roseae (Yes, we read about him a couple of weeks ago).

Our second examples of vertebrates are Amphibians (Frogs, Salamanders and Toads). Amphibians appeared over 350 MYA on Earth.

Amphibians, unlike fish have legs and are tetrapods. They also had moist skin meaning they needed to live near water in order for gas exchange to be possible by diffusion through the skin. This was because the lungs had positive pressures put on them and were inefficient. Amphibians were also different from fish because they contain a three-chambered heart in which the veins traveled from the lungs back to the organism’s heart. They are similar to fish because they are also ectothermic and partake in external reproduction (fertilization is outside of organism). But amphibians such as frogs have offspring that metamorphosize from tadpoles to adults.

The third examples of vertebrates are the Reptiles (Dinosaurs, Turtles, Lizards, Snakes, Alligators and Crocodiles). Reptiles appeared over 250 MYA on Earth.


They are very different from our first two vertebrates. For example reptiles have drier skin, scales and armor on their external body. They also have lungs for gas exchange and use thoracic breathing or negative pressure (unlike fish or amphibians). But Reptiles are similar because they are Ectothermic creatures and have a three-chambered heart. Reptiles partake in internal fertilization but have offspring that develop externally in an amniotic egg. In this egg there is a structure called a Allantois, which allows for the exchange of gas to occur.

The Fourth examples of Vertebrates are Birds (Finches, Hawks, Ostriches, Turkeys and Chickens). Birds appeared 150 MYA on Earth. Birds happen to be very different from the other three vertebrate groups. Birds have feathers and wings on their bodies and contain an endoskeleton of bones that are thin and hollow allowing to flight to be possible.

Birds are also different because they have extremely efficient lungs and air sacs. Birds are Endothermic creatures (the complete opposite of Exothermic creatures making birds very different) and have a four-chamber heart containing 2 ventricles and 2 atriums. Birds are similar to reptiles because they reproduce through internal fertilization and have offspring develop in an amniotic egg.


Our fifth and final vertebrate group appeared 65 MYA on Earth, with the extinction of the Dinosaurs, Mammals! (Finally, Humans,!) When the dinosaurs went extinct, many niches were needed to be filled giving mammals a great opportunity. Mammals have specialized teeth and have hair. Like birds, mammals are endothermic and have a four chambered heart, 2 atriums and 2 ventricles. Like birds and reptiles mammals contain lungs and have negative pressure (Mammals also possess a diaphragm). What makes Mammals special from the rest of the vertebrate groups is the fact that mammals not only reproduce by fertilizing internally our offspring develop internally as well in a uterus where nourishment occurs through a placenta making the offspring live young. Mammals also have mammary glands to feed their young after they have been born (Yes, Breastfeeding just like the woman on the subway lol).

* Vertebrates also have many subgroups. For example there are the Monotremes, which are egg-laying mammals. Only the Duckbilled Platypus and the Echidna and a minute number of mammals partake in this process. There are the Marupials, which are pouched mammals. The offspring have a short-lived placenta therefore the parent needs a pouch in order to care for its young by sheltering it. Kangaroos, Opossums and Koalas are known for this. The last examples of a mammalian sub-group are the Placental mammals. These mammals are the true placenta users for example the Shrew, Bat, Whale and Humans.

Well that’s it guys so thanks for reading, hope its helpful enough. The sherpa for Monday night will be Saad. Sorry Saad Man lol