Read the Overview and launch this ecolosystem simulator. Familiarize yourself with the simulator interface. Notice that you can control which species are present in your environment initially and what the diets of each species are. The types of species possible in the program are Plants (A,B,C), Herbivores (A,B,C), Omnivores (A,B) and one top Predator. You can control the diet of each by indicating what they feed on. By setting up different starting configurations you can investigate the evolution of this simulated ecological system.

A. In a couple of sentences describe what happens when you start with only two (A&B) and then all three plant species present.

When only A & B plant species are there and we run the stimulator, the population of Plant a increases and becomes maximum and that of plant B decreases to 0. As the time passes by, species of A decreases and that of B increases such that in long run we have equal distribution of Species A & B.

When we run the simulator with all the three plant species, The consequence of Plant A & B is same but there is no plant of type C.

 

In this case there are only producers. They harness the sun energy and grow. The favourable ones boom and the others are overshadowed in the process.

B. Describe how many herbivores and omnivores you added (and what they eat) in order to create an ecosystem in which all three plant species can coexist. (if you cannot accomplish the survival of Plant C describe your best configuration. Describe your ecologies by identifying the species present and their diet, for instance:

Omnivore A eats Herbivore A, Herbivore A eats plant A and plant B, Herbivore B eats plant A, All plants present.

All the three varieties of plant A, B & C co-exists when we add Herbivore A, B, & C

Herbivore A eats Plant A & C, Herbivore B eats Plant A & B and Herbivore C Eats Plant B & C.

Omnivore A eats Herbivore A & B and Omnivore B eats Herbivore B & C

Top Predator eats both Omnivore A & B. In this ecosystem all the varieties have a co-existence.

C. If you can accomplish part B, see if you can get all of the species to coexist. (limit your time on this entire experiment to 90 minutes)

D. If we assume that this simulation is a reasonable oversimplification of a typical ecosystems food web what does it tell us about biodiversity and ecology- are they robust or fragile? In general is an ecosystem’s biodiversity preserved as it responds to change?

Virtual Lab 6: Evolution: Sex and the Single Guppy

This simulation follows a set of real life experiments in evolution and natural selection. Familiarize yourself with the interface, guppies, guppy predators, and the experiment. Use an “even mix” of the different guppy color types to start. Run three experiments one with each of the combination of predators. Each experiment should run for five or more generations. Type your solutions in bold face text.

•   State the percentage that each color type makes up in your guppy population both before and after you have let five generations pass. With each experiment state a conclusion that is consistent with your observation.

1. Rivulus only

131 guppies

2. Rivulus and Acara

3. Rivulus, Acara and Cichlids.

•   What two selection pressures are operative?

Virtual Lab 7: Anatomy and Dissections

A. Dissections

1. Earthworm

A. Identify items 1 & 2 on the external dorsal (back side) surface of the worm.

B. Identify items 3, 4, & 5 on the external ventral (belly side) of surface of the worm.

C. Identify item 2 in the image of the worm’s internal morphology w/o the digestive tract.

D. Describe sexual reproduction in worms.

2. Fetal Pig

A. Use the Anatomical References guide. To what region of the body does dorsal, ventral, anterior, and posterior refer to?

B. Investigate the Nervous system. The pig is similar to the human in many ways.

Name four large regions (lobes) of the brain and indicate where they are located and what functions they have in humans.

B. Comparative Hominid Anatomy

•   Compare the the skull casts of a chimp, Australopithicus, Homo erectus, neanderthal, and modern Homo sapiens. Be sure to use the lateral view.

•   Describe features that are common and different between the cranial structure of these creatures. What patterns do you see? •   Describe the basic timeline and sequence of evolution for the creatures listed above. Be explicit.

Virtual Lab 8: Human Impact

A. Water footprints

•   Describe the water crisis. How is it impacting women and children globally? What is happening with the Ogalala (be specific)?

Water crisis refers to lack of access to safe water sources. Inadequate drinking water supply is among the world’s major causes of preventable morbidity and mortality.

Water related health burdens are borne by women and children who may forego schooling and childhood in order to transport water from distant sources. Women and children are also often responsible for the gathering of fuel wood both for cooking and for boiling the polluted water.

The High Plains stretch northward from West Texas to Wyoming and South Dakota, and in natural conditions form a dry grassland. There is less than 16 inches of rain a year near the Rockies and in West Texas, but that increases eastward to 28 inches in central Kansas. The rainfall varies a great deal from year to year, however. The steady gradient of increasing rain to the eastward, but varying yearly rainfall, means that the optimal western limit for growing crops such as corn, rather than grazing cattle, shifts each year. This problem is made worse because there is hardly any water surplus: evaporation levels are very close to precipitation levels. Apart from the constraints on farming, this fact means that there is little recharge of ground water from precipitation: ground water percolates only very slowly eastward in underground aquifers from the areas where Rocky Mountain snowmelt recharges them.

The United States Geological Survey (USGS) began intensive research on the Ogallala in 1978. It found that the Ogallala had discharged perhaps 3 maf/yr into springs and rivers before development: this, then, would be a sustainable yield from the aquifer as it used to be, compared with the 1980 pumping rate of 18 maf/yr.

•   Describe what the water footprint is and how it is estimated.

The water footprint of an individual, community or business is defined as the total volume of freshwater used to produce the goods and services consumed by the individual or community or produced by the business. Water use is measured in water volume consumed (evaporated) and/or polluted per unit of time.

A water footprint can be calculated for any well-defined group of consumers (e.g., an individual, family, village, city, province, state or nation) or producers (e.g., a public organization, private enterprise or economic sector). The water footprint is a geographically explicit indicator, not only showing volumes of water use and pollution, but also the locations. However, the water footprint does not provide information on how the embedded water negatively or positively affects local water resources, ecosystems and livelihoods.

•   Report the two or more estimates of your water footprint (and the calculator(s) that you used).

Virtual Lab 6: Evolution: Sex and the Single Guppy

 

 

ADDITIONAL INFORMATION 

Sex and the Single Guppy

Introduction

Guppies have many lives, and there are many paths that lead them to their end. This is the story of a single guppy who found her way out of a life that was not meant for her—a story about metamorphoses, life after sex, and what happens when a female’s lament turns into male guppies needing a do-over.

A Story of Metamorphoses

You might be familiar with the story of metamorphosis, which describes how a caterpillar turns into a butterfly. But what about the guppy? The fish that lives in a glass bowl and grows bigger by eating other guppies or algae? Can we imagine how this little fish would feel if it were to become all-powerful? This is exactly what happens when you pour water over your garden hose and watch as your pet gets bigger until it reaches an infinite size (or at least until your arm gets tired).

When I was young, my father would always tell me about metamorphoses: “The caterpillar becomes an butterfly.” He explained that there are many different ways for things to change from one form into another—in fact, there are more than 500 different kinds of animals who do this!

The Female’s Lament

If you’re a female guppy, your days of being able to have sex are numbered. The male guppy is not only the one who gets to choose when and if he wants to have sex with you; he also has to decide whether or not he’s going to be able to get pregnant. That means that while the female can’t prevent herself from getting pregnant (at least not until she’s been around long enough), she does have more control over her own reproductive health than her male counterpart does.

Male guppies aren’t always as concerned about their partner’s fertility as females are—and in fact, some males may even go out of their way not only because they know how difficult it can be for females but because they think those females will appreciate it more if they do everything possible for them!

Male Guppies Needing a Do-Over

If you’re a male guppy and you lose the first time, don’t worry—you can get it back. You might have to do this multiple times, but if your tank is large enough, there’s no reason why your chances of re-contesting should be limited.

A do-over also gives him an opportunity to increase the genetic diversity of his offspring by mating with multiple females. This is important because we know that genetic diversity helps with survival rates when faced with environmental challenges like pollution or habitat loss (which happens all too often). The more diverse his genes are, the easier it will be for him to adapt in an environment where conditions change over time due to human intervention or natural disasters like hurricanes or floods.

Guppies can try again after sex.

Guppies can try again after sex. A male guppy will often keep the sperm that he has stored in his testes and then release it into the water when he sees a female guppy with whom he is interested in mating. If both fish are ready for it, they will have sex right away; otherwise, they may wait until later in the day or week before trying again to get pregnant.

Conclusion

There are a lot of fish stories about sex, but none of them quite compare to the life cycle and metamorphosis of the guppy. If you’re looking for a good read, we recommend Sex and the Single Guppy .