7. How do your findings relate to relevant theories in environmental science? Specifically: a. Do your results indicate that any of the species are keystone species? Do they support the theory of bottom-up or top-down control of population dynamics in ecosystems?
The results showed that the increasing of the density leads to a decrease in the biomass of plants and that the experimental groups are not much different than the control groups. This shows that an environment can work to stabilize itself without human interruptions. Plants can ensure they don’t overpopulate an area by self-thinning and species can survive with predators using the environment they were given. Introduction Competition for resources is seen in all species and environments around the world. Since the Earth’s natural resources are limited, it necessary for species of all kingdoms to fight in order to gain enough nutrients in order to not only live but thrive and go on to produce future generations.
Directed Reading 13.1 Section: The Theory of Evolution by Natural Selection In the space provided, write the letter of the term or phrase that best completes each statement or best answers each question. ______ 1. Some individuals of a population or species are better suited to a. evolve than other individuals. b. survive and reproduce. c. become extinct.
A few of those examples includes: Humans, findings of fossil records, record finding of changes in existing species, and biochemical and anatomical similarities. 2. Humans shape their environment in ways that other organisms cannot. Are humans subject to the same pressures of natural selection as other organisms? Why?
Variation 4c. That the organism will have a better chance to survive 4d. Survive and reproduce in its environment 4e. Competition of members of a natural population for a vital resource 4f. Heritable 5a.
Scientists can modify foods to be healthier, adding fats, proteins and sugars to plants so that consumers with a limited income can have a healthy diet. Genetically modifying organisms will benefit the environment too. With traditional farming, farmers spray their crops with herbicides and insecticides around 4
Examine one evolutionary explanation of behavior Before we had the technology to look at genes specifically, a theory was used to explain how we’ve adapted the traits we have today. Darwin’s theory was that those who adapt best to an environment will have a greater chance of surviving, having offspring, and passing their genes to their offspring. As our environment is always changing, we need to adapt our characteristics to survive in that specific environment. It is the whole aspect of adaptation. It is said that those who are better suited for a certain environment will be more like to breed and pass on these genes also known as natural selection.
Although some stressors cause only minor impacts when acting alone, their cumulative impact may lead to dramatic ecological changes. Climate changes and shifts in ecological conditions could support the spread of pathogens, parasites, and diseases, with potentially serious effects on human health, agriculture, and fisheries. c. Humanity’s natural resource base and thus economic security? We as humans must do our part in protecting what is left of our natural resources and must realize that what we do today will affect the future for the next generations and so on. We have to set up guidelines to secure our environments well-being and follow them in order to save them from becoming extinct and hurting us in the long run, we must reduce our waste and pollution rate and restore as much as we can back to create a well-balanced eco-system to try to place it back to some kind of normalcy to secure human a future access to natural resources.
Three ways microevolution can take place. 1. Natural selection a. Survival of the fittest b. Alleles being passed to the next generation c. Individuals with variations that are better suited to their environment produce more offspring d. Process in which individuals that have certain heritable characteristics survive and reproduce e. The environment is like the selective agent 2. Genetic drift.
This often results in a change in the characteristics of an organism. In a given generation the contribution of a mutation will be minimal to a population’s variation, however over an extended time period it will have a significant effect on the phenotypic variation in a population if it better adapts an organism to its environment (Stebbins, 1971). Note that a mutation that causes a dramatic change in an organisms phenotype will not improve the fitness of an organism such as a