• Deep Time Evolutionary History
• Human Ecology
• Human Population and Biodiversity
***DEEP TIME EVOLUTIONARY HISTORY***
The first protocell may have been formulated through a chemical evolution.
Small organic molecules were made from the Earth's early atmospheric gases and an outside energy source. The macromolecules evolved and mixed together to where RNA was made. This was found in the first cells. then amino acid proteins came into view as polypeptides in dry heat.
The protocell lived on preformed rgani molecules in the ocean and eventually became a cell once it had DNA and was able to reproduce. There is sooo much diversity on this planet in the form of life because of a certain form of evolution--biological. In this type of evolution, there is a common ancestor in all of us. That is the reason as to why we all have certain characteristics such as eyes, ears, limbs, skeletal systems, air/water, etc. There are several kinds of evidence that each promote this theory of evolution. The fossil evidence we find on this planet includes that of the dinosaur age. All fossils, including the early humans has similar characteristics. There is also biogeographical evidence where there are organisms covering the entire planet. The theory that the land called Pangea did once exist. Anatomical evidence would be one more. THis is where the anatomies and the common ancestor play their roles in similarities. Finally there is the biochemical evidence were all the organisms on the planet have a similar make up, chemically.
Humans are primates. This means that we are related to the African apes. We are a form of hominid with features and characteristics that would include biedal osture, flat faces, and the brain that we have. Australopithecines are also hominids and were existant around 3million years ago. They had a small brain but they could walk upright and this is looking a bit more like the human way. Homo habilis made and used tools. Then the homo erectus was the first of its kind to be a proud owner of a brain that was 1000 cm3. The homo erectus was expected to have come from Africa then to Europe and then to Asia. Then the Homo erectus used fire and may have been good hunters. There were also Neanderthals and Cromagnons. The Neanderthals were in Europe and Asia long before modern humans came along. They maintained a culture but they were very much unlike the modern humans. Cromagnons were the oldest fossil to be considered a homo sapien because they had sophisticated tools and also had a culture to back it up.
***HUMAN ECOLOGY***
Ecology- the study of the interactions of organism with one another and with the physical environment.
In our project lab we observed our ecological environment.
There are terrestrial ecosystems such as forests, grasslands, and deserts and there are aquatic ecosystems that include salt water or freshwater. There is always a habitat and a role in the community for the individual. Autotrops are producers that produce organic nutrients for themselves and for others from inorganic nutrients and outside energy sources. Heterotrophs are the complete opposite. These are consumers that eat organic nutrients. Consumers include herbivores, carnivores, and omnivores. Dcomposers feed on the detritus and release the inorganic substances back into the ecosystem for the autotrophs to eat. It's a simple cycle that continue on. Energy flow can be describes with a food web. This is show how organisms that may be very different from one another, are related. How would this be? Through eating of all things!
A trophic level is were all the organisms feed in a particular level in the food chain. Ecosystems are always having to deal with different chemicals coming through. These chemicals may be gaseous or sedimentary, have reservoirs with inorganic nutrients, or nutrients that cycle through the biotic communitites. The water cycle would include how freshwater evaporates from the ocean. Then when it falls and hits the ground it is able to be lifted and evaporated once more. There is also the carbon cycle, the nitrogen cycle, and the phosphorus cycles to be discussed. The carbon cycle is where the reservoirs of the carbon are organic matter, limestone, and the ocean. It has an exchange pool which is the atmosphere and through photosynthesis, carbon dioxide is removes from this atmosphere and is put back by respiration and combustion. The nitrogen is the atmosphere. The nitrogen gas is changed by producers into somehting that may be worked with. Then the nitrogen fixing bacteria change this nitrogen gas into ammonium so that producers are able to use it. Then ammonium is changed to nitrate by nitrifying bacteria. Denitrifying bacteria convert the nitrate back to nitrogen and the process rolls on and on. Finally there is the phosphorus cycle. In this cycle its reseroir is the ocean's sediments. Geological upheaval is what makes the phosphate in the ocean sediments available for use. Weathering takes it back to the ocea. Phosphate is relatively scarce in number in such a cycle.
***Human Population and Biodiversity***
Populations generally increase in size. Environmental resistance is what usually holds this back. This population size is expected to level off to a point that will fit the capacity for the area, as others that exceed the limit will die off. Humans use land, water, food, energy, and minerals to the highest extent of our capabilities to date. Resources are either nonrenewable or renewable and they need to be treated like a commodity.
Humans use the land and are ruining life for other organisms but the human population demands this, so it is done. The water we use is renewable but there is a limited quantity at hand, as is food and energy. Minerals are nonrenewable and they are found in the ground in such materials such as sand, gravel, phosphate, or metals. Land that is ruined from mining is not necessarily ruined forever, but it takes an awful long time to recover.
There are five main causes for biodiversity loss and extinction on Earth. These are: habitat loss, introduction of alien species, pollution, overexploitation of plant and animals, and disease. Diodiversity is a good thing to keep because it provides us with medicinal value, agricultural value, and comsummptive use values. They also give waste disposal, freshwater procision through the water biogeochemical cycle, prevention of soil erosion, function of biogeochemical cycles, climate regulation, and ecotourism.
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