These are Population , Animal ,and Mortality Biology Notes
Notes on Population:
-Population is defined as a group of organisms of the same species living in the same habitat. Populations increase by the immigration of new members of the species into the habitat or birth of new members of the species. Population decreases by emigration of members of the species from the habitat or mortality (death) of members currently in the habitat.
-Communities include all the specifics of an area. There is a succession of populations in newly formed ecosystems like a volcanic island, a pond filling in, or a new forest area. Primary succession is defined as the gradual change of populations. Earliest species in a habitat are called pioneer species. These begin the succession as the habitat changes. There remains add to the developing soil. This builds the soil for later species that require better conditions to grow.
-One of the key factors in populations succeeding relates to the biotic potential (I.e. Number of offspring that can survive) and the number of offspring these can produce. As the offspring multiply there is a resulting growth curve like we saw on Easter island. Also like Easter island, we can see the stable population level (carrying capacity) reached and then exceeded causing a "crash."
-Populations have limiting factors in growth or population density. These would include space, food, parasitism, disease, predation, stress and mating potential. Density independent factors are often abiotic and would include change in weather, temperature, humidity, daylight period, and available energy.
-Human population has undergone substantial variation as humans were able to modify their environment. From recorded history we saw a nearly flat growth rate from 6000 BC to about 250 million in 2000BC. By 1850 the population reached 500 million.
-Since 1850 (beginning of industrial revolution) the population has grown nearly exponentially. Today the world human...