mod 1 Flashcards
The human population is growing rapidly. For most of human history, there were _____ on the planet.
fewer than 1 billion people
During the time of the agricultural revolution, 10,000 B.C., there were only _____ on Earth -
which is basically the population of
New York City today.
5-10 million people
In 1800, when the Industrial Revolution began, there were approximately ______
1 billion people on Earth
The world population, or the total number of humans currently living, is estimated to have reached ______
7.5 billions as of April 2017
To date, the absolute growth rate of humans has stabilized at _______
1.1% per year
can be generally defined as a group of individuals of the same species occupying a given area at a given time.
POPULATION
is the study of populations and their interactions with their environment.
POPULATION ECOLOGY
The environment influences populations in terms of its _____, ______, ______, and _____ .
density and distribution, age,
structure, and size.
is the pattern of spacing among individuals within the boundaries of the population.
DISPERSION
is the most common pattern of population dispersion.
CLUMPED PATTERN
when individuals are evenly spaced over the area they occupy. A pattern seen in species whose individuals do not have close interactions.
UNIFORMLY PATTERN
individuals of a population have an unpredictable distribution. This pattern is common in species that prefer solitary lives.
RANDOM PATTERN
Within a particular habitat, a population can be characterised by its _____
population size (N)
the number of individuals within a specific area or volume.
POPULATION DENSITY
are the two main characteristics used to describe a population.
POPULATION SIZE AND DENSITY
represents the maximum population size that a particular environment can support
CARRYING CAPACITY
First of the three major factors account for this population increase
humans developed the ability to expand into diverse new habitats and different climate zones.
Second of the three major factors account for this population increase
the emergence of early and modern agriculture allowed more people to be fed for each unit of land area farmed.
Third of the three major factors account for this population increase
the development of sanitation systems, antibiotics, and vaccines helped control infectious disease agents. As a result, death rates dropped sharply.
Altering Nature to Meet Our Needs
● Reduction of biodiversity
● Increasing use of the earth’s net primary productivity
● Increasing genetic resistance of pest species and
disease-causing bacteria
● Elimination of many natural predators
● Introduction of potentially harmful species into communities
● Using some renewable resources faster than they can be replenished
● Interfering with the earth’s chemical cycling and energy flow processes
● Relying mostly on polluting and climate-changing fossil fuels
WHAT FACTORS INFLUENCE THE SIZE OF HUMAN POPULATION?
increases because of births and immigration, decreases through deaths and emigration.
is the actual level of reproduction of a population per Individual, based on the number of live births that occur.
FERTILITY
also known as birth rate is the total number of live humans births per 1,000 population divided by the length of a period in years.
FERTILITY RATE
also known as death rate is a measure of the number of deaths in particular population, scaled to the size of that population per unit of time.
MORTALITY RATE
