the variety of the earth’s species, the genes they contain, the ecosystems in which they live, and the ecosystem processes (such as energ flow and nutrient cycling) that sustain all life
What are the four components of biodiversity?
Functional, species, genetic, and ecosystem diversity
How many species have scientists identified so far?
4.8 million 270,000 –> plant species 45,00 –> vertebrate animal species
The process whereby earth’s life changes over time through changes in the genes of populations
What did Darwin and Wallace discover/observe?
The two scientists observed that organisms must constantly struggle to obtain enough food and other resources to survive and reproduce. Individuals in a population (with a specific advantage over other individuals are more likely to survie, reproduce, and have offsprin with similar survival skills. The advantage was due to a trait possessed by the individuals but not by others.
Happens when some individuals of a population have genetically based traits that enhance their ability to survive and produce offspring with the same traits
Change in the genetic characteristics of a population from one generation to another
Mineralized or petrified replicas of skeletons, bones, teeth, shells, leaves, and seeds impressed of such items found in rocks Cumulative body: (blank) record
KEY CONCEPT OF BIOLOGICAL EVOLUTION
POPULATIONS EVOLVE NOT INDIVIDUALS! (Only thing I remember from AP Bio :D)
Random changes in the structure or number of DNA molecules in a cell that can be inherited by offspring
Any heritable trait that enables an organism to survive through natural selection and to reproduce more than other individuals under prevailing environmental conditions
The ability of one or more organisms in a population to tolerate a chemical designed to kill it
Process of biological evolution by natural selection
1. Genes mutate 2. Individuals are selected 3. Populations evolve that are better adapted to survive and reproduce under existing environmental conditions
When environmental conditions change, a population of a species face three possible futures:
1. adapt to new conditions 2. migrate to a new area 3. become extinct
Huge flows of molten rock within the earth’s interior break its surface into a series of gigantic solid plates
Two species arise from one. A new species is formed when some members of a population have evolved to the point when they can no longer breed with other members to produce fertile offspring.
Occurs when different groups of the same population of a species become physically isolated from one another for long periods
Long-term geographic separation of members of a particular sexually reproducing species
A situation in which a species ceases to exist
Species that are only found in one area, especially vulnerable to extinction. They exist on islands and in other unique small areas, especially in tropical rain forests where most species are highly specialized.
Normal extinction of various species as a result of changes in local environmental conditions
Average annual background extinction rate
One to five species for each million species on the earth
A significant rise in extinction rates above the background level
The number of different species contained combined with the relative abundance of individuals within each of those species in a given area
Number of different species contained in a community
Relative abundance of individuals within each of the species in a community
Species richness seems to increase the
productivity and stability or sustainibility of an ecosystem.
A species’ way of living in a community and includes everything that affects its way of survival and reproduction, such as how much water and sunlight it needs, how much space it requires, and the temperatures it can tolerate
Those species that normally live and thrive in a particular ecosystem
Other species that migrate into or are deliberately or accidentally introduced into an ecosystem (wild African bees)
Species that provide early warnings of damage to a community or an ecosystem (presence/absence of trout, butterflies, birds, canaries)
Have a large effect on the types and abundances of other species in an ecosystem (alligators, wolves, lions, sharks, leopards)
Play a major role in shaping communities by creating and enhancing their habitats in ways that benefit other species (beavers, elephants)
For every shark that injures a person, we kill at least