unit 2 apes google drive notes Flashcards
Biodiversity
Number and variety of organisms found within a specified geographic region or ecosystem
Variability among living organisms (within/between species/ecosystems)
bioD in all forms is the result of evolution
Evolution
Change in a population’s genetic composition overtime
Speciation
how new species are formed
Evolutionary fitness
individual organisms better adapted for their environment live and reproduce → their genes are part of their population’s next generation
Species
group of organisms that are capable of breeding with one another
Natural selection
habitat selects certain organisms to live and reproduce and others die
-Beneficial characteristics that can be inherited are passed down to the next generation
-Unfavorable characteristics that can be inherited become less common in population
-Nat selection acts upon whole pop, not on an individual organism
Gene pool changes
Genetic drift
accumulation of changes in the frequency of alleles (versions of a gene) over time due to sampling errors (changes that occur as a result of random chance)
Microevolution
when a population displays small scale changes over a relatively short period of time
Macroevolution:
large-scale patterns of evolution within biological organisms over a long period of time
Extinction
species can’t adapt quickly enough tot env change and all members of the species die
Biological extinction
true extermination of a species → there are no individuals of this species left on the planet
Ecological extinction
there are so few individuals of a species that they can no longer perform its ecological function
Commercial/economic extincion
few individuals exist but effort needed to locate and harvest them is not worth the expense
Keystone species
-single species that maintains biotic balance in a community
-Presence contributes to ecosystems diversity
-Extinction of keystone species would lead to extinction of other forms of life
Indicator species
-used as standard to eval health of an ecosystem
-More sensitive to biological changes within their ecosystems than other species → used as an early warning sys to detect dangerous changes to a community