Chapter 15 - Orgins Of Biological Diversity Flashcards
Speciation?
the origin of new species
Biological Species Concept?
defines a species as a population or group of populations whose members have the ability to breed with one another in nature and produce fertile offspring
Macroevolution?
major evolutionary changes
(ex : speciation or extinction)
(Darwin thought was a gradual process)
Reproductive Isolation?
the inability of different species to interbreed
ex : different mating sequences, behaviors of attracting mates
Geographic Isolation?
an event that can lead to speciation that occurs when a population becomes separated from the rest of the species due to geographic change or movement to an isolated place.
______ occurs if the adaptations lead to _______.
Speciation ;
Reproductive Isolation
Adaptive Radiation?
process when populations of a species evolve adaptations to a variety of environments to form diverse, new species.
Punctuated Equilibrium?
evolution occurs with long periods of little change with shorter periods of rapid change.
Embryology?
the study of how organisms develop from fertilized eggs to fully formed organisms.
A fossils ______ in layers of sedimentary rock reveals it’s ____ compared to other fossils. This shows the fossil’s ______ age.
placement ;
age;
relative
Radiometric Dating?
method used to determine absolute age based on the amount of radioactive isotopes in a fossil.
What do scientists use to calculate absolute age?
the fossils half life, which is the time it takes for 50% of the original sample to decay.
The Geologic Time Scale? Name the 4 Eras?
organizes Earth's history into 4 eras : Precambrian Paleozoic Mesozoic Cenozoic
The boundaries between Earth’s eras are marked in the fossil record by __________.
major changes in life forms
can be explained by continental drift
Continental Drift?
the movement of Earth’s continents on large plates of crust
ex : “supercontinent” formed called Pangaea
