Defining Evolution
A group of organisms that can successfully interbreed and produce viable, fertile offspring.
What is a species?
These types of barriers prevent successful mating or fertilization before a zygote is ever formed.
What are prezygotic barriers?
A single cell formed when an egg and sperm fuse together during fertilization.
What is a zygote?
This pattern occurs when a number of different species arise from one common ancestor.
What is divergent evolution?
The permanent loss of all individuals of a species.
What is extinction?
The process of forming a new species from a pre-existing one.
What is speciation?
Isolation that occurs because two species have different courtship behaviors or mating rituals.
What is behavioral isolation?
Speciation caused by a population becoming geographically isolated from one another.
What is allopatric speciation?
A type of divergent evolution that happens over a very short period of time.
What is adaptive radiation?
This percentage of all species that have ever lived on Earth is now extinct.
What is more than 99%?
This pattern of evolution is characterized by slow, constant changes over a very long period.
What is gradualism?
This type of isolation happens when two species mate at different times of the day or year.
What is temporal isolation?
Speciation that occurs without geographic isolation, often due to chromosomal errors in plants.
What is sympatric speciation?
This occurs when unrelated species evolve similar characteristics because they live in similar environments.
What is convergent evolution?
An event where over 50% of species die out in a relatively short period.
What is mass extinction?
This pattern involves bursts of evolutionary change followed by long periods of stability.
What is punctuated equilibrium?
Isolation occurring when two species prefer different environments and are unlikely to encounter each other in the wild.
What is habitat isolation?
A healthy hybrid produced by a male donkey and a female horse that is unable to have its own offspring.
What is a mule?
According to the notes, bears, monkeys, and elephants all evolved from this type of common ancestor.
What is an ancestral mammal?
This type of extinction occurs at a slow rate and can be caused by gradual changes in climate or natural disasters.
What is gradual extinction?
Evolution occurs when two different populations form a specialized relationship and change in response to each other, such as flowers and their pollinators.
What is coevolution?
This barrier occurs when the reproductive structures or bodies of two species are not compatible for mating.
What is mechanical isolation?
The condition of having multiple sets of chromosomes, which can lead to sympatric speciation in plants but is often lethal in animals.
What is polyploidy?
An example of convergent evolution where birds, bats, and even some reptiles all share this ability despite being unrelated.
What is flight?
The theory for the mass extinction 65 million years ago that wiped out the dinosaurs involves these two possible causes.
What are a meteor impact or huge volcanic eruptions?