3.1 Flashcards
What is natural selection?
The process that makes change possible in living things
What happens in natural selection?
Members of a species having certain characteristics that give them an advantage over other members of that species will be in better condition to mate. These characteristics will be passed on to their offspring.
What is adaptive radiation?
The change from a common ancestor into a number of different species that radiate out to inhabit different niches.
What is ecological succession?
The changes in the biotic characteristics in an area over time.
What are the two types of ecological succession?
Primary succession and secondary succession
What is primary succession?
The development of new life in areas where no organisms or soil previously existed.
What causes primary succession?
Retreating glaciers that scrape rock bare, or new rock can form when lava cools after a volcanic eruption.
How does primary succession begin?
When the wind or the rain carries spores of lichens to the rocks.
How do the lichens begin the process of primary succession?
Lichens get nutrients from breaking down the rocks with chemicals, this starts the formation of soil. When the lichens die and decay, they add nutrients to the soil.
What are pioneer species?
The term used to describe the lichens and other plants that are the first organisms to survive and reproduce in the area.
What do pioneer species do?
They decay to create more soil and provide food for other organisms introducing animals into the community.
When does primary succession end?
When a mature community forms.
What are climax communities?
Another word for a mature community, it continues to change over time.
What is secondary succession?
The reintroduction of life after a disturbance to an area that already has soil and was once the home of living organisms.
How does secondary succession begin?
Seeds may already be in the soil or will be blown in by wind or carried in by animals.
