Natural Selection Flashcards
(18 cards)
Define evolution
The change in form and behavior of organisms between generations
What did Plato belief about understanding the word?
To understand the world you have to imagine what an ideal world would look like.
What did Aristotle belief about understanding the world?
To understand the world you need to experience it.
What was Aristotle’s belief about the relationship of organisms to each other?
The ladder of life:
- species are fixed in time
- there are primitive and advanced organisms laid out in a hierarchy
What did George Cuvier add to understanding about evolution?
- fossils change, looking more different to life today, the deeper you dig
- life must have changed overtime (evolution)
- organisms disappear (extinction)
What is catastrophism?
The belief that the Earth has been shaped by catastrophic events that also cause extinctions.
What was Lamarks theory of evolution?
- species don’t become extinct
- overtime they become new species
- offspring inherit characteristics from their parents
Separate lineages improve from generation to generation.
How old is the Earth?
4.5 billion years
What were the factors that brought Darwin to his theory of Natural Selection?
- read ‘The Principles of Geology’ by Lyle, so had knowledge of fossils
- knew the world was very old (allowing for change to occur slowly)
- observed the variation in shape of finches beaks in the Galapagos islands
- concluded that the finches may have had a common ancestor
What is the Darwinism theory?
All species of organisms arise and develop through the natural selection of small, inherited variations that increase the individual’s ability to compete, survive, and reproduce.
What is Malthusianism?
The idea that population growth is potentially exponential while the growth of the food supply is linear
Why must there be a struggle for existence?
- All species could potentially increase their population size exponentially
- But most populations are normally stable in size
Why do organisms characteristics fit well with their environment?
- Individuals in a population vary in their characters
- Much of this variation is heritable
Individuals who’s inherited characteristics fit well with their environment will leave more offspring than less ‘fit’ individuals
Define Natural Selection?
The differential reproductive success of different phenotypes.
What is Neo-Darwinism?
- advantageous variations inherited genetically
- recombination and mutation provides the variation for selection to work on
Define adaptation.
A trait that enables an organism to survive and reproduce better than if it lacked the trait.
Define fitness.
A measure of individual success in evolutionary terms.
The number of genes.
Define function.
The survival benefit of an adaptation, e.g. the function of colour is camouflage.
