Week 8 Flashcards
(24 cards)
What is evolution?
Change in the heritable characteristics of biological populations over generations
All life on earth descended from a common ancestor
What are the outcomes of evolution?
- Changes that generate new species
- Morphological changes within species
- Differences between sexes
- Relationships between species
- Extremely diverse forms of life
Define macroevolution.
Broad scale evolutionary changes over paleontological time
Define microevolution.
Change in genetic frequency in a population
What are the three requirements of natural selection?
- Heritable phenotypic variation within populations
- More offspring are produced than can survive
- Individuals with favourable traits produce more offspring
What does ‘survival of the fittest’ mean?
Competition for resources where individuals with favourable traits survive and reproduce
What trait is advantageous to tortoises observed by Darwin?
Longer necks
What environmental characteristic led to the selection for longer necks in tortoises?
Drought conditions resulting in fewer leaves available
What is required for natural selection to occur?
- Heritable phenotypic variation within populations
- Competition for resources
- Differential survival and reproduction
What is fitness in the context of evolution?
Survival and production of offspring
Fill in the blank: Genetic diversity is caused by _______.
[Mutations, Sexual reproduction, Gene flow]
What are mutations?
Errors during DNA replication that can impact phenotypes
Define adaptation.
Heritable trait that helps an organism survive and reproduce in its environment
What is divergent evolution?
Two species with a common ancestor evolve different adaptations
What is convergent evolution?
Similar phenotypes evolve independently in distantly related species
What is the difference between natural and artificial selection?
Natural selection occurs without human intervention; artificial selection involves human choice in breeding
What are homologous structures?
Structures inherited and modified from a common ancestor
What do all vertebrate embryos have at some point in their development?
Gill slits and tails
What is biogeography?
Development and presence of species based on location
What does molecular biology reveal about evolution?
DNA is universal, and relatedness in DNA reflects evolutionary relatedness
True or False: Evolution is just a theory.
False
True or False: Individuals evolve.
False
True or False: Evolution explains the origin of life.
False
True or False: Organisms evolved on purpose.
False
