5.1 Flashcards
What is evolution?
The process of cumulative change in the heritable characteristics of a population
What is speciation?
The formation of a new species this can occur if enough changes accumulate that two groups of a population are no longer able to reproduce
What DNA evidence is there to support evolution?
Fossils, animal breeding and homologous structures
What evidence do fossils provide for evolution?
- Life on earth 500 million years ago was very different than today
- Although earth has been covered with oceans for over 3 billion years, fish fossils have only been found for the last 500 million years
- Although the top predators today are mammals, none of them existed 100 million years ago
What are the differences between natural and artificial selection?
Natural selection: individuals most fit for their environment survive to reproduce so their genes pass on
Artificial Selection:individuals with desired characteristics are chosen by humans to reproduce and pass on their genes
What are homologous structures?
Similar structures found in dissimilar species
What is speciation?
When an evolving population changes is much that members of the population are unable to produce offspring with the original population
What is species divergence?
Two population of a species have diverged to become different species
What is adaptive radiation?
When many similar but distinct species evolve from a single species
What is the process of adaptive radiation?
- Heritable variation within a population allow certain members to exploit are slightly different niche in a more successful way.
- Natural selection, eliminates individuals who aren’t well suited for that environment or niche.
- Summoned a barrier prevents members of different members from breeding
- Species divergence
What is a reason for speciation between Galapagos Finches?
Different food sources on the islands provided different niches, which caused different species with different beaks to develop
