Evolution Flashcards
Who proposed the theory of evolution by natural selection?
Charles Darwin.
What did Darwin observe about phenotypic variation within species?
Organisms within a species exhibit wide variation in their characteristics (phenotypic variation).
What did Darwin conclude about organisms with suitable characteristics for the environment?
They are more successful competitors, more likely to survive, reproduce, and pass on their genes to offspring.
What did Darwin conclude happens to organisms that are less well adapted?
They are less likely to survive and reproduce, therefore less likely to pass on genes to offspring
What is the outcome of natural selection over time?
Beneficial characteristics become more common in the population, leading to evolutionary change within the species.
What were some limitations of Darwin’s theory of evolution?
Darwin couldn’t explain how new characteristics appeared or how beneficial adaptations were passed on to offspring.
How did the discovery of genetics support Darwin’s idea?
Genetics explained how organisms pass on beneficial characteristics via genes
What role do genetic variants play in causing the devolpment of more suitable phenotypes?
Genetic variants give rise to phenotypes that are suited to the environment.
What evidence from fossils supports the theory of evolution?
The fossil record shows gradual changes in organisms over time
How does the evolution of antibiotic resistance in bacteria support the theory of natural selection?
Bacteria evolving antibiotic resistance demonstrates the process of natural selection in action.
What is speciation?
-When over a long period of time, the phenotype of organisms changes so much because of natural selection that a completely new species is formed.
-Speciation happens when populations of the same species change enough to become reproductively isolated — this means that they can’t interbreed to produce fertile offspring.
Why do species become extinct?
-when the environment changes to quickly e.g. destruction of a habitat
-a new predator kills them all e.g. humans hunting them
- a new disease kills them all
-a new species outcompete them for food
- a catastrophic event happens that kills them all (e.g. a volcanic eruption or collision with an asteroid)
Explain how the process of natural selection leads to an organism evolving:
•RANDOM MUTATIONS lead to VARIATION in a population. This give some individuals an ADVANTAGE so they will SURVIVE,REPRODUCE and pass on their GENES to their offspring
•overtime the population will have the advantageous characteristics
