B1- Evolution Flashcards
What is Darwin’s theory on evolution?
Charles Darwin’s theory states that evolution takes place by a process of natural selection.
In simple terms: Variation➡️Best adapted survive➡️Reproduce➡️Pass on genes.
Why was Darwin’s theory only gradually accepted?
- The theory challenged the idea that God made all animals and plants that live on earth (Creation).
- Many scientists weren’t convinced because they didn’t think there was enough evidence.
- Mechanism of inheritance not yet known.
Define evolution.
Evolution is the gradual change in a species over a long period of time.
How do we know that animals have evolved from simpler forms?
Fossils were found, which keep imprints. The fossils are different to modern animals, but carry similarities suggesting they have changed and adapted over time.
Describe the generic mark scheme for evolution.
- Mutation causes variation within a species.
- The organisms with characteristics better adapted to the environment are more likely to survive.
- The organisms which survive are more likely to breed successfully, thus passing on the genes for the desired characteristics to the offspring.
*Evolution happens over a very long time period*
What was Lamark’s theory on evolution?
Lamark suggested a theory which stated that characteristics developed over an organism’s lifetime can be passed onto the next generation.
E.g: A giraffe’s neck was stretched out over a lifetime and this long neck theory was passed on to offspring This theory has been discredited.