Evolution Flashcards
What is the theory of evolution?
That more than 3 billion years ago, life on Earth began as simple organisms from which all the more complex organisms evolved
What similarity do all plants have?
They make their own food (by photosynthesis) and are fixed in the ground
What similarity do all animals have?
Move about the place and can’t make their own food
What similarity do all microorganisms have?
Different to plants and animals (eg, bacteria are single celled)
What do species with similar characteristics have?
Similar genes because they share a recent common ancestor, s they’re closely related.
What do evolutionary trees show?
Common ancestors and relationships between organisms.
Ecological relationships: What might it mean if 2 species, in the same environment have similar characteristics?
They might be in competition
Ecological relationships: What might it mean if 2 species, in the same environment have very different characteristics?
Can show a predator-prey relationship
Who came up with an explanation for evolution? Who was it?
Charles Darwin came up with the idea for natural selection
Explain natural selection (3)
1) Individuals within a species show variation because of the differences in their genes
2) Individuals with characteristics that make them better adapted to the environment have a better chance of survival and so are more likely to breed successfully.
3) So, the genes that are responsible for the useful characteristics are more likely to be passed on to the next generation
Evolution can occur due to mutations. Explain
1) Most of the time mutations have no effect, but occasionally thy can be beneficial by producing a useful characteristic. This characteristic may give the organism a better chance of surviving and reproducing
2) If so, the beneficial muation is more likely to be passed on to future generations by natural selection
4) Over time, the beneficial mutation will accumulate in a populaion
What is a mutation?
A change in an organism’s DNA
Why did people not agree with Darwin? (Religious)
1) It went against common religious beliefs about how life on earth developed – it wad the 1st plausible explanation for our own existence without the need for a creator
Why did people not agree with Darwin? (Evidence)
2) Darwin couldn’t give a good explanation for why these new, useful characteristics appeared or exactly how individual organisms passed on their beneficial characteristics to their offspring
3) There wasn’t enough evidence to convince most scientists because not many other studies have been done into how organisms change over time
Describe Lamarck’s theory
1) He argues that if a characteristic was used a lot by an organisms then it would become more developed during its lifetime
2) He believed that these acquired characteristics would be passed on to the next generation
