B1 7 Theories Of Evolution Flashcards Preview

AQA GCSE Science > B1 7 Theories Of Evolution > Flashcards

Flashcards in B1 7 Theories Of Evolution Deck (9)
Loading flashcards...

What does the theory of evolution state?

The theory of evolution states that all species alive today (and many that are now extinct) evolved from simple life forms more than 3 billion years ago.


Through what does Darwin's theory of evolution take place?

Through natural selection.


What was Lamarck's theory?

Lamarck believed in inheritance of acquired characteristics. He believed that the way organisms behaved affected the phenotype of the offspring.


How does natural selection take place?

Eg: for a giraffe
There's a wide range of neck sizes for giraffes
Mutation in the gene causes some giraffes to have longer necks
Longer necked giraffes get more food
Outcompete shorter necked giraffes
Longer necked giraffes survive and reproduce
This passes the long neck gene to the offspring
Population of long necked giraffes increases


Why was Darwin's theory of evolution gradually accepted?

• Conflict with the widely held belief that God made all the animals and plants on earth
• Insufficient evidence
• No mechanism for explaining variety and inheritance at the time


How does natural selection work?

Natural selection works by selecting the organisms best adapted to a particular environment


What is classification?

Classification is the organisation of living things into groups according to their similarities


How does classification help us?

Classification helps us to understand evolutionary and ecological relationships


Classification Groups:

The biggest group is a kingdom
Animal and plant kingdoms
Kingdoms contain organisms with many differences but a few important similarities

The smallest group is a species
Members of the same species are very similar
A species is a group of organisms that can breed together and produce fertile offspring