Fossil Evidence
What is the main source of evidence for evolution?
Fossils
What is variation?
Differences between individuals of the same species
What do organisms compete for?
Resources
What is the process called where better adapted organisms survive and reproduce?
Natural selection
What is evolution?
The change in characteristics of a species over generations
What are fossils?
The remains or impressions of organisms from millions of years ago found in rocks
Which type of variation can be inherited?
Genetic/inherited variation
Name one resource animals compete for.
Food, water, shelter or mates
What is meant by fitness in evolution?
How well an organism survives and reproduces
Does evolution happen in one generation or many generations?
Many generations
Where are the oldest fossils found in rock layers?
Deeper in the rock
What is environmental variation caused by?
Differences in surroundings or lifestyle
Name one resource plants compete for.
Light, water, space or minerals
Why did black peppered moths become more common during the Industrial Revolution?
hey were better camouflaged against soot-covered trees
What caused some crickets to lose the ability to sing?
A mutation/change in the genome
What can fossils show scientists about species?
How species have changed over time
What is the difference between continuous and discontinuous variation?
Continuous can be any value in a range; discontinuous has limited categories
What is an adaptation?
A feature that helps an organism survive
What happens to advantageous alleles over generations?
They become more common
Why would birds with longer legs survive better when water levels rise?
They can reach more food in deeper water
How did the horse fossil record provide evidence for evolution?
It showed changes in the horse’s foot over time
Why is height considered both inherited and environmental variation?
It is affected by genes and the environment
Why are wide feet useful for animals living in deserts?
They stop the animal sinking into sand
Why did the number of lighter peppered moths increase after clean air legislation reduced industrial pollution?
Factories stopped pumping out so much black soot, which let the trees become light-coloured again. This meant the lighter peppered moths were better camouflaged so weren't eaten by predators, allowing them to survive and reproduce
Why is it incorrect to say organisms evolve because they “want” to survive?
Evolution happens through random variation and natural selection, not choice