Organisms changing through time Flashcards
What is a fossil?
The remains or traces left of organisms that once lived
Name the four types of fossil formation.
- Mineral replacement
- Mummification
- Moulds and Casts
- Trace Fossils
What is mummification?
A ‘mummy’ forms when conditions are too cold/acidic for soft tissue to decay
What is mineral replacement?
Mineral replacements occur when the hard parts of organisms are replaced by minerals over time
What are trace fossils?
Traces - footprints, burrows, foot tracks - left in soil.
What is mould and cast formation?
As an organism decays the shape left in the sediment is filled with other minerals making a cast. The shape in the sediment is a mould
Why would you be unlikely to find a fossil of an ancient earth worm?
Soft bodied organisms may decay completely before they can become fossils
Which important biological theory has fossil evidence been used to support?
The theory of evolution
The theory of organisms changing over time is called…?
Evolution
Explain how organisms change over time using the following words: random mutation, variation, advantage, survive, reproduce, genes, natural selection.
There is a random mutation which causes a variation that must be an advantage that helps the organism survive. The organism reproduces and passes on the genes to the offspring which is known as natural selection
Name 4 physical changes to the environment that may cause species to go extinct
Any From: Volcanic Eruptions, Earthquakes, Disease, Predators, Competition
What is the name we use for large numbers of species go extinct?
Mass Extinction
Name the two main causes of mass extinction
Drastic Temperature change and Rise in sea level
What is meant by rapid speciation?
One species may evolve over time into a new species as conditions change
What can cause rapid speciation?
Natural Selection
