Paleontology Flashcards
How are fossils formed?
animal and plant remains are preserved in rocks
over long periods of time, sediment is deposited on the earth to form strata of rock
different layers correspond to different geological eras
How does the age of samples found provide evidence for evolution?
simpler organisms such as bacteria and simple algae are found in the oldest rocks
while more complex organisms are found in more recent rocks
this supports the theroy that simple life forms gradually more complex over time
How does the sequence of animals and plants being found support evolution?
supports ecological links
plant fossils appear before animal fossils, which is consistent with the fact that animals require plants to survive
How does the structure of fossils support evolution?
shows how closely related animals come from a related ancestor with similar anatomies
spans millions of years
shows links between extinct and extant organisms
Why is the fossil record not complete?
many soft bodied organisms decompose quickly before they have a chance to fossilise
conditions are not present
destroyed by volcanoes and movements
others lie undiscovered
