Speciation (additional) Flashcards
Name a hard part of an animal which will not decay easily
bones, teeth, shells or claws
Why are some fossils destroyed over time?
geological activity e.g. volcanoes
How can a new predator cause extinction of a species?
kills and eats all of the species
Suggest a factor which could have caused dinosaurs to die out
a disease could have killed them all
How do populations become isolated? (3)
islands break away from mainland, rivers separate land, mountain ranges
What is meant by genetic variation?
wide range of alleles that control the characteristics of a population
What is a fossil?
dead remains of plants and animals from a long time ago
What are the different forms of fossils? (5)
1-hard parts of animals 2-imprints in soft rock 3-whole organisms 4-hard parts replaced with mineral ions 5-POOP
What do fossils teach us?
how organisms change over time
What is meant by extinction?
a species that once existed has completely died out
What may have caused a species to become extinct? (4)
1-natural disaster
2-predators
3-disease
4-new competitor
How do new species arise?
existing species being isolated from the rest
What is meant by speciation?
the formation of new species
