Extinction Flashcards
1
Q
From all the species that appeared on Earth since Cambrian (544mya), how much aare extinct ? What are the 2 exceptions ?
A
99%. Lingula and horseshoe crabs that are considered as living fossils because they haven’t changed since a long period of time.
2
Q
What are the [2] types of extinction ?
A
- Uniform or background extinction
2. Catastrophic or mass extinction
3
Q
Define uniform extinction.
A
It is a gradual loss of species, mostextinctions happened like that. ACcording to The Red Queen (Leight Van Valen). species need to evolve quickly to adapt to environmental changes and competition.
4
Q
What are the 5 mass extinctions ?
A
Ordovician Devonian Permian Triassis Cretaceous
They all mark the end of different periods
