The fossil record shows that about four millions years ago the vast majority of species that
have existed are now extinct. In order for an animal to be classified as extinct, it must not have been seen in the past 50 years. Background (natural) extinction refers to the naturally occurring extinction of a species. If a species can not succeed in adapting to its surroundings it eventually becomes extinct. In mass extinctions, large numbers of species become extinct each year for tens of thousands to millions of years. Each species will have different reasons for becoming extinct; these may include lack of food, climate change, diseases/epidemics, etc.
1. How many mass extinctions have taken place in the past 500 million years? What were two of these species, (besides dinosaurs)?
2. Take two of these species and classify them using today's classifications.
3. Give two ways that humans unintentionally contribute to extinctions.
1. There are considered to be five mass extinctions in the past 500 million years. Ginkgos were plants and were one species that were part of a mass extinction. As well the Saber-toothed cat was also involved in a mass extinction.
ReplyDelete2. Kingdom: Plantae
Division: Ginkgophyta
Class: Ginkgoopsida
Order: Ginkgoales
Family: Ginkgoaceae
Genus: Ginkgo
Kingdom:Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Felidae
Subfamily: Machairodontinae
Genus: Smilodon
3. One way is hunting a specialist predator's prey animals to extinction. Another way is bringing a non-native predatory animal into the environment