Chapter+4+Questions

=﻿Chapter 4 Questions-=

1. New Zealand's biodiversity was formed from isolation of small islands. The high percentage of endemic species make New Zealand’s native biodiversity both special and highly vulnerable. After splitting from other continents 80 million years ago, evolution on land took an eccentric course, leading to plants, animals and ecosystems so distinctive that New Zealand has been described as the closest scientists will come to studying life on another planet. From then, until the arrival of humans, it had the longest period of isolation of any non-polar landmass on earth. Around the New Zealand shores is where many new species have shown up by humans bringing them or by them evolving.

2. As recently as 2008, fossils have been found on a beach in New Zealand showing the bones of some birds. They were found along a remote stretch of beach on the Chatham Islands. The fossils possibly show four new species of seabirds from the late Cretaceous Period around 65 million years ago. They fossils found show that the present day cormorant birds could have evolved from these birds found. Some of the birds found look very tall and slender. It was very rare that fossils of birds were found becauase bird bones are very fragile.

3. New Zealand climate influences natural selection in several examples. Because of the warm climate, animals would be smaller because they don't have to survive cold temperatures. Also, animals won't have thick coats to keep them warm. Since it is so warm and so many birds live on the beach, many birds have feathers that are tan or near the color of sand such as the famous New Zealand bird the Kiwi. Because in the center of the island there is colder weather, the animals that live there would have thicker coats and although may be close to the same species as those in the warmer area, since they have both changed to accomodate where they are living they might not be able to reproduce.

4. There have been several large extinction recorded in New Zealand. 444 million years ago two big extinctions happened close to each other. The cause of these are still uncertain. 251 million years ago the largest recorded extinction occured. 96% of all marine species, and 70% of terrestrial species went extinct possibly because of a large climate change or large asteroid impact. 65 million years ago 50% of species became extinct due to a large asteroid impact. Presently however, because of human activity there is a potential for 50% of the species to become extinct.

5. Some of the main indicator species of New Zealand are the short-tailed bat; dactylanthus (a flowering plant); and two bird species, the möhua (yellowhead) and kökako. Some keystone species are Seabirds, Rats, Reptiles and Invertebrates. Some foundation species are those whose actions benefit other species. Such as the sea anename and the clown fish. An example of a specialist species in new zealand is the kiwi, while they can eat worms they prefer mostly meat. Examples of nonnative species are pretty much an animals other than birds. Originally, there were only birds on the island and because of evolution and humans brings some animals over, other animals have started living in the island.