BCB705 Biodiversity: Chapter2 - Evolution of Biodiversity

Table of Contents

1. THE INFINITE VARIETY: THE BEGINNING OF LIFE
2. BUILDING BODIES: INVERTEBRATES OF THE OCEANS
3. THE FIRST FORESTS
4. THE SWARMING HORDES
5. THE CONQUEST OF THE WATER AND THE BIRTH OF THE VERTEBRATES
6. THE INVASION OF THE LAND
7. A WATER-TIGHT SKIN AND THE SHELLED EGG
8. LORDS OF THE AIR
9. EGGS, POUCHES AND PLACENTAS
10. THEME AND VARIATION
    1. Dinosaur domination
    2. Various insect-eating mammals
    3. Shrews: Characteristics
    4. The Mole: Going underground
    5. Mole tunnels as traps
    6. Insectivores: A sticky tongue
    7. The pongolins
    8. Pongolins: Protection
    9. The armadillos: Characteristics
    10. Various species of armadillo
    11. Specialist ant-eaters: Lack of teeth
    12. Taking to the skies
    13. The Colugo: Gliding
    14. Bats: Flapping flight
    15. Bats: Saving weight
    16. Bats: Echo location
    17. Bats: Sonar equipment
    18. Methods for avoiding predation by bats
    19. Bats: Diet
    20. Meat-eating and fish-eating bats
    21. The vampire bats
    22. The Yellow-eared Bat
    23. Cetacean fossils
    24. Whales: An aquatic existence
    25. Whales: Adapting to swimming life
    26. The diet of whales and the sounds of dolphins
    27. Dolphins: A language
    28. Whales: A song
    29. Evolving communities
    30. Test Yourself
    31. Assignments
11. THE HUNTERS AND THE HUNTED
12. A LIFE IN THE TREES
13. THE COMPULSIVE COMMUNICATORS

THEME AND VARIATION

Classifying the Tree Shrew

In the forests of Borneo lives a small, furry, long tailed creature resembling a squirrel but called a Tree Shrew, (Tupaia glis). Unlike a squirrel this creature does not eat vegetable matter, but hunts small invertebrates. When first discovered its phylogenetic relationships with other animals was much debated and it was called a tree shrew based on its dental similarity (small, pointed unspecialized teeth) to insectivores. Some scientists suggested that the structure of its genitals indicated a relationship with marsupials, whereas others analysing the structure of its skull noted an exceptionally large brain, and proposed that it was a very distant ancestor of monkeys and apes. The debate is not over yet. Currently the balance of opinion has swung away from viewing the Tree Shrew as an ancestral monkey and favours classifying it within its own mammalian order (Scandentia) but recognizing that its closely allied to other primitive mammals such as shrews which are classified within the order Insectivora.

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Treeshrews

Madras Treeshrew (Anathana ellioti)

Scientific classification

Kingdom: Animalia

Phylum: Chordata

Class: Mammalia

Order: Scandentia
Wagner, 1855