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
11. THE HUNTERS AND THE HUNTED
12. A LIFE IN THE TREES
    1. An ancestor to the primates
    2. The Ring-tailed lemur
    3. The male Ring-tailed lemur: The use of scent
    4. The Ring-tail: Time in trees
    5. Infant lemurs
    6. Sifakas
    7. The Indris
    8. The nocturnal lemurs
    9. The Aye-aye
    10. Competing with monkeys
    11. The Loris: Sign posting
    12. The Tarsier
    13. Monkeys: Sight is key
    14. Monkeys: The use of colourful displays and sound
    15. Monkeys: Anatomical features
    16. Scent in communication
    17. Marmosets
    18. Adapting to great weight
    19. Prehensile tails
    20. The adaptable Macaque monkey
    21. Macaques: Behavioural patterns
    22. Bi-pedalism
    23. The Orang Utan
    24. The Orang Utan: Supporting the great weight
    25. The Orang Utan: It's repertoire
    26. The Orang Utan: Solitude and size
    27. The Gibbons
    28. Gibbons: Family life
    29. Gorillas: The use of the arms
    30. Gorillas: Family groups
    31. Similarities between Gorillas and humans
    32. Gorillas: A placid existence
    33. Chimpanzees: Their diet
    34. Chimpanzees: Maternal support
    35. Chimpanzees: A friendly gesture
    36. Chimpanzees: The toolmakers
    37. New situations lead to greater change
    38. Test yourself
    39. Assignments
13. THE COMPULSIVE COMMUNICATORS

Bi-pedalism

However, one of the most significant behavioural patterns that occurred in the evolving primates was bipedalism. Moving on to two legs, would free the upper limbs, and particularly the hands to explore objects which eventually lead to the use of tools by ape-men. To trace the origins of these animals, we have to go back some thirty million years.

At that time, one group of lower primates were increasing in size. This brought a change in the way they moved through the trees. Instead of balancing on the top of a branch and running along it, they began to swing along beneath it. Swinging successfully involves physical changes. Arms lengthened, a tail that was used for balancing, disappeared; and the musculature and skeleton of the body changed so that the backbone and abdomen was supported in vertical rather than a horizontal plane. Those changes produced the members of the Family Hominidae and include Gibbons (Hylobates); and the Great Apes which includes the Orang-Utan (Pongo pygmaeus) from Asia, the Gorilla (Gorilla gorilla), the Chimpanzee (Pan troglodytes), the Bonobo (Pan paniscus) from Africa and Humans (Homo sapiens).

Walking gibbon