McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved Chapter Seven: The Primates

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved The Primates What is our place in nature; that is, where do we fit in- from a scientifically objective point of view- in the world of living things? What are the characteristics of the primates- the group of animals of which we are a part? In what ways are humans like the other primates? In what ways are we unique?

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved The Primates Naming the Animals  “the fish of the sea,” “the fowl of the air,” “ every herb of the field,” “every beast of the earth.”

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved The Primates Linnaean Taxonomy  The idea that species shared similarities so struck Swedish botanist Carolus Linnaeus that he devised a taxonomic system to name and thus categorize all living creatures.

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McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved definitions Taxonomy  A classification based on similarities and differences. Notochord  The evolutionary precursor of the vertebral column. Phenetic Taxonomy  A classification system based on existing phenotypic features and adaptations. Taxa  Categories within a taxonomic classification.

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved The Primate Cladistics  A Linnaean taxonomy can be translated into an evolutionary tree.  Cladistics works the opposite way by starting with the evolutionary tree and placing organisms in taxonomic categories based on their order of branching regardless of how their present-day appearances and adaptations might assort them into groups.

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McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved definitions Cladistics  A classification system based on order of evolutionary branching rather than on present similarities and differences. Shared Derived Characteristics  Phenotypic features shared by two or more taxonomic groups that are derived from a common ancestor and that are not found in other groups.

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved definitions Bipedal  Walking on two legs. Quadrupedal  Walking on all four limbs.

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved The Primates What is a Primate?  Primates range from the very small, such as the mouse lemur of Madagascar, which weighs less than 3 ounces, to  the gigantic- Gigantopithecus, an extinct ape from China, Vietnam, and India that may have stood 12 feet tall and weighed over half a ton.

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McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved The Primates The Senses  Vision is the primates’ predominant sense. Most primates see in color, and all primates see in three dimensions. Movement  Unlike most mammals, primates have extremely flexible limbs, and their hands have the ability to grasp objects.

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved The Primates Reproduction  Mostly because of their large, complex brains and because of the importance of learning, young primates are dependent on adults and take a long time to mature. Intelligence  Of all land mammals, the primates have the largest relative brain sizes.

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved The Primates Behavior Patterns  Primates recognize individuals, and the individual primate holds a particular status relative to others in its group and to the group as a whole.

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved definitions Stereoscopic Vision  Three-dimensional vision: depth perception. Prehensile  Having the ability to grasp. Brachiation  Locomotion by swinging arm-over-arm. Opposability  The ability to touch the thumb, to the tips of the other fingers on the same hand.

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved definitions Postnatal Dependency  The period after birth during which offspring require the care of adults to survive. Intelligence  The relative ability of the brain to acquire, store, retrieve, and process information.

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved definitions Dominance Hierarchy  Individual differences among group members in terms of power, influence, and access to resources and mating. Grooming  Here, cleaning the fur of another animal, which promotes social cohesion.

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved The Primates A survey of the Living Primates  Prosimians The “pre-apes” represent the most primitive primates, that is, those that most closely resemble the earliest primates. There are 40 or so living species of prosimians.

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved The Primates  Anthropoids The anthropoid (“humanlike”) primates include monkeys, apes, and humans. All the New World platyrrhine primates are monkeys. The Old World catarrhine primates comprise monkeys, apes, and humans.

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McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved The Primates The Human Primate  Each of the 200 living primate species has its own unique expression of the primate adaptive strategy. Humans are no exception.

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved The Primates The Senses  Our senses are essentially the same as those of the anthropoid monkeys and the apes. Movement  Bipedalism is the characteristic that in broad evolutionary perspective defines the hominids.  We are the only primate that is habitually bipedal, and we have been for over 4 million years.

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved The Primates Reproduction  Although we are not the largest living primate, we have the longest period of postnatal dependency, and we take the longest time to mature. Intelligence  We are clearly the most intelligent primate, as we have defined that term.  We can store, retrieve, and process more information in more complex ways than all the other primates.

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved The Primates Behavior Patterns  Like most Old World primates, humans live in societies that are based on the collective conscious responses of a group of individuals.

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved definitions Estrus  In nonhuman primates, the period of female fertility or the signals indicating this condition. Symbolic  Here, a communication system that uses arbitrary but agreed-upon sounds and signs for meaning.

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved The Primates Summary  Taxonomy provides us with a way of naming and categorizing species so as to indicate their biological relationships.  The primates are one of nineteen order of mammals.  They may be characterized as being adapted to arboreal environments through manual dexterity, visual acuity, and intelligence.

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved Questions for further thought Birds evolved from a group of small bipedal dinosaurs. Cladistic analysis justifies lumping birds and dinosaurs into the same taxon. Some have taken this to mean that the caged parakeet in your living room is a dinosaur.

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved Questions for further thought What do you think of this? Is your dog, then, really a wolf? Are humans apes? How far can we take cladistic taxonomies in our popular nomenclature? Is there some inherent contradiction in cladistic taxonomies, or can you see a resolution?

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved Questions for further thought The primates come in a wide variety of shapes and sized and live in a broad range of environments. It’s tempting to attribute this adaptive success to the primates’ big brains. But it’s more complex than that. Thinking about the processes of evolution, speciation, and adaptive radiation, how would you account for the seeming success of the primate order?

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. All Rights Reserved Questions for further thought Given the problems that now beset the human species on the African continent-- AIDS and other diseases, poverty, civil unrest, and warfare – How can we justify expressing so much concern for the plight of the nonhuman primates, much less expending money and time on their behalf? Are these separate concerns that should be considered in order of priority? Or are they actually inextricably linked?