Evolution

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Evolution

• Principles of Natural Selection
• Contributors
• Related Terms

2
Evolution

• Scientific way to explain how species appear and
  change over time
• Based on testable ideas
• Evidence for evolution is so overwhelming that
  most scientist accept it as fact

3
Creationism

• A common part of all cultures is a mythology that
  explains how humans came about on earth
• Based on faith and religious doctrine
• Mythologies and creation stories differ from
  evolution, which relies upon scientific language

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Carolus Linnaeus (1707-1778)

• Classified plants and animals in a systema
  naturae
• Systema naturae placed humans in the same order
  (Primates) as apes and monkeys
• Hierarchical classification scheme (kingdom,
  class, order, genus, and species) provided
  framework for idea that human, apes, and monkeys
  had a common ancestor

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Jean Baptiste Lamarck (1744-1829)

• Proposed that acquired characteristics could be
  inherited and therefore species could evolve
• Individuals who in their lifetime developed
  characteristics helpful to survival would pass
  those characteristics on to future generations
• Classic example Long neck of giraffe as the
  result of successive generations of giraffes
  stretching their necks to reach the high leaves

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Charles Darwin (1809-1882)

• Read the work of Lyell (suggested that the earth
  is constantly being shaped and reshaped by
  natural forces that have operated over a vast
  stretch of time) before and during famous Beagle
  voyage
• Rejected the notion that each species was created
  at one time in a fixed form
• Wrote Origin of Species by Means of Natural
  Selection

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Natural SelectionDefinition3 Principles
Necessary

• Natural Selection
• the main process that increases the frequency of
  adaptive traits through time.
• 3 Principles
• Variation every species is composed of a great
  variety of individuals, some which are better
  adapted to their environment than others
• Heritability offspring inherit traits from their
  parents, at least to some degree
• Differential reproductive SUCCESS since better
  adapted individuals generally produce more
  offspring over the generations than the poorer
  adapted, the frequency of adaptive traits
  gradually increases in subsequent generations

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Gregor Mendel (1822-1884)

• Pioneered studies in science of genetics and
  heredity by breeding several varieties of pea
  plants
• Significance
• Explains how variation arises and present basic
  laws of heredity
• Individual level Illustrates how parents pass
  traits on to their offspring
• Population level reveals evolutionary processes
  and how it affects patterns of biodiversity on
  earth

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Heredity Terms

• Dominant allele of a gene pair that is always
  phenotypically expressed in the heterozygous form
• Recessive allele phenotypically suppressed in
  the heterozygous form and expressed only in the
  homozygous form
• Genotype genetic makeup
• Phenotype observable appearance
• Mutation a change in the DNA sequence, producing
  an altered gene

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Georges Cuvier (1769-1832)

• Leading opponent of evolution
• Theory of catastrophism proposed that a quick
  series of catastrophes accounted for changes in
  the earth and fossil record
• Invoked to help explain the disappearance of
  certain species, while still being faithful to
  religious doctrine

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Behavioral Ecology

• Study of how all kinds of behavior may be related
  to the environment.
• The theoretical orientation involves the
  application of biological evolutionary principles
  to the behavior (including social) of animals
  (including humans)

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Journey of Man

• Spencer Wells geneticist
• Y-Chromosome
• Skin Pigmentation
• San Bushmen
• Hunting
• Language
• Skin color
• Chukchi adaptive example

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Primatology 3 Goals

• Primate Adaptation To understand how different
  primates have adapted anatomically and
  behaviorally to their environments. Results may
  help us understand the behavior and evolution of
  human primates.
• Primate Evolution Differing adaptations of
  living primates may also suggest why certain
  divergences occurred in primate evolution
• Primate Preservation
• Key Example Jane Goodall
• Study of Chimpanzee behavior and preservation
• Language
• Tool Making

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Classification of Primates

• Prosiminians
• Anthropoids

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Prosiminians

• Resemble other mammals more than anthropoids
• Depend more on smell for information
• More mobile ears, whiskers, longer snouts,
  relatively fixed facial expression
• Similar to other primates in that they have
  grasping hands, stereoscopic vision, enlarged
  visual centers in brain
• Examples Lemurs, lorises, tarsiers

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Anthropoids

• Humans, apes, monkeys
• Rounded braincases
• Reduced, non-mobile outer ears
• Relatively small, flat faces instead of muzzles
• Dextrous hands
• Examples New world monkeys, old world monkeys,
  lesser ages (gibbons, siamangs), great apes
  (orangutans, gorillas, chimpanzees), humans

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Anthropoids are divided into 3 groups

• New World Monkeys, Old World Monkeys, and
  Hominoids

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New World Monkeys (Platyrrhines)

• Found in South and Central America
• Shape of the nose and position of the nostrils
  (broad, flat-bridge noses, with nostrils facing
  outward)
• Have 3 premolars
• Prehensile (grasping) tails
• Completely arboreal vary in size of their
  groups
• Food ranges from insects to nectar and sap to
  fruit and leaves

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Old World Monkeys (Catarrhines)

• Found in Africa, Asia, and Europe
• Shape of the nose and position of the
  nostrils(Narrow noses with nostrils facing
  downward)
• Have same number of teeth as apes and humans
• Have 2 premolars
• Do not have prehensile tails
• Live in great variety of habitats

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Hominoids

• Brains of relatively large, especially the areas
  of the cerebral cortex
• Have fairly long arms, short, broad trunks and no
  tails
• Have greater range of movement because of their
  wrist, elbow and shoulder joints
• Dental features are related to diets
• Include gibbons and siamangs, orangutans,
  chimpanzees and hominids

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Hominoids

• Hominoids (under the suborder anthropoids) that
  includes both apes and humans.
• Classified into 3 families
• lesser apes (gibbons and siamangs)
• greater apes (orangutans, gorillas, and
  chimpanzees)
• hominids (humans) group of hominoids consisting
  of humans and their direct ancestors

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Primates

• Primatology
• Primate Characteristics

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List and describe the physical traits that set
primates apart from the other mammals.

• Complex of all the following traits is unique to
  primates
• Skeletal features reflect arboreal (tree living)
  existence
• Grasping feet
• Flexible forelimb
• Clavicle or collarbone freedom of movement-
  throw spears, turn doorknob
• Prehensile grasping hands
• Opposable thumbs precise grabbing, can touch all
  other fingers
• Stereoscopic vision eyes are directed forward
  rather than sideways (allows for focus on object
  with both eyes at once)
• Relatively larger portion of brain devoted to
  vision rather than smell
• Relatively large brain to body size ratio
• Mature slower and longer life span
• Reproductive Organs
• Females have 2 nipples
• Uterus for single fetus
• Quality over quantity
• Infants well developed at birth

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List and describe the social traits that set
primates apart from other mammals.

• Diurnal-active during the day
• Learning from others
• Dependency and development in social context
• More time to observe and learn complex behaviors
• Play
• Peer behavior, racing through trees (help escape
  predators)

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What traits distinguish humans from other
primates?

• Bipedalism humans are only primates to
  consistently walk erect on two feet
• Heads balance on spinal column
• Dish shaped pelvis, lumbar curve in spine,
  straight lower limbs
• Arched, nonprehensile feet
• Greater length and flexibility of opposable thumb
• Sophisticated brain cerebral cortex- center of
  speech and higher mental activities
• Sexually of females all year rather than purely
  in heat
• Advance tool making
• Language- complex and symbolic (written language)
• Longest dependency period

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What are the possible explanations, suggested by
research, for the various primate adaptations?

• Body size
• Determined by when and where active and what it
  eats
• Brain size
• Larger brain means more capacity for memory
  however it also means it requires more oxygen and
  glucose
• Group size
• Nocturnal animals tend to have small group sizes,
  this way they are be able to avoid attacks by
  predators, as they are quieter.
• However, larger groups have advantages in the
  daytime as there are more eyes, ears and noses in
  a group to detect predators.