Anthropology Exam 2

Classification

Grouping of all living things into simpler categories

Taxonomy

Rules for classifying organism based on evolutionary relationships

Linnaeus

Pioneered the system of binomial nomenclature for naming species based on physical characteristics, not evolutionary relationships

Six Kingdoms of Life

Animals, Plants, Fungi, Protists, Archaebacteria, Eubacteria (all of these are simple micro organisms)

Animals

consume other creatures for food

Plants

make their own food

Fungi

mushrooms and molds

Protists

slime molds, algae, malarial parasite

Archaebacteria

found in extreme environments

Eubacteria

most bacteria, harmful or helpful (yogurt/cheese)

Primates

most rare of all animals; special things about primates: big brain and walks on two feet

the more similar=

closer ancestry

Focus on Homologies

similar physical structures due to common ancestry; tetrapod forelimb; result of evolutionary relationship

Beware of Analogies

homoplasy=similar structures with similar functions, but evolved independently of ancestry

Example of homoplasy

wings in butterflies, bats, and birds all make them fly but in different ways

Tetrapod Evolution

4 limbed creatures that evolved from fish that share a common ancestor

Primitive

ancestry goes back more remotely (older) that was exhibited among many organisms (structures with more remote ancestry) Example: fur in mammals

Derived

Shared among more recent ancestry like the feathers in birds or echolocation in bats; acquired within a subgroup as a result of specific adaptations

Why are snakes derived

Snakes are tetrapod’s that have lost their limbs during evolution

Tetrapodophis Fossil

Shows a snake that has a tetropod limb (form between lizard and snake)

What kind of animals are tetropods

mammals but different animals have different tetrapod limbs

Cladistic Taxonomy

looks at different things like fish v tetropod’s (like measuring fish scales) and establishes relationships by grouping based on characteristics

Cladogram

shows how each step adds a new attribute (all wagons have wheels then it branched out and some have engines and some are auto)

DNA based cladograms

analyze genomes of different species to evaluate relatedness

Species

most precise taxonomic level (its a group of interbreeding individuals that share board ecological adaptations like diets)

Genus

group of closely related species that share derived characteristics not seen in other genera

Individual variation

individuals within a species with variation due to meiosis, recombination, sexual reproduction (different stages in life cycle and sexual dimorphism)

Defining genus/species in hominins

is very difficult because DNA increasingly used

Who found the vast time scale “geological time”

Charles Lyell

Paleozoic Era

1st vertebrates by 500 mya (fishes, amphibians, reptiles)

Trilobite

wisconsin’s state fossil, one of the most Paleozoic species

lystrosaurus

1st mammal like reptile

Permian Extinction

90% of Paleozoic species went extinct during an intense volcanic activity

Mesozoic Era

age of reptiles (dinosaurs)

adaptive radiation

certain type of species became very successful

KT Extinction Event

Asteroid that sent all species (dinosaurs) into extinction

What animals survived during the KT Asteroid

mammals due to adaptive radiation of mammals during the Cenozoic Era

Cenozoic Era

Evolution of Mammals

Why were mammalian Adaptively Successful?

larger, more complex brain, live births (viviparous), varies dentition (heterodonts), warm blooded (endothermic), and produce milk for young

Why is a larger more complex brain better for adaptive success?

it processes more information and the Neocortex is greatly enlarged in mammals which means higher mental function and slower brain development

Viviparous species

give birth to live young

what happens in utero development

high nutrition during development in the egg

Heterodontic Dentition

Eat their food whole, can go weeks without eating, and different teeth serve different functions

Endothermic Metabolism

can keep their body temperature within (constant)

ectothermic

maintain body temperature based on the environment

metabolism

drives body temperature that is active in a variety of climates

Monotremes

egg laying trait (retain primitive)

What animals are monotremes?

Platypus and Echidna species (spiny anteaters)

What animals are Marsupials?

Kangaroo, Wallaby, Tasmanian Devil, Koala, Wombat

Placental Mammals

more developed central nervous system so they don’t have to be in the stomach as long (also the most common)

What’s special about Placental Mammals?

long period of mother-infant bonding “Bond of Milk”

How are placental mammals categorized?

fur, long gestation, live birth, mammary glands, heterodonts, warm blooded, and increased brain size. Primates are typical placental mammals.

Primatologists focus on 4 primate characteristics

limbs and locomotion, dentition and diet, enhance brain capacity, and social learning

Limbs and Locomotion

tendency toward erect posture (sitting, leaping, frees hands for things other than locomotion) and flexible (carrying offspring, bipedal, etc.)

Dentition and Diet

lack dietary specialization (eat everything) = omnivorous diet

Brain and the Senses

color vision in diurnal (active during day) but nocturnal (activate at night) primates lack color vision

Arboreal Hypothesis

adaption to life in the trees, grasping hands and feet, omnivorous diet consistent with arboreal resource base

Visual Predation Hypothesis

earliest primates lives in shrubby undergrowth and low in canopy, stereoscopic 3D vision (characteristic of most predators), and grasping hands/feet, tactile pads, and nails rather than claws

Angiosperms hypothesis

flowering plants that were fruits for the first primates

Primatologists

strive to understand primate adaptation