Ant 301 2

Front 1

Evolution

Back 1

Change in allele frequency within a population from one generation to next.

Front 2

Important Notes for Evolution regarding population and genes

Back 2

1. Populations evolve, individuals do not
2. Genetic material must change for evolution to occur. ( good nutrition is not evolution)

Front 3

Micro Evolution

Back 3

-short time frame (months,years)
-genetic changes within a specieis

Front 4

Marco evolution

Back 4

long time frame
origin and extinction of species

Front 5

James Usher

Back 5

- Archbishop of Armagh
- Vice-Chancellor of Trinity
- Primate of All Ireland
- Earth created on Sunday October 23, 4004 BC
(John Lightfoot - vice chancellor of Cambridge: 9 AM - London time)

Front 6

Plato

Back 6

“World of Ideals”

For everything, there is an ideal or perfect counterpart

(If species based on a fixed “Ideal type”, how could they change through time?)

Front 7

Aristotle

Back 7

“Scala Naturae” Organisms can be grouped on a linear scale from simple to complex (Of course, humans above beasts and plants

- Ladder of Nature

Front 8

Teleology

Back 8

- the use of ultimate purpose or design as a means of explaining natural phenomena (think divine purpose)

Front 9

Scala Naturae

Back 9

1. World young and at center of universe
2. Fixity of species (no evolution - everything based on a platonic “ideal” type)
3. Humans at top of scala naturae
4. Organisms are good at what they do, because that’s how they were designed

Front 10

Copernicus

Back 10

came up with heliocentric model of universe

Front 11

Galileo

Back 11

other stuff, refined refracting telescopes

Front 12

Carolus Linnaeus

Back 12

- Swedish Naturalist
- Founded modern taxonomy with Systema Naturae
- Binomical classification
- Believed in teleological explanations of natural phenomena & fixity of species

Ironic twist

- Used common attributes to group organisms
- Grouped humans with other primates in animal kingdom
Profound shift in thinking about place of humans in nature

Front 13

Richard Owen

Back 13

- English Comparative Anatomist
- Anti-Evolutionist
- Homology - Defined an 1843 as “the same organ in different animals under every variety of form over function

Owen’s explanation: there is a divinely-ordained Archetype for living organisms (common anatomical plans for diff. groups)

Front 14

Buffon

Back 14

-French aristocrat and naturalist
- Historie Naturelle - 44 volume encyclopedia
- One of the first prominent scientists to suggest that:
(1) the earth is older than 6000 years
(2) species change over time
(3) noted anatomical similarity between humans and apes and discussed possibility of common ancestry (no mechanism though)

Front 15

Lamarck

Back 15

- Evolutionist
- First to propose a coherent mechanism
- Change through STRIVING
- ACQUIRED CHARACTERISTICS passed on to offspring (results cumulative - e.g. giraffe)

Mechanism was wrong

but - said that stability of species is proportional to stability of the environment

Therefore, if the environment changes, then species have to change to survive

i.e., adaptation occurs over time in response to environmental change

Front 16

Georges Cuvier

Back 16

- French Paleontologist and comparative Anatomist
- Anti-evolutionist and vocal critic of Lamarck
- Work with fossils from paris basin established extinction as a fact
- explanation: Catastrophism
- Provided further evidence that earth was old

Front 17

Charles Lyell

Back 17

Didn’t buy Cuvier’s catastrophism
UNIFORMITARIANISM
- Same geological processes observable today also happened in past
- Given enough time, small changes can have a large effect
- Inescapable conclusion: Earth very old

Front 18

Thomas Malthus

Back 18

- English Clergyman, Economist, and Natural Scientist
- Essay on the Principle of Population (1798)
- Compared European population growth with food production capacity - unchecked pop. Growth faster
- Disease and other factors keep population in check

- Observation that (if left unchecked) the population will tend to increase faster than the food resources it uses

Front 19

NEW ideas floating around by Darwin’s time

Back 19

NEW ideas floating around by Darwin’s time:
1. World very old and not at center of universe (Copernicus, Galileo, Cuvier, Lyell)
2. Humans are animals and have the same basic anatomical features as many other animals (vertebrates, mammals, primates)(Linnaeus, Owen)
3. Species can change over long periods of time in response to changes in the environment (Buffon, Lamarck)
4. Some species that were alive in the past no longer exist today (cuvier)
5. Incremental changes over long periods of time can have a BIG effect (lyell)
6. When resources are limited, there is COMPETITION for resources(malthus

Front 20

Darwin's Observations

Back 20

1. Within a population, no two individuals look alike
Much natural VARIATION
Some variation must be inherited
2. There is a huge ability for animals to reproduce
But: populations usually seem stable
Therefore: Mortality must be high
STRUGGLE FOR EXISTENCE

Front 21

Natural Selection - 3 Fundamental Points

Back 21

1. Ability of population to expand is infinite, but carrying capacity of environment is finite
2. Individuals of a given species vary in morphology and behavior, and this variation leads to differential survival and reproduction
3. Some of this variation is transmitted from parents to offspring
- Traits that confer advantages in survival and reproduction are retained in population
- Disadvantageous traits disappear over time, selected against

Front 22

Alfred Russel Wallace

Back 22

- Another English naturalist
- Worked in Amazonia and Malay Archipelago
- Independently came up with Natural Selection

Front 23

In order for natural selection to occur:

Back 23

1. Trait must be heritable
2. There must be variation in the trait within the population
3. There must be differential reproductive success

Front 24

Fitness

Back 24

relative measure of lifetime reproductive success

Front 25

Points on variation with natural selection

Back 25

Natural selection acts on pre-existing variation in a population
- But: Natural selection DECREASES variation in a population

Front 26

Darwin and wallace couldn’t explain:

Back 26

- How variation is maintained (Blending Inheritance)
- Where new variation comes from

Front 27

Gregor Mendel

Back 27

His conclusions
- An individual two “particles” controlling each discrete trait; one inherited from each parent
- Some traits mask others (dominant vs. recessive)
- Traits are discrete
- There is no blending inheritance
- There just seems to be if you look at features controlled by multiple genes

Front 28

Where does new variation come from

Back 28

Mutation

Front 29

Mutation

Back 29

Random process by which environmental factors or errors in cell duplication change genetic material (e.g., create new alleles; switch off genes; duplicate entire genes, etc.)

Front 30

Mutagens

Back 30

- Radiation (e.g., cosmic rays)
- Chemical (e.g., ethidium bromide)
- Viruses (e.g., HPV)

Front 31

if natural selection removes less fit than why are there individuals with lower fitness

Back 31

A1: No blending Inheritance
A2: Mutation
A3: Environments change

Front 32

important points on mutation and evolution

Back 32

Mutation occurs in INDIVIDUALS
- Natural selection also occurs at the level of the INDIVIDUAL
- Evolution occurs at the level of the POPULATION (individuals don’t evolve, populations do)

Front 33

Mechanisms of evolution

Back 33

1. Natural Selection
2. Mutation (adds new variation; by definition changes gene frequencies
3. Gene flow - change in gene frequencies within a population due to migration from a population due to migration from or interbreeding with individuals from ANOTHER population
4. Genetic Drift - RANDOM changes in gene frequencies within a population (not mutation)

Front 34

Biological species concept

Back 34

If you CAN or COULD mate and produce fertile offspring, you’re in the same species

Front 35

Reproductive Isolation

Back 35

- Prevention of gene flow between populations by genetically determined differences between them
- Something that prevents act of mating/ reproduction of viable offspring
- Parts don’t fit
- Different body sizes
- Diff. courtship rituals
- Genetic differences cause offspring to be sterile (e.g. mule

Front 36

Ecological Species concept

Back 36

- Emphasizes the role of natural selection in maintaining species boundaries

- Gene flow CAN occur, but separate species are recognized because natural selection acts against hybrid individuals

I.e. Baboons are ecological species not biological species
-Hamadyras Baboon and Olive Baboon lowlands of E. Africa

Front 37

ALLOPATRIC speciation

Back 37

occurs when a population is divided by some type of physical barrier (river, mountain range, ocean), and then the separated populations diverge over time

Front 38

PARAPATRIC speciation

Back 38

occurs when two populations are physically adjacent, but adapt to different environmental conditions over time

Front 39

SYMPATRIC

Back 39

individuals of a single population in one habitat gradually diverge over time (no large scale spatial seperation of physical barrier - rare)

Front 40

Cladogenesis

Back 40

Speciation by splitting of lineages

Front 41

Anagenesis

Back 41

gradual transformation of one species into another

Front 42

Adaptation

Back 42

Any trait that increases an organism’s fitness
adaptations don’t have to arise by natural selection but it must be maintained by natural selection

Front 43

Taxonomy

Back 43

scientific classification

Front 44

Phylogeny

Back 44

a model of presumed evolutionary relationships based on shared characteristics

Front 45

Homoplasy

Back 45

independent evolution of similar features in two or more lineages (usually in response to similar niche / environmental pressures

Front 46

Convergence

Back 46

- evolution of similar structures/abilities using DIFFERENT anatomical features as a starting point

Front 47

Parallelism

Back 47

evolution of similar structures / abilities using the same anatomical feature as a starting point

Front 48

Principle of parsimony

Back 48

- Assumes that features will evolve as few times as possible
- In effect, minimizes homoplasy

Front 49

Euarchontra

Back 49

primates+ scadentia+ dermoptera

Front 50

euarchontoglires

Back 50

euarchonta + rodentia+ lagomorhpa

Front 51

Plesiadapiformes

Back 51

- earliest believed primate relative fossils
- Primarily from the paleocene (65-55 MYA)
- Purgatorius
- Ecologically diverse group

Front 52

Why are plesiadapiformes traditionally grouped with primates?

Back 52

Remarkable molar similarities between Paleocene plesiadapiforms and definite primates from the eocene

Front 53

Palaechthon

Back 53

- Relatively unspecialized / primitive plesiadapiform
- Middle Paleocene
- Orbits small and directed laterally
- Orbits NOT protected by a bar
- Large Infraorbital Canal for maxillary nerve
- Snout probably had many vibrissae / good tactile abilities
- has only THREE premolars
- Earliest definite primates had FOUR premolars
- Small, specialized insectivore
- Small laterally-facing eyes & sensitive snout

Front 54

Carpolestes

Back 54

-plesiadapiform
-- Grasping hands and feet
- Nail on big toe instead of claw

Front 55

Paleocene

Back 55

65 to 54 mya

Front 56

Eocene

Back 56

55 to 34 mya

Front 57

What do we know about adapids and omomyids

Back 57

1. Definitely primates
- Grasping hands and feet
- Nails instead of claws
- Postorbital Bar (prosimians)
2. They evolved somewhere else, and migrated into holartic continents
3. Earliest representatives of two groups very similar...

Front 58

Adapids

Back 58

- larger, diurnal, folivores or frugivores
- small eyes
- long snout
- small incisors
- large canines
- ring in ear

Front 59

Omomyids

Back 59

smaller, nocturnal, insectivores or frugivores
-large eyes
- short snout
- large incisors
- small canines
- ear tube

Front 60

Tetonius

Back 60

Omomyid
- 150-300g
- P-O Bar
- Large Orbits (Nocturnal)
- very well-developed molar shearing
- Projecting pointed anterior teeth
- Specialized insectivore ecology similar to mouse lemur or dwarf bushbaby

Front 61

Notharctus

Back 61

Adapid
- Middle Eocene (N. America)
- 5-7 kg ( large sifaka)
- P-O bar
- Small Orbits (diurnal
- molars w/ well-developed shearing crests: Folivory (+frugivory)
-Canine sexual dimorphism:
- Strong male-male competition
- Gregarious (permanent social groups)
- Grasping hands and feet with nails instead of claws
- Arboreal quadruped
- Locomotion & ecology similar to ruffed lemur (ruffed lemur smaller & more frugivorous)

Front 62

Darwinius

Back 62

-recept adapid primate
-excecentlly preserved
-43 mya’=
What about phylogenetic relationships?
- No tooth comb
- No grooming claw
BUT: tarsals have strepsirrhine synapomorphies

Front 63

Adapids are probably primitive

Back 63

strepsirrhines

Front 64

Omomyids are probably primitive

Back 64

halorhines

Front 65

Eosimias

Back 65

OLDEST definite Anthropoids
-- 90-180g
- Dentition: Insectivory ( + Frugivory )
Eosimias tarsals show:
- Arboreal quadruped
- Less leaping than omomyids

Front 66

At Shanghuang you can expect to find

Back 66

- Adapids and omomyids
- Tiny haplorhine relatives
- tiny tarsiers
- tiny anthropoids

Front 67

at fayum you can find

Back 67

-first toothed combed streps

-adaptive radiation of anthropoids

-ancestors of living platryrrhines

-earliest catarhines

-increase in size

Front 68

karanisia

Back 68

Karanisia (37 MYA)
- basal lorisiforme
- found at Fauyum
- earliest known toothcomb

Front 69

Proteopithecus

Back 69

- small anthropoid
- close relative of platyrrhines (earliest platyrrhine relative)

Front 70

Catopithecus

Back 70

- Postorbital plate
- 2 premolars
- small (750g-1g)
- well-developed molar shearing (earliest cattarhine relative) suggest frugivory but eating leavies as protein source

Front 71

Aegyptopithecus

Back 71

- 2 premolars (catarrhine)
- Larger (6.7 Kg), Big
- Less molar Shearing (Frugivorous)
- Arboreal quadraped

Front 72

Oligocene

Back 72

34 to 23 mya

Front 73

Brantisella (27 MYA)

Back 73

- Earliest platyrrhine

-Salla, Bolivia

- thick molar enamel, hard object feeding or terrestriality?

Front 74

Miocene

Back 74

25 to 5 mya