Anthro Test 2

What did Plato say?

"World of Ideals": for everything there is an ideal or perfect counterpart

In order for natural selection to occur?

(1) Trait must be heritable (2) There must be variation in the trait within the population (3) There must be differential reproductive success based on the trait

Who was James Ussher?

-1581-1656 -Archbishop of Armagh -Primate of All Ireland -Said Earth was created on Sunday October 23, 4004 BC

Who is Carolus Linnaeus?

-1707-1778 -believed in teological explanations of natural phenomena and fixity of species -used common attributes to group organisms -grouped humans with primates

Who is Georges Buffon?

-1707-1788 -french aristocrat and naturalist -wrote Historie Naturelle (44 volume encyclopedia) -one of the first prominent scientist to suggest that (the earth is older than 6000 years, species change over time, and noted anatomical similarity between humans and apes and discussed the possibility of common ancestry (no mechanism though))

Jean Lamarck

-1744-1829 -Philiosophie Zoolgique (1809) -Evolutionist -First to propose a coherent mechanism to explain how evolution might occur -Change through striving -Acquired characteristics passed on to offspring (results cumulative- eg. giraffe's neck, one kept stretching and got a bigger neck and this continued to happen until its later offspring had tall enough necks to reach the leaves on the trees. -mechanism was wrong -stability of species is proportional to stability of environment -environment changes then species must change to survive

Thomas Malthus

-1766-1834 -essay on the principle of population (1798) -compared European population growth with food production capacity-unchecked population growth faster -disease and other factors keep population in check

Georges Cuvier

-1769-1832 -paleontologist -anti-evolutionist and vocal critic of Lamarck -works with fossils from Paris Basin, established extinction as a fact -explanation: catastrophism -provided more evidence that earth was old

Charles Lyell

-1797-1875 -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 is very old

Who is Richard Owen?

-1804-1892 -anti-evolutionist -comparative anatomist -homology: 1843, the same organ in different animals under every variety of form and function -came up with the explanation that there is an archetype (common anatomical plans for different groups)

Charles Darwin

-1809-1882 -Natural selection (correct process by which evolution occurs) -wrote Origin of Species (1859) -knew work was controversial as it disputed fixity of species -his work was only published because someone else came up with the idea

Effect of Chicxulub asteroid

-66 MYA marks boundary between Cretaceous (dinosaurs) and Paleogene (mammals) periods -non-avian dinosaurs go extinct, along with 50-70% of all living species. Mammals survive and begin to diversify (lots of empty niche space after K-pg extinction)

3 Fundamental Points of Natural Selection

-Ability of population to expand is infinite, but carrying capacity of the environment is finite -Individuals of any given species vary in morphology and behavior, and this variation leads to differential survival and reproduction -Some of this variation is transmitted from parents to offspring (traits that confer advantages in survival and reproduction are retained in population (selected for) and disadvantages traits disappear over time (selected against))

Principle of Parsimony

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

Where and when do the earliest definite fossil primates first appear in the fossil record?

-At the beginning of the Eocene epoch (56-32 million years ago) -Nearly simultaneously in North America, Europe, and Asia

Why did climate deteriorate?

-Before the oligocene, Antarctica connected to South America, this forced warm water to circulate from tropics down to coasts of Antarctica. This warmed the entire planet. By the eocene-oligocene boundary, South America had detached and drifted north opening up a deep sea channel (Drake passage). This allowed cold water to circulate around Antarctica (Antarctic circumpolar current) cooling the entire planet. AFter the eocene-oligocene boundary, global temps never recover. -This means primates must have survived this colling event. They went extinct in N. America, Europe and North Asia, but survived in lower tropic regions where they are found today like South America, Africa, and South Asia.

What things did the Europeans believe in the Middle Ages?

-Earth is the center of the universe (Ptolemy around 140 AD -Earth is very young -No evolution -Humans at the top of Scala Naturae -Organisms were successful at what they do because that's how they were designed

What are the 4 forces of evolution?

-Mutation: source of variation in nature (can occur by substitution or insertion) -Genetic drift: effect of random changes in allele frequencies within a population (species killed by disease or natural disaster) -Gene flow: transfer of alleles between populations (must have migration and mating) -Natural selection: non-random survival due to heritable phenotypes

Adapoids

-Notharctus: middle eocene (N. America), 5-7 kgs (around a large sifaka), post-orbital bar, small orbits (diurnal), molars with well developed shearing crests: folivory +frugivory, canine sexual dimorphism: (strong male-male competition) and (gregarious social groups), grasping hands and feet with nails instead of claws, limb proportions suggest arboreal quadruped, locomotion and ecology similar to ruffed lemur, no tooth comb, has a grooming claw (probably a derived trait of strepsirrhines) -probably are primitive strepsirrhines

Reconstructing phylogenies

-Why: it's the basis for the identification and classification of organisms. Helps explain why a species evolved certain adaptations and not others. Helps us deduce the function of morphological features or behaviors by comparing the traits of different species. -How: 2 methods (phenetics: old method, group organisms on basis of similarity) and (cladistics: new method, group organisms on basis of derived features) -focus on homologous features (traits resulting from shared ancestory)

Sexual Selection

-a special case of natural selection that results from the differential mating success of one sex -Intersexual selection: sexual selection driven by members of one sex showing preferences fro mates with specific characteristics -Intrasexual selection: driven by members of one sex engaging in contest competition for access to individuals of the opposite sex

Exaptation

-adaptations that evolve for one function, but are then useful in another context. -Ex: feathers originally adaptation for keeping warm, then exaptation for flight

Adaptation

-any trait that increases an organism's fitness (lifetime reproductive potential) -don't have to arrive from natural selection, but they must be maintained by natural selection

Significance of Shanghuang- China?

-cave site, or "fissure fill" full of primate fossils from owl pellets (Adapoids and omomyoids). ALso have Tarsius Eocaenus (tiny early tarsiers) -Oldest definite anthropoids: Eosimias, 90-180 g, dentitions: insectivory and frugivory, unknown whether it had complete post orbital closure, teeth and mandible resemble living anthropoids, tarsal synapomorphies, tarsals show arboreal quadruped and less leaping than omomyoids

Gregor Mendel

-did pea experiment -concluded that an individual has 2 alleles controlling each discrete trait; one inherited from each parent -some traits mask others -no blending inheritance -came up with basic rules of heritablilty (principles of segregation and independent assortment) -genotype vs. phenotype

Biological species concept

-group of organisms 1. actually or potentially interbreeding 2. reproductively isolated from other groups -reproductive isolation: prevents gene flow between populations by genetically determined differences between them. (parts don't fit, different body sizes, different courtship rituals, genetic differences cause offspring to be sterile ex: mule) -Problems: some very different groups can produce viable offspring (female ligers)

Percentage differences and similarities between chimps and humans?

-only 1.23% difference between human genome and chimp genome -humans and chimps are 97% identical

Mutations

-random process by which environmental factors or errors in cell duplication change in an individual's genetic material -most are neutral, but some can be disadvantageous or beneficial -in order for evolution to occur, the genes must be passed on. So, the mutation must occur in your gametes (eggs or sperm).

Alu

-retrotransposons found in primates and close relatives -originally a small RNA molecule -1 in 3,000,000 Alu elements independently inserting in the same exact position in two different lineages

Omomyoids

-small, (e.g. tarsiers or mouse or dwarf lemurs), short snout. -Tetonius: Early eocene of North America, 150-300 grams, post-orbital bar, large orbits (nocturnal), well developed molars shears, projecting point anterior teeth, insectivore/frugivore, ankle morphology shows generalized arboreality (not specialized leaper or slow climber) -lack most synapomorphies of haplorrhines -may be closely related to tarsiers, but evidence is weak

Species

-smallest unit in the Linneaen hierarchy -all individuals of a given specific type

Ecological species concept

-species are interrelated organisms that share the same niche -emphasizes role of natural selection in maintaining species boundaries -gene flow can occur, but natural selection acts against hybrids -Problems: niches can be flexible

primitive vs derived

1)Primitive: features shared by a group that are inherited from a more distant common ancestor (plesiomorphy) 2)Derived: evolutionary innovations that evolved in the most recent ancestor (apomorphies)

3 Modes of Speciation

1. Allopatric speciation: population is divided by some type of physical barrier (river, mountain) and then separated population diverge over time. 2. Parapatric speciation: 2 populations are physically adjacent, but adapt to different environmental conditions over time (example may be that species are next to each other but just prefer to mate with their own kind but still will occasionally mate with other species) 3. Sympatric speciation: individuals of a single population in one habitat gradually diverge over time (no large scale spatial separation or physical barrier- rare) (example may be of mating at different times of the day, that is why gene flow doesn't occur)

3 Types of Homoplasy

1. Convergence: evolution of similar structures using different anatomical features as a starting point (analogous) 2. Parallelism: evolution of similar structures using the same anatomical feature as a starting point. Ex: parallel evolution of prehensile tails in South America (tails primitive for mammals) spider monkeys (homologous) 3. Evolutionary Reversal: apparent re-evolution of a plesiomorphic feature. Ex: evolution of claws in some primates (Aye-Ayes)

2 problems with reconstructing phylogenies

1. You can't use shared primitive characteristics to reconstruct evolutionary relationships, only shared derived characteristics 2. Homoplasy

What were Darwin's 3 postulates for the theory of adaptation?

1: the struggle for existence 2: the variation in fitness 3: the inheritance of variation

Adapoids vs. omomyoids

A: larger, diurnal, folivores or frugivors O: smaller, nocturnal, insectivores or frugivores

Primates that appear in Holarctic continents at beginning of Eocene belong to 2 groups?

Adapoids and Omomyoids

Why are there no adapoids or omomyoids today?

Because the eocene was very warm, but that period ended with the largest temp. drop in the last 66 my. Tropical forests were replaced by temperate grasslands, leading to the extinction of some primates.

Land Bridge?

Beringia: a bridge between Siberia and Alaska over the entire Cenozoic that explains how animals moved to different continents.

Next closing living non-primate relatives

Bunnies (order Lagomorpha) and Rodents (order Rodentia)

Difference between continuous and discontinuous variation?

C: phenotypic variation in which there is a continuum of types. Ex: height D: phenotypic variation in which there is a discrete number of phenotypes with no intermediate types. Ex: blood groups

What is Biological Evolution?

Change in gene (allele: variants in genes) frequencies within a population from one generation to the next. Population is a unit of evolutionary change (individuals don't evolve). Genetic material must change for evolution to occur.

Cladogenesis Anagenesis

Cladogenesis: Splitting of lineages over time (Adaptive radiation: rapid species of multiple cladogenic events. Often occurs following colonization of a new landmass) Anagenesis: gradual transformation of one species into another

2 of primates' closing living relatives

Colugos (Order Permoptera) and Tree shrews (Order Scandentia)

First radical departure of worldwide views?

Copernicus: sun is at the center of the universe Galileo: came up with telescope and said Copernicus is right, and also said the moon wasn't smooth and perfect

Central Dogma of Biology?

DNA-transcription-RNA-translation-protein

Origin for primates

East or Southeast Asia

Examples of empirical and non-empirical subjects?

Empirical: science and engineering Non-empirical: ethics, morality, law, religion, and philosophy

What was the warmest epoch of the Cenozoic era?

Eocene, it spread farther north and south of the equator making everywhere sort of a tropical climate.

Where were adapoids and omomyoids found?

Found in Holarctic landmasses and they aren't found in S. America or Africa because they are islands in the eocene.

Oldest definite fossil primate?

Genus: Teilhardina Species: Asiatica From China and is the earliest eocene

What did Aristotle come up with?

How to classify things. "Scala Naturae": Ladder of Nature, Great Chain of Being (organisms can be grouped on a linear scale from simple to complex.

Difference between a hypothesis and a theory?

Hypothesis: untested but consistent with prior known facts Theory: hypothesis supported by substantial empirical data

How are oxygen isotopes measured?

In the calcium carbonate CaCO3 shells fo tiny marine plankton. -Foraminiferans(zooplankton): unicellular shelled amoeba-like protists -Coccolithophores(phytoplankton): unicellular golden-brown algae

Alfred Wallace

Independently came up with the idea of natural selection

PETM marked by Carbon Isotope Excursion

Indicates a massive release of C12 into biosphere, 100,000 year period of extreme greenhouse conditions, maybe from methane hydrates

What makes scientific knowledge different than other types of knowledge?

It is empirical: based on observations of the world (often quantitative) Testable: potentially falsifiable, often through experimentation Repeatable

Difference between light oxygen and heavy oxygen

Light: O16 Heavy: O18 Heavy has more neutrons

2 Types of Evolution?

Microevolution: short time frame (months/years). Genetic changes within a species. Macroevolution: long time frame (often millions of years). Origin and extinction of species.

Modern Synthesis

Natural selection and other evolution processes + laws of heritablity (Mendel and others) + understanding of protein synthesis= modern synthesis

What are the 3 Holarctic continents?

North America, Europe, and Asia

What is the relationship between oxygen isotopes and water temperature?

Oxygen isotopes can be measured by marine plankton, once you have these measured you put the heavy oxygen of the light oxygen to form a ratio giving us an idea of water temperatures.

What is the PETM?

Paleocene-Eocene Thermal Maximum: Boundary between Paleocene and the Eocene, warmest time interval in the last 66 million years.

Observations about Natural Selection

Within a population, no two individuals look alike, a lot of natural variation and some must be inherited. There is a huge ability for animals to reproduce (since populations seem stable, mortality must be high)

Did primates originate in tropics of east or southeast asia before the PETM?

Yes, very warm green house gases allowed them to cross the Beringia.

Clade

a group that includes all of the organisms that share a single common ancestor

Cladograms

diagram showing the branching sequence of evolutionary relationships

Homoplasy

independent evolution of similar features in 2 or more lineages (usually in response to similar niche/ environmental pressures)

Synapomorphies

shared derived characteristics

Symplesiomorphies

shared primitive characters

What primates are considered "living fossils"?

tarsiers

What is Teleology?

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