Anthropology Test 2

Scientific knowledge is:

Scientific knowledge is:

1.) Empirical- based on observations of the world (often quantitative) 2.) Testable- potentially falsifiable, often through experimentation, repeatable (including by independent observers)

Examples of Empirical Knowledge

science and engineering

Examples of Non-Empirical Knowledge

ethics, morality, law, religion, & philosophy

Scientific Theory

well-established explanation of some part of the natural world that can incorporate FACTS, LAWS, INFERENCES, AND TESTED HYPOTHESIS

True or False: No amount of validation can change a multi-part theory into a law.

TRUE

Biological Definition of Evolution

change in gene/allele frequencies (1) within a population (2) from one generation to the next (3)

Gene

small section of DNA that codes for a protein

Alleles

variants of the same gene

Microevolution

studies genetic changes within a species in a short time frame (months, years)

Macroevolution

studies origin and extinction of a species in a long time frame (often millions of years)

What are the 2 levels of evolution?

Microevolution & Macroevolution

Claudius PTOLEMY

proposed the planetary hypothesis -the Earth is the center of the universe

James USSHER

-used the Bible to calculate the exact date of the beginning of the Earth -Sunday, October 23, 4004 BC

PLATO

-wrote "World of Ideals" & "Theory of Forms" -there is a pure counterpart of every material object -if species have an "ideal" form, how can they show directional change or one give rise to another?

ARISTOTLE

-classified things -"Scala Naturae" i.e. the Ladder of Nature of the Great Change of Being

Scala Naturae

organisms can be grouped on a linear scale from simple to complex (humans most complex)

True or False: The Scala Naturae doesn't still influence our thinking today.

False, i.e. lower primates and higher primates

Teleology

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

Middle Ages Knowledge:

1.) The Earth is young and at the center of the universe. 2.) Fixity of species (no evolution, everything has an ideal form) 3.) Humans at the top of Scala Naturae. 4.) Organisms are successful because that's how they were designed.

Who were the first challengers of the medieval consensus of the natural world?

Copernicus and Galileo

COPERNICUS

-Earth not at the center -used hypothesis testing and empirical data

GALILEO Galilei

-identified craters on moon's surface -discovered 4 of Jupiter's moons -supported Copernicus' idea of heliocentric universe

Carolus LINNAEUS

• founded modern taxonomy with Linnaeus Taxonomy

• binominal classification

• used common attributes to group organisms

• shifted the idea of humans' place in nature

Richard OWEN

• anti-evolutionist

• homology

• archetypes are divinely-ordained for living organisms

• identified similarities in very different groups of organisms

Homology

the same organ in different animals under every variety of form and function

George Louis Leclerc, Comte de BUFFON

• author of 44 vol. encyclopedia, Historie Naturelle

• suggested that Earth is older than 6000 y.o., species change over time, and that there were anatomical similarities between humans and apes that indicated a possible common ancestry -proposed no mechanism of evolution

Jean Baptiste LAMARK

• Philosophie Zoologique

• evolutionist

• proposed first coherent explanation of the mechanism of evolution (STRIVING AND AQUIRED CHARACTERISTICS) -stability of species is proportional to the stability of the environment

True or False: Lamark's mechanism of evolution was correct.

False

Georges CUVIER

• critic of Lamark

• anti-evolutionist

• fossil guy

• established extinction as a fact

• Catastrophism

• provided evidence that the Earth is old

Charles LYELL

• didn't agree with catastrophism

• geologist

• uniformitarianism

Uniformitarianism

• Geological processes are observable in the present and happened in the past

• small changes -> big effects

• proves Earth is old

Thomas MALTHUS

• Essay on Principle of Population

Essay on Principle of Population

• European pop. growth vs. food production

• an unchecked pop. grows faster

• disease and other factors keep pop. in check

Charles DARWIN

• Origin of Species

• correctly identified one mechanism of evolution, natural selection

Darwin's Observations

1.) Within any pop., no two individuals look alike. There's a lot of natural variation and some variation must be inherited. 2.) Huge ability for animals to reproduce, but populations seem stable. Therefore, mortality must be high. "Struggle for Existence" said being an animal is hard.

True or False: Darwin was the first evolutionist.

False

3 Points of Natural Selection:

1.) Ability of a pop. to expand is infinite, but the carrying capacity of the environment is finite. 2.) Individuals of a given species vary in morphology and behavior leading to different survival and reproduction tactics. 3.) Some variation is inherited from parents to offspring. Advantages are retained/ "selected for". Disadvantages disappear/ get "selected against"

True or False: Darwin's work supported the fixity of species, making it well-received by the scientific community.

False, Darwin waited a long time to publish the Origin of Species because it was controversial by not supporting the idea of the fixity of a species.

Alfred Russel WALLACE

-English Naturalist -INDEPENDENTLY CAME UP WITH NATURAL SELECTION -worked in Amazonia and Malay Archipelago -like Darwin, was also inspired by Malthus

True or False: Natural selection was an idea whose time had come.

True, Darwin and Wallace's discovery was a product of its' time, an obvious thought from years of previous ideas/research.

In order for natural selection to occur:

1.) the trait must be heritable 2.) there must be variation in the trait within the population 3.) there must be differential reproductive and survival success

True or False: Even when all three components of natural selection are present, evolution still might not occur.

False, if all three components of natural selection are present, then evolution is inevitable.

Fitness

RELATIVE measure of lifetime reproductive success

Natural selection _________ variation in a _____________ by removing less fit variants.

decreases; population

Blending inheritance

intermediate form of a characteristic (PROVEN WRONG BY MENDEL)

Gregor MENDEL

• monk

• worked out basics of genetics and inheritance

• PEA PLANTS

• pointed out problems with blending inheritance

• masked variation

Mendel's Conclusions:

• 2 factors control each discrete trait; one inherited from each parent

• some traits mask others (dominant vs. recessive)

• traits are discrete

• there is no blending inheritance, just seems to be present if you look at features controlled by multiple factors

Mendel's Contributions:

• basic rules of heritability

• Principles of Segregation and Independent Assortment

• genotype vs. phenotype

• NO blending inheritance; variation IS maintained in population from one generation to the next

True or False: Mendel discovered DNA.

False, Mendel didn't know about DNA at all.

DNA

• big molecule in cells that contains genes

• genes provide the "recipe" for producing different proteins

All living organisms are primarily composed of:

water, proteins, and things made by proteins.

Where does new variation come from?

Mutation

Mutation

the random process by which environmental factors or "errors" in cell duplication change an individual's genetic material/genome, adds new variation via definite changes in allele frequencies

Nucleotide Base A

adenine

Nucleotide Base G

guanine

Nucleotide Base C

cytosine

Nucleotide Base T

thymine

Nucleotide Base U

uracil

What nucleotide base in DNA is replaced by uracil in RNA?

thymine

DNA molecules are made up of ____________.

nucleotide bases

DNA is a _________ molecule; gets damanged over time.

delicate

True or False: The body has one main mechanism for repairing damage to DNA.

False, the body has multiple mechanisms for repairing damage.

Examples of mutagens from the environment that can cause mutation:

• radiation

• chemicals

• viruses

True or False: Errors inevitably happen as genes are copied during mitosis and meiosis.

True, errors inevitably happen as genes are copied during mitosis and meiosis.

Is meiosis or mitosis more important for evolution?

Meiosis because it controls the reproductive cells that get inherited.

Why are there still individuals with lower fitness?

1.) no blending inheritance 2.) mutation 3.) environments change

Most mutations are ________.

neutral

True or False: Much of your genetic material has little or no apparent function.

True, much of your genetic material has little or no apparent function.

Some disadvantageous traits are selected _________.

against

Some advantageous traits, given the current state of the environment, are selected ____.

for

Natural selection occurs in ____________.

INDIVIDUALS

Mutation occurs in ___________.

INDIVIDUALS

Evolution occurs in ____________.

POPULATION

In order for evolution to occur the gene must be passed on. Therefore, the mutation must occur in your _______.

gametes

4 mechanisms of evolution:

1.) natural selection 2.) mutation 3.) gene flow 4.) genetic drift

Sexual selection

a "special case" of natural selection that results from the differential mating success of one sex, Darwin's peacock "Dissent of Man"

2 kinds of sexual selection:

intersexual selection and intrasexual selection

Intersexual selection

selection driven by members of one sex showing preferences for mates with specific characteristics

Intersexual selection favors:

evolution of traits that make the displaying sex more likely to be chosen by the choosy sex

Example of intersexual selection in primates:

flanges/cheek pads on male orangutans as secondary sex characteristics

Intrasexual selection

selection driven by members of one sex engaging in contest competition for access to individuals of the opposite sex

Intrasexual selection favors:

characteristics that make the competing sex more successful in contest competition in access to mates

Example of intrasexual selection in primates:

male gorilla size and baboon canines

Gene flow

change in allele frequencies within a population due to migration from interbreeding with individuals from another population, all happens within the same species

Genetic drift

the sum effect of random changes in allele frequencies within a population that aren't caused by mutation (RANDOM FALLING TREE)

Effects of genetic drift are most pronounced in:

small populations

Genetic drift is often modeled as a _______________ in allele frequency across generations.

"random walk"

Over time, random processes can have a ___________________ effect.

large, cumulative

Natural selection & other mechanisms of evolution PLUS laws of heritability (Mendel & others) PLUS understanding protein synthesis EQUALS...

modern synthesis

species

smallest fundamental unit in the Linnaean hierarchy, all individuals of a given specific type

biological species

a group of organisms that are (1) actually or potentially interbreeding and (2) are reproductively isolated from other groups (no gene flow allowed)

reproductive isolation

prevention of gene flow between populations by genetically determined differences between them

-AKA something that prevents mating or production of fertile offspring

What's an example of reproductive isolation?

mules

What's the problem with the biological definition of species?

Some very different groups CAN produce viable offspring i.e. Tigons and Guenons

ecological species concept:

species that are interrelated and share the same niche, emphasizing the role of natural selection in maintaining species boundaries, gene flow can occur but natural selection can act against hybrids

Baboons are __________ species but not _______________ species.

ecological; biological

ecological species

groups of interrelated organisms that share the same niche (gene flow allowed)

True or False: Niches are flexible.

True, niches are flexible.

3 modes of speciation:

1.) Allopatric speciation 2.) Parapatric speciation 3.) Sympatric speciation

Allopatric speciation

occurs when a population is divided by a type of physical barrier and then the separated population diverge over time.