Anthropology 101 Test 1 Review

Diploid number (2n)

The total number of chromosomes in a diploid cell.

the structure of a DNA molecule

is key to its ability to transmit genes from one generation to the next

local adaptation

when a population of organisms has evolved to be more well-suited to its environment than other members of the same species

Evolution

Change over time

Evolutionary Theory

A concept developed by Charles Darwin to explain the ways in which animals adapt to their environments

natural selection

the process whereby any heritable features that enhance fitness of an organism, relative to its peers, increase in frequency in the population in succeeding generations

fitness

Ability of an organism to survive and reproduce in its environment

Variation

differences in physical traits of an individual from the group to which it belongs

Inheritance

The process in which genetic material is passed from parents to their offspring. (encoded in DNA)

selection

environmental pressure

competition for resources

A cause of conflict that occurs when the demand for resources is greater than the resources available.

Adaptation

A trait that helps an organism survive and reproduce, change in phenotype

Scala Naturae (Great Chain of Being)

The scala Naturae (scale of nature) was a Greek notion for how to rank the biological world. At the bottom were "simple" organisms, like worms, and at the top were " complex" organisms and at the very top of the heap were humans, which were seen as being the most god-like of organisms. This ranking system was borrowed by Christian thinkers where it was expanded into the Great Chain of Being. It's the same ranking system, but here the ranking includes various classes of people, various types of angels, and goes on up to God. I bring this up in class because it speaks to this notion that we often have that sees humans as being apart, or distinct from, the rest of nature. Thus, natural laws are often thought not to apply to humans. This is part of that notion that I spoke of as the "the special place of humans in nature." It's one of the biases, or misconceptions, that people have. According to this principle, humans could not have evolved.

Al-Jahiz

an Islamic scholar who lived in the 800s and who presented a theory about the evolution of animals.

Al-Beruni

from 973-1048 AD, Turkmenistan/Uzbekistan, Muslim evolutionary scholar

- Similar to Ibn Miskawayan, Al-beruni held the view that humans migrated through various "lower" lifeforms on the way towards humanity

- Noting similarity between monkeys and humans, he stated monkeys were the final through which humans passed before coming human

Fixity of species

all species remained unchanged throughout the history of the earth

Carlos Linnaeus

Father of taxonomy, Swedish botanist, zoologist, taxonomies, and physician. He established the system of binomial nomenclature.

binomial nomenclature

Classification system in which each species is assigned a two-part scientific name

Systema Naturae (1735)

Carl von Linnaeus- tried to classify every living things

Linnaean Classification System

Kingdom, Phylum, Class, Order, Family, Genus, Species

Kingdom

First and largest category used to classify organisms

Phylum

Group of closely related classes

Class

in classification, a group of closely related orders

Order

in classification, a group of closely related families

Genus

A group of similar species

Species

A group of similar organisms that can breed and produce fertile offspring.

King Phillip Came Over For Good Spaghetti

Kingdom, Phylum, Class, Order, Family, Genus, Species

Rules of Linnaean Classification

-Unique name

-Latin or Greek

-Genus and species in italics

-Genus is capitalized

-Species is lowercase

-A species without a genus is meaningless

Linnaean Classification of Humans

Kingdom: Animalia

Phylum: Chordata

Class: Mammalia

Order: Primates

Family: Hominidae

Genus: Homo

Species: sapiens

Buffon (1707-1788)

Noted that different geographical regions had slightly different looking plants and animals despite similar habitats. Environment could change species, but not create new species. Idea that species are not completely static; they may change and the environment may drive that change.

Erasmus Darwin

Also proposed the idea that species could change over time due to environmental changes.

Idea that living species descended from common ancestors.

(So the idea of evolution existed before C. Darwin, but no mechanism to explain how it worked)

Lamarck's theory

an organism acquires its trait through its lifetime and passes it to offspring (use and disuse). We now know that genetics do not work as Lamarck imagined, but his theory was accepted by many for a number of years (one can't inherit most acquired characteristics from one's parents)

George Cuvier

Developed the theory of catastrophism

Catastrophism

A principle that states that geologic change occurs suddenly by sudden events

Charles Lyell

effectively discredited the long-standing view that the earth's surface had been formed by short-lived cataclysms, such as biblical floods and earthquakes-his principle: uniformitarianism: same geological processes that are at work today slowly formed the earth's surface over an immensely long time

Uniformitarianism

Charles Lyell's idea that geologic processes have not changed throughout Earth's history.

Thomas Malthus

Said that populations increase faster than food supplies

Alexander von Humboldt

"father" of modern physical geography/biogeography

Charles Darwin

English natural scientist who formulated a theory of evolution by natural selection (1809-1882)

Voyage of the Beagle

Charles Darwin's famous global voyage, where he found his first evidence of evolution

Galapagos Finches

cactus eater

seed eater

insect eaters

The Galapagos Finches demonstrate natural selection through adaptation.

Origin of Species

1859: Charles Darwin's book explained how various species evolve over time and only those with advantages can survive and reproduce. Darwin built off of concepts from Lyell and Malthus

Darwin's mechanism for evolution

natural selection and genetic variation

adaptive radiation

An evolutionary pattern in which many species evolve from a single ancestral species

Alfred Russel Wallace

British naturalist who developed a hypothesis of natural selection similar to Darwin's

Wallace Line of Biogeography

separates flora and fauna of islands as associated with mainland Asia or mainland Australia

Natural selection (Darwin's)

1) More offspring are produced than the food supply can support

2) There is variation among individuals withinnall species

3) There is variation on heritable traits

Darwin hypothesized that those individuals with variations that allow them to better compete will survive and reproduce more frequently than those individuals without these favorable traits (i.e.., greater fitness). Populations diverge over time to form new species.

Natural selection is not

just survival of the fittest, nor is it the only force of evolution. other foces include mutation, migration, and genetic drift

genetic drift

change in the genetic composition of a population from generation to generation ti the chance sampling events

founder effect

extreme change in the genetic makeup of a population when only new population is established by only a few individuals.

inheritance of acquired characteristics

Lamarckian belief that characteristics acquired during the lifetime of an organism can be passed on to offspring

common ancestry (common ancestor)

a group of organisms share common descent if they have a common ancestor thus all living organisms on Earth are descended from a common ancestor. It explains why different species share similar traits.

adaptations

Changes in physical structure, function, or behavior that allow an organism or species to survive and reproduce in a given environment.

Patterns of Evolution

anagenesis, stasis, cladogenesis

phyletic gradualism

gradual change in the morphology of a population of organisms through time, either anagenetic, cladogenetic, or both (Darwin thought of evolution in this way)

Prokaryotes vs. Eukaryotes

- Prokaryotes have no nucleus or membrane bound organelles

- Eukaryotes have a nucleus and membrane bound organelles

- Both can reproduce and respond to the environment

RNA

ribonucleic acid, a molecule in the cell, which contains genetic information

haploid number (n)

the number of homologous pairs in a diploid cell.

meiosis

occurs to form gametes (sex cells), one cell divides into 2 cells, then those 2 cells divide again into 4 cells.

4 bases of DNA

Adenine, Thymine, Guanine, Cytosine (or A, T, G, C)

DNA bases

weak hydrogen bonds. each base only binds with a certain other base, each pair known as a "base pair"

DNA replication

the process of making a copy of DNA

DNA transcription

the formation of an RNA strand complementary to the DNA strand by RNA polymerase

gene

region of DNA that codes for a specific protein, a basic unit of heredity in a living organism

Transcription

DNA sequence in a gene is copied into mRNA

Translation

RNA is translated into an amino acid chain (or protein)

for transcription, thymine (t) basss are replaced by what as the complementary base to adenine?

uracil (u)

amino acids

building blocks of proteins

alternative splicing

splicing can occur more than one way to produce different products (same gene, different products)

protein coding genes

Genes that encode instructions for making proteins.

regulatory genes

genes that control gene expression

Pangenesis

(outdated) Darwin's hypothetical mechanism for heredity- reproductive cell contains gemmules or invisible germs derived from an individual. those eventually get to gametes and pass on traits to their offspring

phenotype

An organism's physical appearance, or visible traits. (observable expression of an organism's genotype)

With genes, we can trace heritability

use laws of probability to compute how alleles will be distributed

Law of Dominance

In many traits one allele is dominant over the other allele. The "weaker (recessive" allele is only expressed when it is paired with another recessive allele

Homozygous

Having two identical alleles for a particular gene (TT or tt)

simple traits

Traits whose variations are controlled by different versions of a single gene (mendel's traits are these) (they include pea color, pea texture, Hitchhiker's thumb, detached ear love, certain diseases)

Complex traits

traits that are influenced by more than one gene (polygenic) or environmental factor (such as height, skin color, many inherited diseases)

population

a group of organisms of the same species that live in a specific area

population genetics

the study of how genes (alleles) evolve in populations

the study of allele frequency distribution and change under the influence of four evolutionary forces

Hardy-Weinberg equilibrium

- a populations allele and genotype frequencies are constant unless there is an evolutionary force acting on them

- equation that was developed to determine the frequency of two alleles at one locus in a population

- mathematical model which we compare null prediction against actual observed data

- if A population is in "Hardy-Weinberg Equilibrium" then evolution has NOT occurred

Mathematics of Hardy-Weinberg Equation

(p^2)+(2pq)+(q^2) = 1

p is the frequency of dominant allele

q is the frequency of the recessive allele

(p^2) is the homozygous dominant

(2pq) is heterozygous

(q^2) is homozygous recessive

in a population with no evolution, genotype ratios will remain constant

natural selection allele frequencies

if one phenotype is associated with higher fitness (greater ability to survive and reproduce), then alleles that result in that phenotype will increase in the population

-evolution by natural selection at the genetic level

sexual selection

A form of natural selection in which individuals with certain inherited characteristics are more likely than other individuals to obtain mates.

mutations

errors which happen during DNA replication

insertion mutation

a mutation in which one or more nucleotides are added to a gene

deletion mutation

a mutation in which one or more pairs of nucleotides are removed from a gene

X-linked disorders

disorder is on the X chromosome and can affect both female and males depending on the carrier. X linked disorders skips a generation- fathers don't pass it on to sons, daughters are carriers and have a 50% chance of getting the disorder because they inherit one X from mom, one X from dad. (Examples- hemophilia, colorblindness, deafness)

genetic drift

A change in the allele frequency of a population as a result of chance events rather than natural selection. (no selection, random effects through sampling variation can produce changes in allele frequencies, particularly prevalent in small populations, can cause small isolated populations to become genetically distinct from larger ones)

bottleneck effect (genetic drift)

when a large population is reduced in size and alleles are lost, variation is reduced. (cheetas as an example)

continuous characters

characters that have continuous distributions

continuous variation

range of small differences in a shared trait

(bell curve for distribution)

variation is difficult to eliminate completely through:

natural selection, rare deleterious alleles tend to be maintained at low levels

correlated characters

when individuals with a particular variant of one character also tend to have a particular variant of another character

if there is a strong selection on one trait, other traits may het "dragged" along with it

Other constraints of evolution

Evolution is also constrained by the laws of physics and chemistry

Surface area to volume ratios

DNA

deoxyribonucleic acid, a molecule in the cell containing genetic information. it is the "backbone" of sugar and phosphate molecules. attached to the sugar is of of 4 "bases."

scientific theory

a well-tested explanation for a set of observations or experimental results

Darwin vs. Lamarck

Lamark - Individuals lose characteristics that they do not use, and develop further on characteristics that they use a lot and that these changes would be inherited

Darwin - Some genetically programmed traits increase an organism's chances of surviving, do survive better, and spread through the population

process of evolution by natural selection

variation in heritable traits within a population

+ differential survival and/ or reproduction

= change in traits in a population over time

Continuous vs. Discontinuous variation

Continuous: Individuals vary within a range, generally due to multifactorial inheritance (e.g height)

Discontinuous: Two or more distinct categories of which a person can only fall into one, generally due to polygenetic or monohybrid inheritance (e.g blood type)