ANT 251- Exam 1-Dew

What do anthropologists study?

humans across space and time; the human biological and cultural variation and evolution

culture

shared behavior

evolution

change in living organisms over time

why do people behave differently from one another and why do they vary anatomically?

humans have adapted to their natural and social environments in a variety of ways: biological and cultural

archaeology

study of past populations/people through what they left behind

linguistic

study of human language and its development overtime (not just humans)

physical

study of biological evolution of humans both in the present and past

what are the 4 subfields of anthropology?

cultural, linguistic, archaeology, physical

what sort of questions do physical anthropologists work to address through their research?

what is the origin of the human species? How are humans related to other organisms? Why do humans around the world vary?

what is science?

the approach to knowledge acquisition

what is the relationship to knowledge and truth?

knowledge is the intersection of truth and belief

what are the basic elements of science?

pattern searching (looking for associates in nature), brainstorming (attempting to explain these associations), and testing hypothesis (designing a test of one or more explanations)

what are the steps of the scientific method?

observe, generate hypotheses, deductive reasoning, and test the hypothesis

scientific theory

a well substantiated explanation of some natural world phenomena

what is the principle of parsimony?

the simplest explanation is generally the correct one

how did lamarck theorize species change?

physical form changes based on physical needs; considered to be improvements that accumulated over the course of an individual's lifetime; Acquired characteristics are passed on to the next generation. (Giraffe example)

how did Darwin explain changes in a species over time?

natural selection; change in a trait frequency in a population overtime (evolution) that is caused by environmental stress and has the capacity to lead to species change

Darwin's 3 postulates

there is a struggle for existence within species, within any species there is variation fitness, this variation is inheritable

what are some examples of environmental stress?

temperature/weather change, natural disasters, and continental drift

what determines a species survival?

survival of enough individuals each generation, high enough population density to allow reproduction, successful raising offspring to adulthood

how was inheritance understood prior to Mendel's work?

blending hypothesis (skin color, hair, height). Blending is not the norm for inherited traits (tongue rolling)

what is Mendel's first principle?

The principle of segregation

what is the principle of segregation?

each organism has 2 units per trait, the units separate during reproduction into different gametes (sex cells), all offspring inherit one from each parent

Genotype

the alleles present for a given trait (if seed is yellow the genotype is (YY) or (Yy)

Phenotype

the outward appearance of a trait

allele

one of 2 or more forms of a gene (yellow allele, green allele for seed color)

Phenotype

the outward appearance of a trait (if seed is yellow, phenotype=yellow)

what if 2 alleles are codominant?

both traits will show up in the phenotype

what is Mendel's second principle?

independent assortment; genes controlling different traits are inherited independently of one another

what is the composition and structure of DNA?

DNA is a double helix structure; 2 chains of alternating sugar and phosphate held together by chemical bonds between bases

where can DNA be found?

in the cell nucleus

what is mtDNA?

mitochondrial DNA

how is mtDNA inherited?

from the mother

how many chromosomes are there in the human genome?

humans have 23 pairs of chromosomes (46 total)

What are the DNA bonding rules?

A (Adenine) bonds with T (Thymine) and G (Guanine) bonds with C (Cytosine)

How are proteins synthesized?

through transcription

in what ways do humans adapt to their environment?

biologically and culturally

how were species thought of before darwin?

Fixity of Species (no change, created as they are)

what are adaptations?

features in an organism created through natural selection

under what circumstances do adaptations develop?

when a mutation occurs that is passed down through generations

what is fitness? what effects it?

how well a species is able to reproduce in an environment and it is specific to the environment

Process of Transcription

initiation, elongation, termination

How many mRNA codons are there?

64

how many amino acids?

20

what is mitosis?

only one cell division occurs, the 2 daughter cells contain 46 single stranded chromosomes

what is meiosis?

undergoes 2 cell divisions that results in 4 daughter cells containing 23 single stranded chromosomes.

what are mitosis and meiosis?

both are forms of cell replication

how much of our DNA is non-coding?

98%

What are pseudogenes?

a section of genes that are nonfunctional, not used for coding. Mutations have affected the initiation area

what are point mutations?

mutations where only one nucleotide in the sequence is affected

point mutations are the...

most common source of genetic variation

what are simple mendelian traits?

one gene/trait, at least 2 or more alleles, usually and dominant/recessive relationship

large time scale (thousands and thousands of generations) speciation events, higher up in taxonomic classification events

macroevolution

what is sickle cell anemia?

a disease of the blood which makes the hemoglobin molecules less soluble- in which red blood cells form an abnormal crescent shape

what causes sickle cell anemia?

a point mutation occurs in the gene for hemoglobin

how is sickle cell related to malaria?

those who only have one sickle cell gene develop a protective advantage to malaria.

blood types

A and B are codominant and both dominant over O

what are polygenetic traits?

traits that are influenced by multiple genes

what is pleiotropy?

one gene has an influence on a variety of traits

what is a population?

a discrete group of organisms that share the same gene pool

large time scale (thousands and thousands of generations) speciation events, higher up in taxonomic classification events

macroevolution

microevolution

refers to small scale changes in allele frequencies over time, usually referring to a shorter time period (decades/generations)

4 mechanisms of evolution

mutation, gene flow, genetic drift, natural selection

mutation

only source of new variation in a species, rare, random, usually recessive and minor in effect

gene flow

source of new variation in a population

genetic drift

changes in allele frequency due to random chance, more dramatic effects in small populations. (Founder Effect)

natural selection

fitness, traits must be heritable and affect fitness, lead to macroevolution, opposite of genetic drift, not random and effect on large populations

balancing selection

different processes by which multiple alleles are maintained in the gene pool of a population at frequencies larger than expected from genetic drift (ex: sickle cell anemia)

artificial selection

is the processes by which humans use animal/plant breeding to selectively develop certain phenotype traits (ex: dogs)