Studied by 41 people
Anthropology
The study of humankind
Subfields of Anthropology
Cultural Anthropology: Study of cultures and human societies in the recent past
Archaeology: Study of past societies and their cultures
Linguistic Anthropology: The study of and evolution of language
Physical Anthropology: Study of human evolution and variation
Big Six Events
Bipedality: (6+ mya) upright walking
Non-Honing Canines: (5.5 mya) chewing
Material Culture and Tools: (3.3 mya) use of stone tools
Speech: (2.5 mya) express complex thoughts and speech
Hunting: (1 mya) group organizes to pursue animals for food
Domesticated Foods: (11 kya) farming plants and animals
Domestication
The process of adapting wild plants and animals for human use
Darwin’s Ideas
Natural Selection
Descent with Modification
Lamarckism
Physical changes in organisms during their lifetime (greater development of an organ) could be transmitted to their offspring
Alfred Wallace
The Wallace Line: Biogeographic “barrier” that separated Asian origin animals and Australian origin animals for millions of years
Adaptation
Physical or behavioral traits that enhance an organism’s ability to survive and reproduce
Evolution
A change in the allele frequencies of a population over time
Parallel Evolution
When two unrelated organisms evolve a similar trait due to environmental factors
Artificial Selection
Intentional breeding of plants and animals in favor of specific traits which produce offspring with those desired traits
Natural Selection
Process by which some organisms with traits that allow them to adapt to the environment pass on these traits, increasing the frequency in the population
Mutation
Random change in a gene or chromosome making a new trait
Gene Flow
Exchange of alleles between populations of organisms
Genetic Drift
Change in allele frequency from one generation to the next, often due to random events; bigger effect on small population (bottleneck and founder effect)
Homology/Analogy
Homology: Structures that are similar in related organisms
Analogy:
Gregor Mendel
Laws of Inheritance
Bred pea plants, discovered plants had either yellow or green peas, never a mix of colors
DNA
Molecules in all living things that carry specific genetic code; heritable material
RNA
A nucleic acid similar to a single strand of DNA
Genes
Basic unit of inheritance; a sequence of DNA on a chromosome coded to produce a specific protein
Allele
Alternative form of a gene (T or t)
Dominant/Recessive Genes
Dominant: T; overrules the recessive
Recessive: t; overruled by the dominant
Evidence for Continental Drift
Marsupial fossils on different continents even though they aren’t in these locations today, we can measure the slow drifting of continents, continental land masses fit together like a puzzle
Sexual Selection
The frequency of traits that change due to those traits being preferred to members of the opposite sex (colorful male birds)
Sexual Dimorphism
Body size differential between sex of organisms (males bigger than females)
Eukaryotes
DNA contained in a nucleus; some single-celled and all multicellular organisms
Prokaryotes
Single-celled bacteria; no nucleus or organelles
Endosymbiotic Hypothesis
Free living proteo-bacterium incorporated into the early eukaryotic cell
Forms of Sex Determination
XY: Humans; male is XY, female is XX
ZW: birds, most reptiles, fish, insects; male is ZZ, female is ZW
XO: Some insects, bony fish, arachnids, crustaceans, mollusks; males have XO, females have X
Meiosis
Cell division that leads to haploid sex cells (gametes)
A diploid stem cell divides twice but DNA is only replicated one, so the four end products are haploid (non-identical)
Mitosis
Somatic cell replication and division, forming two identical diploid “daughter cells” (genetically similar to parent)
DNA Replication
Parent strand unwinds
Forms two template strands which display “unpaired” nucleobases (DNA “unzips”)
Pair with respective compliment on the template strand
Two new identical strand are made from one initial strand
DNA Transcription
First step of protein synthesis
A strand of DNA is copied into a new molecule of messenger RNA (mRNA)
DNA Translation
Second step of protein synthesis
Transfer of amino acids by transfer RNA to the ribosomes which are then added to the protein chain
Polygenic Traits
When multiple genes contribute to a single effect
Pleiotropic Traits
When a single gene has multiple biological effects
Epigenetics
Chemical changes in the genome that affect how DNA is used in production of proteins without altering the DNA sequence
Gene Expression
Process in which the gene code is used in the synthesis of a functional gene product
Malaria/Sickle-Cell Anemia/Heterozygote Advantage
Heterozygote in case of malaria and sickle-cell anemia is more evolutionary than either homozygotes
Four Types of Reproductive Isolation
Geographic Isolation: Separation of species from mating due to physical barriers in the environment
Temporal Isolation: When populations reproduce in different times of the year
Ecological Isolation: When populations live in same general area but inhabit different habitats within that are, rarely encounter one another
Behavioral Isolation: When two populations of the same/closely related species develop difference in behavior (mating rituals) that leads to divergence
Types of Selection
Directional: Selection for one allele over the others, causes shift in allele frequency
Disruptive: Selection for both extremes of the phenotype, may lead to speciation event
Stabilizing: Selection against the extremes of the phenotypic distribution, decreases genetic diversity
Hardy-Weinberg Equilibrium
Hypothesizes that gene frequencies remain the same because no evolutionary change takes place
Evolutionary “Fitness”
Average number of offspring produced by parents with a particular genotype compared to those with another genotype
Hox Genes
Regulatory genes that determine the form and arrangement of tissues (eye on fly butt)
Microevolution
Small-scale evolution; changes in allele frequency
Macroevolution
Large-scale evolution; speciation event, occurs over hundred of thousands generations
