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Origin
Origin usually refers to the geological time and/or geological place associated with the appearance of a new species or new trait. (anatomy, paleontology, archaeology, molecular genetics, geology, geography)
Variation
Variation refers to the range of differences within a species or between several species.
Intraspecies variation
Within species variation (involves a single species). Primary focus of intraspecies variation studies are population variation (single population or comparative studies of multiple populations; can be short-term or long-term studies across generations)
Interspecies variation
Between species variation (involves two or more species). Interspecies variation studies often concern adaptive explanations for differences.
Variation/Anatomy
Anatomy (looks) can be deceiving. Wolves/dogs were long thought to be separate species because of anatomical variation, but genetic data indicate they belong to a single species (canis lupus).
Anthropos-
Greek term for "human"
Anthropology
The study of all aspects of the human experience.
Adaptation
1. the process of successful interaction between an organism and its environment 2. a product of the past and a condition of the present 3. how an organism "makes a living" (survives)
4 subfields of anthropology
1. cultural anthropology 2. linguistic anthropology 3. biological anthropology 4. archaeology
Cultural anthropology
The study of human culture in all of its complexity. Culture: the patterns of behavior human societies exhibit in their everyday interactions.
Linguistic anthropology
(Often considered a subset of cultural anthropology.) The study of language, its structure, function, and how it changes over time. Language: a complex system of communication particular to a culture or community. (Focus on the socio-cultural role of language/its use in the formation of i…
Archaeology
The study of the patterns of behavior and the material record of humans in the past.
Difference between archaeology/paleontology
Archaeologists study artifacts: anything made or used by humans in the past. Paleontologists study fossils: evidence of past life.
Biological (physical) anthropology
The study of the biological and biocultural facets of human and nonhuman primates.
Primate skeletal biology
The comparative analysis of primate (human & nonhuman) skeletal and dental remains.
Anthropological primatology
The study of nonhuman primates for the purpose of understanding aspects of human behavior.
Forensic anthropology
The analysis of human remains to provide identification and cause of death information in legal cases & demographic data for archaeological research.
Paleoanthropology
The study of primate (nonhuman and human) evolutionary biology & paleontology in order to understand human origins and variation.
Comparative human biology
Focuses on adaptive and genetic explanations for variation in modern human populations.
Fact vs preference
Science is driven by facts, not preferences. (Ex. gorillas are Nichols' favorite nonhuman primates, but she can't say they are our closest nonhuman primates because of preferences; chimps are our closest nonhuman primates.)
Hypothesis testing
1. Hypotheses are formalized questions testable by data. 2. Test results either support or fail to support hypotheses. (NOTE: hypothesis testing is never used to prove anything- hypotheses are timeless/can be modified by new data)
Scientific hypothesis vs. scientific theory
Theory: A well-substantiated explanation of some aspect of the natural world that can incorporate facts, laws, inferences, and tested hypotheses.
3 criteria of scientific theory
A scientific theory... 1. Must provide a conceptual framework for research and inquiry. 2. Must be based upon a coherent group of principles that explain a class of facts and must be verifiable 3. Must withstand the test of time and the appearance of new evidence. (Ex. Modern evolutionar…
Evol-
Greek root meaning to unfold from.
Aristotle
"The father of biology"; attempted to establish the rules that govern life using the scala naturae: aka the ladder of life, aka great chain of being, implies that life forms unfold from each other moving upward in complexity toward a goal (goal-driven scheme)
Issues with the scala naturae (3)
It implies nonhuman organisms are: 1. less complex 2. less evolved 3. trying to become human
Orthogenesis
The concept of directed evolution. (guided evolution toward a fixed goal- issue: we now know that evolutionary outcomes are a product of chance and are not goal directed)
Carl Linnaeus
Established the modern, hierarchical, taxonomic classification system in 1758- taxonomic units range from most inclusive (domain) to most exclusive (subspecies); taxonomic classification doesn't support orthogenesis. Every taxonomic unit is a discrete unit holding a select group of organ…
Taxonomy
The science of classification. Taxonomic classification provides insights on genetic relationships/implies evolutionary relationships.
Binomial nomenclature
A system of identifying species by two names. The first, the genus, is always capitalized. The second, the species, is never capitalized.
Who believed the earth was 6,000 years old? (3)
Kepler, Ussher, Lightfoot
Law of superposition (Steno & Arduino)
Lower rock layers are older than higher rock layers (youngest to oldest: quaternary, tertiary, secondary, primary)
James Hutton
First scientist to publicly state that the earth is older than 6,000 years old- the earth had always been in a constant state of change/its rock layers were the product of large amounts of time. 1. horizontal rock layers are uplifted/tilted by tectonic activity 2. erosion levels off thes…
Biostratigraphy (William Smith)
First geologic dating technique- each stratigraphic layer in a vertical column of rock holds a unique assemblage of fossil organisms (able to tie distant rock exposures together/age rock layers & their fossils relative to each other); does not provide chronometric dates in years.
Principles of geology (uniformitarianism)
1. Uniformity of law (through space/time, natural laws remain constant) 2. Uniformity of process (past events were caused by the same variables that cause modern events) 3. Uniformity of rate (change occurs at a slow & steady pace) 4. Uniformity of state (change is non-directional; it has…
When were the "principles of geology" published/who wrote them?
Charles Lyell; this was a 3 volume publication from 1831-1833
Approximately how old is the earth?
4.6-5 billion years old
Catastrophism
Non-evolutionary hypothesis: 1. catastrophic events cause the extinction of organisms in a particular place 2. unrelated organisms replace the extinct organisms
Georges Cuvier
Established the fact that fossils represent extinct life forms. Supported catastrophism. Not an evolutionist. Thought that species were produced by spontaneous generation/are immutable (do not change over time)
Cuvier's conclusions (3)
1. Fossils are evidence of extinction 2. past/present communities are not identical 3. past/present communities are unrelated (first two are supported but the last is not)
Lamarck
Inheritance of acquired traits; didn't support extinction, rather each fossilized organism was evolving to become a higher species (orthogenesis). Correctly determined that the "fixity" of species was an illusion and that species do evolve, but his mechanism of evolution was incorrect.
Lamarckism (Theory of Evolution by means of the Inheritance of Acquired Traits)
1. New species are produced by spontaneous generation 2. Environmental change creates new challenges 3. In response, each species shifts its bodily fluids to create new body parts/improve old body parts 4. Through use, body parts become better; disuse leads to resorption of old and unnece…
HMS Beagle voyage
1831-1836: Darwin's job as the ship's science officer was to obtain type specimens (the ideal representative of a species) of extant plants/animals for research collections in England. Also collected behavioral data/fossils of extinct organisms.
Geological events Darwin experienced during HMS Beagle voyage (3)
1. Volcanic eruption 2. Earthquake 3. Tsunami (Lyell's principles of geology provided Darwin with insights about these events/Darwin began corresponding with Lyell)
Galapagos species
1. Tortoise (largest of all modern tortoises) 2. Only known marine iguana 3. Cormorant (only cormorant that can't fly) 4. Blue-footed booby 5. Penguin 6. Albatross 7. Hawk 8. Finches (despite large amounts of variation, Darwin didn't identify natural selection as the mechanism of evolutio…
What did Darwin learn during his time aboard the HMS Beagle?
There is a prevalence of variation in nature.
When was Darwin's "Origin of Species" published?
1859 (sold out on the first day/2nd edition with modifications was printed in 1860)
Darwin/barnacles
Darwin conducted 8 years of anatomical research on barnacles to test his hypotheses on variation
Darwin/earthworms
Darwin studied the behavior of earthworms/tested their contribution to soil turnover.
Darwin/pigeons
Darwin used pigeons to breed for specific traits to study artificial selection.
Thomas Malthus
Wrote the principle of population which was published in 1798. (Thomas Malthus goes with population thinking.) Believed that increasing population size was a warning that population size would soon decline.
Concepts on which Malthus' population principle is based (2)
1. Resources are finite 2. Reproductive potential of resource users is infinite (population size increases until it surpasses resource capacity; population size crashes; survivors of the crash have advantages that are absent in non-survivors [survivors are more fit]; Darwin applied Malthu…
Basis of natural selection
Environments are in a constant state of change. Population variation provides options for population responses to environmental stressors. Some traits are favored under certain conditions while others are favored under other conditions. (Operates on intraspecies variation that over time …
TH Huxley
Birds evolved from dinosaurs. Horses evolved from a 5 toed ancestor. Aldous Huxley's grandfather. Apes are our closest relatives. HMS Rattlesnake: ship's assistant surgeon.
Alfred Wallace
Biogeography: the study of the geographical distribution of species. Supported natural selection. Prompted Darwin to publish the origin of species.
Social Darwinism
Victorian England supported social darwinism to justify social inequities (class distinctions were interpreted as biological facts- higher social classes were the result of good breeding); developed into later racist eugenics policies.
How is population variation maintained?
Proposed answer of blending inheritance: 100% of each parent's heritable materials are transferred to offspring & blend together. (Doesn't support population variation: if every gene is inherited by every offspring, then population variation will disappear)
Principles of Heredity
Established in 1865 (published in 1866) by Gregor Mendel. This work was not known until 1900- 18 years after Darwin's death.
Classical Genetics (Mendelian Genetics)
The study of the patterns and processes of inheritance; it combines Mendelian hereditary principles with chromosomal inheritance.
Molecular Genetics
The study of DNA properties and functions.
Simple traits
1. Controlled by a single gene 2. Discrete expression (present or absent) 3. Not susceptible to environment (Mendel studied simple traits for his research)
Complex traits
1. Controlled by multiple genes 2. Continuous expression (range of variation) 3. Susceptible to environment
Trait
Characteristic with alternate phenotypes
Phenotype
Physical expression of a trait variant
Dominant phenotype
Tends to be most common
Recessive phenotype
Tends to be less common
Genotype
The allelic pair for the same gene
Allelic pair
The 2 alleles that form the genotype for a trait in the offspring (1 allele from each parent)
Allele
One of two alternative forms of alleles (dominant, recessive) for the same gene
Dominant allele
Causes expression of the dominant phenotype regardless of the type of allele with which it is paired.
Recessive allele
Cannot express the recessive phenotype if paired with a dominant allele- it will only be expressed if its allelic partner is recessive.
Characteristics of Mendelian traits
1. Each Mendelian trait has two phenotype variants 2. Each Mendelian trait phenotype is the expression of a specific genotype 3. Simple traits only
Why did Mendel use the common pea plant to study heredity?
1. It's easy to grow 2. Pollination is easy to control 3. Pure lines (pure lines breed true for a specific traits) were available and could be easily checked 4. Reproduces in large numbers (pea plant study didn't support blending inheritance- there were no yellow-green peas)
The heterozygous condition
Expression of the dominant phenotype but carrier of the allele for the unexpressed recessive phenotype- heterozygosity maintains variation
Law of segregation
States that each parent contributes half of an offspring's genetic material
Law of independent assortment
States that genes controlling different traits are inherited independently of other traits. (This applies as long as genes are located on different chromosomes); dihybrid crosses support this law
Modern evolutionary theory
The combination of Darwinian natural selection and Mendelian heredity principles.
Autosomal/sex chromosomes
We have 23 chromosome pairs (46 total chromosomes); pairs 1-22 are autosomal chromosomes. The 23rd pair are sex chromosomes.
Variable expressivity
Variability in the expression of a trait- polydactyly (extra toes/fingers- can vary in number of extra digits)
Environment/detectability of traits
The environment can influence our ability to detect some traits. PTC strength as it relates to ability to taste it. Tongue is influenced by age/behavior
Which parent determines the sex of a child?
The male- males can contribute an x or y chromosome and females can only contribute an x chromosome.
Why are sex-linked genetic disorders less likely to occur on the y chromosome? (4)
1. It's shorter (shortest chromosome in the body) 2. Holds fewer genes 3. Only 50% of the population has a y chromosome 4. That population only has one y chromosome
Why are most sex-linked genetic disorders associated with the X chromosome? (4)
1. It's longer 2. Has more genes 3. 100% of the population has an X chromosome 4. 50% of the population has 2 X chromosomes
Hemophilia
A debilitating disease typified by excessive bleeding because blood cannot clot. Hemophilia A/B are X-linked recessive traits
X-linked recessive genotypes in females
Homozygous dominant; homozygous recessive; heterozygous
X-linked recessive genotypes in males
Hemizygous dominant (doesn't express the trait-normal); Hemizygous recessive (expresses the trait); males are more likely to express x-linked recessive traits than females because they only have one X chromosome (hemi means half)
The Romanov story
1. Cultural behavior, preferential mating within a small group of related individuals, spread and maintained the allele for hemophilia within the royal houses of Europe 2. The same cultural behavior also resulted in the genetic data that allowed forensic identification of murder victims a…
Mutation
The source of entirely new genetic variations; a random change in a gene or chromosome, creating a new trait that may or may not be advantageous.
Hugo Devries
Discovered mutations
Thomas Hunt Morgan
Discovered that genes are located on chromosomes (used chemicals to stimulate mutations in fruit flies).
Morgan's discoveries (3)
1. Sex chromosomes carry genes that code for traits 2. Fruit fly eye color was carried on the X-chromosome 3. Fruit fly white eye color was a recessive X-linked trait (first time a gene for a trait was was attributed to a specific chromosome)
Hermann Muller
Radiation causes genetic mutations/increases mutation rates. Earned a nobel prize for demonstrating that radiation accounts for many lethal mutations in humans/warned against excessive radiation exposure.
Mechanisms of evolution proposed by the early 1900s (3)
1. Lamarckism (inheritance of acquired traits) 2. Natural Selection (Darwin) 3. Mutation (the only source of entirely new genes)
Why didn't people support the concept of natural selection?
Most evolutionary scientists did not recognize its compatibility with genetic heredity.
Population genetics (3 people associated with it)
Fisher; Haldane; Wright. Population genetics involves the investigation of the genetic makeup of a biological population; any change in gene frequencies (percentage of genotypes/alleles for a trait within a population) indicates evolution.
Hardy-Weinberg model
States that, in the absence of evolutionary forces, a population's allele and genotype frequencies will remain in equilibrium (stable) over time. In other words, changes in allele/genotype frequencies are due to evolutionary forces (evolution = change over time)
Fisher
Formalized the relationship between natural selection and heredity in "The Genetical Theory of Natural Selection"; he synthesized Mendelian principles with Darwinian evolution.
Haldane
Explained how an evolutionary force known as gene flow contributes to genetic variation
Gene flow
Involves the movement (migration) of genes between populations; the process has greatest effect when large numbers of genes migrate. (Interpopulational gene movement)
Wright
Recognized an evolutionary force known as genetic drift.
Genetic drift
Involves random changes in allele frequencies across generations, with most effect in small populations. With genetic drift, a population is isolated from a larger population; by chance, its gene pool (sum of all population alleles) has a changed allele frequency and some alleles that we…
Principle subsets of genetic drift (2)
1. Founder Effect 2. Bottlenecking
Founder Effect
Involves the isolation of a small founding population. By chance, its allele frequencies differ from those of the original population. Over time, natural selection on different phenotypes under different conditions reshapes the gene pool further.
Bottlenecking
Involves dramatic loss of genetic diversity usually due to natural disaster. By chance, individuals and their alleles are removed from the gene pool. Smaller survivor populations have a changed gene pool. Natural selection operates on survivor phenotypes under new conditions and this resh…
Variables that must remain stable to prevent evolution from occurring (4)
1. No mutations 2. No emigration or immigration (gene flow) 3. No change in population size or population isolation (genetic drift) 4. Traits have equal fitness; no differential reproduction (natural selection)
Natural selection
Operates on population phenotypes; individuals with favored phenotypes are most likely to contribute alleles for these traits to the next generation. This changes population allele/genotype frequencies.
Forces of evolution (4)
1. Mutation 2. Gene flow 3. Genetic drift 4. Natural selection (each evolutionary force contributes to population variation)
Why is natural selection the primary mechanism of evolution?
Genes do not directly interact with the environment. Mutation, gene flow, and genetic drift concern genotypes for phenotypes. Natural selection is the only mechanism of evolution that acts at the phenotypic level.
Julian Huxley
Gave the fusion of Darwinian evolution/Mendelian heredity its name: Modern Synthesis.
Ernst Mayr
Mayr replaced the "typological species concept" with the "biological species concept"
Typological species concept
Conforms to an ideal "type"- it lacks variation- this concept doesn't work well with natural populations and an evolutionary theory based upon population variation as normal/necessary
Biological species concept (Mayr)
A group of interbreeding natural populations that can produce fertile offspring. This works well with living species but is difficult to apply to extinct species (reproductive variability is hard to measure in fossilized bones/teeth).
Sexual dimorphism
(ex. men are normally taller than women) Physical differences in adult males/females of the same species that do not include reproductive organs.
GG Simpson (evolutionary paleontology)
Applied the modern synthesis of evolution (natural selection + heredity) to the fossil record. Demonstrated that there is NO support for orthogenesis in the fossil record.
Sherwood L Washburn
Biological anthropology (holistic approach): brought the modern synthesis of evolution to anthropology. Replaced "race-based" exercises with adaptive studies of human variation. (Developed an accurate account of what the first humans looked like before they had been discovered.)
Characteristics of the earliest humans (3)
1. In their trunks/arms, the earliest humans would look like apes. 2. In their hips/legs/feet, the earliest humans would have bipedal adaptations. 3. Modern human large brain size/small face are later adaptations associated with the development of language, technology, and culture.
Sexual selection
A special subset of natural selection, which also contributes to population variation; involves changes in reproductive success due to selection for traits that enhance mating opportunities. (male competition/female choice)
Male competition
Male armaments used to defeat other males/win the right to reproduce (ex. male stag beetle has large pincers). Often tied to seasonal breeding/hormone production.
Female choice
Females choose males with the most attractive traits; drives most sexual dimorphism. (Among primates, female choice is more common than male competition.)
Ringtail lemurs (choice/competition?)
Male competition- engage in stink fights.
Pygmy Marmosets (choice/competition?)
Female choice- females pick males that will babysit/carry their offspring around.
Proboscis Monkeys (choice/competition?)
Female choice- females pick males with larger noses.
Female choice- females pick males with larger noses.
Female choice- females pick males with colorful faces/butts.
Savanna Baboons (choice/competition?)
Female choice- females pick males that are nice/guard their offspring.
(T/F) Some biological anthropologists today study adaptive variation in modern human populations in connection with cultural adaptations, others work in forensics and skeletal biology, and others focus on primate behavior.
True
Adaptive job
Niche
Adaptive address
Habitat
Archaeologist's task
Studies cultural behaviors in prehistory
Cultural anthropologist's task
Studies cultural behaviors in the present
Key contributors to our understanding of earth's deep age (3)
Hutton; Smith; Lyell
Mitosis
Somatic cell division
Meiosis
Gamete cell division
What directs protein synthesis?
DNA
Diploid Cell
46 chromosomes
Haploid cell
23 chromosomes
Who were the founders of modern synthesis? (3)
1. Mayr (biologist) 2. Simpson (geologist) 3. Washburn (anthropologist)
Who lacked knowledge of the principles of heredity?
Darwin
Who understood heredity but didn't know the source of new genetic variation?
Mendel
Who understood heredity and mutation?
DeVries

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