GeoSci 110 Evolution & Extinction

Neoplatonism

The universe is interconnected and there is no distinction between living & nonliving things; plastic force

Glossopetra

("tongue stones"), were fossilized giant shark teeth taken from limestone deposits; used by magicians and was believed to come from Heaven

Aristotelianism

The difference between living and nonliving is more distinct and includes spontaneous generation

Nicolas Steno

Laws of Superposition, Original Horizontality, and Lateral Continuity; Shark direction disproves glossopetrae

Low Probability of Fossilization

Soft organisms: slug

Small parts: star fish

High Probability of Fossilization

Hard organisms

Big parts

Carl Linnaeus

Hierarchical classification of animals/animal kingdom

Prokaryote

no nucleus, Archaea and Bacteria

Eukaryote

has nucleus, Eukarya

James Hutton

Father of Western Geology, importance of angular unconformities

Uniformitarianism

Things today can be used to infer the past, some processes that occur today have always operated in the past and will continue to operate in the future.

Charles Lyell

Uniformity in nature, empiricism and observation

George Cuvier

Vertebrate paleontology, subordination of characters

Correlation of Parts

animals/vertebrates are machine-like and ordered, body shows purpose, comparative anatomy

Subordination of Characters

all traits are important to an organisms survival, comparative anatomy

Comparative Anatomy

the study of similarities and differences between living and fossil organisms.

Jean Baptiste Lamarck

Studied invertebrates, extinction of lineages does not happen, organisms continue increasing complexity until reaching ideal perfection

Homologous Structures

shared similarities in structures that are not necessary

Analogous Structures

functionally similar structures that are constructed differently

Vestigial Structures

structures with no apparent purpose, often reduced in size

William Smith

Faunal succession and geological time (geological map of England)

Faunal Succession

fossils are consistent within strata, showing its age

Charles Darwin

Origin of coral reef atolls, Survival of the Fittest, Origin of Species

Allometric Growth

Shaped change, differences between juvenile and adult forms

Isometric Growth

Proportions are relatively the same throughout development

Heterochrony

changes in timing of developmental events

Heritability

predictability of traits from one generation to the next being transferred

Geographic variation

morphologically different from place to place, isolation, small population

Temporal variation

morphologically different over time in the same region

Density-Independent Checks on Population Growth

checks that are not impacted by population density, natural disasters

Density-Dependent Checks on Population Growth

checks that are affected by population density, disease

Logistic Growth

Increase in population until it reaches carrying capacity

Variability

Offspring are not exact copies of parents

Heritability

Traits passed to offspring

Differential Reproductive Success

Individuals with advantages contribute to more successful offspring

Fitness

Relative ability of an individual to reproduce and contribute offspring to the next generation

Directional Selection

Over time the population move along with fitness

Stabilizing Selection

Fitness is average and common

Disruptive Selection

Increase extremes, two distinct populations form

Drift

No heritability, completely random selection

Phenotype

Physical expression of traits

Genotype

Genetic makeup that determines phenotype using two alleles from each parent

Homozygote

two copies of the same allele

Heterozygote

one dominant and one recessive allele

Incomplete Dominance of Alleles

Both alleles of a gene are partially expressed, an intermediate

Co-Dominance of Alleles

Equal expression of alleles

Pleiotropism

one generation where a single gene influences multiple phenotypic traits

Epistasis

the effect of a mutation is dependent on genetic background

Ecopheqotypic variation

interaction of genes and the environment, one set of genes with many possible outcomes

Chromosomes

location of alleles and hereditary materials, humans have 23 pairs

DNA

deoxyribonucleic acid, fixed composition, sugar and phosphate with nitrogenous base

Purines

Adenine and Guanine

Pyrimidines

Thymine and Cytosine

Helicase

unzips double stranded DNA

Primase

generates short strands of RNA to initiate DNA synthesis

DNA Polymerase

adds to the 3-prime end, replicating the leading strand and assembling new strands

Point Mutation

mistake made during replication

Proteins

chemical compounds, single linear chain of amino acids

R-groups

determine protein shape and function

RNA polymerase

synthesizes RNA strands from DNA strands

RNA

Ribonucleic acid, hydroxyl group on 2-prime

Pyrimidines (RNA)

Uracil and Cytosine

mRNA

messenger, basic info for sequencing amino acids

Ribosome

coordinate the interaction between mRNA and tRNA to make amino acid chains (proteins)

tRNA

transfer, RNA with double and single stranded regions

Codon

3 base sequence identifying 1 of 20 amino acids

Insertions and deletions

slippage during replication, causes addition or deletion of bases, shorter or longer strands

Gene

regions of DNA that are transcribed and translated

Exons

directly translated, determine sequence of amino acids in proteins

Introns

untranslated pieces of DNA between exons, removed after making RNA

Reverse transcription

transfer into from RNA back to DNA, retroviruses (HIV)

Regulation of gene expression

extent to which genes are transcribed into functional mRNA to proteins

Transcription factors

proteins that regulate gene expression via transcription

Specificity factors

affect affinity of RNA polymerase for specific promoters for a gene on the DNA strand

Activators

recruit RNA polymerase to the promoter gene to increase expression

Repressors

bind to non-coding portions of DNA near or on promoters, interfere with RNA polymerase and prevent transcribing

Chromatin

complex of DNA and proteins, compact structure of chromosomes in eukaryotes

Open chromatin

allows RNA polymerase access and facilitates gene expression

Pre-transcription

before mRNA formation, controlling RNA polymerase, inhibit/promote transcription, regulate amount of transcript produced

Post-transcription

interception of mRNA prior to transition into protein in a ribosome, prevent expression

Pluripotent Cells or Cell Fate

cells can become anything if given the right signals, stem cells

Homeobox Genes

code for transcription factors that initiate a regulatory cascade of gene expressions during developments that determine cell fate and differentiation, used to make mRNA and proteins

Morphogenetic Mutations

individuals that display abnormal or altered patterns of development

Antennapedia Mutant

In fruit flies, anteriorly causes segment identity to be confused

Ultrabithorax Mutant

Wings and legs in insects, homozygous for reduced function of alleles,

Hox Gene

a group of genes critical for the development of the body plan

Viruses

a protein coating surrounding nucleic acids and proteins that infect living cells to reproduce

Synonymous Mutation

DNA changes that do NOT affect the protein sequence, environmentally neutral and functionally silent, cannot be removed from populations by natural selection

Non-synonymous Mutation

change protein sequences, subjected to natural selection

Genetic Switches

small segments of DNA that do not code for proteins that affect recruitment of RNA polymerase (pre-transcription regulation), turn on and off the genes that are expressed

Mitosis

cells replicates chromosomes and segregates them, producing two identical nuclei to prepare for cell division

Meiosis

type of cell division where the number of chromosomes in gametes (sex cells) is reduced, produces gametes

CRISPR

harnessing bacterial viral defense mechanisms for genetic engineering

Species

groups of interbreeding populations that are reproductively isolated from other groups

Reproductive isolation

continuity of information between generations, permits local adaptation and/or drift to result in divergence, allows natural selection (think Hawai'i!)

pre-zygotic isolation

union of egg and sperm never occurs, does not permit viable fertilization, caused by differences in number of chromosomes or chemical signals

temporal isolation

peaks of sexual activity in different populations/species do not overlap in time to reproduce

behavioral isolation

different displays and rituals like mating calls