What is the biological term for reproductive success?Fitness November 24, 1859The day Charles Darwin publishedOn the Origin of Species by Meansof Natural SelectionAlfred Russell Wallacepublished hisown article on the topicthe same day. Darwin and Wallace made two major points:1. All organisms on Earth are related, and descend from a single ancestral species.2. This diversity resulted from a processcallednatural selection. The Greek philosopherAristotleViewed species as fixed and unchanging Carolus Linnaeus

Believed that a God designed each species for a specific purpose.

He created the Linnaeus system of classifying species for the greater glory of God

studying fossilshelped to lay the groundworkfor Darwins and Wallaces ideas. Fossilsremains or traces of organisms from the past What are fossils usually found in?Sedimentary or volcanic rock What are the layers of sedimentary rock called?strata PaleontologyStudy of fossils George CuvierFrench scientist that developed paleontology.He came up with the idea of "Catastrophism" catastrophismspeculating that each boundary between strata represents a catastrophe. GradualismIs the idea that profound change can take place through the cumulative effect of slow, continuous processes. Lamarckhypothesized that species evolvethrough the inheritance ofacquiredtraits Ernst MayrLays out the logic of Darwins and Wallaces theory:1. not all offspring survive and reproduce2. Resources are limited (struggle for existence)3. No two individuals are exactly alike

Therefore:Individuals whose traits give them ahigher chance of surviving and reproducing willleave more offspring than others.

Natural selectionthe survival and reproduction of someindividuals and not others. Examples of natural selection drivesthe adaptation of organismsto their environmentA flower mantid in Malaysia

A stick mantid in Africa

Choosing between cloning and reproducing, when would cloning be best?When the environment is favorable and stable. Homologysimilarity resulting from common ancestry

example: Cats- lions, house cats....

HomologousstructuresAre similarities that show variations of a trait that was present in a common ancestor

The evolutionary tree of life explainshomologies biogeographygeographic distributions of species, formed an important part ofDarwin's theory. -Biogeography can trick you. speciationThe origin of new species Dolphin With Four Fins Shows Terrestrial OriginsNational Geographic News: Japanese fishers have foundan unusualbottlenose dolphinwith an extra set of fins that are an evolutionary throwback to the time when the mammals' ancestors walked on land.

Macroevolution

is evolutionary change that produces newtaxa TaxonA named group of organisms

two basic patterns of evolutionary change:Anagenesis (transformation)-phyletic evolution, the accumulation of changes associated with the gradual transformation of one species into another.

Cladogenesis (branching off)- branching evolution, the budding of one or more new species from a parent species. - promotes biological diversity by increasing the number of species.

CladeIs a group of taxa including an ancestral species and all of its descendants

Each branch in an evolutionary tree Cladisticsthe studyof this branchingprocess speciesA population whose members have the potential to interbreed in nature and produce fertile offspring Diversity within a species.

As diverse as we are in appearance, all humansbelong to a single species (Homo sapiens), defined by our capacity to interbreed

Reproductive Isolationprevents members of two species fromproducing viable hybridsThere are different forms of reproductiveisolation: 1. Prezygotic 2. Postzygotic Prezygoticbarriers

Impede mating or hinder fertilization ifdifferent species attempt to mate

Postzygotic barriers

prevent a hybrid zygote from developing into a fertile adult

habitat isolationwhen individuals of different species evolve genetic preferences for different habitats in which they live or mate, they may never come into contact during their respective mating periods. Temporal isolationSpecies may breed at different times of year or different times of day Behavioral Isolation Specificcourtshipbehaviors, signals/calls, or pheromonesmust be observed before reproduction mechanical isolationprezygotic; can't link up; mating is attempted, but morphological differences prevent it successfully completing Gametic IsolationOccurs when male gametes do not survive in the environment of the female gamete (such as in internal fertilization) or when female gametes do not recognize males gametes. reduced hybrid viability.genes of the different parent species may interact and impair the hybrid's development or survival in its environment. reduced hybrid fertilitypostzygotic barrier in which hybrid offspring are vigorous but sterile Hybrid BreakdownPostzygotic barrierSome first generation hybrids are viable and fertile, but when they mate with one another or a parent species, offspring are either feeble or sterile. morphospeciesCharacterizes a species in terms of its body shape, or other structures

paleospeciesMorphologicallydiscrete speciesknown only fromthe fossil record ecologicalspeciesViews a species in terms of its ecologicalnicheex: Huia phylogenetic speciesDefines a species as a set of organismswith a unique genetic history EpigeneticsStudy of how environment can alter gene expression or function Speciation can occur in two ways1. Allopatric Speciation2. Sympatric Speciation

Allopatricspeciationa new species formsafter isolation.

Sympatricspeciationpart of a population becomes a new species without geographicseparation. Selective Breeding and Wild MustardKohlrabi - StemKale - LeavesBroccoli - Flower buds and stemsBrussels Sprouts - Lateral BudsCabbage - Terminal BudsCauliflower - Flower Buds Adaptive radiationEmergence of many species from one common ancestor when introduced to a new environment -Ex: African lake cichlids- fish with different colors at different depth levels. Researchers placed two fish species together. Under orange light, the two appear identical,what happened?The resulting hybrids were fertileIt appears that that mate choice by females is the main barrier that keeps these two species separate.Since they can still interbreed, the genetic divergence between the species is probably small. This suggests that speciation has occurred relatively recently.

punctuated equilibriuma model of macroevolutionary change in which long periods of little evolutionary change are followed by relatively short periods of rapid evolutionary changecoined by Gould and Eldredge. GradualismSpecies descended from a common ancestor gradually diverge as they acquire unique adaptations PunctuatedequilibriumA new species changes most as it buds from a parent species and then changes little for the rest of its existence. Macroevolutionary change

Is thecumulativechange of thousands of smallchanges

neotenyretention of juvenile features in adult form.ex: Humans have retained the early growth patterns of chimps

phylogenyThe evolutionary history of a taxon systematicsA technique for analyzing relatedness between organisms

Systematistsdevelops hypotheses about relatedness-That are tested and updated as science advances

Phylogenies(or family trees) are based onthree kinds of evidence of common ancestry: -Fossil, Morphological, and Molecular analogyconvergent evolution

homologysimilarity due to shared ancestry One potential miss-step in constructing aphylogenyIs similarity due toconvergent evolution,calledanalogy, Convergent evolutionoccurs

when similar environments produce similar adaptations in unrelated organisms.Ex: Flying squirrel and sugar glider

TaxonomyIs the grouping of organisms into categories based on their similarities

Phylogenetic systematicsconnects taxonomywith evolutionary history

note: getting it right is difficult. cladogramIs a graphic depiction of a clade

monophyleticit consists of the ancestor species andallof its descendants

paraphyletic cladeIs an erroneous grouping that consists of an ancestral species and some, but not all, of the descendants

polyphyleticgroupingcombines multiple organisms that are not close relatives

ex: Pachyderms

Shared primitive character- is a homologous structure that predates the branching of a particular Clade- it's a characteristic that is shared beyond the taxa your trying to define. shared derived charactercharacteristic evolutionary novelty to a clade

ex: hair to mammals, found on all mammals but not in their ancestors ultrametric tree

contains data from the fossil record to place branches in the context of geological time parsimonious tree

is the one that requires thefewestevolutionary events (or shared derived characters) to have occurred

It's the simplest answer Molecular Clockuses DNA comparisons toestimate length of time that 2 species have been evolvingindependentlyex: Has been used to estimate that human and chimpanzees probably diverged around 5 million years ago

The tree of life is divided into three great clades called domains-Bacteria-Archaea-Eukarya the bacteria and archaea are combined into a group called the prokaryotes eukaryotesAre everything else that is not a prokaryote, ranges from single-celled organism up to complete multi- cellular organism

The theory ofendosymbiosis

Proposes thatmitochondriain animals andchloroplastsin plants were formerly smallprokaryotes living within larger host cells

cyanobacteriaOxygenic photosynthesis probably evolved about 3.5 billion years ago in prokaryotic organism called cyanobacteria.

still doing fine today Modified Cyanobacteria Converts CO2 into Fuel

The combustion of gasoline releases hugeamounts of CO2, a greenhouse gas directlycontributing to climate changeThis new system will recycle CO2And its done naturally using solar energy Oxygen began accumulating in the atmosphereabout?2.7 billion years ago

AnaerobicMetabolic processes that does not require oxygen.

- upon mass extinction anaerobic organisms were driven away to survive in only the tiniest corners of the planet where oxygen could not reach. prokaryotesMost prokaryotes are unicellular, microscopic and can live almost everywhere.the number of living prokaryotes in ahandful of soil Is greater than the number of people who haveever lived

some form coloniesThey have remarkable genetic diversity(Which you might expect, since theyve been evolving for a very long time

Prokaryotic shapes round (coccus) rods (bacillus) spirals (spirochetes) fimbriaeHairlike structures, which some prokaryotes have that allows them to stick to their substrate or other individuals in a colony

FlagellaStructure: microtubule-containing extension that projects from some cells function: acts as a locomotor appendage.How most motile bacteria propel themselves. Binary fissionA method prokaryotes quickly reproduce by.-Can divide every hour if conditions are good. plasmidsSome also have smaller rings of DNA called Horizontal gene transfer Gene transfer occurs when genes are passed between different species gave rise to all modern species -viruses (transduction) endosporesA form which many prokaryotes can remain viable in harsh conditions for centuries Obligate aerobes

requires oxygen

Obligate anaerobes

- Require no oxygen for growth-poisoned by oxygen Facultative anaerobes

can survive with or without oxygen The two largest groups of bacteria are:

TheproteobacteriatheGram-positive bacteria

ArchaeaDiscovered recently, they share some traits with bacteria and other traits with eukaryotes.-No Archaea are known so far to cause disease-None form spores

thermophilesSome archaea live in extreme environments- live in very hot environments

halophilesLive in high saline environments

MethanogensLive in swamps and marshesProduce methane as a waste product

decomposersThey break down corpses, dead vegetation,and waste products

Prokaryotes play a major role inrecyclingchemicals in ecosystems.

SymbioticLiving very near or within another organismMany prokaryotes have symbiotic relationships commensalbacteria are mostlycommensal,sharing our food but doing no real harm.

pathogensare harmful organisms that cause infection, such as viruses and bacteria. bioremediation

using organisms, prokaryotes to remove pollutants from the environment

polymerizewhen two molecules concentrate together and form chains ProtobiontsAre clusters of molecules surrounded by a membrane-like structure.

- They form spontaneously from organic compounds

liposomesmembrane-bound droplets calledliposomesform when organic lipids are addedto water

The steps for creating life?1. The formation oforganic molecules2. These joining intopolymers.3. Then collecting intoprotobionts, withmembranes.4. The origin ofself-replicating moleculesthat made inheritance possible. The first genetic materialwas probablyRNA Index fossilsAre similar fossils found in the same strataThey allow us to date strata at different locations radiometric datingFossils ages can be found withradiometric datingFossils contain elements that accumulated whilethe organisms were alive. Four EonsHadean, beginning about 4.5billion years agoArchaeanbegan 3.9 billion years agoProterozoic-began 2.5 billion years agoPhanerozoicbegan 540 million years ago

HadeanBegan about 4.5 billion years ago

when the Earth and solar system were forming. Archaeanbegan 3.9 billion years ago.

Life on Earth arose during this eon.

Proterozoicbegan 2.5 billion years ago-Earth developed an oxygenatedatmosphere during this time.-And multicellular life arose. Phanerozoicbegan 540 million years ago

Each time period ends with major changes in fossils. Twomass extinctionsare the best knownThePermian extinction,248 million years ago Killed about 96% of marine species May have been caused by volcanic eruptions

TheCretaceous extinction, 65 million years ago Doomed half of all known organisms, Is thought to have been caused by a huge meteor

stromatolitesThe oldest known fossils arestromatolitesLayers of bacteria and sedimentWhich date back 3.5 billion years The First EukaryotesThe oldest eukaryotic fossils were tiny algae that date back 2.1 billion years The first multicellular organisms

Molecular clocks date the ancestor ofmulticellular eukaryotes to 1.5 billion yearsMulticellularity has actually evolved multipletimes coloniesThe first multicellular organisms -Clusters of autonomously replicating cells -Later, some cells in the colonies becamespecialized for different functions

Two animal groups that date back from the late ProterozoicTwo animal groups, Cnidaria and Porifera are somewhat older, dating from the late Proterozoic Photoautotrophs

autotrophs that use light as an energy source

which containchloroplasts HeterotrophsOrganism that obtains energy by eating other organisms (consumer) mixotrophsusing photosynthesis and heterotrophy Protozoansthe single-celled wigglers:-Some live in anaerobic environments-Others are aerobic

Euglenozoansmove with flagellaThey can be photosynthetic AND predatory KinetoplastidsSomeKinetoplastidsare pathogenssuch astrypanosomewhich causes sleeping sickness in humans trypanosomecauses sleeping sickness in humans-fatal if not treated-found in Africa

Apicomplexans

Are animal parasitesAre named because one end, the apex, ispointed for penetrating tissuesex: malaria Darwin mayhave sufferedfromthe NewWorld version,called Chagasdisease Dinoflagellates

Are abundant marinephytoplankton

Rapid growth of some dinoflagellatesIs responsible for causing red tides, whichcan be toxic to fish and human

Ciliatesa large group of protistsAre named for their use of cilia to move andfeedAn example:Paramecium conjugationa sexual process that produces genetic variationConjugation isseparatefrom reproduction, whichgenerally occurs by binary fission Oomycetesaka: water moldswere onceconsidered fungiNow we know that they are protistsTheir bodies composed of filaments-Irish channel Diatomsare unicellular algaeWith a unique glass-like wall ofsilica Foraminiferans

or foramsAre protists named for their multichambered shellsThese are commonly fossilized little shells of calcium carbonate can tell youthe sea level, temperature, andocean conditions of Earth millions of yearsago. (T/F) Tiny shells can help assess recovery after oil spillTrue Amoebozoansextend their bodies into lobeshapedpseudopodiaThey envelop their prey in them GymnamoebasAre common in soil as well as freshwaterand marine environmentsMost gymnamoebas consume bacteria andother protists EntamoebasAre parasitesOne causes amebic dysentery in humansAnother can eat your brain mycetozoansaka: Slime molds,were oncethought to be fungiDNA studies show that that they are giantamoebas ChlorophytesGreen algae Volvoxa colonial chlorophyte phaeophytesaka: Brown algae,are multicellularAre the largest and most complex algaeWe call them seaweeds