Evolution

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Evolution!
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What is Evolution?

• Evolution- the genetic change of populations over
  time
• Population- group of organisms of the SAME
  species that occupies certain area
• Species- organisms that can interbreed and
  produce FERTILE offspring
• Ex) populations in Sauerman Woods Crown Point
• -whitetail rabbits -deer
• -sparrows -squirrels

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Liger (lion and tiger)-infertile
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Cama (camel and llama)-infertile
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How Do We Know Populations Evolve?

• Population Sampling- technique uses part of
  population to represent whole population
• Capture 100 random rabbits
• These rabbits are a representation of all the
  rabbits in the area.
• We can study many things within this group

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Genetics of the Population

• Gene Pool- all of the genes of every individual
  in population sample
• Frequency- how often something occurs
• Population genetics involves studying the
  frequency with which certain alleles occur in a
  populations gene pool
• In 50 years, will the ? allele frequencies be the
  same?

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Hardy-Weinberg

• Hardy-Weinberg Equilibrium Principle
  frequencies of the dominant and recessive alleles
  in a population change in time due to 5 things
• Mutations
• Migration
• Natural selection (survival of fittest)
• Small population
• Non-random mutation
• If these things occur, then the frequencies
  change and a population evolves

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History of Evolutionary Thought

• Before 1850, most people believed
• Earth formed by supernatural events and never
  changed
• Earth only a few thousand years old
• Each species was made to fit its environment
• Species never changed and did not go extinct

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Early Scientists Ideas

• Darwin deserves credit for the Theory of
  Evolution as we know it today
• He was not the first to come up with the idea
• Carl Linnaeus proposed a new system of
  organization for plants and animals based on
  their similarities (noticed relationships)
• Erasmus Darwin considered how organisms could
  evolve through mechanisms such as competition
• Jean-Baptiste Lamarck presented evolution as
  occurring due to environmental change over long
  periods of time

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Carl Linnaeus

• Developed a classification system for the huge
  variety of living things he found
• Wrote book Systema Naturae in 1735 to reveal his
  classification system
• My closet!
• There are currently 1.9 million species that
  have been identified using his method
• Linnaeuss system of classification reflects
  evolutionary relationships

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Jean Baptiste Lamarck

• A French naturalist who proposed that populations
  of species evolve
• His idea proposed
• Changes in an environment cause an organisms
  behavior to change, leading to greater use or
  disuse of a structure or organ
• The organism would pass on these acquired changes
  to its offspring, so a species would change in
  time
• Idea called Evolution by inheritance of acquired
  characteristics
• Wrong on several accounts

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Charles Darwin

• At 22, was invited to sail on the HMS Beagle
• Was going to school to be a minister-believed God
  created each species to match its habitat and
  they never changed
• Thought Earth was about 6,000 years old and
  didnt change, just like everyone else

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Darwins Observations

• One place of note that he visited was the
  Galapagos Islands
• During journey, he made observations and recorded
  them in a journal
• Darwin observed fossil and geologic evidence
  supporting an ancient Earth

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Darwins Finches

• When Darwin traveled to the Galapagos he took
  interest in the finches
• He noticed the finch species on the islands were
  different, but all resembled one from S. America
• Darwin thought some migrated and new species
  evolved

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Darwins Finches

• This is what Darwin proposed
• Finches migrated from South America to the
  islands
• Populations on different islands adapted to
  different environments and food sources they
  found
• Those that could survive passed on their genes
• Those that couldnt survive perished

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Darwins Finches

• Over time different mutations accumulated in the
  different finch populations on the different
  islands
• The populations diverged, or became more and
  more different from each other

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Darwins Finches

• The populations on the islands became so
  different they no longer mated if they met
• Several new finch species evolved from a common
  ancestor from S. America
• This is an example of macroevolution

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Recent finch research
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Speciation

• Geographical isolation- members of a population
  are separated geographically
• Major step that leads to speciation
• Due to volcanoes, earthquakes, flooding, etc.
• Can lead to divergence and then speciation

Geographic Isolation!
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Artificial Selection

• Artificial selection- human intervention in
  animal or plant reproduction to ensure that
  certain desirable traits are passed on
• Instead of NATURE selecting which traits are
  favorable, HUMANS selectively breed those animals
  with favorable traits
• Ex. dogs or racehorses
• Darwin bred pigeons to
• explore this idea

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Darwins Results

• In 1859, Darwin published The Origin of Species
• His book stirred up controversy
• Idea called Evolution by natural selection

Darwin Video
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Darwins Book Explained Natural Selection

• Natural selection- organisms best suited to their
  environment survive and reproduce
• Darwins proposed mechanism of evolution
• Survival depends on the particular environmental
  conditions a species finds itself innature!
• If the environment changes, so do the populations
  that live there
• Adaptation- using inherited genetic
  characteristics to increase chance of survival in
  new environment
• Natural Selection and Salamanders

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Natural Selection

• Three conditions necessary for natural selection
  to occur
• Genetic variation Individuals within a
  population must be genetically different
• Random mutations are the raw material for
  evolution to occur!!!!!!!
• Overproduction of offspring More organisms are
  born than can survive
• Differential reproduction Certain traits enable
  individuals to survive and have more offspring
  than others

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Result of Natural Selection

• Genes that help a population survive in their
  conditions stay in their gene pool, while
  unfavorable genes gradually decrease in
  frequency
• This causes changes in the genetics of
  populations? EVOLUTION!!!!!
• As new mutations accumulate over a long time, the
  new populations no longer can mate with the
  original they started as. New species have
  formed!
• Natural Selection Animation

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Whose idea for evolution is this?
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What We Know Now

• Evolution is a Scientific Theory
• Not a hypothesis, or an educated guess, or a
  theory in laymans terms
• Unending amount of evidence to support it and
  NONE to reject it
• Evolution is called the unifying principle of
  Biology
• Isn't Evolution JUST a Theory?

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Types of Evolution

• Evolution - genetic change of a population of
  organisms over time? descent with modification
• Microevolution
• Small genetic changes of a population
• Shorter amount of time
• Bengal tiger simulation was microevolution

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Types of Evolution

• MACROevolution-When new species are formed over
  long periods of time
• Due to tremendous amounts of accumulated genetic
  changes in a population
• Speciation- formation of new species due to
  accumulated microevolution and mutations

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How does macroevolution work?

• dibosirdsaur
• GEOGRAPHIC ISOLATION
• dibosirdsaur
  dibosirdsaur
• 10 million years of accumulated mutations
• diosirdsaur
  ibosirdsaur
• 10 million years of accumulated mutations
• diosirdsaur
  iboirdsaur
• 10 million years of accumulated mutations
• dinoirdsaur
  boirdsaur
• 10 million years of accumulated mutations
• dinordsaur
  boirdsur
• 10 million years of accumulated mutations
• dinodsaur
  boirdsu
• 10 million years of accumulated mutations
• dinodsaurs
  boirds
• 10 million years of accumulated mutations
• DINOSAURS
  BIRDS

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EVOLUTION by natural selection
MACROevolution
Microevolution
Changes in gene frequencies in a population
Accumulated microevolution and mutations to
form whole new species
Examples Peppered moth and Bengal tiger
Shorter times
Examples Darwins finches and geographical
isolation
Longer times
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Evidence for Evolution

• Three types of evidence
• Fossils
• Anatomical
• Molecular

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Fossil Evidence

• Fossils- any traces of dead organisms
• dinosaur bones
• insects trapped in tree sap
• leaf impressions
• footprints

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Fossil Evidence

• Transitional species- species that have been
  found in the fossil record that are intermediates
  between two other species in the evolutionary
  process
• Radiometric dating- a dating technique that
  measures amount of radioactive material in a rock
  or fossil
• Relative dating- a dating technique that
  estimates the date of a fossil by relating it to
  the age of the layers of rock around it

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Fossil Evidence
Relative Dating
Radiometric Dating

• To fossilize an organism must be buried by
  sediment
• In swamps, mud, tar pits, or the ocean bottom
• Hard stuff fossilizes (bones, nails)
• Radiometric and relative dating are used to find
  out how old the fossil is

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Fossil Evidence

• Fossils show
• Life has been around for millions of years
• Transitional species link older to newer species
• Darwin proposed the idea of transitional species,
  though he had no evidence
• Today we have evidence
• Archaeopteryx
• Tiktaalik Fossil, etc.
• Whales

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Fossil Evidence-Archaeopteryx
WINGS
BEAK
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Fossil Evidence

• Whales--60 million years of evolution
• Descended from 4-legged wolf-like animals that
  were also ancestors to cows and horses
• Fossil evidence shows slow loss of legs
• Pelvis still remains with no rear legs

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Anatomical Evidence

• Anatomical evidence- evidence for evolution which
  is based on similarities and differences between
  the physical structures of different species.
• What can we tell about the relatedness of the
  three species below?

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Anatomical Evidence

• Homologous structures-Bone structure the same
  (homo) but not function
• Bird wing, dolphin fin, and a human arm
• Function these structures is not the same!
• Show that these species shared a common ancestor
• Similar structures resulted from accumulated
  mutations and modifications

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Homologous Structures
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Anatomical Evidence

• Analogous structures- Bone structure different
  but serve the same function
• Function flight
• Butterfly wing, bat wing, fly wing
• These structures, although they have the same
  function, are not built the same!
• Show different species evolved structures with
  similar function through different evolutionary
  pathways
• EVOLUTION IS NOT RANDOM!

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Anatomical Evidence
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Anatomical Evidence

• Vestigial structures-structures that no longer
  serve a function
• These structures are the remnants of an
  evolutionary past and show common anatomy with
  other species

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Molecular Evidence

• Molecular evidence- evidence concerning the
  comparison of DNA and protein molecules between
  species
• Ultimate tools for scientists studying evolution
• Same genetic basis for all organisms A, C, T,
  and G shows we are all related

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Molecular Evidence

• Mutations and sexual
• reproduction are a cause of
• variation in a species DNA
• DNA?mRNA?protein
• Transcription- copying the DNA code into mRNA
• Translation- converting the code of mRNA into a
  long chain of amino acids?protein
• Differences in DNA are seen in differences in
  protein and therefore, traits

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Molecular Evidence

• Species with more similar DNA are more closely
  related on the evolutionary tree
• Less time since they split to accumulate
  mutations (and, therefore, differences)
• Common ancestor- any species in the past from
  which two or more related species has evolved
• Evidence for Evolution

speciation event mutation

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Early Earth

• Earth is estimated to be about 4.6 billion years
  old
• Atmosphere was harsh
• Very Hot
• Lots of water vapor
• Volcanoes
• NO BREATHABLE OXYGEN GAS!
• CO2, ammonia, methane present

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Finding Evidence of Early Life

• Scientists had hard time finding evidence of
  early life
• 45 years ago we found out why.
• Most ancient life was microscopicmicrofossils in
  stromatolites
• 1st organisms to evolve were prokaryotes
• Oldest microfossil?3.5 billion years old!!

Stromatolites
Cyanobacteria fossil about 1,000,000,000 (1
billion) years old found in stromatolites
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How did life begin?

• 1.)Extraterrestrial origin
• 2.)Creationdivine forces
• 3.)From non-living matter (Chemical
  Evolution)--Organic compounds
• assembled creating 1st
• bacterial cell

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Lifes Chemicals Proteins, Lipids, Carbs,
Nucleic Acids
Early Earths atoms and molecules
First Prokaryotic Cells
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Origin of Lifes Chemicals

• Miller-Urey Experiment
• Hypothesis Can organic compounds form in early
  Earth conditions?
• Experiment recreated atmosphere of early Earth
• Results building blocks of life were formed
• Amino acids (proteins)
• Nucleotides (DNA, RNA)
• Lipids
• Carbohydrates

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Origin of Lifes Chemicals

• The first genetic material was RNA
• Earths early surface was inhospitable due to
  immense UV radiation that destroys nucleic acids
• Deep sea vents may have provided sheltered
  location for nucleic acids, as well as life, to
  evolve
• Oldest living prokaryotes found there today
• RNA can form under conditions similar to deep sea
  vents

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Lifes Chemicals Proteins, Lipids, Carbs,
Nucleic Acids
Early Earths atoms and molecules
First Prokaryotic Cells
Miller Urey and deep sea vents
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Origin of Cells

• Some molecules can spontaneously form into
  droplets and hollow spheres
• Solution with lipids and proteins will self
  assemble into a lipid bilayer like a cell
  membrane
• First cell membrane and beginning of prokaryotic
  life took 1 billion years

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Lifes Chemicals Proteins, Lipids, Carbs,
Nucleic Acids
Early Earths atoms and molecules
First Prokaryotic Cells
Miller Urey and deep sea vents
Self assembly and 1 billion years
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Road to Modern Organisms

• 1st life was bacteria? unicellular prokaryotes
• Cyanobacteria- photosynthetic blue-green
  prokaryotes later changed Earths
  atmosphere?released O2!
• 2nd was unicellular eukaryotes? Endosymbiotic
  Theory
• 3rd was multicellular eukaryotic organisms

Endosymbiotic Theory3min
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How Modern Day Biologists Classify

• 1. Comparing anatomy (physical traits)
• 2. Looking at genetic similarities differences
• 3. Biochemical make-ups
• 4. Behavioral similarities
• Origin of Life Video

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Cladograms

• Cladogram- a branching diagram that shows
  evolutionary relationships
• We use taxonomy the science of classifying
  living things, to help us determine the cladogram

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Writing Scientific Names

• Binomial nomenclature- unique 2-word Latin naming
  system used by scientists
• 1st word is the genus, 2nd is the species
• Genus is always capitalized
• Species is always lower case
• The whole name is underlined if written or
  italicized if typed
• Example Homo sapiens
• Homo genus
• sapiens species
• Common name humans

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Scientific Naming Examples

• Genus- group of organisms that share similar
  characteristics
• Species- group of organisms that can successfully
  breed within their group, but not others
• Panthera leo-lion
• Panthera pardus-leopard

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6 Kingdoms

• There are six kingdoms all living things are
  classified into
• Animals
• Plants
• Fungi
• Protists
• Eubacteria
• Archeabacteria

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Classification

• Scientists have determined seven levels of
  classification
• Kingdom Kings
• Phylum Pass
• Class Classes
• Order to Order
• Family Families
• Genus and their Good
• Species Sons around

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Classification of Modern Humans

• Kingdom Animalia
• Phylum Chordata
• Class Mammalia
• Order Primates
• Family Hominidae
• Genus Homo
• Species sapiens

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Evolution of Primates

• Primate- mammal with 5 flexible fingers
• Earliest dwelled in trees-arboreal and evolved
  special adaptations for this
• Opposable thumb.Why?
• Binocular vision- eyes in front of head in which
  field of vision of eyes overlapdepth
  perception.Why?
• Rotating Shoulders

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2 Types of Primates

• Primates are divided into 2 groups
• 1. prosimians and 2. anthropoids
• Prosimians- nocturnal primates that were the
  first to evolve
• i.e. Loris and Bush Baby
• 30-40 million year fossils show they were common
• Nighttime huntersHow can you tell?

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2 Types of Primates

• Anthropoids- day active primates
• Monkeys, apes, and humans
• Smaller eyes
• Color vision
• Larger brains
• Replaced prosimians rapidly

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2 Types of Primates

• Anthropoids3 categories
• Monkeys
• Have tails
• Old WorldAsia and Africa
• New WorldCentral and S. America
• Apes
• NO TAILS
• Larger brains than monkeys
• Chimps, gibbons, orangutans,
• bonobo, etc.
• Humans
• Our closest genetic primate
• relative is?

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Evolution of Humans

• Vocab
• Bipedal- walk upright on two legs
• Hominid- bipedal primates such as humans and
  their closest fossil relatives

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Hominids

• Hominids are the ONLY bipedal primates
• Locking knee joints
• Spine enters skull at
• bottom of head
• Femurs (thigh bone)
• tapers in
• Big toe in line with
• others
• Laetoli Footprints

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Hominid vs. Chimpanzee

• Chimps most closely related primate to humans95
  similarity in the sequence of our genes!
• Differences
• Humans jaw arc shaped with smaller canines
  chimps are U shaped with larger canines and
  larger gaps.

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Hominid vs. Chimpanzee

• Hominid spine S chimps is C shaped
• Hominid pelvis is bowl-shaped, chimps long
• Hominid thigh bones taper inchimps out
• Human Evolution Video Clip

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Early Hominids

• Darwins Descent of Man
• 1871
• African apes are close genetic relatives of
  modern humans
• Said fossilized remains of ape and human common
  ancestor should be found in Africa

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Early Hominids

• Genus Australopithecus
• A. afarensis
• Genus Homo
• Homo habilis
• Homo erectus
• Homo sapiens
• NOT A COMPLETE LIST! THERE ARE OTHERS!

Time
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Australopithecus

• Genus Australopithecus
• Lucy?Australopithecus afarensis
• Fossil found in Africa
• They were hominids
• Shape of pelvis and femurs showed they were
  bipedal.
• Locking knee joints
• Short36
• Brain size of chimps
• Jaws more rounded than apes
• Teeth like humans

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LUCY

• 3.5 million years old
• 40 complete
• Female
• Showed us
• Walked upright first
• Brain size grew LATER.

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SKULLS

• A. afarensis (Lucy) Homo sapien

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SKULLS

• Lucy had a small skull like an ape, but she
  wasnt one
• LUCY APE

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APES
Homo sapiens

• 
  Homo erectus
• transitional species Homo
  habilis
• 
  
  Australopithecus afarensis
• 
  common ancestor to
• 
  ape and H. sapiens
• 
  

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Homo habilis

• Means handy man
• Small structure like Lucy
• Skull 2Xs the size of Lucy
• 2- 1.8 mya in Africa
• Tools made of bone and stone

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Homo erectus

• Peking man
• Africa / Asia / Europe
• Larger than H. habilis
• Larger brain
• Excellent tools, used fire
• 1.5 mya immediate ancestor

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Where Did H. sapiens evolve?

• Out of Africa hypthothesis- idea like Darwins
  which states H. sapiens evolved IN Africa and
  spread to rest of world
• Out of Africa hypothesis supported by fossils of
  modern-like humans found in Africa

H..sapiens
H. erectus
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Early H. sapiens

• Homo neanderthalensis -discovered in Neander
  Valley in Belgium
• Massive skulls and
• protruding brows
• 400,000-100,000 years ago

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Early H. sapiens

• Great controversy did they die off (genes no
  longer) or did they interbreed with us so their
  genes are still in our gene pool?
• Modern H. sapiens probably evolved in Africa and
  replaced Neanderthals.

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APES Homo neanderthalensis
Homo sapiens
Mated????

• 
  Homo erectus
• transitional species Homo
  habilis
• 
  
  Australopithecus afarensis
• 
  common ancestor to
• 
  ape and H. sapiens
• 
  

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Recent Discoveries

• 2009 Recent analysis of Ardipithecus ramidus aka
  Ardi found in 1994
• A hominid with opposable big toes like chimps and
  apes
• 1.2 million years OLDER than Lucy, and our oldest
  known common ancestor with other primates (4.4
  mya)!
• 47 inches tall
• Show that chimps have actually evolved MORE than
  humans since our common ancestor

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APES Homo neanderthalensis
Homo sapiens
Mated????

• 
  Homo erectus
• transitional species Homo
  habilis
• 
  
  Australopithecus afarensis
• 
  common ancestor to
• 
  ape and H. sapiens
• 
  ARDI?????

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Evolution Summary

• The Theory of Evolution by Natural Selection
  holds the high status of near certainty its a
  scientific theory
• There are no observations of life, living or
  extinct, that evolution cannot explain
• Why is evolution controversial anyway?