Transcript Evolution and Taxonomy

Evolution and Taxonomy
Goals 3.05 and 4.01
Where did life come from?
• Abiogenesis
– Life came from non-living
material
• Biogenesis
– Living things come other
living things
The Beginning of Life
• Early Earth:
– No oxygen
– Primordial soup
• Abiogenesis had to happen
once – Oparin
• Believed that at high
temperatures and with
electrical charge the early
gases could form simple
organic compounds
Oxygen
Miller & Urey
First cells
• Organic compounds
came together to form
prokaryotic cells that were
anaerobic
– Did not use oxygen
– Why?
– There was no oxygen on
primitive Earth
– Plants had not yet evolved
First Prokaryotic Cells in the Primordial
Soup
• Prokaryotic cells were
undergoing Natural Selection
– They were eating each other
– Survival of the Fittest
• One way to be more fit if you
are small is to live in larger
prokaryotic cells
– Endo (In)
– symbiotic (both benefit)
Endosymbiosis
• One prokaryotic cell
engulfs another
• Example Mitochondria in a
cell
– Mitochondria get protection
from larger cell
– Larger cell gets energy from
mitochondria
• Evidence: Mitochondria
and chloroplast
– Have own DNA
– Can divide on own
Evidence for Evolution
• Biochemical similarities
• Use differences in DNA
to show relationships
– Few differences = Groups
split more recently in time
– More differences =
groups split farther back
in time
• Fossils
• Show evolutionary
history
– Oldest fossils on bottom
– Youngest fossils on top
Embryology
• The study of the
embryonic states of
different organisms
– Look for the
similarities
– Shows that they
have a common
ancestor
Homologous and Analogous Structures
• Homologous structures are similar in
structure but different in function
– Example – Human are and bat wing
• Analogous structures are similar in
function but different in structure
– Example – Bat wing and insect wing
Charles Darwin
• Natural Selection
– The most fit organisms survive
• Environment selects
adaptations
– Environment changes and puts
pressure on the organism to
change as well or die
– The most fit to the change
survive
Speciation – Making new species
• Geographic isolation
– A physical barrier slits a
population into 2
– Each population has it’s own
adaptations
– Over time they become so
different they can no longer
interbreed
– Now have 2 distinct species
Antibacterial Resistance
How natural selection works
Resistance to antibacterial soap
Generation 1: 1.00 not resistant
0.00 resistant
How natural selection works
Original
population
Resistance to antibacterial soap
Generation 1: 1.00 not resistant
0.00 resistant
Generation 2: 0.96 not resistant
0.04 resistant
mutation!
A mutation occurs, it happens to be
resistant to the antibacterial soap
How natural selection works
Resistance to antibacterial soap
Generation 1: 1.00 not resistant
0.00 resistant
Generation 2: 0.96 not resistant
0.04 resistant
Generation 3: 0.76 not resistant
0.24 resistant
How natural selection works
Resistance to antibacterial soap
The best fit survive and
breed– Antibacterial
resistant
Generation 1: 1.00 not resistant
0.00 resistant
Generation 2: 0.96 not resistant
0.04 resistant
Generation 3: 0.76 not resistant
0.24 resistant
Generation 4: 0.12 not resistant
0.88 resistant
Classification
• Organisms are classified into
groups based on:
– Phylogeny – How closely related
organisms are
– DNA – How similar the DNA is
– Embryology – Embryotic similarities
– Morphology – Structural similarities
Classification
Least Specific
• Kingdom = King
• Phylum = Phillip
• Class
= Came
• Order
= Over
• Family
= For
• Genus
= Great
• Species = Spaghetti
Most Specific
• Binomial nomenclature
= Two names
• Genus species
• Genus is capitalized
• species lowercase
• In italics or underlined
• Homo sapians
Phylogenetic Tree
• A tree showing
the evolutionary
relationships
between species
that have a
common
ancestor.
• Uses evidences
for evolution
Dichotomous Keys
• A tool for identification of
plants and animals.
• It is written as a sequence
of paired questions (2)
• The questions are followed
a name or identification is
reached