unit v: darwin’s voyage and the theory of evolution ms. buechler int.sci. 4/biology
TRANSCRIPT
Unit V: Darwin’s Voyage and the Theory of EvolutionMs. BuechlerInt.Sci. 4/Biology
EW 3/27What do you know about Charles
Darwin? What theory did he come up with? What’s the name of famous island that he made many of his observations that lead to this theory?
Bill Nye: EvolutionOld School Bill Nye the Science Guy: Evolu
tion
Bill Nye Great Discoveries: Evolution
Darwin’s Voyage Book Resources Life and Times of Ch
arles Darwin
http://topics.nytimes.com/topics/reference/timestopics/people/d/charles_robert_darwin/index.html
http://www.aboutdarwin.com/voyage/voyage04.html
http://evolution.berkeley.edu/evolibrary/article/0_0_0/history_14
Videos Darwins' Voyage
Revisted in 2014 Darwin v. Lamarck's
view of Natural Selection
Vocab for Darwin Book Adaptive Radiation-
when a species derived from a common ancestor (like with Darwin’s Finches) adapts to the environment by natural selection, causing a change in the gene pool of a population.
Evolution- biological change in a population’s gene pool over time…
Natural Selection- process in which organisms adapt to their environment:◦ Species tend to produce more
offspring than what will survive.◦ Variations are found among
individuals of a species.◦ Some variations enable members
of a population to survive and reproduce better than others… they are better suited for survival in the given area.
◦ Over time, offspring of individuals with helpful variations make up more and more of a population… they have adapted to the environment.
Vocab for Darwin Book Selective Pressures- changes in
resources, mates, and/or environment that lead to a change in allele frequency in a population.◦ Ex> change in climate and the
wooly mammoth to modern elephants
Species- smallest level of classification, in which organisms can mate and produce viable offspring.
Speciation- formation of a new biological species
Variation- unique qualities of individuals of the same species in a given population.
Acquired Characteristics- traits that develop after birth… like Lamarck’s explanation of how giraffes got long necks.
Mutations- permanent changes in the DNA
Adaptation-“An alteration or adjustment in structure or behaviors by which a species or individual improves its condition in relationship to its environment”
Reproductive Isolation- physical or geographical barriers that restrict the interbreeding of populations.
Natural Selection: Wallace, Lamarck & Darwin
EW 4/1
What year did Darwin visit the Galapagos Islands?
When was his paper “Voyage of the Beagle” published?
3 Influential Scientists Perspective’s on Natural SelectionInto to Theory of Evol
ution.doc
http://evolution.berkeley.edu/evolibrary/article/0_0_0/history_14
Lamarck Similar species arose from common ancestor organisms change
over time Acquired trait= not determined by genes, but arises during an
organisms lifetime in response to behavior and or experiences Acquired traits are then passed onto offspring
Wallace1st to propose the theory
of “Natural Selection”◦ Organisms best suited to
their environment reproduce more successfully than other organisms
◦ “Intelligent evolution” is a theory of common descent based upon natural selection strictly bounded by the principle of utility
Wallace recognized that useful variations allowed organisms to better survive in their environment those successful variations occurred with greater and greater frequency in the population (increase gene frequency)
Darwin
Descent with Modification via Natural SelectionNewer organisms are
modified decedents of older species
Natural Selection causes these modifications primary mechanism changing organisms from their origin to a species well adapted to its environment
Summary of Theories on Natural Selection
Lamarck Wallace Darwin
Driving
Mechanism for Changing Traits
Acquired TraitsOrganisms changed in response to their environment/habitat
Natural Selection- favorable traits are passed onto offspring to increase their chances of survival
Descent with Modification via Natural Selection- Newer organisms are modified descendants of a few original organisms this modification occurs via Natural Selection
Do Species Change?
Yes- individual organisms can
change within their lifetime
Yes- Populations change over time
Yes- Populations change over time
End Result: Where to
species come from?
Common Ancestor? Species created based on environment
Common Ancestor- but a product of their environments
Common Ancestor all species from one or more original organisms
Principles of Natural Selection
Organisms produce more offspring that can survive.
Variations are found among individuals of a species.
Some variations enable members of a population to survive and reproduce better than others.
Over time, offspring of individuals with helpful variations make up more and more of a population