Transcript Survival of the Fittest

Week 25, Day Three
HW # 83- Vocabulary Booklet (due Friday)
HW TOC will be collected FRIDAY 3/15
Complete your notes.
Warm up
What is the significance of “pie/ π” day?
Warm up Response
Pi is a name given to the ratio of the circumference
of a circle to the diameter
Explained on You tube
Homework Response/Check
• Did you work on your vocabulary booklet?
•
Evolution Notes
Evolution Notes
Part 1
Charles Darwin
• Born in England
• Traveled around on
HMS Beagle - Set Sail
in 1831
• Collected many
specimens
• Father of the idea of
Evolution
Voyage of The Beagle
Darwin & The Galapagos
• Galapagos Islands are a
small group of islands
1000km west of South
America
• Studied Tortoises and
Finches on the islands.
• Used geography of islands
and differentiation of
species to figure out
evolution
Galapagos Islands
Galapagos Islands
• Although they were close together, the islands had
very different climates.
• The smallest, lowest islands were hot, dry, and nearly
barren.
– Hood Island - sparse vegetation.
• The higher islands had greater rainfall and a different
assortment of plants and animals.
– Isabela Island - rich vegetation
• Allowed for different species of the same animal -->
formed through evolution!
Galapagos Finches
Galapagos Finches
Galapagos Tortoises
Galapagos Blue-Footed Booby
• Male dances and shows
its feet to the female to
attract her
• Female chooses male with
brightest feet and best
dance
• Sexual selection!
• Sexual selection is a trait
or behavior that acts on
an organism's ability to
obtain a mate
Darwin’s Thoughts
• On his travel home, he began to think of his
observations.
• He found…characteristics of many animals and plants
varied noticeably among the different islands of the
Galapagos
• According to this hypothesis, these separate species
would have evolved from an original South American
ancestor species after becoming isolated from one
another
Inherited Variation and Natural
Selection
• Darwin noted that plant and
animal breeders used
heritable variation, what we
now call genetic variation,
to improve crops and
livestock.
• Artificial selection: nature
provided the variation, and
humans selected those
variations that they found
useful.
– A.K.A Selective Breeding
Better Picture of Artificial Selection
Natural Selection
• Each organism has different advantages and
disadvantages
– Individual best suited for environment survive and
REPRODUCE
– Pass these traits onto offspring, and they are more
able to survive and reproduce
• Occurs only when a few survive
• Remember: differences (genes) in offspring
occur at random!
Darwin’s Concept of Evolution
• Biggest contribution is his idea of the
mechanism behind Evolution
– The Struggle for Existence
– Survival of the Fittest
– Descent with Modification
Struggle For Existence
• Struggle for existence: means that members of
each species compete regularly to obtain food,
living space, and other necessities of life.
– Predators that are faster win
– Prey that are better camouflaged or
protected win
Survival of the Fittest
• Fitness: ability of an
individual to survive and
reproduce in its specific
environment.
– Result of adaptations
• Adaptation: any inherited
characteristic that
increases an organisms
chance of survival
Survival of the Fittest
• Survival of the Fittest:
the idea that individuals
that are better suited to
their environment
survive and reproduce
more successfully
– A.K.A. Natural
selection
Descent with Modification
• Natural selection
produces organisms that
have different structures
• Descent with
modification: each living
species has descended,
with changes, from
other species over time