Download 10.2 Darwin`s Observations

10.2 Darwin’s Observations
KEY CONCEPT
Darwin’s voyage provided insight on evolution.
10.2 Darwin’s Observations
Charles Darwin – The “father” of Evolution
10.2 Darwin’s Observations
Overview
• All life formed from a single common
ancestor
• Life forms change by adapting the best
features to survive in their environment
• The “fittest” survive to pass the new
adaptation (genetic traits) to their
offspring
• The mechanism is Natural Selection
10.2 Darwin’s Observations
Life on Earth has Unity and Diversity
All of Earth's life
forms are related
and function
universally the
same way.
All species
evolved from a
single common
ancestor at life’s
origination 3.5
bya.
>200 million living species on Earth
10.2 Darwin’s Observations
Voyage of The Beagle 1835: Darwin describes species
of the Galapagos Islands
10.2 Darwin’s Observations
Darwin observed differences among island species.
• Variation is a difference in a physical trait.
– Galápagos tortoises that live in areas with tall plants
have long necks and legs.
– Galápagos finches that live in areas with hard-shelled
nuts have strong beaks.
10.2 Darwin’s Observations
• An adaptations is a feature that allow an organism to better
survive in its environment and mate.
– Species are able to adapt for
survival in their environment.
• Competition for resources
• Forage/ Hunt to Eat, Attract mates to
Reproduce, Defense
– Adaptations can lead to genetic
change in a population.
10.2 Darwin’s Observations
Darwin observed fossil and geologic evidence supporting
an ancient Earth.
• Darwin found fossils of extinct animals that resemble
modern animals.
• Darwin found fossil shells high up in the Andes mountains.
10.2 Darwin’s Observations
• He saw land move
from underwater to
above sea level,
due to an
earthquake.
• Darwin extended
his observations to
the evolution of
organisms.