Download Themes in Biology - Sonoma Valley High School

Themes in Biology
Lecture 1-2
diversity
evolution
interdependence
I. Diversity and unity of life
Diversity = variety
Unity = things in common
 Over 1.5 million species
 All living things share a
exist on Earth.
 It can be 1-celled, or a
whale with a trillion cells.
 Each species is different
from every other.
genetic code.
 All life descended from a
single common ancestor.
 Diversity came from genetic
changes happening over time.
Streptococcus
Domain Bacteria
Kingdom Fungi
Amoeba
Kingdom Protista
Domain Eukarya
Domain archaea
Kingdom Plantae
Kingdom Animalia
Three domains of life
 Archaea: simple cells, most ancient organisms
 Bacteria: simple cells
 Eukarya: cells with more complexity. All multicellular life is
in this domain.
 4 kingdoms of eukaryotes: Protista, Plantae, Fungi, and
Animalia
The “tree of life”
Which domain has the most kingdoms?
II. Interdependence of organisms
 Ecosystems are living things interacting with each other and
their environment.
 Life has changed our planet.
 Humans have impacted all life on Earth.
What process put oxygen into the air?
rainforest
Slash and burn farming
III. Evolution of life
Populations change, or evolve, over time.
Over time, new species arise, others go extinct.
Evolution explains how life today is related to life in the past.
Natural Selection
 In a changing world, organisms have
to also change to survive.
 Ones with traits that help them live
and reproduce will continue (natural
selection).
 Adaptations are traits that help an
organism survive.
 Those traits, over time, may cause a
change in the whole population.
(descent with modification).
How are the jack rabbit, musk ox, and snow hare
adapted to their environments?
Summary: give examples of the 3 themes of
biology in our local ecosystem.
Oak woodlands ecosystem