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Do Now
• Self-reflect: think about your progress, how do
you think keeping a homework/exit slip
tracker help you improve in class?
• 3-4 sentences
• P. 37
Think about
• Think about where you live and where you came
from (place, city, etc.)
• Who is in your circle of friends, family,
neighborhood?
• Write on a half-sheet of paper and place it on the
board
• I will read a few
• Anonymous posts!
Biodiversity and Evolution
Today we will…
Discuss and explain what the origins of life are, as
well as natural selection and evolution
Relate as to how these things have led to the
current biodiversity on earth
Define what biodiversity is
Explain and justify why phenomena such as
catastrophes, climate change, and extinction
affect evolution and biodiversity
We can define what an ecological niche is, as well
as develop an explanation as to how it helps a
species adapt to its environment
Think
• Discuss at your table what this image is showing. How might
this relate to today’s lesson?
• Make you you are ready to explain!
Origins of Life
• Scientists argue that the origins of life began in deep-sea
hydrothermal vents
• Common ancestry for all organisms began with an aquatic
microorganism
– Came from a biotic soup synthesized from the atmosphere
otherwise known as chemical evolution
Origins of Life
• Chemical evolution occurred in the formation
of biomolecules needed for the basics of life.
• Selection occurred from single-celled
bacteria, to multicellular organisms
• Most of this evidence comes from fossils
– Remnants of mineralized bones, leaves, or
impressions.
White board Quick Check!
• Draw, write a definition OR an explanation
you would give a college professor on what
• what the origins of life are stated to be!
• Do so on your whiteboards!
• 1 minute!
Evolution, Natural selection, and Adaptation
• Evolution can be defined as “descent with modification”
– Biological evolution is a change in a population’s genetic makeup
– Populations, not individuals, evolve.
– It all begins with mutations in the gene pool of a population
• Can be random (errors in DNA replication) or caused by mutagens—xrays, harmful chemicals etc.
• Must occur in reproductive cells in order to be passed on.
– All of this then leads to natural selection.
Evolution, Natural Selection, and Adaptation
• Natural Selection occurs when some individuals have
favorable heritable traits that are passed down allowing
for survival and reproduction.
– Being favored for natural selection allows for the
organism’s survival and for the ability to pass
down these favorable genes
– These favorable genes become more prominent
within the population
– for this to even occur, there must be genetic
variability within the gene pool!!!
Survival of the Fittest?
• What does this really mean?
• Explain how this phrase applies to natural
selection.
• What is one way people use this phrase
incorrectly? How would you correct them?
• Discuss with a partner, I will call out.
Evolution, Natural Selection, and Adaptation
•
•
Natural selection occurs on individuals, but evolution occurs in populations
An adaptation is any heritable trait that is passed down that enables an
organism to survive and reproduce under certain environmental conditions
– Natural selection preserves beneficial adaptations.
– Species can either adapt, migrate, or go extinct.
– *Remember: IT ALL STARTS WITH MUTATIONS FOUND IN THE GENE
POOL!!!!!*
Evolution, Natural Selection, and Adaptation
• Coevolution occurs when two species interact with each
other over time
– Can occur with changes in a gene pool of 1 species
leading to changes in another species
– Ex. Bats and moths bats eat moths, therefore moths are
adapted to be hypersensitive echolocation frequencies in
order to avoid predation
– Goal: each species in a race to produce the largest
number of surviving species.
White-board Quick Check!
• Draw an image, write a definition, or write an
explanation you would give a college professor
on what:
• Natural selection is
• Coevolution is
• What an adaptation is
White Board Quick Check
• Write an explanation using academic vocabulary
and specific detail on your whiteboards about
• How natural selection leads to evolution
• I will come by and check.
• 3 minutes
Lets come back
Evolution: catastrophes, climate change, and extinction
• Think!
• What might occur if an asteroid hit China right
now?
• Make sure you elaborate the specific events
that would take place
• Hint: Think about evolution
Evolution, Catastrophes, and climate change
• Tectonic Plates move over time, this then leads to locations of
plants and animals to change
– Species adapt and form new species as a result
– Locations of plates also determines climate
– Climate change leads to changes in temperature which
then DETERMINES WHERE PLANTS AND ANIMALS LIVE.
• If climate changes too rapidly it can lead to decrease in
survival of species no time to adapt.extinction
Evolution, Catastrophes, and
climate change
• Asteroids and meteors hitting the earth have caused large
wipeouts of species aka mass extinctions.
• After each catastrophe, large environmental stress followed
• Allowed for opportunity of new species to be favored by
natural selection ALLOWING THEM TO EVOLVE
– Ex: mammals were able to be favored because dinosaurs
went extinct
Whiteboard Quick check!
• Write an explanation on your whiteboards.
• You will have 5 minutes
• How does a catastrophe, such as an asteroid,
or an ice age, allow for evolution to occur?
Ecological Niches
•
Each species has a specific role or way of life in an environment,
otherwise known as a niche
– Ex: a bird’s niche might be to forage for worms as a way of maintaining
balance of decomposers
– Fundamental niche: the FULL POTENTIAL of range of physical,
biological, and chemical conditions an organism can THEORETICALLY
USE.
• Avoiding direct competition from other species
Ecological Niche
• Fundamental niche is often not the case, because species
compete with each other for resources. Niches of competing
organisms often overlap.
• in order to survive, a species only takes up a portion of its
fundamental niche, aka REALIZED NICHE.
– Restricted to a particular portion due to competition from
other organisms.
Ecological Niche
• https://www.youtube.com/watch?v=6COob_bymw
White board Quick Check!
• Draw a picture, an explanation, or a definition
on:
• The differences between a realized niche and
fundamental niche
• How can niches allow for a species to adapt?
• 1 minute to respond.
Biodiversity
• Biodiversity: refers to the diversity of
individuals, genetic information, habitats, etc.
within the biosphere.
•
Biodiversity
• Why is it important?
– Biodiversity is important in the stability of an
ecosystem or population
– Minimal biodiversity results in the risk of
extinction and instability within an ecosystem
– Every organism has a specific role to play in their
environment
– ***Theme of biology: Everything is
interconnected**
P. 37 of NB’s
• What was the main find in the research the scientists
at UCSB conducted?
• What methods did they use to conduct research and
gather data?
• Describe the conflict of the two hypotheses on
biodiversity and niche importance presented within
the article.
• Why would species loss in niches that maintain
diversity have such a significant impact on plant
production?