Download Evolution Review

Evolution Review—Unit 6

Evolution is the process by which species ________________ over time. It is a ____________,
gradual process that takes hundreds or thousands of years…or even longer!
EVIDENCE FOR EVOLUTION
1. How do fossils provide evidence for evolution?
2. What do these fossils tell us about the evolution of the whale?
3. Scientists study organisms’ _______________ structures, or anatomies, to determine how different
species are related to each other.
4. Bird wings, human arms, and whale flippers are considered _______________ structures. They have a
_________________ structure but ________________ functions. Homologous structures indicate that
these organisms evolved from a _________________ ancestor.
5. Bird wings and butterfly wings are considered _________________ structures. They have a similar
_________________ but not a similar structure. These organisms did not _____________ from a common
ancestor.
GENETICS AND EVOLUTION
WORD BANK: behave, adaptations, environment, variation, extinct, survive, genetics, reproduce, natural selection
The driving force behind evolution is _____________, or the study of inherited traits. All organisms look
and ____________ in certain ways because of their genes. Individuals in the same species display different
traits because of genetic _______________. Examples of this are that humans have different eye colors
and hair textures. Genetic variation is advantageous when a species is faced with a change to their
_________________, such as volcanic eruption or a long period of drought. Individuals in the population
with traits that work with the new environment ____________ and ______________. This process is called
___________________________, or “survival of the fittest.” Their traits are passed on to their offspring.
Over time, these traits become “normal” for the species and are called ____________________. Species
that cannot adapt to changing environmental conditions often become _________________.
ADAPTATIONS
Example
What is the adaptation?
How does it help the species
survive?
Several animal species, including
scorpion fish and leaf frogs, can change
their appearance to match their
surroundings. Others can make
themselves appear to be something
boring, like the walking stick, which
looks very much like a twig.
A lot of animals hibernate, including
chipmunks, hedgehogs, bats and bears.
Some animals, such as the America
black bear, snooze through winter but
can be aroused from their slumber
somewhat easily.
All rat snakes have similar diets, are
excellent climbers and kill by
constriction. They all have the same
reaction when startled (they remain
motionless) and will avoid confrontation
whenever possible. Some will bite if
threatened, although they are nonvenomous. However, rat snakes come
in a wide variety of colors, from yellow
striped to black to orange to greenish.
The warrior ants in Africa are probably
one of the most impressive examples of
adaptation. Within any single colony,
ants emit a chemical signal that lets the
others know they all belong to the same
compound. Or, put more simply, a
signal that says "Don't attack me, we're
all family." However, warrior ants have
learned how to imitate the signal from a
different colony.
*Use the example of the peppered moth to explain why genetic diversity is important to the survival of a
species:
Up until the Industrial Revolution, peppered moths were typically whitish in color with black spots, although they were
found in a variety of shades. As the Industrial Revolution reached its peak, the air in London became full of soot, and
the once-white trees and buildings that moths used for camouflage became stained black. The birds began to eat
more of the lighter-colored moths because they were more easily spotted than the darker ones. Over the course of a
few months, dark moths started appearing in the area and lighter moths became scarce. Once the Industrial
Revolution peak passed, lighter moths made a comeback.