Chapter
21
Animations
Art
Unit 3: Genetics
Genomes and Their Evolution
Review
Genome comparisons can reveal
relationships
among species.
Chapter
22
Animations
Art
Unit 4: Mechanisms of Evolution
Descent with Modification
Review
Charles
Darwin
explained the
diversity
of life by
through
with
from a common
ancestor.
Humans have modified other species over generations by
and breeding individuals that possess desired traits. Darwin called this
selection.
Darwin proposed
selection as the mechanism driving evolution. He formed this
hypothesis
by drawing two
based on four
.
Observation #1: Members of a population exhibit
in their
traits.
Observation #2: Much of this
variation
is
.
Observation #3: Most species tend to
of
offspring.
Observation #4: Resources are
; many of these offspring do not survive.
Inference #1 (
selection): Individuals whose inherited traits give them a high probability of surviving (
struggle
for
) and
are likely to leave more
offspring
than others:.
Inference #2 (
): A population will gradually accumulate favorable characteristics over generations and become more
to its
environment.
Drug resistance in bacteria and viruses such as
HIV
are probably due to
and
for individual organisms that possess the resistance.
anatomical structures, such as the
among mammals, provide evidence of common
ancestry
with modifications.
Comparative
reveals
anatomical
not visible in adults.
Unrelated species that occupy similar ecological
may look similar by
evolution.
Darwin's theory of evolution predicts
forms during the evolution of species, and this is supported by
records.
Homologous characteristics derived from a common
can be used to establish evolutionary
relationships
among organisms.
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