“LIFE CHANGES
OVER TIME “
STUDY GUIDE
1
A species is a group of
organisms that look
alike and can reproduce
among themselves.
2
Evolution is the process
by which species change
over time.
3
An adaptation is a
feature or trait that
helps an organism
to live in a
certain environment.
The giraffe’s neck has
grown longer over time so
it can eat leaves that grow
at the tops of trees.
4
A sudden change in a
gene is called a mutation.
It can be harmful
or helpful .
This albino snake’s
mutation makes it
more vulnerable to
predators.
5
Animals or plants that no
longer exist are said to
be extinct.
Animals like this
dinosaur no longer
live on earth
because they’re
extinct.
6
Fossils are the remains
or traces of once-living
organisms.
7
Amber is fossilized tree
sap in which ancient
insects are sometimes
preserved.
8
Homologous structures are body
parts that have the same basic
structure like the arm of a
human, the leg of a cat, the
flipper of a whale, or
the wing of a bat.
9
Vestigial structures are
body parts that seem to
have no function like a
human being’s appendix.
10
Darwin’s theory of natural
selection is that offspring
with the most
favorable traits
survive and reproduce.
11
Differences in traits
among organisms in a
species is called
variation.
There are
variations in the
color of these
Sweet William
flowers.
12
Anthropology is the
study of human
beings.
13