Evidence of Evolution Notes
Name:
Evolution



Evolution means __________________________________.
Evolution occurs through ____________________________ which is also known
as ______________________________________.
Can also occur through __________________________. An example of artificial
selection is _________________________.
Speciation

Natural selection can explain how ________________ occurs, when one species
evolves into a new species. Speciation happens in 3 steps.
1. __________________ - a portion of the species becomes isolated. Examples of
how ___________________ occurs include ___________, ______________, or
a _______________.
2. _____________________ - as the environment changes, so does the population
that lives there. Over many generations the separated group adapts to their
environment.
3. _____________________ - over many generations, the two groups of
populations are so different they can no longer interbreed. They are no longer
the same species.
Evidence for Evolution
Common Ancestor

Scientists believe living thing evolve from a common ancestor.
Fossils


___________________ - the solidified remains or imprints of once living
organisms
Usually formed in sedimentary rock, there are 2 types of fossils. _________ are
an imprint of the once living organism. _____________ are a preserved form of
the organism.
Fossil Record




________________ - a historical sequence of life, supplying evidence about
the order in which evolutionary changes occurred.
Older fossils are buried deeper. Newer fossils are found closer to the Earth’s
surface.
Gaps in the fossil record exist because the conditions necessary to make
fossils do not always occur.
Vestigial Structures


_________________________ are remnants of once useful structures
(leftovers).
Examples of vestigial structures include __________________,
________________, and _________________.
Homologous Structures

If you look at bone structure in mammal arms, you can see similarities in how
the bones are arranged, indicating a ______________ mammal ancestor.
Embryonic Structures

You look at embryos of vertebrate animals, ____________________ in structure
suggest a common animal ancestor.
Molecular Evidence



DNA is the genetic material for ________ living things.
Similar organisms have many codes of DNA in common.
For example, the DNA of __________________ and _______________ has
more common than the DNA of __________________ and_______________.