Name:______Date:______
EVOLUTION
Relationships Among Organisms
Similarities Among Organisms
All organisms on Earth are ______
Some relationships are easier to ______than others – though most organisms have some similarity in ______
Common Descent
Living things have ______changed over time
Each living species ______from other species over time
Principle of common descent –______
______
Anatomists discovered that when comparing ______animals with four ______, similarities exist among the ______of the various types of arms and legs
These are called homologous structures – ______
______
Means they come from common ______– share a common ______
There are also ______similarities
Discovered vestigial organs – ______
______
Similarities Among Organisms
Each species has a “______” containing visible and invisible tools that perform essential ______functions
Tool kits are the result of ______of years of evolution by ______
It is easier to ______existing tool kits than to create entirely new ones
The Role of Chance
Random change in population is called ______
Can be caused by ______, random mating ______
These are ______that have nothing to do with natural selection
The Birth of New Species
Speciation is ______.
New population must ______enough that breeding cannot occur with original population
Genetic changes can be from ______or natural selection, but must lead to ______isolation
Usually, speciation in plants and animals occurs when two groups of individuals become ______
______p. 251
The Pace of Evolution
Gradualism is the view that ______
______
Punctuated equilibrium is the view that ______
______
Adaptive Radiation
When a new species evolves in a relatively ______period of time, or when an organism or a group of organisms ______a new area where other species ______for life’s necessities
Results in a ______tool kit
Leads to ______structures
Sometimes called ______
Convergent Evolution
Unrelated species may independently ______superficial similarities because of adaptations to similar environments.
Example: ______and ______both fly
Leads to analogous structures – ______
______
Homologous vs. Analogous
Homologous structures – ______
Ex. ______
Analogous structures – ______
Ex. ______
Distant Relationships
Looking at homologous structures, fossils, embryological similarities can show ______relationships
What about ______celled organisms?
______similarities
Molecular Unity
Many ______are shared by a wide range of organisms
The same ______amino acids make all ______
All cells need ribosomes – almost ______genes
The more ______two organisms are related, the more closely their ______resemble each other
Muscle Proteins – in Yeast!
______is a protein found in muscle cells in animals – and yeast cells
______do not move, so why do they need myosin?
They use it to move products around ______the cell