Darwin's Theory
A female fish lays 100s of eggs.
Overproduction of offspring
How well an organism produces offspring
Fitness
This creates genetic variation.
Sexual reproduction
Chicken's, lizard's and human fetuses all have tails.
Embryology (Embryological evidence)
Newer or younger fossils are found in newer layers of the earth's crust.
The Law of Superposition
Some deer have thicker fur than other deer.
Genetic variation
Why do fish and insects lay or produce 100s of eggs.
Most do not survive.
Polar bears have white fur and live in snowy habitats.
An adaptation
Carbon-14 can be used to determine the age of a fossil.
This is radiometric dating.
What are our (human) tailbone and appendix?
Vestigial structures
All organisms have to compete for space, mates, food, etc.
Struggle to survive
What are traits organisms have that help them survive?
Adaptations
When females choose to mate with males bases on the males trait(s).
Sexual Selection
Millions of species have existed during the earth's past.
(Mass) Extinctions
have eliminated millions of different species.
An insect's wings and bird's wings are both used for flying.
These are
Analogous structures
Well adapted organisms produce more offspring
Differential reproduction
Which has bird below has better fitness? (A or B?)
A. Bird that produces five offspring.
B. Bird that produces two offspring.
Bird A
What has a better chance of survival against pathogens and parasites?
Offspring produced sexually
Chimpanzees and humans have almost identical hemoglobin molecules.
Biological molecules
What are a whale's fin, a bird's wing and a human arm?
These are
Homologous structures
because theses species have a common ancestor