Chapter 9.1 Darwin's Theory of Evolution Flashcards
What is evolution NOT?
- A theory about the origin of life
- A theory that implies life evolved randomly or by chance
- A way for an individual organism to evolve during a single lifespan
- Just a theory
What year did Darwin’s voyage occur?
1831
What ship did Darwin travel on?
HMS Beagle
Where did Darwin’s voyage begin?
England
Where did Darwin travel?
Around the world
How long was Darwin’s voyage?
5 years
What was Darwin’s job on the voyage?
To study the natural world
On what islands did Darwin make many of his observations?
Galapagos Islands
What were three of Darwin’s observations?
- The world includes a tremendous diversity of living things throughout a wide range of habitats
- Animal species, like those in the Galapagos Islands, that are related, can have different characteristics or occupy different habitats in the same area
- Bones of animals that had died long ago were present
What are fossils?
Preserved remains of ancient organisms
What is the scientific theory of evolution that was developed by Darwin?
A theory which explains how modern organisms evolved over long periods of time by natural selection.
What is a scientific theory?
A well-tested concept that explains a wide range of observations
What is evolution?
The process of gradual change in a species over time
What is adaptation?
A trait that helps an organism survive and reproduce
What three species did Darwin study on the Galapagos Islands?
- Galapagos tortoise
- Marine iguana
- Finch
What characteristic of finches did Darwin study?
Beak size and shape
What did Darwin observe about finch beaks that allowed them to adapt to the life they led?
Finches who ate seeds had strong, wide beaks
Finches who ate insects had sharp, needle-like beaks
What is “The Origin of Species”?
A document published by Darwin which explained that evolution occurs through natural selection.
What other scientist along with Darwin proposed an explanation for how evolution occurs?
Alfred Russel Wallace
What is natural selection?
The process by which individuals that are better adapted to their environment are more likely to survive and reproduce than other members of the same species.
What factors affect natural selection?
- Overproduction
- Competition
- Variations
What is overproduction?
Most species produce far more offspring than can possibly survive.
Many do not survive due to limited resources (food, water, living space)
What is an example of overproduction?
A female sea turtle may lay 100+ eggs, but not all survive
How does competition affect natural selection?
Usually not direct fight between members of a species.
More indirect competition over limited resources.
What is an example of competition as it relates to natural selection?
Some turtles may fail to find enough to eat. Only few will survive long enough to reproduce.
What is variation?
Any difference in traits between individuals of the same species.
Give an example of variation.
Some newly hatched turtles are able to swim faster than others.
