Chapter 6 Flashcards
Who was Charles darwin
Naturalist who observed and studied the world
Species
Group of similar organisms that can mate w/ each other and produce fertile offspring
Fossil
Preserved remains or traces of organism that lived in the past
What happened to the animals on the islands
They had became different from the main land relatives over time
What else did Darwin notice amount the islands
There were differences in the organisms from island to island
Adaptation
Trait that increases an organisms ability to survive and reproduce
Evolution
Process of change over time
What was darwins hypothesis
Species change over many generations and become better adapted to new conditions
Well tested concept that explains a wide range do observations
Scientific theory
Why was darwins hypothesis considered a scientific theory
He provided evidence from Galápagos Islands that were well tested and explained
When organisms with desired characteristics are bred
Artificial selection
Natural selection
Process by which individuals that are better adapted to their environment are more likely to survive and reproduce
What are factors of natural selection
Overproduction, variation, competition, selection, environmental change, genes and natural selection
Overproduction
Most species produce more offspring than can survive
Variation
Difference between individuals of the same species that helps them survive
Competition
Not enough food space and other resources so species members compete for it
What is natural Selection
Over a long period of time natural selection can lead to change. Helpful variations may accumulate in species while unfavorable ones disappear
What does environmental change affect
Organisms traits ,ability to survive ,reproduce
What evidence supports evolution
Fossils, patterns of early development, similar body structures, and similarities in DNA and protein structures
How do fossils support evolution
Show that organisms that lived in the past were very different from current organisms
What is the fossil record for
Stores all fossils collected by scientist and provides clues about how and when species evolved and how organisms are related
How does similarities in development support evolution
Scientists compare early developments between organisms to find similarities that infer evolutionary relationship
How does similarities in body structure support evolution
These similarities provide evidence that organisms could’ve evolved from a common ancestor
How does similarities in DNA and proteins structures support evolution
Scientists compare DNA and nitrogen bases sequences to infer how closely related species are
How do new species form
When group of individuals remain isolated from the rest of its species long enough to evolve different traits that prevent reproduction
How does isolation occur
When members of species become cut off from rest of species sometimes by natural barriers
What patterns describe the rate of evolution
Gradualism and punctuated equilibrium
Gradualism
Small changes that add up to major changes over a long period of time
Punctuated equilibrium
Pattern in which species evolve rapidly during short periods of time and then don’t change much
