Darwin and Natural Selection
Charles Darwin studied finches and helped explain this process.
What is natural selection?
A helpful inherited trait that increases survival or reproduction is called this.
What is an adaptation?
Question: Differences in inherited traits within a population are called this.
What is genetic variation?
20 of 100 beetles are dark. What percentage are dark?
What is 20%?
Preserved remains or traces of past organisms are called these.
What are fossils?
The evolutionary process through which new species arise is called this.
What is speciation?
Finches with different beaks could eat different types of these.
What are food sources or seeds?
A white rabbit blends into a snowy landscape. What is this called?
What is camouflage?
A change in DNA that can introduce a new genetic variation is called this.
What is a mutation?
Dark beetles increase from 20% to 50%. What is the increase in percentage points?
What is 30 percentage points?
Similar structures inherited from a common ancestor are called these.
What are homologous structures?
A mountain separates two populations. What type of isolation is this?
What is geographic isolation?
Organisms with helpful inherited traits are more likely to survive and do this.
What is reproduce?
A harmless insect resembles a dangerous wasp.
What is this adaptation?
What is mimicry?
Why might some beetles survive a pesticide while others die?
Some may have inherited genetic variations that increase resistance.
Birds eat more light moths on dark bark. Which inherited color may increase?
What is dark coloration?
Bird and insect wings have similar functions but different evolutionary origins. These are what?
What are analogous structures?
Do different mutations alone prove two populations are separate species?
No. Mutations alone do not establish reproductive isolation.
What happens to helpful inherited traits over many generations?
They generally become more common when they increase reproductive success.
How do thick, waxy leaves help desert plants?
They reduce water loss, increasing survival and reproduction in dry conditions.
Thicker-feathered birds survive a cold winter more often. Predict a long-term change.
Thicker feathers may become more common if survivors reproduce and pass on the trait.
Explain why resistant bacteria may become more common after antibiotic treatment.
Resistant bacteria survive more often, reproduce, and pass on resistance
Whale pelvic bones are an example of what type of structure?
What is a vestigial structure?
Two fish populations live in the same lake but breed in different seasons. What type of speciation might occur?
What is sympatric speciation? Different breeding seasons create reproductive isolation without geographic separation.
During a drought, mostly hard seeds remain.
Explain why large-beaked finches may increase
Large-beaked finches may obtain food more successfully, survive, reproduce, and pass on inherited traits
Does a cold spell randomly killing insects automatically prove natural selection?
No. Natural selection requires inherited variation associated with differences in survival and reproduction
Why might low genetic variation make a population vulnerable to disease?
Few individuals may carry resistance, so disease could threaten much of the population.
Does a trait rising from 10% to 75% alone prove natural selection? Explain.
No. We also need evidence linking the inherited trait to differences in survival and reproduction.
How can embryology and homologous structures support evolutionary relationships?
Shared developmental patterns and inherited structures can provide evidence of common ancestry.
Separated populations can no longer produce fertile offspring together. Why does this support speciation?
Reproductive isolation supports the conclusion that separate species have formed under the biological species concept