Term to Know about Evolution

Evolution – the process by which populations accumulate inherited changes over time

Fossils – the solidified remains or imprints of once-living organisms

Fossil record – a historical sequence of life indicated by fossils found in layers of the Earth’s crust

Adaptation – a hereditary characteristic that helps an organism survive and reproduce in its environment

Traits - a distinguishing quality that can be passed from one generation to another

Charles Robert Darwin (1809-1882) was an English naturalist who achieved fame by convincing the scientific community that species develop over time from a common origin. His theories explaining this phenomenon through natural and sexual selection are central to the modern understanding of evolution.

Inherit – to receive characteristics from parents

Natural selection – the process by which an organism with favorable traits survive and reproduce at a higher rate than organisms without the favorable trait

Speciation – the process by which two populations of the same species become so different that they can no longer interbreed

The three steps speciation – separation, adaptation, division

Causes of changes in Evolution and Speciation: weather Land Water Food Other species Survival of the fittestMimicry CamouflageWarning colorationDNA MutationCatastrophic event

Selective breeding - the intentional mating of two animals in an attempt to produce offspring with desirable characteristics or for the elimination of a trait

Dominant traits - a trait observed when at one dominant allele for a characteristic is inherited Recessive trait – a trait that is apparent only when two recessive alleles for the characteristic are inherited

DNA- DeoxyriboNucleic Acid; hereditary material that controls all the activities of a cell, contains the information to make new cells, and provides instructions for making proteins

Mutation - a change in the order of the bases in an organism’s DNA; deletion, insertion, or substitution

Mutagen – anything that can damage or cause changes in DNA

"Darwin's Eden"

Watch the Scientific American Frontiers special Voyage to the Galapagos (Show 1001), and then test your knowledge by answering the following questions.

1. All the animals in the Galapagos exhibit this unusual trait in the presence of people.

2. Darwin referred to them as "aboriginal species." Biologists today call them:

a. endemic species. b. endangered species. c. extinct species. d. primitive species.

"Evolving Beaks"

3. The 13 species of these birds, made famous by Darwin, are a classic example of how living things adapt to their environment.

a. mockingbirds b. finches c. parrots d. boobies

4. According to Darwin, the driving force of evolution is:

"Lizards of the Sea"

5. How did large land animals get to the Galápagos?

6. The 1997-98 El Niño was especially devastating for marine iguanas because it (choose two):

a. made ocean water colder. b. killed the algae. c. made ocean water warmer. d. caused predators to invade.

"Masked Killers"

7. According to biologist Dave Anderson, about ___% of eggs laid by the masked booby hatch.

a. 10 b. 25 c. 60 d. 75

8. Anderson's observations suggest that for masked boobies, "siblicide" is a successful adaptive behavior because:

"Paradise Lost?"

9. What caused land iguanas to became extinct on Santiago?

10. In tortoises and other reptiles, the sex of the offspring depends upon the:

a. ocean temperature. b. weather. c. time of year when eggs were laid. d. temperature of the nest.