Study Guide

Changes Over Time

Species / A group of similar organisms whose members can mate with one another and produce fertile offspring
Variations / Any differences between individuals of the same species
Adaptation / A characteristic that helps an organism survive in its environment or reproduce
Evolution / Change over time due to inherited characteristics
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
Selective breeding / The human practice of breeding animals or plants that have desired traits
Sedimentary rock / A type of rock that forms when particles from other rocks or the remains of plants and animals are pressed and cemented together
Fossil / The preserved remains or traces of an organism that lived in the past
Generation time / The period between the birth of one generation and the birth of the next generation
Geologic Time Scale / The method used to divide the Earth’s long natural history into manageable parts
Fossil record / The millions of fossils that scientists have collected which tell the story of the Earth’s history.
Relative dating / A technique used to determine which of two fossils is older ….fossils in the top layers of rock are younger than the fossils found in the bottom layers of rock
Absolute dating / A technique used to determine the actual age of a fossil by looking at a radioactive element’s constant rate of decay
Page 175 – How did the beak shapes of the finches on the Galapagos Islands help them survive? / -The large ground finch has a wide, strong beak that is uses to crack open the big, hard seeds.
-The cactus finch has a tough beak that it uses for eating cactus parts and insects. Its beak is like a pair of needle-nose pliers.
-The warbler finch has a small, narrow beak that it uses to catch small insects. Its beak works like a pair of tweezers.
Page 178 – What are the four parts of natural selection? / 1. Overproduction – Some of the offspring will survive and others will not.
2. Inherited variation – Every individual has its own combination of traits.
There are many combinations of traits which equals
variations.
3. Struggle to survive- Can the population survive predators and diseases?
4. Successful reproduction – Those that are best adapted to their environment are likely to have many offspring that survive.
Page 180 – How did the elephant population in Uganda change as a result being hunted for their tusks? / In the 1930’s, elephants were hunted for their ivory tusks because they were so valuable. So, fewer of the elephants that had tusks survived to reproduce. The elephants that did not have tusks did survive and they reproduced and passed the tuskless gene to their offspring. Today 15% of the elephants do not have tusks.
Page 182 Study figure 3 about the changes that the finches went through on the Galapagos Islands. /
What are the three eras on the geologic time scale? Page 196 / Paleozoic era – Oldest
Mesozoic era – Middle era – Dinosaurs
Cenozoic Era – Present time
Know about the peppered moths of England during the Industrial Revolution. / During the Industrial Revolution in England, the soot from the factories darkened the bark of the trees. The dark colored moths survived because they were camouflaged on the dark tree bark. The birds ate the lighter colored moths. So, there were fewer lighter colored moths because they were eaten. The dark colored moths survived and reproduced passing the dark gene on to their offspring. There were then many dark colored moths. This is an example of natural selection.
Know the difference between natural selection and selective breeding. / Natural Selection is the process by which organisms that have inherited the adaptations to help them survive in their environment… will survive and reproduce and pass the genes to their offspring.
Ex. The saddle back tortoises who inherited the gene for long necks will survive in the dry environments because they can reach the leaves on the shrubs and trees. There will be many of them in this environment.
Selective breeding is controlled by humans. It is the human practice of breeding animals and plants that have the desired traits.
Ex. Humans can breed a fast racehorse with a strong racehorse and get a fast and strong racehorse.