Unit 6 Flashcards
What is the definition of evolution?
The gradual change in organisms over time
How fast does evolution occur?
Millions of years
What are these changes due to?
They are due to sexual reproduction (variations in genes) and mutations.
Inherited adaptations help organisms______ and _______ in their enviroment
Survive, reproduce
What is the definition of fossils?
A preserved trace of once-living organisms
What are three objects that organisms can be preserved in?
Ice, tar, or amber (resin)
Parts of an organism are sometimes replaced by minerals. Give an example of something that this happens to.
Petrified wood - minerals replace the cell wall of decaying wood
What type of rock is most commonly found with molds, casts, or imprints trapped of other organisms in them?
Sedimentary Rock
What is a fossil record?
When decayed organisms are organized by their estimated age.
Ex) newer, upper layers of rock are more similar to present day organisms
True or False- A rock closer to the surface is older than a rock deep into the ground
False
What is the method called when you look at the layers of rock to figure out how old something is?
Relative-Dating
What is the definition of Absolute-dating?
A method that measures the age of fossils or rocks in years by examining the half-lives of radioactive atoms.
In what year did major movements in DNA based science occur?
1958 (ex. Rosiland Franklin and Watson and Crick)
Biochemical similarities: Closely related organisms have very many similarities in their _______?
DNA
What are vestigial structures?
Remnants of once-useful structures
What are some vestigial structure in humans?
The tonsils, appendix, and wisdom teeth.
Whales most likely evolved from ____________ NOT _______
Land mammals, fish
What are homologous skeletal structures?
Hint: Homologous means similiar
Parts of organisms that have similar structures (internally) but different functions
True or False- Analogous parts are similar in external apperance but differ in internal stucture.
True
Is this picture an example of homologous or analogous structures?
Homologous
What is embryology?
When you compare the similarities in the early stages of development
Directions: Fill in the blanks with the appropriate answer.
________________ suggests a common ancestor between salamanders, pheasants, and ____________. When these three animals are _____________, they all have gill slits and tail bones. In humans, the gill slits become inner _______________.
Embryology, humans, embryos, ear bones
True or False? If false, correct the answer.
Charles Darwin sailed on the HMS Beagle and landed at the Galápagos Islands in 1836.
False. Charles Darwin sailed on the HMS Beagle and landed at the Galápagos Islands in 1835.
What were the Galápagos Islands?
At one time, they were underwater volcanoes.
On the Galápagos Islands, Darwin noticed a large number of different species of organisms. Give a few examples.
- Black lizards (marine iguana)
- Tortoises
- Finches
Speciation is the development of a new species. List the four things that occured with Darwin’s finches.
- Some finches left the mainland and reached one of the islands, as a result of this, they resembled the finches found on the mainland (England)
- The different finches had differently shaped beaks
- These variations allowed some finches to feed more effectively when they reached the islands (from flying over from the mainland)
- Certain finches were more likely to survive, reproduced, and slowly established themselves on certain islands (due to different foods)
After all of Darwin’s research, he concluded that organisms _____________ for food to sruvive. Only organisms that are better able to _________ will survive. Those that are not will _____________.
compete, adapt, die off
What was the name of Charles Darwin’s book? When did he create it?
It was titled: On the Origin of Species By Means of Natural Selection, and it was created in 1859
When Darwin was writing his book, there were two significant men who inspired him. Who were they, and what did they teach Darwin?
- Thomas Malthus - Humans will reproduce faster than food supply can handle
- Charles Lyell - Earth is way older than we think and it has changed over time, and it will continue to change, so humans must adapt
Explain what was wrong with Jean Baptiste Lamarck’s reasoning.
He believed that a change in structure followed a change in function. For example, the giraffe eats leaves from top branches. So the exercise of stretching up to reach high leaves altered their neck and legs.
List the four steps of natural selection.
- Each species produces many more offspring that can survive and reproduce which leads to a struggle for survival (overproduction)
- There are differences among organisms of the same species (inherited variation)
- Individual organisms with certain traits have a better chance of surviving (survival of the fittest)
- These organisms reproduce, passing on the favorable traits (successful reproduction)