History of Life / Evolution Study Guide KEY


Miss Colabelli

Define the following terms

Biogenesis: principle that all living things come from other living things

Spontaneous generation: belief that living things arise from non-living things

Vital force: the idea that organisms grew from the air from an all knowing force

Half-life: the length of time it takes for one-half of a radioactive isotope to decay to a stable form

Radiometric dating: method of establishing the age of materials using half-life of isotopes

Explain Redi’s experiment.

 Jars were set up with meat inside and allowed to rot. The control group had jars exposed to the environment and not covered. The experimental group had jars covered with cloth so air can flow through, but organisms cannot enter or leave.

 Results: The uncovered jars that were exposed to flies had maggots growing that eventually turned into flies. The covered jars did not have any maggots

Explain Spallanzani’s experiment.

 Boiled clear, fresh broth until the flasks filled with steam. The control group had a flask that remained open during experiment time. The experimental group had a flask that was immediately covered before cooling so not to allow air or bacteria to enter

 Results: The uncovered flask

(control group) became contaminated with microorganisms when air entered.

The experimental group flask did not have any growth.

Explain Pasteur’s experiment.

 Started the experiment by boiling broth in the curved neck flask to kill any microorganisms inside. Left the flask to sit for one year – the broth was still clear. After a year, the neck of the flask was broken

 Results: After one day being exposed to the air, the broth became contaminated with microorganisms.

List the chemicals Oparin believed to have been our early atmosphere.

Ammonia (NH



Hydrogen gas (H


Water vapor (H


Methane (CH





In the Miller-Urey experiment, what were the starting reactants?

 The starting reactants were water vapor, methane gas, ammonia, and hydrogen gas. These are all inorganic compounds.

• Who is Darwin and what is he best known for?

• British naturalist that came up with the theory of evolution by the means of natural selection.

• What is the theory of acquired traits? Give an example of an acquired trait and an inherited trait.

• The theory of acquired traits is a hypothesis that Jean-

Baptiste Lamarck had to explain how organisms evolve.

His theory was that organisms do change over their lifetime. As organisms use and disuse their organs, it will determine what will become more prominent and passed on to their offspring. An example of an acquired trait would be an accent in language or a scar from a cut, or clipping wings short in flies.

• Where did the common ancestor of the finches come from?

• Darwin believed that the common ancestor of the finches came from the mainland of South America (most likely


Define the following terms:

 Biogeography: The study of where species and their ancestors live.

Adaptation: The process by which a population becomes better suited to its environment

Fossil: The ancient remains of an extinct organism

Divergent evolution: The accumulation of differences between populations that once formed from a single population (ex: dog breeds from wolves)

Coevolution: The process by which two or more species becomes more adapted over time to each other’s presence and evolve together (ex: bacteria and antibiotics)

Adaptive radiation: When a new population in a new environment will undergo evolution until the population fills many parts of the environment (ex: finch beaks in Galapagos)

 What does the phrase “survival of the fittest” mean?

 Survival of the fittest is the continued existence of organisms that are best adapted to the environment that enable them to reproduce.

 What was the main idea of Darwin’s book On the

Origin of Species?

 The main idea of Darwin’s book, On the Origin of Species, is that species evolve very slowly over a long period of time through the process of natural selection.

 What is the difference between homologous and analogous structures? Give examples of each.

 Homologous structures: similar structure different function ex: wing of a bird and a human arm

 Analogous structures: similar function different structure ex: wing of bat and wing of butterfly

 What are vestigial structures? Give an example.

 A vestigial structure is an organ that no longer serves a function in the body of an organism. Ex: human tail bone, pelvis in whales

 What contributions did the following scientists do to influence


 Hutton: Geologist that explained the Earth is changing and much older than a few thousand years old

Lamarck: French naturalist that supported the idea that organisms changed over time (lifetime), created the theory of acquired traits. Darwin later explained that this was false.

Wallace: scientist who came up with the same idea of evolution.

He wrote to Darwin and told him about the idea of evolution, pushed Darwin to publish his book before him

 What is the difference between natural and artificial selection?

 Natural selection – When organisms that are best adapted to their environment will live and mature. These organisms will then choose their mate by means of fitness

 Artificial selection – when humans choose the traits and control breeding

 Explain Darwin’s theory of descent with modification.

 The theory of descent with modification is the idea that every species must have descended with small changes over a long period of time by reproduction from a preexisting species

 Explain the differences between the finches on the Galapagos

Islands and why they have these adaptations.

 Finch beaks are different on each island because of the different food that is found in their environment. They had to adapt to survive and through natural selection, new species arouse. Darwin believed they had a common ancestor because they had many similar internal structures.

 Compare a homologous structure to a modern day species. How would this show a common ancestry between the species?

 By comparing a homologous structure like a bat wing to a human arm can show common ancestry because the bone structure is very similar and during development the cells responsible for creating these structures are the same in each organism. Based on the function of the organ, the changes begin to differentiate them between organisms. The common ancestor that each of these organisms’ shares would have had the same development in the structure.