Charles Darwin (GW2) Flashcards
Scientists thought that similar species descended from a common ____ by a process of ___ change.
Ancestor
Gradual
What is the theory of evolution?
The theory of evolution is based on the idea that all species are related and gradually change over time.
Darwin was a British ___. In 1831 he set sail on the survey ship HMS ____. He traveled around the world. Darwin visited many different islands studying the ____. He was impressed by the huge variety of plants and species that he found. He brought back a large collection of plants, animals, and _____.
Naturalist
Beagle
Wildlife
Fossils
What famous work did Darwin publish in 1859?
On the Origin of Species
What was in his book?
He presented evidence to support his ideas. He also described how evolution might have taken place. He called the theory ‘natural selection’.
About the same time, ____ Russel Wallace also presented his ideas on evolution. Their ideas were based upon the same ideas.
Albert
What island did he find the most research?
The Galapagos.
What animal did he study?
He studied a variety of finches. he suggested that they must be descended from birds that had flown to the islands, or been blown there from the mainland.
What did he notice about the beaks of the finches?
He noticed differences in the beak of the finches. They had different beaks for different diets. Some had thick beaks to crush seeds, while others had slender beaks to catch insects.
How did these finches display natural selection?
He suggested the seed-eating finches reached the islands from the mainland, but that there was not enough food for all birds. Finches with slightly different beaks were able to eat other types of food. These finches survived to breed and passed on their adaptations to their offspring.
Define natural selection.
The process whereby organisms better adapted to their environment tend to survive and produce more offspring.
Natural selection results in ____ to the environments being selected and passed on. So with time, a population will become better adapted.
Adaptation
Explain how some species build resistance, using insects as an example.
Insecticides are used to kill insect pests, a few individuals do not die. These individuals have a gene mutation. This enables them to produce an enzyme that is able to break down and make it harmless. We say that they are resistant.
Explain how these resistant insects breed.
Those that survive will breed, so the number of resistant insects in the population will increase. Resistance can spread quickly because insects reproduce rapidly.
The amount of insecticide need to be used is larger. Eventually, a different insecticide is tried. But in time, the insects develop ____.
Resistance
