EVOLUTION Flashcards
(57 cards)
What is a mutation?
A mutation is a change in genetic information ( DNA ) that can have an immediate/direct affect on an individual, but they can also influence future generations when those mutations are inherited.
What are the three types of mutations?
Neutral mutation
Harmful mutation
Beneficial mutation
What are Neutral mutations?
They have no immediate benefit/harm to an individual
They dont affect reproductive success or survival
Not selected by natural selection
No selective advantage or disadvantage
What is an example of a neutral mutation?
Receding hairline
What are Harmful mutations?
Reduces the organisms reproductive success and is therefore selected against
Harmful mutations do not accumulate over time ( not selected for )
What is an example of a harmful mutation?
Cystic fibrosis
What is a beneficial mutation?
Increases the organism’s reproductive success
Beneficial mutations are favoured by natural selection and accumulate over time
Provide advantage - better chances of survival
What is an example of a beneficial mutation?
Lactose tolerance
What is Artificial selection ( selective breeding )
Occurs in captivity
Humans choose which animals or plants are bred ( have certain desired traits )
Used to improve/modify certain traits
Can produce drastic changes in certain traits
Can result in new breeds/varieties of animals and plants
What is domestication?
Domestication is the changing of a member of a species to suit human needs through controlled and captive breeding
What are consequences of mutations?
1.) Bacteria becoming resistant to antibiotics
2.) Insects becoming resistant to pesticides
3.) Influenza virus - always changing, enhancing its ability to spread
What did philosophers and other religious experts think about species?
They thought all species that lives on earth were immutable (unable to change)
What did buffon discover?
He wondered about vestigial body parts ( seemed to serve no purpose/barely functioned )
Believed species had been created in a more perfect form but had changed over time
What did linnaeus propose?
He proposed that life changed over time
Who was Erasmus Darwin and what did he propose?
He was the grandfather of charles darwin and proposed that all life might have evolved from a single original source
Who was Lamarck?
Lamarck was a student of buffon and was the first scientist to offer a possible mechanism for the evolution of species
What were Lamarcks 2 principles?
1st principle : Use and disuse
2nd principle : Inheritance of acquired characters
What is use and disuse
When an individual uses a structure/muscle a lot it becomes larger and stronger
When an individual doesnt use a structure/muscle a lot it becomes smaller and weaker ( vestigial )
What is inheritance of acquired characters?
Individuals could pass on characteristics they had acquired during their lives
What are fossils?
Fossils are preserved ancient remains of dead organisms
How are fossils formed?
1.) Remains of a buried organism are gradually replaced by mineral deposits
2.) If the remains sink to the bottom of a body of water and is quickly buried by sediments, the resulting lack of oxygen can prevent decomposition
3.) As sediments accumulate the body gets compressed and very gradually chemical changes occur that result in the body becoming mineralized
What did Cuvier find? Explain.
Cuvier founded the theory of catastrophism
The theory states that the species themselves did not change and global catastrophes such as floods caused widespread extinction of species
Extinct species fossilized, and replaced by a newly created set of species.
What did lyell find? Explain.
Lyell founded the theory of uniformitarianism
The theory states that Earth has been changed by the same processes in the past that are occuring in the present
Geological change is slow and gradual/uniform
What is biogeography?
The study of past and present geographical distribution of organisms
