Topic 4 - Darwin And Wallace’s Theories And Evolution By Natural Selection Flashcards
Who developed the theory of speciation?
Alfred Russel Wallace
Wallace’s contributions were crucial in the formulation of evolutionary theory alongside Darwin.
What happens to individuals lacking survival characteristics in a changing environment?
They die out.
With whom did Alfred Russel Wallace publish joint studies?
Charles Darwin.
What was the impact of the publication of ‘On the Origin of Species’?
Darwin received credit for the theory of evolution.
What was one of Wallace’s important works related to animal characteristics?
Warning colouration in animals.
What is the first step in the process of speciation?
Variation exists within a population as a result of genetic mutations.
What is selected for through natural selection?
Alleles which provide a survival advantage.
What can cause populations of a species to become isolated?
Physical barriers such as a rock fall.
What may lead to the selection of different alleles in a new environment?
Different alleles may be advantageous.
What increases genetic variation between two isolated populations over time?
The selection of different alleles.
What occurs when two populations can no longer breed together to produce fertile offspring?
A new species has formed.
What was Charles Darwin’s profession?
Scientist and naturalist.
What theory did Charles Darwin put forward?
The theory of evolution.
What supported Darwin’s theory of evolution?
Experimentation and knowledge of geology and fossils.
In what year did Darwin publish ‘On the Origin of Species’?
1859.
What causes variation within species?
Mutations in DNA.
What is referred to as ‘survival of the fittest’?
Organisms with characteristics most suited to the environment survive to reproductive age.
What happens to beneficial characteristics in a population over generations?
They are passed on to the next generation.
What happens to the frequency of alleles for advantageous characteristics over many generations?
It increases within the population.
What was one reason for the controversy surrounding his ideas?
It contradicted the idea that God was the creator of all species on Earth.
This reflects the conflict between scientific theories and religious beliefs at the time.
What was a significant limitation in supporting his ideas?
There was not enough evidence at the time as few studies had been done on how organisms change over time.
This highlights the early stages of evolutionary biology and the need for more empirical research.
What was unknown at the time that contributed to the controversy?
The mechanism of inheritance and variation were not known at the time.
This lack of understanding hindered the acceptance of evolutionary theories.