Answer:
Lamarck:
The inheritable traits of species may change over time.
Malthus:
In every species in nature, some individuals survive while may others die.
Hutton, Lyell:
The environment of organisms may change over time.
Explanation:
Darwin's revolutionary ideas were influenced by a number of scientists and thinkers of the time:
Jean Baptiste Lamarck:
A botanist and zoologist, Lamarck, for, the first time, proposed the idea of evolutionary changes or adaptations in organisms in response to changes in the environment. He introduced the concept of inheritance of acquired characters.
Thomas Malthus:
Thomas Malthus was not a biologist, but an economist who proposed the ideas that at the rate of the current population growth, human population would eventually suffer from famine and starvation.This would lead to the deaths of the weakest of the population. This idea inspired Darwin to formulate the idea of "the survival of the fittest".
Charles Lyell and James Hutton:
Charles Lyell and James Hutton were famous geologists who greatly influenced Darwin with their theories about the beginning and evolution of the Earth. Charles Lyell proposed that the present state of the Earth was a result of small, gradual changes. James Hutton theorized that the processes that too place at the beginning of the Earth were still in progress.
Lyell and Hutton's work paved the way for the formulation of the theory of natural selection.
