Darwin observed that high birthrates and a shortage of life's necessities forced organisms into a constant "struggle for existence", both against the environment and against each other is which led Darwin to propose his theory of constitution
The idea that life changes over time, and the idea that modern species evolved from earlier species, was already widely accepted when Darwin began his research - although nobody yet understood how, and although most naturalists were unwilling to apply those ideas to the human species as well.
The belief that organisms originate from a common ancestor was much of the basis that the theory of natural selection was based on. Evidence of animals sharing the same trait, even though for some it appears to have no benefit to them, appears to have been at the root of this belief.
Darwin did not comment of the origin of life. He said that modern life is the result of adaptations guided by natural selection.
That all life had a single common ancestor.
Because they did.
The evolution of numerous species, such as Darwin's finches from a single ancestor is called adaptive radiation.
Darwin's theory of common descent states that all organisms _____.
Darwin's theory of common descent states that all organisms evolved from past organisms.
The finches were different species that shared a common ancestor
Darwin used the phrase "descent with modification" to reflect the unity he perceived in life. He believed that all organisms are related from an ancestral organism through descent. As time passed, the descendants of this ancient ancestor spilled into various habitats all over the world and began to accumulate modifications that fit their specific ways of life.
Species originate through adaptation by natural selection. Strange thing really, Darwin didn't even believe in evolution.
The structural and biochemical similarities among living organisms are best explained by Darwin's conclusion: Living organisms evolved through a gradual modification of earlier forms --- descent from a common ancestor.
The evolution of numerous species, such as Darwin's finches from a single ancestor is called adaptive radiation.
The evolution of numerous species, such as Darwin's finches from a single ancestor called adaptive radiation.
That all organisms on earth are related and rose from a probably universal common ancestor. That all organisms can be placed on the " tree of life " in nested hierarchies of ever growing ( for the most part ) complexity.
South America
Darwin's theory of common descent states that all organisms _____.
Darwin's theory of common descent states that all organisms evolved from past organisms.
Charles Darwin theorized that all species come from one common ancestor through evolution.
Charles Darwin
a common ancestor
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