Ideas that Shaped Darwin's Thinking 16.2

How did Lamarck pave the way for the work of later biologists?

Because he was among the first to try to explain evolution scientifically using natural processes. He also recognized that there's a link between an organism's environment and its body structures

How do humans affect natural selection? What role does nature play?

Darwin stated that nature provides the variation among organisms, and humans select and breed for the variations they find useful or appealing

True or False: Hutton realized that Earth was much younger than previously believed

False, Hutton realized that the Earth was much older than previously believed

True or False: Lyell thought that most geological processes operated extremely quickly

False, Lyell thought that most geological processes operated extremely slowly

True or False: The processes that changed Earth in the past are different from the processes that operate in the present

False. The processes that changed Earth in the past are similar to the processes that operate in the present

Describe how you could use artificial selection to breed pigeons with large beaks

Find pigeons that naturally have larger than normal beaks. Mate these pigeons. Repeat this process over several generations until you achieve the desired beak size.

What did Lamarck believe?

He believed that all organisms have an inborn urge to become more complex and perfect. He thought that organisms could change the size or shape of their organs by using their bodies in new ways. He also thought that organisms could pass on acquired traits to the next generation.

What did Lyell believe?

He believed that laws of nature are constant over time and that scientists must explain past events in terms of processes they can observe in the present. He also believed that Earth was much older than a few thousand years.

What observation caused Thomas Malthus to form his theory about population growth?

Human birth rate was higher than the death rates

Artificial Selection

Humans choose the characteristics that we want.

What did Hutton and Lyell conclude about Earth's history?

Hutton and Lyell concluded that Earth is extremely old and that the processes that change Earth in the past are the same processes that operate in the present

How did James Hutton contribute to Darwin's Theory of Evolution?

Hutton argued that Earth is many millions of years old. Knowing that Earth was very old convinced Darwin that there had been enough time for life to evolve.

What idea did Thomas Malthus come up with about the human population?

If the human population grew unchecked,, there wouldn't be enough living space and food for everyone

How is inherited variation used in artificial selection?

In artificial selection, nature provides the variations, and humans select those they find useful.

In what two ways did an understanding of geology influence Darwin?

Knowing that the Earth could change over time helped him believe that life might change as well and knowing that the Earth was very old assured him that there has been enough time for life to change

How did Lamarck propose that species evolve?

Lamarck suggested that organisms could change during their lifetimes by selectively using or not using various parts of their bodies. He also suggested that individuals could pass these acquired traits on to their offspring, enabling species change over time.

How did Jean-Bapiste Lamarck contribute to Darwin's Theory of Evolution?

Lamarck was one of the first scientists to recognize that evolution has occurred and that organisms change to live more successfully in their environment. His general ideas about evolution and adaptation influenced Darwin.

How did Charles Lyell contribute to Darwin's Theory of Evolution?

Lyell argued that the process that changed Earth in the past were the same as the processes that are still changing Earth in the present. Knowing that Earth could change over time helped Darwin realize that life might change as well.

What was Malthus's view of population growth?

Malthus reasoned that if the human population grew unchecked, there wouldn't be enough living space and food for everyone.

How did Thomas Malthus contribute to Darwin's Theory of Evolution?

Malthus thought that if the human population continued to grow unchecked, it would run out of living space and food. Darwin realized that this was true of all organisms, not just humans.

Malthus's ideas led Darwin to conclude what?

Organisms are able to evolve through a process known as artificial selection

What is another name for artificial selection?

Selective breeding

Which of Lamarck's ideas turned out to be false?

That organisms have an inborn drive to become perfect and traits acquired by an individual can be passed down to its offspring

Which of Lamarck's ideas turned out to be true?

That there is a link between an organism's environment and body structures

How would Lamarck have explained the length of a giraffe's neck?

The giraffe neck is long because of the tall trees and leaves on the trees in its environment. For the animal to be able to gain access to these leaves, the giraffe's neck grows longer and when this giraffe reproduces it gives the trait of its long neck to its offspring

True or False: Lyell's work explained how large geological features could be built up or torn down over long periods of time

True