22 2 Descent with modification Evolution through natural

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22. 2 Descent with modification

22. 2 Descent with modification

Evolution through natural selection It was Darwin’s research that was the catalyst that would

Evolution through natural selection It was Darwin’s research that was the catalyst that would change the way in which we understand evolution. All life is interconnected in some way. It is through observing both the unity and diversity of life that we begin to understand how Darwin arrived at his conclusions. Unity and Diversity of life?

The HMS Beagle and Darwin’s Voyage He noticed that along his travels around Chile,

The HMS Beagle and Darwin’s Voyage He noticed that along his travels around Chile, he noticed that after a violent earthquake, several small crags were jetting out of the water a few feet in the air. The crags contained fossils of sea life in them. Darwin considered much about geology in his travels. He was well read on Lyell’s works on geology and understood the mechanics by which geologic processes worked. He also made this same observation in the Andes mountains, where he found the same phenomena of sea shells on tops of mountains. He concluded that these mountains were created by the same types of earthquakes, which reinforced the idea that the Earth was more than just a couple thousand years old.

continued. . . Another important thing Darwin noticed was in the Galapagos islands. A

continued. . . Another important thing Darwin noticed was in the Galapagos islands. A large and diverse population of organisms that had some similar features of a mainland South American bird were unique and only found on those islands.

Darwin’s Focus on Adaptations are inherited characteristics that helps an organism enhance its chances

Darwin’s Focus on Adaptations are inherited characteristics that helps an organism enhance its chances of survival and reproduction.

Natural Selection in the finch populations Natural selection is a process by which individual

Natural Selection in the finch populations Natural selection is a process by which individual that have a certain trait tend to survive and reproduce at higher rates than other individuals because of those traits. Darwin still felt he did not have enough evidence and did not publish his work right away.

Wallace and his theory on natural selection Alfred Russel Wallace, a British naturalist sent

Wallace and his theory on natural selection Alfred Russel Wallace, a British naturalist sent a paper to Darwin in 1858 that outlined, nearly identically, all of the points and conclusions drawn by Darwin, asking him if it were worthy of being published. Soon after, Darwin quickly finished his book, On the Origin of Species By Means of Natural Selection. Although Wallace published first the credit still remains Darwin’s.

On the Origin of Species Evolution was not used in the book’s first edition.

On the Origin of Species Evolution was not used in the book’s first edition. The words “Descent with modification” were used instead. It was explained that all organisms that share common traits must have some form of common ancestor that through migration to various places, accumulated modifications, or adaptations that fit them to a certain way of life. Darwin the concluded that descent with modification led to a rich diversity of life.

Artificial Selection, Natural Selection, and Adaptation Artificial Selection Also called selective breeding, this has

Artificial Selection, Natural Selection, and Adaptation Artificial Selection Also called selective breeding, this has allowed for desirable (chosen) characteristics and even animals to survive over long periods of time. Processes like artificial selection often lead to organisms that are next to nothing like their ancestors. Natural Selection Individual that have a certain trait tend to survive and reproduce at higher rates than other individuals because of those traits. Darwin concluded that processes like artificial selection mirror those of natural selection, only by different means of selection.

Darwin’s Observations and Inferences about Natural selection Observations Inferences Members of populations often vary

Darwin’s Observations and Inferences about Natural selection Observations Inferences Members of populations often vary in inherited traits. Individuals whose inherited traits give them a higher probability of surviving and reproducing tend to leave more offspring. All species can produce more offspring than their environment can support, and many of these offspring fail to survive and reproduce. The unequal ability of individuals to survive and reproduce will lead to the accumulation of favorable traits in the population over generations.