1.Where did Charles Darwin made most of his observation in order to come with the theory of evolution?
He did most of his observations in Galapagos.
2.What is the fossil record?
It is the sequence in which fossils appear within layers of sedimentary rocks-provides some of the strongest evidence of evolution.
3.What are some evidence that reinforce the evolutionary view of life?
Some of the evidence that reinforce the evolutionary of life are biogeography, comparative anatomy, and molecular biology.
Five main facts about the chapter:
1.Charles Darwin proposed natural selection as the mechanism of evolution.
2.Scientists can observe natural selection in action.
3.The study of fossils provides strong evidence for evolution.
4.Homologies indicate patterns of descent that can be shown of an evolutionary tree.
5.Populations are the units of evolution.
Diagram:
This diagram shows homologous structures: vertebrate forelimbs.
Link: http://www.myspace.com/roiscience
Summary:
The introduction of this chapter talked about the blue-footed boobies, which are well adapted and very interesting birds. Their big webbed feet, stream-lined shape, large tail, and specialized salt-excreting glands are all good examples of evolutionary adaptations. Charles Darwin came up with the study of evolution - the core theme of biology. A sea voyage helped Darwin frame his theory of evolution. The most important things that helped Darwin to form his theory of evolution were his cultural and scientific context, his sea voyage, his writings, and the study of fossils. Darwin also proposed natural selection as the mechanism of evolution. Darwin devoted much of On the Origin of Species to how organisms become adapted to their environment. First, he discussed familiar examples of domesticated plants and animals. Humans have modified other species by selecting and breeding individuals that possess desired traits - a process called artificial selection. Darwin then explained how a similar selection process could occur in nature, a process he called natural selection. Scientists can observe natural selection in action. The study of fossils provides strong evidence for evolution. Many of the fossils that paleontologists find in their digs are not the actual remnants of organisms at all, but are replicas of past organisms. The fossil record - the sequence in which fossils appear withing layers of sedimentary rocks-provides some of the strongest evidence of evolution. A mass of other evidence reinforces the evolutionary view of life. Some of them are biogeography, comparative anatomy, and molecular biology. Homologies indicate patterns of descent that can be shown on an evolutionary tree. Populations are units of evolution. In other words, a population is a group of individuals of the same species living in the same place at the same time. In studying evolution at the population level, biologists focus on what is called the gene pool, the total collection of genes in a population at any one time. Mutation and sexual reproduction produce genetic variation, making evolution possible. The Hardy-Weinberg equation can be used to test whether a population is evolving. It is also useful in public health science. Natural selection, genetic drift, and gene flow can alter allele frequencies in a population. Natural selection is the only mechanism that consistenly leads to adaptive evolution. It also can alter variation in a population in three ways: stabilizing selection, directional selection, and disruptive selection. Sexual selection may lead to phenotypic differences between males and females. Darwin was the first to explore the implications of sexual selection, a form of natural selection in which individuals with certain characteristics are more likely than other individuals to obtain mates. The evolution of antibiotic resistance in bacteria is a serious public health concern. Diploidy and balancing selection preserve genetic variation. Balancing selection occurs when natural selection maintains stable frequencies of two or more phenotypic forms in a population. Natural selection cannot fashion perfect organisms.
Key Terms
1. Evolution - the core theme of biology.
2.Artificial selection - the process by which humans have modified other species by selecting and breeding individuals that possess desired trait.
3.Fossil record - the sequence in which fossils appear within layers of sedimentary rocks-provides some of the strongest evidence of evolution.
4.Biogeography - the geographic distribution of species.
5.Vestigial organs - structures that are of marginal or perhaps no importance to the organism.
6.Population - a group of individuals of the same species living in the same place at the same time.
7.Mutation - a change in the nucleotide sequence of DNA.
8.Genetic drift - a change in the gene pool of a population due to chance.
9.Founder effect - differences in a gene pool of a small colony compared with the original population.
10.Sexual dimorphism - the distinction in appearance.
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