Bio Chapter 14 + 15

steps of natural selection

1. Variation 2. Reproduction 3.Struggle to survive 4. Survival of the Fittest

Adaptation

A characteristic that improves an individual's ability to survive and reproduce in a particular environment.

Natural Selection

A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.

Geologic Timeline

Cenozoic,Mesozoic, Paleozoic,Proterozoic,Archean, Hadean

Lyell's influence on Darwin

Charles Lyell's writings were read by Darwin as he was voyaging on the Beagle. Lyell proposed that gradual geological processes could explain the physical features on Earth today. Past structures/processes can be explained by present processes.

Describe molecular evidence for evolution.

DNA sequences of different species also can be compared. The more similar the sequences, the more recently the species shared a common ancestor.

2 points of Darwins theory

Descendants of early organisms accumulate adaptations or variations, according to their environment. Natural selection occurs, giving some individuals advantages over others allowing them to survive longer and produce more. The result of natural selection is adaptation.

Explain how similarities in structure and development among different species are evidence for evolution.

For similarities in structure, the variations of a common structural theme - one that has adapted to different functions show the evolution that has taken place. Such similar structures in species sharing a common ancestor are called homologous structures. These homologous structures support other evidence that evolution is a remodeling process and structures that originally functioned one way in ancestral species become modified as they take on new functions.For Similarities in Development, embryos of closely related organisms often have similar stages in development.

Evolution

Generation-to-generation change in the proportion of different inherited genes in a population that account for all of all the changes that have transformed life over an immense time.

Lamarck's influence on Darwin

Lamarck recognized that species do not have permanent characteristics. Lamarck also believed in inheritance of acquired characteristics. This proposed enhanced characteristics, which were developed by an organism using or not using a part of the body, were passed on to that organism's offspring. He thought organisms just kept needed traits which is different from Darwin who observed they gradually change traits over generations.

How did the work of Lyell and Malthus influence Darwin as he developed his theory of evolution?

Lyell's observations that gradual processes shape Earth influenced Darwin to believe that over time life forms could also gradually change. Malthus inspired Darwin's idea of survival of the fittest.

Hutton's influence on Darwin

Proposed Earth is older than 1 million years old. He also observed that gradual changes shape Earth.

Buffon's influence on Darwin

Proposed the Earth is older than 10,000 years.

Why are older fossils generally in deeper rock layers than younger fossils?

Sedimentation places younger rock layers on top of older ones.

Observations from Darwin's voyage

Species from South America were similar and unique to that land. Species on the Galapagos Islands were similar but different from mainland animals. Individual islands have differences in species. Observed fossils,plants, and animals. All organisms have a common ancestor.

Homologous structures

Structures in different species that are similar because of common ancestry.

What characteristics of the Galapagos Islands were particularly important for Darwin?

The Galapagos Islands had many different species allowing Darwin a lot of evidence and animals to make observations from. Also, they were different from European species so he could make new observations and verify or change any inferences he had made only from European species. There were also many fossils available for Darwin to study.

How can evolutionary theory explain why Australia is home to relatively few native placental mammals

The marsupial species were related to a common animal of another continent that was isolated fromt the placental mammal.

What can you infer about species that differ significantly in their DNA sequences?

They are not closely related and did not come from the same ancestor.

Malthus's influence on Darwin

Thomas Malthus concluded that human suffering, like disease and famine was caused by the ability of the human population to grow. He inspired survival of the fittest.

Describe information the fossil record contains about life

We can see the chronological collection of life's remains in rock layers. The fossil record shows evidence of Earth's changing life. It records evolution of various group of organisms.

Tell how the geographic distribution of organisms relates to evolution

a big clue to how modern species evolved from their ancestors. There is evidence of creatures being very similar to each other in different parts of the world, or Darwin's finches being slightly different from island to island to adapt to their environment, but they are all the same basic finch. They all derive from a common ancestor because of their similar structures.

analogous structures

not inherited from a common ancestor, but perform similar functions

Descent with Modification

process by which descendants of ancestral organisms spread into various habitats and accumulate adaptations to diverse ways of life

vestigial structure

remnant of a structure that may have had an important function in a species' ancestors, but has no clear function in the modern species.

Artificial Selection

selective breeding of domesticated plants and animals to produce offspring with desired genetic traits

Embryology

study of multicellular organisms as they develop from fertilized eggs to fully formed organisms