Biological Evolution Overview

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Questions and Answers

What is evolution?

The process which things change over time.

What is biological evolution?

Modern organisms evolved over long periods of time through descent from common ancestors.

Where was Darwin's journey to, and what was he sailing on?

The HMS Beagle's five-year voyage to South America.

What three patterns of biodiversity did Darwin note on his voyage?

Species vary globally, species vary locally, and species vary over time. Signup and view all the answers

What did Darwin note about the varying of species globally?

Different, ecologically similar, animal species inhabited separated, but ecologically similar habitats around the globe. Signup and view all the answers

What did Darwin note about the varying of species locally?

Different, yet related, animal species often occupy different habitats within a local area. Signup and view all the answers

What did Darwin find to help prove that species vary over time, and what did that prove specifically?

Fossils, and that some fossils of extinct animals are similar to living species. Signup and view all the answers

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

He understood that the Earth is constantly changing slowly, over long periods of time. Signup and view all the answers

How did Hutton contribute to Darwin's theory of evolution?

Earth had enough time for evolution because it was very old, and geological processes formed the earth's geological features over a long period of time. Signup and view all the answers

How did Lyell contribute to Darwin's theory of evolution?

He came up with uniformitarianism: the geological processes we see today are the ones that shaped the Earth. Signup and view all the answers

How did Lamarck contribute to Darwin's theory of evolution?

He said that species aren't fixed, evolution is explained through natural processes, and there is a link between an organism's environment and its body structures. Signup and view all the answers

How did Lamarck propose species changed over time?

By selective use or disuse of organs, organisms acquired or lost certain traits in their lifetimes, and these traits could be passed to their offspring. Signup and view all the answers

How did Lamarck pave the way for later biologists?

Lamarck was the first to develop a scientific theory of evolution and realize organisms adapt to their environment. Signup and view all the answers

Which of Lamarck's ideas were true, and which were false?

Evolution comes through natural processes. Signup and view all the answers

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

Human birth rate was higher than death rate. Signup and view all the answers

Which of the following is an idea attributed to Malthus?

If human population grew unchecked, there wouldn't be enough living space and food for everyone. Signup and view all the answers

What did Malthus conclude?

Many more organisms are born than will survive and reproduce. Signup and view all the answers

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

Nature provides the variation in organisms, and humans choose the traits they like and breed ones with the trait. Signup and view all the answers

What is another name for artificial selection?

Selective breeding. Signup and view all the answers

What is struggle for existence?

Competition for limited resources. Signup and view all the answers

What is adaptation?

Organisms' ability to survive and reproduce in its environment. Signup and view all the answers

What is fitness and how does it relate to an organism's chance of survival and reproduction?

If one has high fitness it will do well, and if one doesn't, it won't. Signup and view all the answers

What does natural selection act on?

Inherited traits. Signup and view all the answers

What is an inherited characteristic that increases an organism's chance of survival considered?

An adaptation. Signup and view all the answers

What does natural selection depend on?

The ability of organisms to reproduce (leave descendants). Signup and view all the answers

Where did organisms all descend from?

Ancestors who survived and reproduced. Signup and view all the answers

What does common descent suggest?

All species, living and extinct, are related. Signup and view all the answers

What is descent with modification?

The principle that living species descend with changes from other species over time. Signup and view all the answers

What does the fossil record provide?

Physical evidence of descent with modification over long periods of time. Signup and view all the answers

What is biogeography?

Study of where organisms live now and where they and their ancestors lived in the past. Signup and view all the answers

How does geographic distribution of species today relate to their evolutionary history?

Patterns in the distribution of living and fossil species tell us how modern organisms evolved from their ancestors. Signup and view all the answers

What is a homologous protein found in almost all living cells?

Cytochrome c. Signup and view all the answers

What is similar in all organisms' genetic code?

DNA and RNA. Signup and view all the answers

What are HOX genes?

They help determine the head-to-tail axis in embryonic development. Signup and view all the answers

What happens when there are minor changes in an organism's genome?

There are dramatic structural changes. Signup and view all the answers

Why are organisms who are closely related found in different habitats?

Natural selection in different yet close places makes different, but closely related species. Signup and view all the answers

Why are organisms who are distantly related found in similar habitats?

They evolved from different species but similar selection pressures caused them to develop similar adaptations. Signup and view all the answers

What did the Grants document show?

Natural selection takes place in wild finch populations often, and sometimes rapidly. Signup and view all the answers

What are vestigial structures?

Inherited from ancestors but lost most of original function. Signup and view all the answers

What are some traits about the rheas, ostrich, and emu that demonstrate convergent evolution?

Long necks (to see over tall grass) and long, strong legs (to run fast to avoid predators). Signup and view all the answers

What are some of the differences between the large tortoises of Isabella and Hood Islands?

Isabella tortoises have dome-shaped shells, while Hood tortoises have shells that curve near the neck. Signup and view all the answers

What was the major contributing factor that led to changes in beak shape for the Galapagos finches?

The type of food found on the different islands. Signup and view all the answers

Study Notes

Evolution Overview

Evolution refers to the gradual change of organisms over time.
Biological evolution occurs through descent from common ancestors.

Darwin's Voyage

Charles Darwin embarked on a five-year journey aboard the HMS Beagle, primarily to South America.
He noted three main patterns of biodiversity: species vary globally, species vary locally, and species vary over time.

Biodiversity Observations

Globally, distinct but ecologically similar species inhabit separate yet comparable habitats.
Locally, related species often occupy different habitats within the same geographic area.
Fossils demonstrated that extinct species show similarities to existing organisms, supporting the theory of change over time.

Influence of Geology

Hutton established that the Earth is ancient, allowing sufficient time for evolutionary changes.
Lyell introduced uniformitarianism, suggesting that current geological processes are the same that shaped the Earth, implying life also changes over time.

Contributions of Early Theorists

Lamarck proposed that species evolve through natural processes and adapt to their environment, emphasizing the non-fixed nature of species.
He erroneously claimed that acquired traits can be inherited and that organisms have an inherent drive towards perfection.

Malthus's Influence

Malthus theorized that human population grows unchecked, leading to competition for limited resources.
Darwin inferred from Malthus that more organisms are born than can survive, setting the stage for natural selection.

Natural Selection and Adaptation

Natural selection relies on inherited traits; advantageous traits lead to better survival and reproduction rates.
Adaptation describes an organism's ability to thrive in its environment.
High fitness signifies a greater chance of survival and reproduction.

Common Descent and Modification

All current organisms descend from ancestors that successfully reproduced.
Common descent suggests all species, both living and extinct, share a related lineage.
Descent with modification indicates species evolve with changes over time.

Genetic Evidence

Fossil records provide concrete evidence of modification across vast periods.
Biogeography studies the distribution of species and their ancestors, revealing evolutionary history.
Homologous proteins, like cytochrome c, and universal genetic codes (DNA and RNA) support the concept of common ancestry.

Evolutionary Genetics

HOX genes play a crucial role in determining body plans during embryonic development.
Minor genomic changes can lead to significant structural transformations in organisms.

Adaptive Radiation

Species in similar habitats may exhibit analogous adaptations due to similar environmental pressures despite being distantly related.
Closely related species might differ significantly due to natural selection acting in diverse habitats.

Observations from Finch Studies

Research by the Grants demonstrated rapid shifts in finch populations, impacted by competition and environmental variability.
Increased variation within a species fosters adaptability during environmental changes.

Vestigial Structures and Convergent Evolution

Vestigial structures arise from ancestors but have lost most original functions.
The rheas, ostrich, and emu exhibit convergent evolution with traits like long necks and strong legs for escaping predators.

Case studies of Adaptation

Differences between Isabella and Hood Island tortoises highlight adaptive traits related to food source availability.
Beak shape variations in Galapagos finches correlate with the types of food prevalent on different islands, showcasing evolutionary responses to environmental factors.

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Description

Explore the fundamental concepts of evolution, including Darwin's observations during his voyage on the HMS Beagle. This quiz covers the patterns of biodiversity and the geological influences that shape evolutionary processes over time.