Chapters 10-12 Evolution Pre AP Bio Simons

Linneaus

Naturalist and the taxonomist whose system we still use today. He is the father of taxonomy which is the classification system from kingdom to species.

Buffon

Naturalist who proposed that species shared ancestors rather than arising separately

E. Darwin

stated that more-complex life forms developed from less-complex life forms

Lamarck

French naturalist who proposed that evolution resulted from the inheritance of acquired characteristics. He also stated that environmental change leads to use or disuse of a structure.

Three theories of geologic change

catastrophism, gradualism, uniformitarianism

Cuvier

catastrophism: believed that the extinction of species and the formation of all landforms was caused by catastrophic events such as floods, volcanoes, and earthquakes. He also thought that species could not change, but they could go extinct.

Hutton

A geologist who proposed the theory of Gradualism: changes in landforms resulted from slow changes over periods of time

Lyell

A geologist and the 'Father of uniformitarianism' - belief that the earth was old, and the geologic processes that shape Earth are constant, or uniform through time.

Law of superposition

States that in a sequence of sedimentary rock layers, each later of rock is older than the layer above it and younger than the rock layer below it.

Evolution

The biological change process by which descendants come to differ from their ancestors, a change in a species over time.

Species

A group of organisms that can reproduce and have fertile offspring.

Variation

a difference in a physical trait

Examples of variation

Galápagos tortoises that live in areas with tall plants have long necks and legs, Galápagos finches that live in areas with hard-shelled nuts have strong beaks.

Interspecific variation

Variation among members of different species

Intraspecific variation

Among individuals of the same species

Adaptation

A feature that allows an organism to better survive in its environment

What can adaptations lead to?

genetic change in a population

What did Darwin observe in the Andes Mountains? What did they suggest?

Fossils shells high up in the mountains. This suggests that the mountains were once underwater.

What did Darwin observe during an earthquake?

Land moved from underwater to above sea level

What did Darwin observe in fossils?

He found fossils of extinct animals that resemble modern animals

What is the difference between acquired characteristics and change over time?

Acquired characteristics are changes in function or structure of an organism that were caused after birth by disease, injury, accident, deliberate modification, variation, repeated use of the structure, disuse, or misuse. Acquired traits cannot be passed on to offspring. Change over time is the process by which species adapt over time in response to their changing environment.

How can variation benefit a population?

It enables some individuals within a population to adapt to the environment while maintaining the survival of the population.

What age did Darwin conclude the Earth was?

Several hundred million years old

Natural selection

A natural process by which individuals that have inherited beneficial adaptations produce more offspring on average than do other individuals.

Artificial selection

The process by which humans select traits through breeding

What is the selecting agent in artificial selection?

humans

what creates the selective pressure in nature?

the environment

Four main principles to the theory of natural selection

variation, overproduction (of offspring), adaptation, descent with modification

Fitness

The measure of survival ability and ability to produce more offspring

Natural selection can act only in traits that don't exist yet, True or false?

False

What happens to the function of existing structures in natural selection?

They take on new functions in addition to their original functions.

Overproduction of offspring

Organisms produce more offspring than needed to sustain the population. This leads to increased competition for resources and struggle for survival within a population due to the large population.

What did Thomas Malthus propose?

Resources such as food, water, and shelter were natural limits to human population growth.

Heritability

The ability of a trait to be passed down

What did Darwin propose about adaptations?

That they arose over many generations

What did Darwin find about populations?

He found that populations vary

What is a population?

All the individuals of a species that live in an area

Descent with modification

Variations came about as adaptations over many generations

What does Darwin's theory not explain?

Genetics

Peppered moth example

Originally, the majority of these moths were light-colored, due to natural selection and then when the trees turned black due to the Industrial Revolution in England and the coal from factories, the black colored moths came into the majority because of natural selection.

What is the central theme in all fields of biology?

evolution

Evidence for evolution

Fossils, geography, embryology, anatomy, and molecular & genetic evidence

How do fossils provide evidence for evolution?

They provide the evidence of the organisms that lived years ago, they can show how much or little organisms have changed over time.

Paleontology

the scientific study of fossils or extinct organisms

How does geography provide evidence for evolution?

Biogeography, a subunit of geography, shows how populations can change from their mainland species and from one island to another.

Biogeography

Study of the distribution of organisms around the world

How does embryology provide evidence for evolution?

Embryos go through similar processes, showing that the probably had a common ancestor. For example fish, reptiles, birds, and mammals have very similar embryos with gill slits and tales, but all but fish get rid of the gills as they mature

Embryology

study of embryos and their development

Anatomy

The study of body structure

Homologous structures

Body parts in different species that are similar in structure but different in function because of common ancestry.

How are homologous structures evidence of evolution?

They show a common ancestor because they have the same bones that just developed different functions to suit the organisms's environment.

Analogous structures

Body parts that share a common function, but not structure.

Are analogous structures evidence of a common ancestor

No

Example of homologous structures

wing of a bat and the arm of a human

Example of analogous structures

The wings of a bat and the wings of a dragonfly

vestigial structures

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

How are vestigial structures evidence for evolution?

Vestigial structures are evidence for evolution because they suggest an organism has an ancestor that may have used the otherwise "useless" structure.

Example of vestigial structure

Ostrich wings

What will the DNA of two closely-related organisms be like?

They will have similar DNA sequences

Pseudogenes

Former genes that have accumulated mutations over a long time, are carried with functional DNA, and no longer produce functional proteins. They can be clues to a common ancestor

Can pseudogenes disappear?

No

Hox genes

series of genes that control the development of specific structures. They are found in many organisms.

Protein comparisons

the basis of molecular fingerprinting, which reveals similarities among cell types of different organisms.

What is the theory of natural selection combined with genetics called?

The modern Synthesis of Evolutionary Theory.

How are mutations important to the theory of evolution?

Mutations give rise to new traits. Those with the more favorable traits will survive and will eventually become the majority of the population.

Transitional fossil

Any fossilized remains of a life form that exhibits traits common to both an ancestral group and it's derived descendant group.

Permineralization

The process by which minerals that are carried by water are deposited around or replace the hard structure of a dead organism, creating a fossil.

Natural casts

Fossils that form when flowing water removes all of the original bones, leaving the impression in sediment. Minerals then fill in the mold.

Trace fossils

They record the activity if an organism. These include nests, burrows, imprints of leaves, and footprints. These are not organisms.

Amber-preserved fossils

Organisms that become trapped in tree resin that hardens into amber.

Preserved remains

These fossils form when entire organisms become encased in material such as ice, volcanic ash, or immersed in bogs.

What rock do most fossils form in?

sedimentary rock

What is the most common fossilization process?

Permineralization

What are the best environments for fossilization?

wetlands, bogs, rivers, lakebeds, and floodplains

Relative dating

The estimate of the age of a rock layer by comparing the placement of fossils in the layers

Radiometric dating

The process of measuring the absolute age of geologic material by measuring the concentrations of radioactive isotopes and their half-life.

Isotopes

Atoms of the same element that have different numbers of neutrons.

Half-life

Length of time required for half of the isotope in a sample to decay into a different element, or its product

Radiocarbon dating

A chemical analysis used to determine the age of organic materials based on their content of the radioisotope carbon-14. Since organisms consume carbon by eating and breathing, it is abundant in their system.

What is Earth's age?

4.5 billion years old

Geologic time scale

Scale used by paleontologists to represent Earth's history based on major events

Index fossils

Fossils of an organism that existed only during specific spans of time over large geographical areas. They can provide the relative age of a rock layer.

Examples of index fossils

fusulinids and trilobites

How long do eras last?

tens to hundreds of millions of years

What are the three eras?

Cenozoic, Mesozoic, Paleozoic

Within the eras what defines the boundaries between the periods?

Mass extinctions

In the geologic time scale, how long do periods last?

Tens of millions of years

What is the unit on the geologic time scale that is most commonly used?

Periods

How long do epochs last?

several million years

When Darwin noted adaptations in finches and tortoises, what did he think was the best explanation about different species?

Each island only has selective types of food, so the animals that had structures better suited to eat the food would survive and reproduce. This would lead to a new species separate from the mainland species.

After Darwin returned from the Beagle, how soon after did he publish his book?

1 year later

Who prompted Darwin to finally publish his theory of evolution?

Alfred Wallace

What was the main adaptation in the finches that Darwin noted while on the Galápagos?

Finches that live in areas with hard-shelled nuts have strong beaks. Each finch from each island has a different beak to suit the food they eat.

Does natural selection act on alleles, genotypes, phenotypes, or mutations?

Phenotypes

The event at which huge numbers of species disappear at once in the fossil record is known as

A mass extinction

Who proposed that organisms have an innate tendency toward complexity and perfectionism?

Lamarck