Ch 15: Evolution

What contribution did James Hutton make to Darwin’s theory of evolution?

Hutton proposed that the Earth is shaped by slow-moving geological forces, suggesting a much older Earth which allowed for gradual evolution.

What contribution did Charles Lyell make to Darwin’s theory of evolution?

Lyell expanded on Hutton's ideas and emphasized that past geological events are similar to those occurring today, supporting the idea of gradual change over time.

What contribution did Thomas Malthus make to Darwin’s theory of evolution?

Malthus suggested that populations grow exponentially while resources grow linearly, leading to competition and survival of the fittest.

What contribution did Jean Baptiste Lamarck make to Darwin’s theory of evolution?

Lamarck proposed the inheritance of acquired characteristics, influencing Darwin’s thoughts on adaptation and change.

Who was Charles Darwin?

Charles Darwin was a naturalist who formulated the theory of evolution by natural selection.

What were the three observations Darwin made while on board the Beagle?

1. Variation among species; 2. The geographical distribution of species; 3. The fossil record showing transitional forms.

Where for Darwin make some of his most important observations that helped him develop his theory of evolution?

Galapagos Islands

What is NOT one of the observations Darwin made while on the voyage of the Beagle?

A. Species vary over time

B. Specified vary globally

C. Species vary locally

D. Species always stay the same

D

What is artificial selection?

Artificial selection is the human-controlled breeding of plants and animals for desired traits.

How did artificial selection contribute to Darwin’s theory of natural selection?

It demonstrated that selection can lead to changes in species, showing that natural selection could work similarly but through environmental pressures.

Define natural selection.

Natural selection is the process by which individuals with favorable traits are more likely to survive and reproduce.

What are the four principles of natural selection?

1. Variation; 2. Inheritance; 3. Overproduction; 4. Differential survival and reproduction.

How are evolution and natural selection different?

Evolution is the change in species over time, while natural selection is the mechanism by which evolution occurs.

What are the different types of evidence of evolution?

Fossil record, embryology, comparative anatomy, vestigial structures, molecular biology

Theory of evolution states all organism on Earth….

Have descended from common ancestor

Fossils provide record of species that lived ____

Long time ago

What can fossil records show?

How species ancient species are similar to living species and how some species reinan unchanged for millions of years

Transitional fossils

Fossils that contain features shared by different species, providing detailed patterns of evolutionary change

Two major classes of traits when studying transitional fossils…

Derived traits and ancestral traits

Derived traits

Newly evolved features (like feathers) that do not appear in the fossils of common ancestors

Ancestral traits

More primitive features (liek teeth and tails) that appear in ancestral forms

What are homologous structures?

Anatomically similar structures inherited from a common ancestor (forelimbs in different animals which show the animal in different ways but share similar construction)

Vestigial structures are….

Structures that are the reduced forms of functional (no functions) inherited other organisms/ancestors

What are analogous structures?

Structures that are similar in construction/function, but not inherited from a common ancestor ( bird wings and insect wings)

What is an embryo?

An early, pre-birth stage of an organism’s development

Vertebrate embryos show…

homogous strucutres during certain phases of development and suggests that vertebrates evolved from a shared ancestor

What can be seen in comparative biochemistry?

Common ancestry can be seen in complex molecules that many different organisms share

What does the fact that many organisms have the same complex molecules suggest?

Because may organisms have the same complex molecules, it suggest the molecules evolved early in history of life

Geographic distribution

Species vary globally; ex: migration patterns explain why islands have more plant diversity than animal diversity

The heart of Darwin’s theory lies in adaption. What is an adaption?

Trait that is shaped by natural selection that increases an organisms reproductive success; the better an organism is adapted to its environment the greater its chances of survival

What is fitness? How is it measured?

Measure of the relative contribution that an indivuality trait makes to the next generation. Measured as the number of reproductively viable offspring an organism produces

Types of adaptions

Camouflage, mimicry, antimicrobial resistance

Camoflauge Adaptions

Morphological adaptions that allow them to blend in with their environment; more likely to survive and reproduce

Mimicry adaptions

Once species evolves to resemble another, looks the same but have different traits

Antimicrobial resistance

Bacteria that were killed by penicillin and other antibiotics have developed drug resistance; some diseases that were once contained have re-emerged in more harmful terms

What is the importance of the fossil record as evidence of evolution?

The fossil record provides chronological evidence of past life forms and their changes over time.

What are transitional fossils? Give an example.

Transitional fossils are remains of organisms that exhibit traits common to both ancestral and derived groups; example: Archaeopteryx, which shows features of both dinosaurs and birds.

What are the two types of traits examined when studying transitional fossils?

1. Morphological traits; 2. Developmental traits.

Define homologous structures and give an example.

Homologous structures are anatomical features that share a common ancestry; example: forelimbs of mammals.

Define analogous structures and give an example.

Analogous structures are features that serve similar functions but do not share a common ancestry; example: wings of birds and insects.

Define vestigial structures and give an example.

Vestigial structures are reduced or nonfunctional remnants of features that served a function in an organism's ancestors; example: human appendix.

How does embryonic development provide evidence of evolution?

Similarities in embryonic development across different species imply common ancestry.

How can DNA sequences of organisms indicate an evolutionary relationship?

Similarities and differences in DNA sequences can show how closely related different species are and the evolutionary paths they have taken.

What is biodiversity?

Biodiversity refers to the variety of life in a particular habitat or ecosystem.

Define adaptation.

Adaptation is a trait that enhances an organism's fitness in its environment.

What is fitness? How is it usually measured?

Fitness is the ability of an organism to survive and reproduce; it is usually measured by the number of offspring produced.

Describe camouflage adaptation.

Camouflage is an adaptation that allows organisms to blend in with their surroundings to avoid detection by predators.

Describe mimicry adaptation.

Mimicry is an adaptation where one species evolves to resemble another that has a better defense mechanism.

Describe antimicrobial resistance adaptation.

Antimicrobial resistance is an adaptation where bacteria evolve to survive exposure to antibiotics.

What is gene flow?

The movement of allies into or out of a population (not by chance, purposely)

What is genetic drift?

Genetic drift is the change in the frequency of a gene variant in a population due to random sampling.

Mutations

The random change in the DNA of an organism

Non-random Mating

Individuals have a choice in who they mate with—not random

Natural selection

Better adapted (more fit) indivuals to their environment survive and reproduce

How does genetic drift affect large and small populations differently?

It has a more significant impact on small populations, where chance events can lead to larger shifts in allele frequencies.

Define founder effect.

The founder effect occurs when a small group establishes a new population, leading to reduced genetic diversity.

Define bottleneck.

Bottleneck is a sharp reduction in population size due to environmental events, resulting in decreased genetic diversity.

What is gene flow?

Gene flow is the transfer of genetic variation from one population to another.

What are the three types of natural selection?

1. Directional selection; 2. Stabilizing selection; 3. Disruptive selection.

Explain the difference between allopatric and sympatric speciation.

Allopatric speciation occurs when populations are geographically isolated, while sympatric speciation occurs when populations are in the same area but become reproductively isolated.