Evolution Study Methods Lecture 2

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Why are you encouraged to participate in lectures via iClicker?

iClicker will help you learn the course material better.

iClicker allows the instructor to track your attendance and participation.

iClicker participation is mandatory for this course, and grades are awarded for participation.

iClicker allows you to actively engage with the course content in real-time. (correct)

What does the lecturer suggest about the relationship between evolution and your beliefs?

Students should be able to reconcile their personal beliefs with their understanding of evolution. (correct)

Evolutionary theory contradicts common religious beliefs.

Students should be prepared to challenge their personal beliefs in order to understand evolution.

Evolutionary theory is a complex subject that may not be compatible with all personal beliefs.

What is one possible reason why students may feel underprepared to study evolution compared to other areas of biology?

Students may be more interested in other areas of biology and therefore may have less motivation to learn about evolution.

Evolution is a more complex and difficult subject to grasp than other areas of biology.

Students may not have been exposed to evolutionary concepts in their high school education. (correct)

Evolutionary theory is often portrayed in a negative light, which can make students feel intimidated.

Which one of the options best describes a well-supported scientific theory?

A theory that has been tested and supported by multiple lines of evidence. (D) Signup and view all the answers

What does the lecturer mean by "Turtle Island"?

An ancient cultural term for North America used by indigenous people. (A) Signup and view all the answers

Which of these is NOT a subject area mentioned in the text as being taught in high school biology?

Physics. (D) Signup and view all the answers

What is the purpose of using the iClicker system in this course?

To provide students with immediate feedback on their understanding of the lecture material. (D) Signup and view all the answers

How does the lecturer open the lecture with a statement acknowledging the land the University of Toronto operates on?

To highlight the history and cultural significance of the land. (D) Signup and view all the answers

What is a common misconception about evolution?

Evolution is just a theory, it’s not a fact. (B) Signup and view all the answers

How does a scientific theory differ from a casual use of the term 'theory'?

Scientific theories are established explanations based on evidence. (C) Signup and view all the answers

What role do scientific laws play compared to theories?

Laws provide descriptions without explaining why. (A) Signup and view all the answers

Which of the following represents a challenge in teaching evolution?

The complex mechanisms of speciation. (D) Signup and view all the answers

Why might people question the validity of evolution, despite evidence?

People often misunderstand the nature of scientific theories. (C) Signup and view all the answers

What is the primary mechanism driving the evolution of SARS-CoV-2?

Natural selection (B) Signup and view all the answers

What is the significance of the process known as viral reassortment in influenza?

It can create new strains with increased transmissibility. (D) Signup and view all the answers

How do SARS-CoV-2 variants that evade the immune system become dominant in the population?

They have a higher rate of reproduction. (B) Signup and view all the answers

Which one of these is NOT a key concept in the evolution of SARS-CoV-2 and influenza?

Evolution is a slow and gradual process that takes place over long periods. (C) Signup and view all the answers

Which of the following pandemics had the highest death toll?

1918 Spanish Flu (B) Signup and view all the answers

What is the main reason for the continued concern about the evolution of influenza?

Its ability to mutate rapidly and create new strains. (C) Signup and view all the answers

Which influenza pandemic had the highest death toll in the 20th century?

1918 Spanish flu (B) Signup and view all the answers

How is the information about newly evolved strains of SARS-CoV-2 and influenza obtained?

Through monitoring and analysis of genetic sequences. (C) Signup and view all the answers

What is the estimated time frame for the divergence between humans and chimpanzees?

5 to 7 million years ago (B) Signup and view all the answers

How many years does 1 million years equate to in the given context?

20 years x 50,000 (A) Signup and view all the answers

Which of the following organisms are mentioned as having shared a timeline with the evolution of primates?

Gibbons and Orangutans (A) Signup and view all the answers

What does 3.5 billion years represent in the context of evolution?

The time life first originated on Earth (D) Signup and view all the answers

How do 5-7 million years of divergence compare to the entire span of evolutionary history?

They are considered recent (C) Signup and view all the answers

Which statement reflects a common misconception about the evolution of primates?

Humans evolved from chimpanzees. (B) Signup and view all the answers

What percentage of genome similarity do humans and chimpanzees share?

99% (D) Signup and view all the answers

When considering geological time, how does 1 million years appear to humans?

As a significant and incomprehensible amount of time (A) Signup and view all the answers

What unique feature do whales, as mammals, share that distinguishes them from fish?

Mammary glands for nursing young (B) Signup and view all the answers

Which of the following is an example of convergent evolution related to whales?

Fish developing streamlined bodies for water (C) Signup and view all the answers

Which fossil provides evidence of the transition from land mammals to whales?

Pakicetus (D) Signup and view all the answers

What kind of fossil evidence helps document the transition of whales from land to water?

Isotopic analysis of fossil teeth (D) Signup and view all the answers

Which of the following describes the evolutionary relationship of cetaceans like whales?

They share a common ancestor with even-toed ungulates. (D) Signup and view all the answers

What indicates the evolutionary loss of hindlimbs in early cetaceans?

Fossil analysis of hindlimb loss over time (D) Signup and view all the answers

The shape of the astragalus bone provides insights into what evolutionary connection?

Linking cetaceans to their land mammal ancestors (D) Signup and view all the answers

Which of the following statements about hair in whales is true?

Whales possess hair only during their embryonic development. (B) Signup and view all the answers

What is the main takeaway about the early evolution of whales as presented in the content?

Whales evolved from terrestrial mammals. (C) Signup and view all the answers

How did the oxygen isotope ratio (18O/16O) help scientists understand the evolution of whales?

It indicated the salinity of the water that early whales drank. (A) Signup and view all the answers

Based on the content, what is the evolutionary significance of the changes in gene expression leading to hindlimb loss in whales?

It demonstrates the adaptation of whales to aquatic life by eliminating unnecessary structures. (A) Signup and view all the answers

According to the content, which of the following is NOT a key concept concerning the evolution of whales?

The evolution of baleen in whales is independent of the development of teeth. (A) Signup and view all the answers

What is the best interpretation of the statement "Ancestors of modern whales had teeth...and small patches of baleen!?"

Evolutionary transitions are often characterized by the co-existence of ancestral and derived traits. (B) Signup and view all the answers

What is the main advantage of baleen over teeth in whales?

Baleen allows whales to filter large quantities of water for food. (B) Signup and view all the answers

Which of the following statements directly relates to the process of natural selection in the evolution of whales?

Changes in gene expression led to hindlimb loss in whales. (D) Signup and view all the answers

What does the statement "genes for building teeth have been disabled!" imply about the evolution of baleen whales?

The inactivation of teeth genes was a key step in the evolution of baleen whales. (B) Signup and view all the answers

Study Notes

Lecture 2: How We Study Evolution

The lecture acknowledges the traditional land of the Huron-Wendat, the Seneca, and the Mississaugas of the Credit, and recognizes the Indigenous people still residing on this land.
Students are encouraged to participate in lectures via iClicker, which is free with the purchase of the textbook and Achieve.
The lecture introduces a questionnaire, asking students to specify their current view of evolution. Possible answers include: a well-supported scientific theory; a topic with some scientific controversy; a concept that a student is unsure about; or a concept that conflicts with their beliefs.
Evolution is compared to other biology topics (genetics, cells, photosynthesis, mitosis). Students were asked to reflect on their preparedness for studying evolution.
Evolution is a challenging concept to learn and teach. Some challenges in teaching evolution are: difficulties in describing mechanisms (e.g., modes of speciation); issues associated with scale and concept of time; and difficulties demonstrating and observing "evolution" in a teaching lab.
Evolution is a scientific theory, different from everyday use. It is a well-supported, well-documented explanation for observations, based on facts. A scientific theory is not a guess or hunch. A theory can become a law, but there's no hierarchy.
Theories explain why, while laws describe. The law of gravity describes that, if something is dropped, it falls to the ground, but doesn't explain why.
The lecture references the concept of 'speciation', presented visually with a diagram illustrating evolutionary branching and timeframes.
The lecture emphasizes the vast timescale of evolution, comparing 1 million years to 20 years x 50,000; and 5 million to 20 years x 250,000, illustrating vast time differences. Evolutionary timeframes can be considered recent (5-7 million years).

Case studies: Whales and Viruses

Two case studies are proposed: whales, as mammals adapted to the sea, and viruses (SARS-CoV-2), highlighting their rapid evolution.
Whales:
- Blue whales: are the largest animals to ever exist; are 100,000 kg (1,000 people); and 30 meters in length.
Viruses (SARS-CoV-2):
- SARS-CoV-2:
- Is approximately 50-140 nanometers in diameter; and 1000 times smaller than the width of a human hair; has 26 protein-coding genes.

A tale of Two Extremes

Whales and viruses are both products of evolution; every organism on Earth is a product of evolution.
Understanding evolution allows one to comprehend: the reasons for the natural world, similarities and differences among and between species; and the geographical distribution and adaptations of living things.
The lecture emphasizes the importance of studying evolution to develop solutions to current problems, for instance, developing new ways to fight viruses and bacteria.
The lecture offers ways to combat problems like insecticide resistance in insects, human impact on the planet, and comparing modern extinctions to past events to predict and combat current extinction rates.

Evolution and Relatedness

Whales share numerous characteristics with mammals, including mammary glands, three middle ear bones, and hair (in developing embryos). The similarities with fish arose through convergent evolution.
Prehistoric cetaceans, like Pakicetus, share traits with modern relatives.
Fossils (e.g., Pakicetus, Ambulocetus, Basilosaurus, Dorudon) provide evidence of the transition from land to water for cetaceans, with supporting evidence such as differences in skeletal structure (e.g., loss of hind limbs).
Transitional fossils reveal links between cetaceans and land mammals. For example, astralgus (ankle bone) demonstrates connections between cetaceans and even-toed ungulates.

Documention of Evolution

Fossil teeth analysis provides insights into the transition from freshwater to saltwater environments, evident from isotopic analysis that identifies higher ratios of 18O/16O in saltwater and marine animals.
Fossil analysis details the loss of hindlimbs over time.
Embryonic analysis reveals changes in gene expression related to hindlimb loss.
The lecture explores the evolution of whale teeth to baleen. Ancestors had teeth, and present-day mysticetes have evolved baleen, which entirely replaces teeth, and the genes for building teeth have been disabled.

Key Concepts

Whales and fish have independently evolved similar body forms.
Fossils of transitional forms document the transition from land to water.
Evolution is a tapestry of phenomena happening over short and long periods.
Multiple lines of evidence study evolution (fossils, DNA, experiments).
In-depth case studies reveal evolution.
Evolution in time scales, both micro and macro, are studied for both whales and viruses.

SARS-CoV-2 Evolution

SARS-CoV-2: is studied to understand viral evolution with its life-cycle and its replication of genetic material within host cells to understand how mutations arise.
The emergence of beneficial mutations in SARS-CoV-2 strains, leading to an increase in frequency due to natural selection (e.g., the inability of the host immune system to identify or destroy the beneficial strains; higher reproduction rates of these strains; and domination of the population by resistant strains in successive generations.
Traceable evolutionary ancestry: shows SARS-Cov-2's origins and the different strains. Traces how viruses have spread and evolved and how strains increase in frequency over successive generations.
Reassortment: can generate strains that are highly infectious and lethal (Influenza H7N9 demonstrates this).
Studying past pandemics (Spanish flu, Asian flu, Hong Kong flu, Swine flu) provides context and comparison, detailing how many died in each.

Additional concepts

Evolution is a process of change in a lineage of organisms through the passage of multiple generations.
Natural selection is driving the diversity in new strains of viruses like SARS-CoV-2.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

This lecture focuses on how students understand evolution, including their personal views on the topic. It discusses the challenges in teaching evolution compared to other biology subjects and encourages student participation through iClicker. The goal is to reflect on preparedness for studying evolution.