Theme 3

Question 1

what did Darwin define as evolution?

Answer 1

as descent with modification
results from changes in population over time

Question 2

what is our BIO 243 definition of evolution?

Answer 2

change in allele frequencies in a population over time

Question 3

primitive organism?

Answer 3

last universal common ancestor also known as LUCA

Question 4

how do we study evolution?

Answer 4

1. genetics
   2.Larger population genetics see how allele frequencies changing over time
2. paleobiology : large scale evolutionary changes
3. modern tech, how genes are mutated. morphology- developmental patterns and evolutionary transitions

Question 5

what are the big ideas that inspired Darwin?

Answer 5

1. GEORGE CUVIER: some species survive while others go extinct
2. CHARLES LYELL:
   geologist that said the Earth must be much older than believed to be, undergoes constant change.
   - landforms form gradually from geological processes, not catastrophes
3. Lamarack: Species themselves must be capable of changing,
   -proposed “transmutation”, mechanisms of inheritance of acquired traits
4. Economist Thomas Malthus: population is always going to be growing faster than there is resources available.
   -Human populations grow faster than available resources, so “fittest” individuals survive

Question 6

what is transmutation

Answer 6

believed that species changed over time

Question 7

what is lamarckism?

Answer 7

acquired traits can be inherited, lost through disuse

Question 8

who believed that species change over time?

Answer 8

Charles Darwin, Jean Baptiste de lamarck, alfred russel wallace

Question 9

What is thomas Maltus book of “principle of populations”

Answer 9

even at our best case scenario resources increase linearly over time but exponential population growth
- human population can increase faster than food supply- leads to competition for survival
- those that are better suited to compete are more likely to survive

Question 10

what are the core ideas of evolution by natural selection CHARLES DARWIN?

Answer 10

variation in traits there is going to be competitions, and individuals in population that achieve reproductive success. DUE to natural selection but not all achieve success but some variations do.
- If variations can be inherited the traits will be passed onto offspring.
- contribute in decrease of variation
but increase in beneficial traits in starting population

Question 11

evolution in response to natural selection is inevitable if ?

Answer 11

there is variation in a trait
-variation is heritable
-some variants survive and reproduce more than others
specific features of the environment can generate natural selection on a trait

Question 12

what did darwin discover during the case study of the finches and natural selection?

Answer 12

darwin noticed species on islands quite close together were quite different from island to island
- the closer they were geographically, the more similar the species were to one another

Question 13

What are the important considerations of the Galapagos islands?

Answer 13

• closer the island the more closely related the species are
• terrestrial species on these islands wont have many relatives nearby
• to prevent variation from happening we can have something called gene flow.
• on these islands there is very little genetic flow between islands and the mainland

Question 14

what is adaptive radiation?

Answer 14

macro evolutionary patterns
- process where a single organism or a group of organisms from the same species. Where there are many ecological niches, and the organisms diversify rapidly from an ancestral species into many new forms

Question 15

what is ALX1 gene?

Answer 15

encodes transcription factor affecting craniofacial development associated with beak shape

Question 16

What can we correlate with evolution and natural selection with heritability?

Answer 16

Natural selection can occur without heritability, but evolution by natural selection cannot

Question 16

What does the word theory mean?

Answer 16

is used interchangeably for “guess” or “opinion” and suggests a hesitation to claim as true
in science we call it a hypothesis

Question 16

what is the common belief of evolution?

Answer 16

that it is only a theory and not 100% accurate

Question 16

what is a scientific theory?

Answer 16

is an explanation about some aspect of the natural world
- incorporated substantial evidence, facts and tests the hypothesis

Question 17

what big piece was Darwin missing?

Answer 17

He knew that there was phenotypic variation and can be selected for, but he didn’t understand how those traits can be heritability to offspring

• he was missing heritability or DNA

Question 18

explain the process of evolution by natural selection in your own words

Answer 18

Evolution by natural selection is a process where organisms with traits better suited to their environment are more likely to survive and reproduce. Over time, these advantageous traits become more common in the population. Here’s a simple breakdown:

Variation: Individuals in a population have different traits.
Inheritance: Traits are passed from parents to offspring.
Differential Survival: Some traits offer a better chance of survival and reproduction in a given environment.
Reproduction: Individuals with advantageous traits reproduce more successfully.
Change Over Time: Over generations, these advantageous traits become more common, leading to evolution.

Question 19

describe the importance of existing variation within a population to the process of natural selection?

Answer 19

Variation in a population is important for natural selection because it means there are different traits among individuals. If all individuals were the same, there would be no traits for natural selection to choose from. Variation allows some individuals to have traits that help them survive and reproduce better, leading to evolution over time.

Question 20

explain why heritable variation leading to differential fitness is essential for the process of evolution short and simple

Answer 20

Heritable variation leading to differential fitness is essential for evolution because it means that some traits can be passed from parents to offspring and help those offspring survive and reproduce better than others. This results in those beneficial traits becoming more common in the population over time, driving evolution.

Question 21

describe the important historical context that preceded the proposed theory of evolution by natural selection from Darwin and Wallace short and simple

Answer 21

Before Darwin and Wallace proposed the theory of evolution by natural selection, several key ideas and discoveries set the stage:

1.Fossils: Scientists found fossils that showed different life forms existed in the past, suggesting life on Earth had changed over time.
2.Geology: Charles Lyell’s work showed that Earth was much older than previously thought, providing enough time for evolution to occur.
3.Malthus: Thomas Malthus wrote about population growth and resource limits, influencing the idea that not all individuals survive and reproduce.
Previous Theories: Earlier scientists like 4.Lamarck suggested that organisms could change over their lifetimes and pass those changes to their offspring, though his mechanism was incorrect.
These ideas helped Darwin and Wallace develop their theory that natural selection drives evolution.