B15. Evidence for evolution, extinction, classification

Question 1

What is evolution?

Answer 1

Evolution is described as a change in the inherited characteristics of a population over time through a process of natural selection (due to mutations) which may result in the formation of a new species.

Question 2

Describe fossil evidence for evolution.

Answer 2

Fossil evidence for evolution includes the remains or traces of organisms preserved in rocks, which show changes in species over time and provide insights into the history of life on Earth.

Question 3

What is a fossil?

Answer 3

Fossils are the ‘remains’ of organisms from millions of years ago, which are found in rocks.

Question 4

What are the 2 major forms of evidence that evolution has and does occur?

Answer 4

1) Remains of dead organisms have been found (i.e. fossils).

2) Bacteria have become resistant to antibiotics (antibiotic resistance)

Question 5

What does a new branch on an evolutionary tree diagram show?

Answer 5

A new branch in the tree shows wherespeciationhas occurred (when a new species has evolved).

Question 6

What are antibiotics?

Answer 6

Antibiotics are chemicals that damage bacteria and eventually kill them. Each types of antibiotic interferes with the bacteria’s life processes, e.g making a cell wall.

They do not kill viruses, protozoa or fungi.

Question 7

Explain how antibiotic resistance provides evidence for evolution.

Answer 7

Antibiotic resistance occurs when bacteria evolve resistance to antibiotics through natural selection, leading to the survival and reproduction of resistant strains and the emergence of new strains over time.

Question 8

Describe the process of natural selection in antibiotic resistance.

Answer 8

In antibiotic resistance, bacteria with genetic mutations that give resistance to antibiotics are more likely to survive and reproduce in the presence of antibiotics, leading to the growth of resistant strains in a population.

Question 9

What is extinction?

Answer 9

Extinction is the permanent disappearance of a species from the Earth, typically due to environmental changes, competition, predation, or catastrophic events.

Question 10

Discuss the role of mass extinctions in the history of life on Earth.

Answer 10

Mass extinctions are events in which a significant proportion of Earth’s species become extinct in a relatively short period, leading to major changes in biodiversity and the evolution of new species.

Question 11

How does the fossil record provide evidence for extinction?

Answer 11

The fossil record contains evidence of species that existed in the past but are no longer present, providing insights into the timing, causes, and consequences of extinction events throughout Earth’s history.

Question 12

Why can fossils be problematic at evidence for evolution?

Answer 12

Fossils form rarely and only in certain conditions.
Parts of early organisms were mostly soft bodied so they couldn’t form fossils.

Therefore there is no trace of some organisms (i.e. there are gaps in the fossils records).
This is why Scientists cannot be certain about how life began on earth.

Question 13

What is the binomial naming system?

Answer 13

The binomial naming system, developed by Carl Linnaeus, is a way of naming species using two parts: the genus name and the species name. It provides a universal and standardized method for identifying and classifying organisms.

Question 14

What is the significance of Carl Woese’s work in the field of classification?

Answer 14

Carl Woese proposed the classification of organisms into three domains: Archaea, Bacteria, and Eukarya. His work provided a more accurate representation of evolutionary relationships among organisms.

Question 15

What is an example of a species name using the binomial naming system?

Answer 15

An example of a species name using the binomial naming system is Homo sapiens, where “Homo” is the genus name and “sapiens” is the species name. This name refers to modern humans.

Question 16

Why is the binomial naming system important?

Answer 16

The binomial naming system provides a universal and standardized way to identify and classify species. It helps scientists communicate effectively about organisms by using consistent and recognizable names. Additionally, it reflects evolutionary relationships among species.

Question 17

The binomial name for pandas is Ailuropoda melanoleuca. Which genus do pandas belong to?

Answer 17

Ailuropoda

Question 18

What are the levels of classification of an organism? (Hint: start with Domain)

Answer 18

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

Question 19

In more recent times, what is classification of organisms mostly based on?

Answer 19

It is mostly based on DNA analysis.
Studies of DNA sequences of different species show thatthe more similar the base sequences in the DNA of two species, the more closely related those two species are(and the more recent in time their common ancestor is).

Question 20

What was the difference between Carl Linneaus’ classification system and that of Carl Woese?

Answer 20

Carl Linneaus’ system had 5 kingdoms, whereas Carl Woese’s had 6.

Question 21

Which scientist first devised the 3 domain system of classification?

Answer 21

Carl Woese

Question 22

How could you find out if 2 organisms that look alike are actually the same species?

Answer 22

DNA analysis or check if they can interbreed to produce fertile offspring.

Question 23

Who is considered the father of modern genetics, and what experiments did he conduct to establish the principles of inheritance?

Answer 23

Gregor Mendel is considered the father of modern genetics. He conducted experiments with pea plants, studying traits such as seed color, seed shape, and flower color, and established the principles of inheritance.

Question 24

Explain the significance of Mendel’s work in the context of the history of genetics.

Answer 24

Mendel’s work provided evidence for the existence of discrete hereditary units (genes) and established the basis for the modern study of genetics.

Question 25

What were the key principles of Lamarck’s theory of evolution?

Answer 25

Lamarck proposed the theory of inheritance of acquired characteristics, suggesting that organisms could pass on traits acquired during their lifetime to their offspring.

Question 26

How did Lamark’s theory differ from Darwin’s?

Answer 26

Darwin’s theory of evolution by natural selection, did not focus on acquired characteristics during the lifetime of an organisms but rather emphasized the role of variation, adaptation, and differential reproductive success in shaping populations over time.

Question 27

Define speciation

Answer 27

Speciation is the process by which new species arise from existing ones.

Question 28

Describe how the finches on the Galapagos islands diverged into new species.

Answer 28

Speciation occurs when a population is geographically isolated from others of its species, leading to reproductive isolation and the formation of a new species. An example is the Galápagos finches, which diversified on different islands due to the different food sources there.