L6: Evidence of Evolution

Question 1

What is the evidence of evolution?

Answer 1

• Fossils
• Selective breeding
• Modern day example of evolution
• Differences on isolated populations
• Similar anatomy
• DNA comparison

Question 2

What are fossils?

Answer 2

Preserved remains of dead organism from millions of years ago. Fossils are found in rocks and can be formed from hard body parts (bones/shells), which do not decay easily or are replaced by minerals if they do

Question 3

What is the fossil record?

Answer 3

Fossil remains have been found in rocks of all ages. Fossils of the simplest organisms are found in the oldest rocks, and fossils of more complex organisms in the newest rocks. This supports Darwin’s theory of evolution, which states that simple life forms gradually evolved into more complex ones. Evidence for early forms of life comes from fossils.

Question 4

Why is the fossil record incomplete?

Answer 4

There are gaps in the fossil record because many early forms of life were soft-bodied. The soft parts of organisms do not form fossils well. This means there is little information about what these organisms looked like. Any traces of fossils that there may have been were likely destroyed by geological activity. This is why scientists cannot be certain about how life began. They do not have enough evidence
.

Question 5

How can selective breeding be evident of evolution?

Answer 5

Desirable traits and new varieties of plants and animals can be produced from selective breeding. This proves that the characteristics of a species can be changed over time

Question 6

How can the difference in isolated populations be evident of evolution?

Answer 6

Two groups are geographically isolated and evolve to become different to adapt to different habitats. This proves that even if species share a comon ancestor, they can evolve to change over many generations by natural selection

Question 7

How can the similar anatomy in organisms be evident of evolution?

Answer 7

Many different organisms share similar bone structure, indicating that there may be a common ancestor. This means that they must evolved from the same ancestor to be better adapted to habitat

Question 8

How can modern day evolution (antibiotic resistance) be evident of evolution?

Answer 8

Because we can witness the process of natural selection first hand, since bacteria reproduces very rapidly

Question 9

How does antibiotic resistance develop?

Answer 9

A random mutation occurs in the DNA of individual bacterial cells.
The mutation protects the bacterial cell from the effects of the antibiotic - it becomes antibiotic resistant.
Bacteria without the mutation die when the antibiotic is present
Antibiotic resistant bacteria survive and can reproduce with less
Competition
from non-resistant bacterial strains.
The genes for antibiotic resistance are passed to the offspring.
Over time the whole population of bacteria becomes antibiotic resistant because the antibiotic resistant bacteria are best suited to their environment.

Question 10

How can DNA comparison be evident of evolution?

Answer 10

DNA and gene sequences of different species can be compared to find similirities between organisms, even if they appear very different visually