Lecture 8: Evidence for Evolution

Question 1

What are some predictions you can make based off of Darwin’s theories?

Answer 1

1. There should be variation among individuals within a species and the variation should be heritable
2. There should be evidence of differential survival and reproduction within populations
3. If there has been common descent, then molecules and cells should indicate that life has a shared history
4. The anatomy and structure of organisms should indicate they shared a common ancestor
5. There should be evidence of transitional (or intermediate) forms in the fossil record
6. There should be evidence for extinction

Question 2

Darwin didn’t know about genetics and knew very little about the fossil record at the time (T/F)

Answer 2

T

Question 3

What is another word for “differential survival and reproduction within populations”
What is an example?

Answer 3

Natural selection, Biston Betularia

Question 4

Molecular homologies

Answer 4

When molecules and cells indicate that life has a shared history

Question 5

Give a list of similarities of molecular features that are shared due to common ancestry (7)

Answer 5

1. The Central Dogma
2. Making proteins and RNA, and copying DNA
3. All cells have membranes composed of lipid bilayers
4. The same 20 amino acids
5. DNA code for protein synthesis
6. Basic biochemical pathways
7. The Building blocks that create the diversity of chemicals

Question 6

What are vestigial traits and Why are they important?

q

Answer 6

Structures that are reduced or incompletely developed but clearly show similarity to functioning structures in closely related species (such as the tailbone)
They give hints to common ancestry

Question 7

Transitional feature

Answer 7

A trait in a fossil species that is intermediate between those of older and younger species

Question 8

Important things about Archaeoptoryx

Answer 8

1) Their fossils have a few characteristics of modern birds that most dinosaurs did not have
2) Display many traits in common with dinosaurs
Therefore, it represents the transition from birds to dinosaurs

Question 9

Why is it difficult to find transitional forms for some species

Answer 9

The fossil record is so sparse and the evidence for transitional forms are incomplete

Question 10

Living fossils

Answer 10

Some organisms have remained unchanged throughout time despite being extinct ie. the coelacanth

Question 11

End-Permian extinction

Answer 11

The largest mass extinction that occurred 205 million years ago in which 80-96% of all species disappeared (especially Marine)

Question 12

End Cretaceous or the K-P Extinction

What is a possible reason for this?

Answer 12

The most recent and best known mass extinction which is when the last living dinosaur vanished from Earth
Evidence believes a large asteroid hit the Gulf of Mexico putting dust in the air and altering the environment

Question 13

What is the current episode of mass extinction due to?

Answer 13

Human meditated extinction at a rate if 1000 to 10000 times above background