Evolution 5-Evidence of Evolution

Question 1

What are the lines of evidence that support Darwin’s Theory?

Answer 1

1. Fossil records
2. Artificial Selection
3. Anatomical Evidence
4. Genetic Evidence

Question 2

How are fossil records a line of evidence that support Darwin’s Theory?

Answer 2

• Layers of sedimentary rock contain fossils.
  1. New layers cover older ones, creating a record over time.
  2. Fossils within layers show that a succession of organisms have populated Earth throughout a long period of time

Question 3

Fossils Definition

Answer 3

Any preserved remains or traces of an organism or its activity; many fossils are of such hardened body parts as bone

Question 4

Fossilization Definition

Answer 4

The process by which traces of past organisms become part of sedimentary rock layers or, more rarely, hardened tar pits, volcanic ash, peat bogs, or amber.

Question 5

Paleontology Definition

Answer 5

The scientific study of fossil remains; Paleao = old/primitive; onto = of being; logy = the study of

Question 6

Fossil Record Definition

Answer 6

A record showing us that today’s organisms descended from ancestral species

Question 7

What are some of the evolutionary changes in horses?

Answer 7

• An increase in size
• A loss of toes
• An increase in size of molars

Question 8

Fossils and Dates-What is one technique used to date rocks?

Answer 8

One technique used to date rocks is radiometric dating.

Question 9

Radiometric Dating Definition

Answer 9

A technique used to date rocks, usually based on a comparison between the observed abundance of a naturally occurring radioactive isotope and its decay products, using known decay rates.

Question 10

How have birds evolved?

Answer 10

-From Archaeopteryx, which
lived about 150 million years ago, and links reptiles & birds.

Question 11

How have land animals evolved?

Answer 11

• In 2006, there was a Fossil Discovery of an Early Tetrapod.
  -This tetrapod was called the “Tiktaalik”
  -It was considered the “missing link” from sea to land animals: from swimming (0 legs) to walking (4 legs).

Question 12

What is involved in Artificial Selection?

Answer 12

Humans “improving” domesticated plant and animal species for thousands of years of selection

Question 13

Artificial Selection Meaning and Examples

Answer 13

• Selecting offspring with desirable traits as breeding stock for succeeding generations.
  -For example:
  1. Farm animals
  2. Cats, and dogs
  3. Flowering plants
  4. Crops

Question 14

Selective Breeding Definition

Answer 14

The process of breeding plants and animals for desirable traits.

Question 15

What are Homologous Features? What are examples?

Answer 15

• Structures that share a common origin/ancestry but may serve different functions in modern species
  -E.g. dolphin flippers and human hands

Question 16

What are Analogous Features? What are examples?

Answer 16

-Structures similar in function but not in origin or anatomical structure
-E.g. wings of birds and bees, or the eyes of lobsters and fish

Question 17

What is the meaning of Comparative Embryology?

Answer 17

When there is similar embryological development in closely related species.

Question 18

What similarities do all vertebrate embryos have with each other?

Answer 18

All vertebrate embryos have similar structures at different stages of development.

Question 19

What is an example of a structure that all vertebrate embryos have?

Answer 19

A gill pouch; they can be found in the embryos of fish, frogs, snakes, birds, humans, etc.

Question 20

What is an example of Convergent Evolution?

Answer 20

• Fish are aquatic vertebrates. - Dolphins are aquatic mammals.
• They have similar adaptations to life in the sea, but are not closely related.

Question 21

Convergent/Parallel Evolution Definition

Answer 21

Describes the acquisition of the same biological trait in unrelated lineages

Question 22

Convergent/Parallel Evolution Example/What leads to the natural selection of similar traits?

Answer 22

Similar environments & niches lead to natural selection of similar traits.

Question 23

What has there been on different continents?

Answer 23

On different continents, there has been evolution of similar looking species that fill similar niches.

Question 24

What is Convergent/Parallel Evolution responsible for?

Answer 24

It is responsible for analogous structures.

Question 25

Vestigial Structures Definition

Answer 25

• Structures that serve no useful function in a living organism but are remains of ancestral structures.
• Rudimentary and nonfunctioning structures that are homologous to fully functioning structures in closely related species

Question 26

Examples of Vestigial Structures

Answer 26

-Dogs have a vestigial toe; although the bones remain, this digit serves no present purpose.
-Pigs’ feet have two well-developed digits; the others are vestigial.
-The horse has only one enlarged digit; the others are vestigial or have been lost entirely.

Question 27

What are vestigial organs traces of?

Answer 27

Vestigial organs are traces of homologous organs in other species.

Question 28

What function do vestigial organs serve?

Answer 28

Vestigial organs are organs that serve no useful function.

Question 29

What are examples of vestigial organs?

Answer 29

-e.g. Appendix, Wisdom Teeth, and Tailbone in Humans
- Pelvic Bones in Whales
- Hind Leg Bones in Snakes
- Dew Claw in Dogs

Question 30

What are other examples of vestigial organs/structures?

Answer 30

-Some beetles have fully developed membranous wings underneath fused covers, so that it is impossible for them to open these wings.
-Humans have muscles for moving ears, much as dogs and other mammals do.
-Very large numbers of vestigial genes in the DNA of living organisms; these genes do not function, yet they bear a striking resemblance to functioning genes.
-Appendix in humans
-Human “goosebumps”
-Rudimentary wings in many flightless insects such as earwigs.
-Rudimentary eyes (or empty eye sockets) in blind cave-dwelling fish and amphibians.

Question 31

Why would Genetic Evidence be a line of evidence that supports Darwin’s ideas?

Answer 31

• The sequence in DNA and proteins is a molecular record of evolutionary relationships.
• You can compare common genes, such as cytochrome C (respiration), and hemoglobin (gas exchange).

Question 32

How can Phylogenetic Trees be considered, “Family” Trees?

Answer 32

Closely related species (branches) share same line of descent until their divergence from a common ancestor

Question 33

Phylogenetic Tree or Evolutionary Tree Definition

Answer 33

A branching diagram or “tree” showing the inferred evolutionary relationships among various biological species or other entities based upon similarities and differences in their physical and/or genetic characteristics

Question 34

Cladogram Definition

Answer 34

A diagram which shows ancestral relations between organisms, to represent the evolutionary tree of life

Question 35

How does Artificial Selection compare with Natural Selection?

Answer 35

Natural selection
1. It is the process where organisms adapt to their environment for their survival.
2. It is a natural selection process.
3. It helps in producing organisms with biological diversity.
4. It occurs in natural populations.
5. It is a slow process.
6. It helps in inheritance of only favourable characters to the successive generations.
7. Example: Selection of long-necked giraffes.

Artificial selection
1. It is process in which a plant breeder selects plants with characteristics to produce offspring with desirable traits. 2. It is a man-made selection process.
3. It helps in producing organisms with selected desirable traits.
4. It occurs in the reared or domestic population.
5. It is a rapid process.
6. It helps in the inheritance of a variety of desired selected traits to the successive generations.
7. Example: Breeding of different varieties of dogs or cattle to produce the desired varieties.

Question 36

What are the disadvantages of Artificial Selection?

Answer 36

-Reduction of genetic diversity.
-Knock-on effects on other species.
-Genetic mutations can still occur.

Question 37

What are the advantages of Artificial Selection?

Answer 37

• Crops with a higher yield
• Crops with a shorter harvest time
• Crops with higher resistance to pests and diseases
• Reduce costs because farmers can identify crops or animals from their resources to be used
• Create new plant and animal varieties with selected desirable traits.

Question 38

What is the end result of Artificial Selection?

Answer 38

Offspring with selected desirable traits.