Evolution By Natural Selection

Question 1

Theory

Answer 1

An explanation with a large amount of evidence and testing behind it.

Question 2

Fossils

Answer 2

• Preserved remains (e.g. Bones and teeth)
• impressions (e.g. Footprints)
• of organisms that lived in the past.

Question 3

A scientist who studies fossils

Answer 3

Palaeontologist

Question 4

The earth science that studies fossil organisms and related remains of past organisms

Answer 4

Palaeontology

Question 5

Any fossilized remains of a life form that exhibits traits common to both an ancestral group and its derived descendant group

Answer 5

Intermediate forms or transitional forms

Question 6

Method name and substance used to determine the absolute age of a fossil

Answer 6

• Radiometric dating
• Using radioactive isotopes

Question 7

Oldest fossils found by scientists

Answer 7

• Microfossils of bacteria
• Roughly 3.5 billion years old

Question 8

Some different types of evidence for evolution

Answer 8

• Fossil record
• Observed microevolution
• Biogeography
• DNA/gene homology
• Embryology
• Anatomical homology
• Vestigial structures

Question 9

Biogeography

Answer 9

The study of the distribution of species and ecosystems in geographic space and through geological time.

Question 10

Biogeography as evidence for evolution

Answer 10

Species tend to be more closely related to other species from the same area than to other species with the same lifestyle and form but living in different areas

Question 11

Genetics or DNA/gene homology as evidence for evolution

Answer 11

• Shared nucleotide sequence between more closely related species than more distantly related species
• as evidence of shared common ancestry

Question 12

Embryology as evidence of evolution

Answer 12

• The embryonic stages of animals are similar.
• For example, fish, bird, rabbit and human embryos are all similar in appearance in early stages.
• They all have gill slits, two chambered hearts, and a tail with muscles to move it.
• Later as embryo’s grow and develop they become less similar.
• Essentially: embryonic homology.

Question 13

Homology

Answer 13

• The existence of shared ancestry between a pair of structures, or genes, in different species.
• A common example of homologous structures in evolutionary biology are the wings of bats and the arms of primates.
• Evolutionary theory explains the existence of homologous structures adaptations to different environments as the result of descent with modification from a common ancestor.

Question 14

Anatomical homology as evidence for evolution

Answer 14

Structural similarity in more closely related species irrespective of the anatomical function.

E.g. Tetrapod limbs contain the same pattern of bones no matter the function of the limb (flying, swimming, walking etc.)

Question 15

Similar structures, sharing function, but not derived from common ancestry. Also provide an example of these structures that are not homologous.

Answer 15

• Analogous structures
• E.g. Butterfly wings and bat wings
• E.g. Fish ray fins and a whales flippers

Question 17

Definition of evolution

Answer 17

• Descent with modification
• accumulation of changes in a population over many generations