Developing theory of evolution

Question 1

Mimicry

Answer 1

A structural adaptation in which a
harmless species resembles a harmful species in coloration or
structure

Question 2

Georges Cuvier

Answer 2

• Developed the science of paleontology
  → study of fossils
• He noticed
  – Simple organisms found in all depths of fossil records
  – Fossils of more complex organisms found only at shallower
  depths
• Proposed the idea of Catastrophism

Question 3

Catastrophism

Answer 3

-The theory that the pattern of fossils could be accounted for by a series of floods, diseases, or droughts that had periodically destroyed species in a particular area
– Species from surrounding areas would then replace the species which were wiped out and this accounted for the new species in the fossil

Question 4

James Hutton

Answer 4

• Idea of Gradualism → Earth’s geological features were in a slow continuous cycle of change
• Geological processes operated at the same rates and in the same ways in the past as they do today

Question 5

Sir Charles Lyell

Answer 5

• Theory of Uniformitarianism

→Earth has changed by same
processes in the past as can be observed occurring today
→ Geological change is slow & gradual
→ Natural laws/processes that influence these changes are constant & eternal (e.g., they operated in the same intensity as they do today)

• Evidence: fossil deposits process of erosion/sedimentation

Question 6

Jean-Baptiste Lamarck

Answer 6

1. Use and disuse
   ➢ Structures used became larger and stronger while structures that were not became smaller/weaker
   ➢ Unused traits would disappear
2. Inheritance of Acquired Characteristics
   ➢ Individuals pass on to their offspring characteristics they
   acquired during their lifetime
   eg. giraffes and long necks

Question 7

Lamarck proposed:

Answer 7

• All species evolve over time
• A species evolves in response to its environment and becomes better adapted
• Changes are passed on from generation to generation

Question 8

Thomas Malthus

Answer 8

Essay on Principle of Population
→plants and animals both produce far more offspring than are able to survive

→individuals had to struggle to survive as resources were not enough to support all offspring

“Populations are limited
in size by their environment”

Question 9

Charles Robert Darwin
(1809 – 1882)

Answer 9

• 1831 – 1836
  →voyage on the H.M.S Beagle where he collected
  plants, animals and fossils
• 1859 – published “On the Origin of Species”
  Observations and Ideas During Voyage
• The plants and animals in different regions he visited were different from what he saw in England and Europe
• Fossils bore close resemblance to species currently living in the same region
• fossils represent ancestral forms of living organisms

Question 10

Galapagos Islands

Answer 10

*Some animals on the Galapagos Islands closely resembled animals on the west coast of South America

*Galapagos species varied slightly between different islands (i.e. the finches)

*At least 13 distinct species of finches found, and they look similar perhaps one species transported from a nearby land gave rise to similar but distinct new species

Question 11

Darwin’s Finches

Answer 11

Different food sources were available on different islands – the individuals with the best shaped beaks were able to eat, survive and reproduce to pass along their genes

Question 12

How Did Malthus’s Work influence his ideas

Answer 12

• Darwin believed that life evolved (biogeography and comparative anatomy) but didn’t know how
  nature chose individuals with certain variations forreproduction
• Recall → produce more offspring than can survive

Question 13

The Theory of Evolution by Natural Selection

Answer 13

Darwin Observed that:
- Individuals with traits that help them survive in their local environment are more likely to survive to reproduce and pass on
these traits to offspring
- Competition for limited resources between individuals of the same species would select for individuals with favourable traits
- A growing proportion of the population has those traits and continues to pass them on
All this together = Survival of the fittest

Question 14

THEORY OF EVOLUTION BY NATURAL

Answer 14

Observations:

1. Individuals within a species vary in many ways.
2. Some variability can be inherited.
3. Every generation produces more offspring than
   can survive and pass on variation.
4. Populations of species tend to remain stable in