🟢 Molecular Evidence
🟠 Fossil Record
🔵 Selective Breeding
🟣 Homologous Structures
🔴 Analogous Structures

2. Create a Visual Display (on Padlet):
include the following:

✅ a clear definition or explanation of the concept.

✅ a real-world example (e.g. dna sequences in humans vs chimps, dog breeding, pentadactyl limb, analogous wings).

✅ a diagram or labeled image to illustrate the idea.

✅ a short quiz question or challenge to test your classmates.

3. Share (10–15 min)

present your branch to the class.

add your work to the class evolution tree, showing how each concept is a piece of the larger picture of evolution.

Real World Example: Chimpanzees and humans turn out to be very similar if you look at their DNA. When scientists determined the entire genetic code of both humans and chimpanzees, they found that we have over 98% identical DNA. The 2nd Chromosome in the human genome is similar to two chimpanzee chromosomes which have been "split apart" showing molecular similarity between the two species and evidence of evolution.

2.  Describe one example of a homologous structure in vertebrates.

3. Explain how homologous structures provide evidence for evolution.
   

• A. A structure in two different species that serves a similar function and was inherited from a common ancestor.

• B. A structure in two different species that serves a similar function but evolved independently, without a common ancestor.

• C. A structure found in all members of a species that performs the same function.

• D. A structure found in all members of a species but serves different functions.

2) Looking at the picture above, which of the following would be considered analogous?

2. Which of the following is an example of selective breeding?
A. Keeping animals in zoos
B. Breeding of wild mustard to create different
types of vegetable
C. Evolution of antibiotic resistance in bacteria
D. The pentadactyl limb of vertebrates

2. Describe the process of selective breeding in plants.

3. Explain the advantages and disadvantages of selective breeding in animals.

1. B

2. B

1. Homologous structures are anatomical features that share a similar basic structure due to common ancestry, even if they serve different functions in different species.

2. The pentadactyl limb in vertebrates (e.g., human hand, bat wing, whale flipper) is homologous. While the bones differ in size and shape to perform functions such as grasping, flying, or swimming, the basic bone arrangement (humerus, radius, ulna, carpals, metacarpals, phalanges) is the same, showing common ancestry.

3.  Homologous structures demonstrate that different species share a common ancestor. The similarity in underlying bone structure, despite differences in function, suggests that species have diverged through adaptive radiation and natural selection, modifying the same basic design to suit different environments.

A classic example of the fossil record demonstrating both evolution and speciation is the evolution of the horse, tracing from the small, dog-sized Hyracotherium with multiple toes to the large, single-toed modern horse, showing gradual changes in size, limb structure, and teeth suitable for different diets over millions of years

Questions:

What does the fossil record primarily provide evidence for?

A. The constant rate of mutation in DNA
B. The theory of acquired characteristics
C. The evolution of life over time
D. The spontaneous generation of species

Which of the following best explains why there are gaps in the fossil record?

A. All organisms fossilize easily
B. Evolution has stopped
C. Conditions for fossilization are rare
D. All transitional species have already been found

Outline how fossil records can provide evidence for evolution? (4 marks)

Discuss the strengths and limitations of using the fossil record as evidence for evolution.

Describe the similarities between the DNA of various species

4) Describe how different species develop analogous structures.

5) State 2 ways in which convergent evolution differs from divergent evolution.

Instructions:

1. Work in your group

2. You have been provided with a set of 6–8 fictional species profiles including:

   • Evolutionary distinctiveness

   • Global endangerment status

   • Habitat type

   • Threats faced

3. Each group must:

   • Rank the species in order of conservation priority using EDGE criteria.

   • Suggest conservation strategies (in situ, ex situ, community engagement, policy measures) for the top 2–3 species.

4. Groups present their rankings and justify their choices to the class.

5. Debrief: Discuss how real-world conservation programs, like EDGE, balance evolutionary importance, extinction risk, and practical feasibility.

2. Silvercrest Lizard-36

3. Bluefin Dartfrog-21 , Silverleaf-orchid-21

5. Crimson tailed tamarin-18

6. Golden-winged bat-16

7. Cloudback lemur-10

8. Emerald tree snake-4

mandate licenses for fishing, create natural reserves (in-situ), and breeding programs in aquariums (ex-situ).

Crimson-tailed Tamarin is 5th on the EDGE score. Conservation strategies include:

creating natural reserves so no new cities can be built (ex-situ), plant native species (in-situ), make policies to create wildlife corridors.

1. Glass-spined Fish- 40

2. Silvercrest Lizard-36

3. Bluefin Dartfrog-21

4. Silverleaf Orchid-21

5. Crimson-tailed Tamarin-18

6.Golden-winged Bat-16

7. Cloudback Lemur-10

8. Emerald Tree Snake -4

3. The more evolutionary distinct and and endangered a species is the more pressure and need there is to take action as losing this species will affect the biodiversity.

1- 40- Glass-spined Fish

2- 36- Silvercrest Lizard

3.5 (tie)-21- Bluefin Dartfrog

3.5(tie)- 21- Silverleaf Orchid

5- 18-Crimson-tailed Tamarin

6-16- Golden-winged Bat

7-10-Cloudback Lemur

8-4-Emerald Tree Snake

2) Silvercrest Lizard: 36 (9 x 4)

3) Bluefin Dartfrog: 21 (7 x 3)

4) Crimson-Tailed: 18 (6 x 3)

5) Silverleaf Orchid: 21 (7 x 3)

6) Golden-Winged Bat: 16 (8 x 2)

7) Cloudback Lemur: 10 (5 x 2)

8) Emerald Tree Snake: 4 (4 x 1)

• Making new policies to stop fishing in areas where coral reefs are depleting

• Coral gardening

• Community engagement 

• Prevent overfishing of herbivorous fish that control algae

• Establish Marine Protected Areas (MPAs)

• Selective breeding and assisted evolution

Silvercrest Lizard is 2nd on the EDGE score. Conservation strategies include:

mandate licenses for fishing, create natural reserves (in-situ), and breeding programs in aquariums (ex-situ).

Silverleaf Orchid is 3rd on the EDGE score. Conservation strategies include:

implementing policies so no new cities can be built, creating natural reserves, plant native species (in-situ), implementing fines for poaching, move to botanical gardens if habitat is too destroyed.

3. The more endangered the species and the higher the evolutionary distinctiveness is, the higher the need is to take action related to conservation decisions.

• Protection of Coral Reef Areas

• Ex-situ Conservation

• Regulation of Overfishing

2) Cloudback Lemur:

• Protection of montane forest regions

• In-situ Conservation

• Anti-poaching measures

1. In-situ conservation

• Habitat Protection:
  Designate desert reserves where mining, off-road vehicles, and land conversion are restricted.

• Climate Action:
  Reforestation of desert margins and creation of “shade corridors” help reduce local temperature extremes.

• Invasive Species Control:
  Remove or manage introduced predators (like cats and dogs) that prey on the lizards.

• Microhabitat Restoration:
  Replant native shrubs and restore sand dune structure, which are vital for shelter and thermoregulation.

2. Ex-situ conservation

• Captive Breeding Programs:
  Breeding individuals in controlled environments (zoos or research facilities) to later release into protected desert zones.

• Genetic Research:
  Studying genetic diversity helps ensure reintroduced populations are resilient and not inbred.

1. In-situ (within natural habitat) conservation

• Marine Protected Areas (MPAs):
  Establish “no-take zones” where fishing and coral extraction are banned, allowing reefs and fish populations to recover naturally.

• Coral Reef Restoration:
  Artificial reefs and coral nurseries (using coral fragments grown on underwater frames) help rebuild bleached or damaged reefs that the fish depend on.

• Sustainable Fishing Regulations:
  Introduce quotas and seasonal bans to reduce overfishing and bycatch that threaten reef species.

• Pollution Control:
  Reduce agricultural runoff and coastal sewage discharge to prevent algal blooms that suffocate coral ecosystems.

• Climate Adaptation Programs:
  Monitor sea temperature and coral bleaching events; develop “climate-resilient reefs” using heat-tolerant coral species.

2. Ex-situ (outside natural habitat) conservation

• Captive Breeding in Aquariums:
  Controlled breeding programs in large public aquariums maintain genetic diversity and can reintroduce individuals into restored reef sites.

• Cryopreservation:
  Storing gametes (sperm/eggs) in biobanks ensures the species’ genes are protected even if wild populations crash.

2) C

3) Outline how fossil records can provide evidence for evolution? (4 marks)

(i) Fossil records show organisms from the past that are different from those present today, demonstrating that changes have occurred in species over time.

(ii) Fossils appear in a chronological order within rock strata, with simpler organisms found in older layers and more complex or modern organisms in newer layers, matching evolutionary expectations

(iii) By comparing fossils with living organisms, scientists observe gradual changes in morphology, showing transitional forms that link ancestral species to their descendants.

(iv) Fossils of extinct species show that many organisms that once existed no longer do, supporting the idea that new species arise from old ones through evolutionary change.

4) Discuss the strengths and limitations of using fossil record as evidence for evolution.

Strengths:

(i) Fossil records show chronological changes in organisms over time, revealing evolutionary trends such as increasing complexity or the appearance of new traits.

(ii) Transitional fossils provide clear links between major groups, such as between reptiles and birds, helping to trace the evolutionary pathway

(iii) Fossils document extinct species, demonstrating that some organisms have disappeared while others have originated, which supports the idea of descent with modification.

Disadvantage

(i) The fossil record is incomplete because not all organisms fossilize; soft-bodied species and those in certain environments may never leave fossils.

(ii) Fossilization is a rare event, so many intermediate forms are missing, making some evolutionary transitions difficult to reconstruct conclusively

(iii) Dating fossils and interpreting relationships can sometimes be imprecise or reliant on indirect evidence, leading to possible errors or controversies in evolutionary sequences.