Undergrad

1. BY1102 Introduction to Evolution, Biodiversity and the Environment
Feeding strategies
&
Species diversity
vianam@tcd.ie

2. BY1102 Introduction to Evolution, Biodiversity and the Environment
1. There are 4 main feeding types of animals. Which are they and give examples.
1. Suspension/filter feeders: feed on particles suspended in the surrounding water
2. Fluid feeders: feed on fluids (e.g. blood, nectar) of another organisms
3. Substrate feeders: feed on what they live in (soil)
4. Bulk feeders: eat pieces of other organisms or swallow them whole

3. BY1102 Introduction to Evolution, Biodiversity and the Environment
2. What does each phylum eat? – Name the animal phylum

4. BY1102 Introduction to Evolution, Biodiversity and the Environment
2. What does each phylum eat? – Main characteristics
Lack symmetry
Lack true tissues
Radial symmetry
Diploblastic (2 germ layers)
Embryonic development
(anus from blasopore)
•Bilateral symmetry Protostome development
•Triploblastic (mouth from blastopore)
•Coelom (body cavity)

5. BY1102 Introduction to Evolution, Biodiversity and the Environment
2.1 Give an example of an animal for each phylum
2.2 What does each phylum eat?

6. BY1102 Introduction to Evolution, Biodiversity and the Environment
2. What does each phylum eat? Give an example of an animal for each phylum
Porifera: Glass or calcareous sponges or demosponges
Filter-feeding
Small particles in water
e.g. small crustaceans
bacteria
Ctenophora: e.g. Sea gooseberries & comb jellies
Bulk feeders
Zooplankton
e.g. fish eggs,
copepods,
amphipods, larvae

7. BY1102 Introduction to Evolution, Biodiversity and the Environment
Cnidaria: e.g. anemones, jellyfish and corals
Bulk feeders
Zooplankton
e.g. small
crustacean
Equinodermata: e.g. starfish, sea urchins, sea cucumbers
Filter-feeding or
Substrate feeders
e.g. small particles
in water or grazers

8. BY1102 Introduction to Evolution, Biodiversity and the Environment
Chordata: e.g. humans and other mammals, birds, fish, frogs, sea squirts...
All types of
feeders
Platyhelminthes : a.k.a. flatworms; e.g. Taenia, planarian, flukes and tapeworms
All types of
feeders
e.g. carnivorous /
parasites (eg.
tissues, small
investebrates)

9. BY1102 Introduction to Evolution, Biodiversity and the Environment
Brachiopoda: a.ka. lamp shells
Filter-feeding
e.g. fine particles
in water
Mollusca: e.g. Octopus, clams, snails
All types
e.g. Herbivores,
carnivores, filter
feeders

10. BY1102 Introduction to Evolution, Biodiversity and the Environment
Annelida: e.g. ringworms: earthworm, leech, lugworm...
Fluid & substrate
feeders
e.g. Blood or
decomposers
(undecayed leaf and
other plant matter)
Nematoda: Roundworms e.g. C. elegans
All feeding types
e.g. Decomposers: bacteria
and detritus / carnivores:
small crustaceans/or
parasites

11. BY1102 Introduction to Evolution, Biodiversity and the Environment
Arthropoda: e.g. Insects (eg. mosquitos), spiders, crustaceans (lobsters)
All types of feeders
e.g. Blood, carnivores,
herbivores...

12. BY1102 Introduction to Evolution, Biodiversity and the Environment
3. Describe the adaptations of herbivores and plants
Plant Herbivores
1. Chemical defences 1. Chemical defences
• chemical compounds that are toxic • enzymes that counteract toxins or
and repel or reduce digestibility (e.g. sensors (less toxins and higher quality
nicotine and cocaine) nutrients)
2. Physical defences
2. Physical defences • specialized mouthparts, teeth, hard
• thorns, spines tongues, fewer soft body parts
3. Metabolic/behavioural adaptations
3. Bodyguards • seasonality, symbioses with e.g.
• induced or constitutive bacteria to help digestion, low
metabolic rates

13. BY1102 Introduction to Evolution, Biodiversity and the Environment
4. Describe the adaptations of predators and prey
Prey Predator
1. Camouflage 1. Senses
• Species resembles its background. • Species resembles its background.
2. Senses 2. Hunting strategies
• Sight, hearing, smell • Stalk, sit&wait, group hunting, lures
3. Warning signals 3. Physical adaptations
• Noises, visual/smell signals (e.g. shunk) • Strength, jaws/claws, stamina, tongues
4. Defensive ‘weapons’ 4. Behavioural adaptations
• Chemical defenses, weapons • Speed, communication
(claws/teeth)
5. Behavioural adaptations
• Living in groups, hiding, mimicry

14. BY1102 Introduction to Evolution, Biodiversity and the Environment
5. Describe the evolutionary consequences of predator-prey coevolution
Describe coevolution.
- two (or more)species reciprocally affect each other’s evolution.
Predation influences the fitness of both predators and prey. Individuals must both feed
and avoid being eaten to survive and reproduce. Genetically-determined traits that
improve an organism’s ability to survive and reproduce will be passed on to its offspring.
Traits associated with improved predation for predators and escaping predation for prey
tend to be positively selected by natural selection.

15. BY1102 Introduction to Evolution, Biodiversity and the Environment
Read:
“The Maintenance of Species Diversity”

16. BY1102 Introduction to Evolution, Biodiversity and the Environment
Next week:
Study week