Lab Assignment Task:
Observing plant-animal interactions Terrestrial plans appeared on land approximately 465 million years ago (ma), followed by terrestrial animals (insects) approximately 400 m. Angiosperms (?owering) appeared approximately 125 m. It is reasonable to postulate that the establishment of plants on land allowed the subsequent establishment of animals, as animals (heterotrophs) need plants (autotrophs) for food, though it is likely that early pre-terrestrial land animals may have walked on land but mostly fed in the water. Hence, the earliest plant-animal interactions were herbivory, with plants evolving defenses to prevent herbivory (e. g., thorns, poisons) and animals evolving traits to overcome plants defense (e. g., grinding teeth, poison defense). Conversely, plants also evolved traits to take advantage of terrestrial animals. Angiosperms developed ?owers (specialized for sexual reproduction, mostly animal pollinated) and fruits (specialized for dispersal, mostly animal dispersed). These adaptations appear highly successful as there are 290,000 plant species and 250,000 are angiosperms (86%)
Protocol: In this lab you will observe many plants around campus. Look for signs of herbivory, pollination and dispersal. In the best case, you will see animals directly interaction with the plants. However, many of the animals are nocturnal or may not ?nd the weather on lab day hospitable. Use the Herbivory (I), Pollination (II) and Dispersal (III) guides to look for the signs of these 'syndromes' in the plants. Use the smartphone camera lens attachments to take pictures of your observations, both to help you identify and record them and for use in your lab report (only use pictures taken by your lab group in the lab report).
Question 1: Do these syndromes appear to be speci?c co-evolutions (e.g., one plant/one animal) or more generalist traits (one plant attracts multiple animals)? Why or why not? Does it depend on interaction (e_.g= pollination versus herbivory)? Why?
Question 2: Consider what traits plants have evolved to both attract and repel animals (including insects). In your observations/photos, what traits appear evolved to attract insects? Similarly, did you observe any that appear evolved to repel insects? In either case, what might be some attractive and repellent traits that you cannot observe visually?
Question 3: Some animals may interaction both in negative (caterpillar stage = herbivory) and positive (butter?y stage = pollination) ways depending on life stage, so how would you categorize the plant/animal relationship? Were any such animals out during your lab?
Question 4: Did weather seem to play a part in your observations? Why or why not?
Question 5: What is your overall re?ection on the lab? On plant/animal interactions?