Question

*Respond must be a Minimum of 400 words*

1. Prey and hosts have evolved a wide range of defensive strategies against predators and parasites over time. Explain at least three of these defensive strategies in detail, noting their benefits and giving an example of a species which utilizes each.

2. Discuss how coevolution becomes a factor for species involved in predator-prey or parasite-host relationships.

Answer 1

2.CO-EVOLUTION :- Co-evolution occurs when two or more species reciprocally affect each other's evolution through the process of natural selection.Co-evolution includes many forms of mutualism,host-parasite and predator-prey relationship/competition between species.

CO-EVOLUTION IN PREDATOR-PREY RELATIONSHIP OR PARASITE - HOST RELATIONSHIP-

Predator-prey relationship are those involving predation , in which a predator eats its prey . The predator often acquires many important feeding adaptations such as acute senses, claws, teeth, fangs, stingers or poison that can help catch and chew the organisms on which they feed.Mobbing and alarm calls are other defense mechanism s commonly utilized by prey along with camouflage or cryptic coloration. Some animals have chemical and mechnical defense mechanism against predators such as poisonous toads and frogs which can synthesize toxins. Animal with such chemical defenses are often time bright in colour , serving as warning to predators.

The result of competition between pairs of species may depend upon the presence or absense of disease inducing parasites.e.g- in Maine and Nova Scotia , white-tailed deer have replaced moose as the dominant cervid because deer are tolerant carrier of meningeal worm which causes harsh neurological damage to other cervids.

1.BEES SAVE ONE ANOTHER BY FECAL COCKTAILS-

Hauke Koch and co-author Paul Schmid-Hempel found that bees that received their “fecal cocktail” from nestmates were affected by Crithidia bombi much less than bees fed artificially cultivated feces or sugar water. The bacteria were acquired socially, not individually. It’s unclear exactly how the bacteria protect the bees, but scientists hope to use this research to help us better understand our own gut bacteria and how it helps us.

Other bees sacrifice themselves to protect the hive from parasites, disassociating with many aspects of bee social life. Scientists once thought that sick honey bees were driven out of the hive, but we now know the process is altruistic—the bees willingly go away to die.

2. ANTS AND MICROBES MAKE PARASITE LANDFILLS-

Attini ants chew leaves into a paste to feed a fungal colony. They maintain these colonies like a garden, to use as both their own food supply and as their home. The ants protect their gardens against soil parasites by separating them from the soil, but for a fungus parasite called escovopsis, the ants needed a better strategy.

3. EASTERN SCREECH OWL BEFRIEND BLIND SNAKES-

The eastern screech owl has hit upon a novel and creepy solution to the problem of ectoparasites. These owls always deliver food dead to their young—with one exception. That exception is Leptotyphlops humilis, a snake with vestigial eyes that resembles an large earthworm. While the owls sometimes eat the snakes, they more often simply drop them into their nest, and owls old and young leave the wiggly reptiles alone.

The snakes live in the nest, feeding upon insect larvae in nest debris. This greatly reduces the young’s chances of contracting parasites—nests with live blind snakes let nestlings grow faster and enjoy a lower mortality rate.