*Species Interactions• *Species within a community develop close interactions, known as symbiosis. – “Sym” means together – “Bio” means life – Symbiosis means “living together” and describes the close relationships developed between species.• *Symbiotic relationships will always benefit at least one organism involved.
Species Interactions• *There are 5 major types of symbiotic relationships: – *Predation – *Parasitism – *Competition – *Mutualism – *Commensalism
*Predation• *Predation is a relationship where one organism captures and consumes another. – Predator – organism doing the capturing – Prey – organism being captured• A predator’s survival depends on its ability to catch its prey. – Ex: rattlesnake venom, spider web, etc.• A prey’s survival depends on its ability to avoid being caught. – Camouflage, mimicry, physical/chemical defenses
*Prey Defenses• *Mimicry – a defense where one organism resembles another that is dangerous or poisonous• There are two types of mimicry: – A harmless organism closely resembles a dangerous one • Known as Batesian mimicry • Predators learn to avoid both species • Ex: King snake and coral snake – Two harmful organisms resemble one another • Known as Mullerian mimicry • Added advantage to their already harmful adaptations • Ex: Bees and wasps have similar striping
Prey Defenses• *Plants have also developed adaptations to protect them from predators. – Physical defenses make them difficult to eat • Ex: Spines, thorns, tough leaves – Can produce secondary compounds • Secondary compounds are synthesized from products of the plant’s metabolism • Usually poisonous, irritating, or bad-tasting • Ex: Poision ivy and poison oak
*Parasitism• *Parasitism – symbiotic relationship where one organism is harmed and the other is helped – Parasite feeds on the host organism – Unlike predation, it does not result in the immediate death of the host • Ex: tapeworms can live in human digestive tract for long periods of time
Parasitism• There are 2 different types of parasites: – Ectoparasites • External parasites – live on the outside of the host • Ex: ticks, fleas, mosquitoes – Endoparasites • Internal parasites – live inside the host’s body • Ex: bacteria, protists, tapeworms
*Competition• *Competition – the use of the same limited resource by two or more species in the same place at the same time – Resource = anything necessity of life (water, nutrients, light, food, or space)• Competition may cause the development of different niches or physical characteristics.
Competition• Competitive Exclusion Principle – No two species can occupy the same niche in the same habitat at the same time – Ex: Paramecia • Two species of paramecia will thrive separately, but when put together, one species is eliminated
*Competition• *Organisms may develop physical differences because of competition for resources.• Character Displacement – evolution of anatomical differences that reduces competition – Happens most where ranges of competitors overlap – Ex: Darwin’s finches • Species found in separate locations have the same beak size • The same species found together have different beak sizes – allows them to feed on different seeds and reduces competition
Competition• Organisms may develop differences in niches because of competition for resources.• Resource Partitioning – species coexist by using only part of the available resources – Ex: some birds eat the same insects, but hunt for them in different places
*Mutualism• *Mutualism is a symbiotic relationship where both organisms are helped in some way.• Ex: *Plants and their pollinators – Pollinators feed on the plants and pollen gets stuck to them. – Pollen is deposited on the next plant, allowing the plants to reproduce sexually.
*Commensalism• *Commensalism is a symbiotic relationship where one organism benefits and the second is neither harmed nor helped.• Ex: *Whales and Barnacles – Barnacles have the benefit of moving through waters attached to the whale – The whale receives no benefit, but is not harmed either
Name the Symbiotic Relationship…• A eagle hunting a mouse. – Predation• A tick feeds on the blood of its host and may carry disease – Parasitism• The flower lives on a tree and absorbs the water from runoff and the tree is unaffected. – Commensalism• Two different types of finches feeding on seeds. – Competition• An ant protects a caterpillar from predators and the caterpillar produces a sweet liquid for it to drink. – Mutualism