Chapter 1 – 3Interactions Among Living things

Natural Selection is that process by which, over time, living things become better suited to their

environments. This was first suggested by Charles Darwn in 1859

Darwin suggested that through reproduction, natural selection encourages organisms to change and adapt

to their environments. Successful evolutionary adaptations ensure the survival of a species.

In a famous 1860 court debate with Bishop Samuel Wilberforce, English Biologist Thomas H. Huxley defended evolution:

His opponents enjoyed it when Bishop “Soapy Sam” Wilberforce asked him, “Are you descended from an ape, Mr. Huxley, from

your mother’s or your father’s side?” Huxley’s reply put Wilberforce’s “science” into perspective. If such a question were to be put to me, Huxley replied, “would I rather have a miserable

ape for a grandfather or a man highly endowed by nature and possessed of great influence and yet who employs these

faculties and that influence for the mere purpose of introducing ridicule into a grave scientific discussion, I unhesitatingly affirm

my preference for the ape.”

The role of an organism in its habitat is called its niche. That is, all the actions including feeding, reproduction, living patterns and

locations are considered parts of an organism’s niche.

Three types of interactions occur among organisms. *Competition

*Predation*Symbosis

All organisms COMPETE for survival!

Competition is the struggle between organisms to survive as they attempt to use the same limited resources.

Predation is interaction in which one organism kills another for food.

Predator/Prey Adaptations include:Speed, Eyesight

False ColoringCamouflage

Symbiosis is a relationship between two species that benefits at least one. Three types of

Symbiosis include:

Mutualism – Both Species Benefit!Yellow-billed Oxpecker & HippoStinging Ants and Acacia Tree

Commensalism – One species benefits and other is unharmed. Not common in nature.

Red-Tailed Hawk & Saguaro Cactus

Parasitism – Parasite benefits and host is harmed.Fleas, Ticks, Leeches, Worms, Mites, Chiggers

If time, Jumping Asian Carp!