Chapter 1 – 3
Interactions 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
Darwin 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
*Symbiosis
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
Camouflage
False Coloring
Symbiosis is a relationship between two species
that benefits at least one. Three types of
Symbiosis include:
Mutualism – Both Species Benefit!
Yellow-billed Oxpecker & Hippo
Stinging 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!