Biological Adaptations • Key terms: • Adaptation • Traits • Variations • Natural Selection Standard 8-2.1 Explain how biological adaptations of populations enhance their survival in a particular environment.
Adaptations • TRAIT: characteristic that helps an organism survive in its environment. • Examples: how do the traits of the animals listed below help them survive? • The giraffe’s neck. • The skunks smell. • The Lions color and claws • The Polar Bear coat, color, claws • Shark – sense of smell • Hunting Dogs ears
Traits • Traits are genetic differences that occur in a species. • Traits are developed as an animal adapts to its environment.
Types of Traits • Color • Camouflage • Food gathering (beaks and claws) • Hair • Sensory abilities • Behaviors
Variations • VARIATIONS: means that there are changes in the genes among the same species. • For example, humans have different hair, eye or skin color. • Sometimes these changes provide an advantage to an organisms survival.
A kitten named Cy was born with a defect called holoprosencephaly. Animals born with holoprosencephaly are born with one eye and an unformed brain. Little Cy, adorable despite his deformity, sadly lived less than twenty-four hours after his birth.
Natural Selection • Species in a particular environment that are better adapted to living conditions there, are more likely to survive. “SURVIVAL OF THE FITTEST!” • These species will then begin to produce offspring with these traits.
Evolution A gradual process in which something changes into a different and usually more complex or better form. Natural selection explains this process and how species can change over time. Example: Horses evolved from small, multi-toed animals into the large, hoofed animals of today. Why? Expanding grasslands favored grazing plant eaters.
In biology, evolution is change in the inheritedtraits of a population of organisms from one generation to the next. These changes are caused by a combination of three main processes: variation, reproduction, and selection. Genes that are passed on to an organism's offspring produce the inherited traits that are the basis of evolution. These traits vary within populations, with organisms showing heritable differences in their traits. When organisms reproduce, their offspring may have new or altered traits. These new traits arise in two main ways: either from mutations in genes, or from the transfer of genes between populations and between species.