Adaptations

Adaptation Any trait of an organism that enhances its chances of surviving and reproducing in its environment.

Content Statement Diversity of species occurs through gradual processes over many generations. Fossil records provide evidence that changes have occurred in number and type of species. Fossils provide important evidence of how life and environmental conditions have changed.

Content Statement cont. Changes in environmental conditions can affect how beneficial a trait will be for the survival and reproductive success of an organism or an entire species. Throughout Earth’s history, extinction of a species has occurred when the environment changes and the individual organisms of that species do not have the traits necessary to survive and reproduce in the changed environment. Most species (approximately 99 percent) that have lived on Earth are now extinct.

What is “diversity of species”? Species diversity refers to the measure of diversity in an ecological community. Species diversity takes into consideration species richness, which is the total number of different species in a community. It also takes into account evenness, which is the variation of abundance in individuals per species in a community. Communities with more species are considered more diverse than those with fewer. A community with less variation in the relative abundance of individuals per species is considered more even than one with more variation. Communities that are more even are also said to be more diverse. The Encyclopedia of Earth http://www.eoearth.org/view/article/156211/

Biodiversity 1. The number and variety of organisms found within a specified geographic region. 2. The variability among living organisms on the earth, including the variability within and between species and within and between ecosystems.

Feature A structure, characteristic, or behavior of an organism, such as eye color, fur pattern, or timing of migration.

Trait The way a feature is expressed in an individual organism, such as brown eyes, small spots, or early migration.

Variation The range of expression of a feature (physiological and/or behavioral) within a population, such as the different eye colors, all the different fur patterns, and all the dates on which migration starts.

Variation is a random occurrence that takes place during the process of reproduction.

Adaptation Any trait of an organism that enhances its chances of surviving and reproducing in its environment.

Adaptations Physiological attributes (structures and functions) or behaviors that enhance an organism’s opportunity to live and reproduce in its environment.

Structural Adaptations Hawk’s talons Sharks broad tail Toad’s long, sticky tongue Clam’s hard shell.

Functional Adaptations Trout’s ability to extract oxygen from water Skunk’s ability to produce and spray disgusting defensive chemicals Bee’s ability to transform nectar into honey Human’s ability to reason

Behavioral Adaptations Squirrel’s propensity for storing nuts Black bears long winter hibernation Herring’s habit of schooling Crayfish’s active territorial defense Artic tern’s annual migration

Changes in structure and behavior that occur during an organism’s life cannot be passed to its offspring. Example: Average person becomes a body builder, their offspring will not be born with large muscles but may be born with a capacity/ability to develop large muscle by working out.

Biological Implications of Variations When factors in the environment change variation is essential to the survival of the species. The individuals that have structures or behaviors that allow them to break slightly harder seeds, run a little faster, produce broader leaves to capture more sunshine, store a little more water, …. will have a survival advantage over other members of the population when the environment changes.

As a result of natural variation in a population, the population may survive failure of a primary food source, invasion by a fleet predator, reduction in solar radiation, or drought. It is important to note that different members of the population will have the advantage, depending on what environmental factors imposes pressure on the population. The result is that some members will survive to reproduce, ensuring the survival of the species and the continuation of the population. Example: With coyotes moving back into Ohio, the rabbits that run faster, are better camouflaged will have a better chance to survive than the slower less camouflaged.