I NVESTIGATION 8 “A DAPTATION ”

W HY DO CHANGES IN AN ORGANISM AFFECT ITS CHANCES OF SURVIVAL ? Living things have basic needs, such as energy, water, gas exchange, etc… to survive. Every organism has varying needs for things like water, gas exchange, etc…

W HY DO CHANGES IN AN ORGANISM AFFECT ITS CHANCES OF SURVIVAL ? The resources for life originate in an organism’s environment. Critical relationship between environment and organism. When an environment changes, organisms that interact with it are influenced. Improve or decrease organism’s chance for survival.

W HY DO CHANGES IN AN ORGANISM AFFECT ITS CHANCES OF SURVIVAL ? Changes enhance one organism’s ability to survive and reproduce more offspring while it decreases the chances of another organism.

A DAPTATIONS Organisms have adaptations that allow them to live an environment. Every organism has a unique set of adaptations to live in its environment. Examples: Sea otters live in the sea. Desert tortoises live in the desert.

A DAPTATIONS Adaptations are: Physical attributes (structures and functions) OR Behaviors that enhance an organism’s opportunity to live and reproduce in its environment.

A DAPTATIONS Organisms have different types of adaptations: Structural Adaptations Functional Adaptations Behavioral Adaptations

A DAPTATIONS The particular combination of adaptations expressed by an individual defines the lifestyle that that organism will lead and the environment in which it can survive.

V ARIATION WITHIN A SPECIES Organisms of the same kind are all members of the same species. All members of a species have similar adaptations and, therefore, the ability to live in the same environment. The members of a species that are living together and interacting constitute a population.

V ARIATION Within a population, there is variation. Variation is the amount of difference in physiological and/or behavioral attributes exhibited by the members of a population. Example: Walkingsticks color

B IOLOGICAL I MPLICATIONS OF VARIATION When the environment provides abundant resources, all members of a population share in the bounty and survive. This is the exception.

B IOLOGICAL I MPLICATIONS OF VARIATION Factors in the environment is in limited supply or pushing the limits of tolerance of the organisms. Variation is essential here!

B IOLOGICAL I MPLICATIONS OF VARIATION The individuals that have structures or behaviors that allow them to break slightly harder seeds, run a little faster, etc…., will have a survival advantage over the members of the populations when the environment changes. What examples have we done in class that reinforces this statement? Why?

B IOLOGICAL I MPLICATIONS OF VARIATION As a result of natural variation in a population, the population may survive failure of a primary food source, invasion by a predator, reduction in solar radiation, or drought.

B IOLOGICAL I MPLICATIONS OF VARIATION *** Different members of the population will have the advantage depending on what environmental factor imposes pressure on the population. The results is that some members will survive to reproduce ensuring the survival of the species and the continuing of the population.

F EATURES AND T RAITS Organisms have distinctive features that make them recognizable. Examples: Snakes have scales, color patterns, eyes, and mouths. Ducks have feathers, beaks, webbed feet, and eyes.

F EATURES AND T RAITS Features : are structures of organisms.

F EATURES AND T RAITS There is tremendous variation in features from species to species, but all individuals of the same species have the same features… HOWEVER… there can be variation in how the features look within a species.

F EATURES AND T RAITS The appearance of a feature within a species is called a trait. A trait is the particular manner in which an organism exhibits a feature, that is, how it looks. Example: Black bears have all the same features: four legs, short tail, small ears, two eyes, long, course fur, and a brown nose, etc… The color of the fur can vary. The fur color is the feature and the color of the fur (brown, black…) is the variation.

F EATURES AND T RAITS Case Study: Peppered Moth Study A classic investigation looked at the feature of wing color in the peppered moth of England. The moth’s wing color can vary from almost white with dark dots to completely black.

F EATURES AND T RAITS A Case Study: Peppered Moths When the Industrial Revolution filled the air with pollutants, the light-colored moths died and the dark-colored moths survived. Why?