PRINCIPLES OF EVOLUTION/BIOETHICS Professor Collier Spring 2012

LEARNING OBJECTIVES HOUR ONE: LAMARCK- THEORY OF ACQUIRED CHARACTERISTICS DARWIN / WALLACE- EVOLUTION THROUGH NATURAL SELECTION COMPARATIVE MORPHOLOGY COMPARATIVE BIOCHEMISTRY ADAPTIVE RADIATIONS EXTINCTION HOUR TWO: WHAT IS BIOETHICS? EXAMINATION OF BIOETHICAL HISTORICAL CASES

LAMARCK vs. DARWIN There is a variation within populations. Many variations are inherited and such traits are passed from parent to offspring. Some variations are favorable, improving the organism’s ability to function and reproduce in its environment. More young are produced in each generation than can survive. Only a few survive long enough to reproduce. Organisms that survive and reproduce are those with favorable variations. Because the offspring of these individuals will inherit favorable variations, a larger and larger proportion of each new generation will have these variations. Over enormous periods of time, small changes accumulate, and populations change. Organisms strive to improve themselves and become more advanced. The effort to improve causes the most used body structures to develop, while unused structures waste away. Once a structure is modified by use or disuse the modification is inherited by the organism’s offspring.

Theory of Natural Selection WALLACE DARWIN There is variation within populations. Some variations are favorable. Not all young produced in each generation can survive. Individuals that survive and reproduce are those with favorable variations There is variation within populations. Some variations are favorable. Not all young produced in each generation can survive. Individuals that survive and reproduce are those with favorable variations Survival of the Fittest! Natural Selection

Processes of evolution Natural Selection Adaptations It is a mechanism for change in a population. It occurs when organisms with favorable variations survive, reproduce, and pass their variations to the next generation. They are features (including structure, function or behavior), which make a species more suited to survive and reproduce in its environment.

Processes of evolution Physiological Adaptations Mimicry/Camouflage Bacteria can become antibiotic resistant over time, i.e. antibiotic resistant pneumonia, etc. Weeds and insects can become resistant to certain pesticides over time, i.e. DDT Mimicry is a structural adaptation that enables one species to resemble another, i.e. Hawk Moth caterpillar resembles a tree snake. Camouflage is an adaptation that enables a species to blend with their surroundings, i.e. chameleon.

Non-resistant vs. Drug Resistant Bacteria

Adaptations in nature

camouflage

camouflage

Processes of evolution Homologous Structures Analogous Structures They are structural features with a common evolutionary origin. They can be similar in arrangement, in function, or in both. Body parts of organisms that do not have common evolutionary origin but are similar in function.

Example of Homologous Structures

Example of Analogous Structures

Divergent Evolution: two or more related species become more and more dissimilar for example the wooly mammoth was well-suited for extreme cold where as modern elephants are well-suited to different environments hot, cold, and/or temperate.

coevolution occurs when two or more species in close interaction undergo joint change, for instance between plants and the animals that pollinate them.

Convergent evolution takes place when two unrelated species becomes more and more similar as they adapt to the same kind of environment.

Adaptive radiation is the evolutionary pattern that occurs when many species evolve from a single ancestral species. It usually occurs when a species of organisms successfully invades an isolates region where few competing species exist.

Parallel evolution is the development of the same characteristics or adaptation in unrelated organisms due to similar environmental conditions. They do not have to occupy same niche in a habitat. An example, the python of asia and the boa constrictor of south america.

extinction It is decreased biological activity brought about by a variety of factors. Deforestation Predators Disease Shift in sea level allowing two different species to mix.

End of hour one: what do you see qualitatively and quantitatively?