Chapter 40 notes - Chapter 40 Basic Principles of Animal...

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Basic Principles of Animal Form and Function Lecture Outline Overview: Diverse Forms, Common Challenges Animals inhabit almost every part of the biosphere. ° Despite their great diversity, all animals must solve a common set of problems. ° All animals must obtain oxygen, nourish themselves, excrete wastes, and move. Animals of diverse evolutionary histories and varying complexity must solve  these general challenges of life. ° Consider the long, tongue-like proboscis of a hawk moth, a structural adaptation  for feeding. ° Recoiled when not in use, the proboscis extends as a straw through which the  moth can suck nectar from deep within tube-shaped flowers. Analyzing the hawk moth’s proboscis gives clues about what it does and how it  functions. ° Anatomy  is the study of the structure of an organism. ° Physiology  is the study of the functions an organism performs. ° Natural selection can fit structure to function by selecting, over many  generations, the best of the available variations in a population. Searching for food, generating body heat and regulating internal temperature,  sensing and responding to environmental stimuli, and all other animal activities  require fuel in the form of chemical energy. The concept of bioenergetics—how organisms obtain, process, and use energy  resources—is a connecting theme in the comparative study of animals. Concept 40.1 Physical laws and the environment constrain animal size and shape An animal’s size and shape, features often called “body plans” or “designs,” are  fundamental aspects of form and function that significantly affect the way an  animal interacts with its environment. ° The terms plan and design do not mean that animal body forms are products of  conscious invention. ° The body plan or design of an animal results from a pattern of development  programmed by the genome, itself the product of millions of years of evolution  due to natural selection. Physical requirements constrain what natural selection can “invent.” An animal such as the mythical winged dragon cannot exist. No animal as large  as a dragon could generate enough lift to take off and fly. Similarly, the laws of hydrodynamics constrain the shapes that are possible for  aquatic organisms that swim very fast. Tunas, sharks, penguins, dolphins, seals, and whales are all fast swimmers. ° All have the same basic fusiform shape, tapered at both ends.
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Chapter 40 notes - Chapter 40 Basic Principles of Animal...

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