Lecture Notes 1-21 - Introduction to Zoology

Lecture Notes 1. Intro to zoology a. What is zoology? -The scientific study of animals b. How do we learn/study zoology?- use the scientific method, utilize what we already know from the laws of physics and chemistry c. What is an animal? i. comprised of eukaryotic cells (membrane bound nucleus, and other organelles) ii. heterotrophic (they have to consume living thing- plants and animals- to gain their nutrition) iii. no cell wall iv. follow the origin of animals to around 600 million years ago d. What is life? How is life defined? i. Reproduction ii. Descent with modification- common ancestor 1. Identity and continuity 2. Life giving rise to life with some modifications 2. General Properties of Living Systems a. Chemical uniqueness: Micro. To macromolecules i. Nucleic acids ii. Proteins iii. Carbohydrates iv. Lipids v. Uniqueness b. Complex, hierarchical organization i. Living vs. nonliving matter 1. Macromolecules  cells  tissues, organs, organ systems  organisms  populations  species ii. Emergence, emergent properties- the appearance of a new property at any given level (from above) iii. Freedom to interact between the various levels c. Reproduction **all levels of the hierarchy** i. Macromolecules- nucleic acids ii. Cells- diving and reproducing iii. Organisms- giving rise to more organisms iv. Populations- can be split apart and evolve different, change occurs separately d. A genetic program- fidelity of inheritance i. Genetic code- DNA (Watson and Crick) to protein e. Metabolism i. Digestion ii. Energy acquisition- respiration iii. Molecular synthesis iv. Both catabolic (breaking down) and anabolic (building up) reactions v. Physiology f. Development i. Characteristic set of changes as they develop ii. Some can be very simplistic- change in size iii. Some are more complex like metamorphosis- sharp changes g. Environmental interaction i. Ecology- the study of an organisms responses to the environment ii. Irritability- how an organism specifically responds to stimuli h. Movement i. Within the hierarchy, required for life ii. Non-living matter? 1. It moves so what is the difference? –it cannot move on its own, in an organism it requires control and energy 3. Life obeys physical laws a. First law of thermodynamics- states that energy can neither be created nor destroyed only transformed- changes form or shape b. Second law of thermodynamics- in a physical system things proceed towards greater disorder or entropy 4. Physical vs. living systems a. How is organization attained and maintained in a living system? b. Where/ how is this acquired in animals? c. What happens when an organism dies (or nears death)? i. There is an input of energy- utilize energy to avoid disorder ii. When an organism dies it is no longer taking in energy, it decomposes- it proceeds towards disorder or entropy 5. Zoological guiding paradigms a. Darwin’s theory of evolution i. 155 years; on the origin of species by means of natural selection ii. Darwinism: different, mutually compatible theories 1. perpetual change a. the living world is neither constant nor cycling, but always changing b. fossils c. regarded as scientific fact d. the remaining 4 theories are based off of this one 2. common descent a. phylogeny b. taxonomic classification c. supported by comparative studies 3. multiplication of species- species give rise to new species a. reproductively distinct b. usually differ in form 4. gradualism a. known to occur, but still being studied b. small changes accumulate over time and as they accumulate they result in much larger changes- beaks of birds 5. natural selection a. variation exists b. at least partly heritable c. different numbers d. ** advantage; preferentially survive e. Adaptations- result; accumulation of favorable variants i. Anatomical structure, physiological process. Behavioral trait iii. Darwin’s problem 1. Heredity- blending process 2. If this were true everything would look the same because the new traits would be diluted in the populations iv. Neo- Darwinism 1. Darwin’s theories modified – the 5 theories modified by the chromosomal theory of inheritance b. The chromosomal theory of inheritance i. Gregor Mendel ii. Basically said the variants/ traits were passed on intact- no blending of chromosomes iii. Experiments with garden peas