Lecture 1: Evolutionary and Ecological Perspective of Zoology PDF

GENERAL ZOOLOGY 1 LECTURE 1: Evolutionary and Ecological Perspective of Zoology Prepared by: DIVINE GRACE S. BATENGA, Msc., LPT Subject Teacher PAGE 1 LEARNING OUTCOMES Upon the completion of this lesson, you are expected to: a) Define zoology as a branch of b...

GENERAL ZOOLOGY 1 LECTURE 1: Evolutionary and Ecological Perspective of Zoology Prepared by: DIVINE GRACE S. BATENGA, Msc., LPT Subject Teacher PAGE 1 LEARNING OUTCOMES Upon the completion of this lesson, you are expected to: a) Define zoology as a branch of biology; b) Identify the different specialization in zoology; c) Explain how our taxonomic system is hierarchal; and d) Give the relationships between human population growth and threats to world resources. PAGE 2 ZOOLOGY ▪ Gr. zoon, animal + logos, to study ▪ Study of animals ▪ One of the broadest fields in all science ▪ Zoologists usually specialized in one or more of the subdisciplines of zoology PAGE 3 SPECIALIZATIONS IN ZOOLOGY ▪ ANATOMY – study of the structure of entire organisms and their parts ▪ CYTOLOGY – study of the structure and function of cells ▪ ECOLOGY – study of interaction of organisms with their environment ▪ EMBRYOLOGY – study of the development of an animal from the fertilized egg to birth or hatching ▪ GENETICS – study of mechanisms of transmission of traits from parents to offspring ▪ HISTOLOGY – study of tissues ▪ PARASITOLOGY – study of animals that live in or on other organisms at the expense of the host ▪ PHYSIOLOGY – study of the function of organisms and their parts ▪ SYSTEMATICS – study of the classification of, and the evolutionary interrelationships among animal groups PAGE 4 SPECIALIZATION IN ZOOLOGY BY TAXONOMIC CATEGORIES ▪ ENTOMOLOGY – study of insects ▪ HERPETOLOGY – study of amphibians and reptiles ▪ ICHTYOLOGY – study of fishes ▪ MAMMALOGY – study of mammals ▪ ORNITOLOGY – study of birds ▪ PROTOZOOLOGY – study of protozoa PAGE 5 ZOOLOGY: AN EVOLUTIONARY PERSPECTIVE PAGE 6  Animals share common evolutionary past and evolutionary forces that influenced their history! PAGE 7 ZOOLOGY: AN EVOLUTIONARY PERSPECTIVE ⮚An estimated 4 to 10 million species of animals living today. ⮚Over 1 million animal species have been described. ⮚About 90% of animals existed in the past and have become extinct. PAGE 8 EVOLUTIONARY PROCESSES ❑ ORGANIC EVOLUTION A change in the genetic makeup of populations of organisms over time. The source of animal diversity, and explains family relationships within animal groups. CHARLES DARWIN Published convincing evidences of evolution in 1895 and proposed a mechanism that could explain evolutionary change. The mechanism proposed by Darwin has been confirmed and now serves as the nucleus of our broader understanding of evolutionary change. PAGE 9 MECHANISM OF EVOLUTION ❑Genetic variation – mutation and recombination ❑Natural selection – organisms become adapted to the environments ❑Speciation – when one population splits into two distinct forms that can no longer interbred PAGE 10 ANIMAL CLASSIFICATION AND EVOLUTIONARY RELATIONSHIPS ▪ Evolution not only explains why animals appear and function as they do, but also explains family relationships within the animal kingdom. ▪ Groups of individuals are more closely related if their share more of their genetic material (DNA) with each other than individuals in other groups. COUSIN YOU BROTHER/SISTER PAGE 11 ANIMAL CLASSIFICATION AND EVOLUTIONARY RELATIONSHIPS ▪ Animals are named and classified into hierarchy of relatedness. ▪ Carl von Linne/Carolus Linneus (17017-1778) Collects and classifies plants BINOMIAL NOMENCLATURE Also adopted for animals Organisms are given with two names (1) genus, (2) species epithet – scientific name Above the genus level, organisms are group into families, orders, classes, phyla, kingdom, and domains, based on hierarchy of relatedness PAGE 12  Organisms in the same genus are more closely related than organisms in the same family. Organisms in the same species are more closely related than organisms in the same genus. PAGE 13 When zoologists classify animals into taxonomic groupings they are making hypotheses about the extent to which groups of animals share DNA. PAGE 14 ZOOLOGY: AN ECOLOGICAL PERSPECTIVE PAGE 15 ECOLOGY ▪ Gr. Okios, house + logos, to study ▪ Study of the relationships between organisms and their environment ▪ Humans depend on animals ▪ Human activities upset the delicate ecological balances PAGE 16 Humans depend on animals PAGE 17 Human activities upset the delicate ecological balances PAGE 18  CICHLIDS Family: Cichlidae ⮚ Cichlids are an extremely diverse family of fishes, most of which are found in rift lakes in Africa. ⮚ Exist in an amazing variety of color patterns, habitats, and body forms. ⮚ New species of cichlids are discovered every year. Cynotilapia ⮚ Because scientists don't know how many types afra there are, creating conservation plans is difficult. ⮚ The female of these species broods developing eggs in her mouth to protect them from predators. ⮚ As with all animals that are intensely specialized in adaptations or behavior, cichlids are vulnerable to habitat changes, such as pollution and the introduction of exotic species, which can Cyphontilapia increase predation, competition, and fontosa hybridization. Cichlids are also threatened by overfishing and collection for the pet trade. PAGE 19 Giant Nile Perch (Lates niloticus) ⮚Introduced to a lake in Africa in 1950’s ⮚In attempt to increase the lake’s fishery ⮚This voracious predator reduced the cichlid population from 80% to