Lecture 13: Animal Classification تصنيف الحيوان Systematic/Taxonomy علم التصنيف Systematic includes taxonomy, which is the naming تسمية and classification تصنيفof species and groups of species. Taxonomy: is that branch of biology dealing with the identificationتعريف and namingتسمية of organisms. Aristotle أرسطو (ancient Greek philosopher) began the science of taxonomy. Carolus Linneus كارلوس لينياس(1700s) (Swedish botanist) classified all then-known organisms into two large kingdoms: a) Kingdom Plantae المملكة النباتية b) Kingdom Animaliaالمملكة الحيوانية . Robert Whittaker in 1969 proposed five kingdoms: Plantae, Animalia, Fungi, Protista, and Monera. Recent studies suggest that three domains be employed: Archaea, Bacteria, and Eukarya

Animal Taxonomy Linneus classified species النوعas the smallest unit, and that each species nested within يندرج تحتa higher category Species is a Latin word meaning “kind” or “appearanceالشكل الظاهري ”. Differentiation between species based on: a)- Morphological differencesاختلافات شكلية b)- The potential to interbreedالقدرة على التزاوج with each other in nature to produce fertile offspringجيل خصيب

Traditional Classification التصنيف التقليدي Traditional Classificationالتصنيف التقليدي : depends on both common ancestryالنًّسب and the amount of differences among groups. The traditional , dating to Linneaus view, is that birds have feathersريش , reptiles have scalesحراشيف , and mammals have hairشعر . Linneus placed each of these groups in a separate class within the Phylum Chordataشعبة الحبليات .

Binomial nomenclature التسمية الثنائية (الاسم الثنائي للحيوان) Linneus developed the concept of binomial nomenclature, whereby scientists could communicate clearly. Under the binomial system, each species is assigned a two-part latinized nameاسم لاتيني من قسمين , (a binomial): The first part, the genusالجنس , is the group to which a species belongs. The second part, refers to the speciesالنوع within the genus. The first letter of the genus is capitalized and both names are italicized and latinized. For example, Linnaeus assigned to humans the scientific name Homo sapiens, which means “wise man”.

Systematic position of human الوضع التقسيمي للإنسان Kingdom: Animaliaالمملكة الحيوانية Phylum: Chordataشعبة الحبليات Class: Mammaliaطائفة الثدييات Order: Primatesرتبة الرئيسيات Family: Hominidaeعائلة البشر Genus: Homo الجنس البشري Species: sapiensالإنسان Scientific name: Homo sapiens (The Wise Man الإنسان العاقل)

Three Kingdoms of life Eukaryota 3 There are three Kingdoms of life" 1 2 3 There are three Kingdoms of life" 1)- Bacteria (Eubacteria), 2)- Archaea, 3)- Eukaryota (Fungi, Protesta, Plantae & Animalia) Viruses are not considered living organisms.

1- Prokaryotes (bacteria & archaea) Current taxonomy recognizes two prokaryotic domains (Kingdoms): domain Bacteria and domain Archaea. Bacteria and archaea exist so early in life and are very different. At the same time, they both are structurally organized at the prokaryotic level.

1- Prokaryotes (bacteria & archaea) Prokarytes exist in habitatsالبيئات that are too cold, too hot, too salty, too acidic, or too alkaline for any eukaryote. Prokaryotes often interact with other species of prokaryotes or eukaryotes with complementary metabolismsللتكامل الأيضي . These relationships called (symbiosisتبادل المنفعة ) in three types: Commensalismالمعايشة : one partner receives benefitsالمنفعة while the other is not harmed or helped by the relationship. Parasitismالتطفل : one partner, the parasite, benefits at the expense of the host. Mutualismتبادل المنفعة : both partners benefit from each other.

A)- Archaea Archaea are extremophiles, “محب للظروف القاسية” of extreme environments and can be classified into: a)- Extreme halophilesمحب للملوحة : live in such saline places as the Great Salt Lake and the Dead Sea. Some species require an extremely saltyشديدة الملوحة environment to grow. b)- Extreme thermophilesمحب للحرارة live in hot environments. The optimum temperatures for most thermophiles are 60 - 80°C.

B)- bacteria Bacteria is considered as the most known prokarotes. The major bacterial taxa (species) are now accorded kingdom status by most prokaryotic systematistsعلماء التصنيف . Different types of diseases are caused by bacteria including cholera, many sexually transmissible diseasesالأمراض الجنسية المعدية , and certain types of food poisoningالتسمم الغذائي . However, more bacteria are beneficialمفيدة . Bacteria in our intestinesأمعائنا produce important vitamins. Bacteria recycle CO2 and other chemical elements between organic matter and the soil and atmosphere. Bacteria often live in close association among themselves and with eukaryotes in symbiotic relationshipsعلاقة تبادل منفعة .

Harmful prokaryotes (Pathogenesالمُمْرضات ) Some pathogens produce disease by invading the tissues of the host. More commonly, pathogens cause illness by producing poisons, called exotoxins السموم الخارجية and endotoxins السموم الداخلية. Pathogenic prokaryotes cause about half of all human disease. The actinomycete that causes tuberculosis is an example of this source of symptoms.

Beneficial prokaryotes (النافعة) Humans have learned to exploit the diverse metabolic capabilities of prokaryotes, for scientific research and for practical purposes. Prokaryotes are used to solve environmental problems. Humans also use bacteria as metabolic “factories” for commercial productsالمنتجات التجارية . The application of organisms to remove pollutants from air, water, and soil is bioremediation مُنَقٍّيات أحيائية