Distinctive Characteristics of Mammals - Biology PDF

Unique Distinctive Characteristics of Mammals Relative to Other Taxa Exploring What Sets Mammals Apart from Other Animal Groups Taxonomy Purpose: Helps us understand evolutionary relationsh Goal: To identify the distinctive charact...

Unique Distinctive Characteristics of Mammals Relative to Other Taxa Exploring What Sets Mammals Apart from Other Animal Groups Taxonomy Purpose: Helps us understand evolutionary relationsh Goal: To identify the distinctive characteristics of Mam is the scientific classification of organisms into hierarchical categories. 2 Annual Review 6 February 2025 3 “ Taxonomy is a branch of Biology that refers to the process of classifying different living species. A taxon is referred to as a group of organisms classified as a unit. “Taxonomic hierarchy is the process of arranging various organisms into successive levels of the biological classification either in a decreasing or an increasing order from kingdom to “ Kingdom The kingdom is the highest level of classification, which is divided into subgroups at various levels. There are 5 kingdoms in which the living organisms are classified, namely, Animalia, Plantae, Fungi, Protista, and Monera. “ Phylum This is the next level of classification and is more specific than the kingdom. There are 35 phyla in kingdom Animalia. For Example – Porifera, Chordata, Arthropoda, etc. “ Class Class was the most general rank in the taxonomic hierarchy until phyla were not introduced. Kingdom Animalia includes 108 classes including class mammalia, reptilia, aves, etc. However, the classes used today are different from those proposed by Linnaeus and are not used frequently. “ Order Order is a more specific rank than class. The order constitutes one or more than one similar families. There are around 26 orders in class mammalia such as primates, carnivora, etc. “ Family This category of taxonomic hierarchy includes various genera that share a few similarities. For eg., the families in the order Carnivora include Canidae, Felidae, Ursidae, etc. “ Genus A group of similar species forms a genus. Some genera have only one species and is known as monotypic, whereas, some have more than one species and is known as polytypic. For eg., lion and tiger are placed under the genus Panthera. “ Species It is the lowest level of taxonomic hierarchy. There are about 8.7 million different species on earth. It refers to a group of organisms that are similar in shape, form, reproductive features “ Major Animal Taxa Mammals (Class: Mammalia) Reptiles (Class: Reptilia) Birds (Class: Aves) Amphibians (Class: Amphibia) Key Point: These taxa share some common features but also have unique characteristics that set them apart. Unique Characteristic 1 – Hair or Fur “ 1. Mammals: All mammals have hair or fur at some stage in life. Function: Insulation, camouflage, sensory functions, and mating displays. 2. Reptiles: Do not have hair; instead, they have scales. 3. Birds: Have feathers, not fur, used for flight, insulation, and MAMMAL BIRD REPTILE AMPHIBIANS POLAR BEAR EAGLE SNAKE FROG 14 “ Unique Characteristic 2 – Mammary Glands Mammals: Females have mammary glands that produce milk to nourish their young. Reptiles, Birds, Amphibians: Do not have mammary glands. Key Point: Milk production is a key MAMMAL BIRD REPTILE AMPHIBIANS WOMAN NURSING A BIRD FEEDING A CHEEK SNAKE WITH NO FROG BABY PARENTAL CARE 16 “ Unique Characteristic 3 – Warm- Blooded (Endothermic) Mammals: Can regulate their body temperature internally, maintaining a constant temperature regardless of the environment. Example: Humans and whales maintain a stable internal temperature. “ Unique Characteristic 3 – Warm- Blooded (Endothermic) Reptiles: Cold-blooded (ectothermic), meaning they depend on external heat sources. Birds: Warm-blooded like mammals, but with adaptations for flight. Amphibians: Cold-blooded, often needing warm environments for survival. “ Unique Characteristic 4 – Live Birth (Mostly) Mammals: Most mammals give birth to live young (with exceptions such as monotremes that lay eggs). Reptiles: Majority lay eggs, although some give live birth (e.g., some species of snakes). Birds: Lay eggs with hard shells. Amphibians: Mostly lay eggs, typically 20 Unique Characteristic 5 – “ Specialized Teeth Mammals: Have different types of teeth (incisors, canines, molars) adapted to different diets. Reptiles: Teeth vary widely (e.g., snakes have fangs for venom, lizards have peg-like teeth). Birds: Have beaks instead of teeth, adapted to their feeding habits (e.g., tearing, cracking). Unique Characteristic 6 – Four- “ Chambered Heart Mammals: Have a four-chambered heart that effi ciently separates oxygenated and deoxygenated blood. Reptiles: Most have a three-chambered heart (except crocodiles, which have a four- chambered heart). Birds: Have a four-chambered heart, similar to mammals, supporting their high metabolism for flight. Amphibians: Typically have a three- 23 Thank you