Evolution and Taxonomy of Animals

Evolution and Taxonomy

• Evolution and taxonomy study the development and classification of life on Earth.

The 9 Major Phyla of Animal Kingdom

• The nine major phyla of the animal kingdom, ordered from simplest to most complex, are represented in the provided images.

Unique Characteristics and Adaptations in Various Taxa

• Various animal groups exhibit unique characteristics and adaptations that define them.

PORIFERA (Sponges)

• Simplest body plan among animals

• Lack of true tissues and organs

• Porous body structure facilitates filter feeding

• Choanocytes are versatile sponge cells, responsible for filtering food particles.

CNIDARIA (Jellyfish, Anemones, Corals)

• Stinging animals
• Possess specialized stinging cells (cnidocytes) for defense and prey capture

PLATYHELMINTHES (Flatworms)

• Ability to regenerate lost body parts
• Flatworms can regenerate entire individuals from small body fragments.
• Regeneration of Planarians is allowed by clonogenic neoblasts which are pluripotent stem cells that provide the cellular basis for planarian regeneration

NEMATODA (Roundworms)

• Complete digestive system with a separate mouth and anus.
• Well-developed muscles and complete digestive tract.

MOLLUSCA (Octopus, Slugs, Snails)

• Presence of a muscular foot in many species.
• The foot is used for locomotion in gastropods (e.g., snails) and burrowing in bivalves (e.g., clams).

ANNELIDA (Earthworms, Leeches)

• Segmented body plan with well-developed organ systems
• Presence of setae, bristle-like structures, aiding locomotion by anchoring the body to the substrate and providing traction

ARTHROPODA (Insects)

• Largest animal phylum.
• Jointed appendages and a segmented body.
• Allows for precise movement and manipulation of objects, as well as specialization of appendages for various functions (walking, swimming, feeding)

ECHINODERMATA (Starfish, Sea Urchins, Sea Cucumbers)

• Unique body plan characterized by radial symmetry and a water vascular system, representing a complex evolutionary lineage.
• Presence of tube feet for locomotion, feeding, and gas exchange.

CHORDATA (Vertebrates)

• Highest level of complexity among animal phyla.
• Dorsal nerve cord, notochord, and pharyngeal slits during embryonic development.
• Notochord develops into a backbone.
• Pharyngeal slits are modified for various functions (respiration, filter feeding, sound production)

Species Diversity

• Variety of different species in a specific area or ecosystem represents species diversity.

Quick Facts about Philippine Biodiversity

• One of the 17 megadiverse countries.
• Has the greatest concentration of unique species per unit area globally.
• 60%-70% of the world's biodiversity.
• Over 52,177 described species, half endemic.
• Among the world's top 10 in terms of endemism (specifically for terrestrial vertebrates).
• 1,238 terrestrial vertebrate species, 50% endemic.

Speciation

• Process by which new species arise from a single ancestral species over time.

• Allopatric speciation occurs when populations become geographically isolated.

• Sympatric speciation occurs within the same geographic area without physical isolation.

• Parapatric speciation occurs when a smaller population is isolated at the periphery of a larger group and becomes differentiated.

• Peripatric speciation involves the rapid evolution of a new species from a small, isolated peripheral population of a larger ancestral population.

Central Dogma of Molecular Biology

• DNA contains instructions for making a protein
• Replication, transcription, and translation are the key processes involved in protein synthesis.
• DNA replication results in identical copies of DNA.
• Transcription converts DNA to RNA.
• Translation translates RNA to protein.

DNA

• A molecule containing the unique genetic code for each individual.
• Building Blocks: Nucleotides

Protein Synthesis

• Proteins are the building blocks of life, forming the structure, enzymes, and functions of every living organism.

Photo 51

• Image captured by Rosalind Franklin
• Revealed information about DNA's three-dimensional structure

Watson and Crick's Model of DNA

• Double-stranded, antiparallel, right-handed helix

Transcription

• The process by which a cell makes an RNA copy from a piece of DNA.
• Three sub-steps: initiation, elongation, and termination.

Translation

• The process by which a protein is synthesized from the information contained in a molecule of messenger RNA (mRNA).
• Ribosomes are the site of protein synthesis.
• Transfer RNA (tRNA) molecules bring amino acids to the ribosome.
• A codon is a sequence of three nucleotides that codes for a specific amino acid.

DNA Replication

• A process to produce identical copies of DNA
• Leading strand synthesized continuously while lagging strand synthesized discontinuously.
• Enzymes involved in replication include DNA polymerase, helicase. Primase, DNA Ligase

Origin and History of Life on Earth

• Earth formed from cosmic dust and gas (~4.6 billion years ago)
• Pre-Cambrian Eons include: Archean, Proterozoic, and Hadean Eons
• The pre-cambrian eons form the oldest part of the geologic timescale encompassing most of the earth's history with the Cambrian explosion marking the start of the Phanerozoic Eon.
• Phanerozoic Eon includes Paleozoic, Mesozoic, and Cenozoic eras
• Paleozoic era corresponds to the "ancient life" and witnessed the emergence of fish, plants, insects, and early terrestrial vertebrates.
• Mesozoic era was the era of middle life, characterized by the dominance of reptiles and dinosaurs.
• Cenozoic era is the most recent era, characterized by the rise of mammals, including the emergence of hominins (ancestors of humans).

Plant Diversity

• Includes 3 primary groups: Nonvascular (mosses), vascular (ferns), and seed plants (gymnosperms and angiosperms)

Animal Diversity

• Includes invertebrates (e.g., sponges, jellyfish, flatworms, starfish, shrimp, spider) and vertebrates (e.g., mammals, birds, fish, reptiles, amphibians)

Microorganism Characteristics

• Unicellular or simple multicellular organisms
• Includes Bacteria, Archaea, Fungi, Protists, and Viruses

Mechanisms of Evolutionary Change

• Genetic mutation
• Gene flow
• Genetic drift (founder effect, bottleneck events)
• Natural selection
• Artificial selection

Evidence of Evolutionary Relationships

• Molecular data, morphological data, and fossils

Developmental Characteristics used in Taxonomy

• Embryonic development and metamorphosis patterns provide insights into shared evolutionary history .

Sex Chromosomes

• Chromosomes that determine an organism's biological sex
  • X and Y chromosomes are the sex chromosomes in humans.

Recombination

• Process that creates genetic diversity by shuffling and recombining genetic material during reproduction.

Explore the fascinating world of evolution and the taxonomy of the animal kingdom. This quiz covers the major phyla, their unique characteristics, and adaptations. Test your understanding from sponges to flatworms and everything in between!