Biodiversity, Systematics and Taxonomy

Introduction

• Biodiversity is the number of species found in a given area.
• Species is the basic unit of classification of living beings.
• Corresponds to a set of organisms that share a set of genes and can only have fertile offspring if they interbreed.

Systematics, Taxonomy and nomenclature

• More than one and a half million species (Eukaryotes) have been cataloged, and it is estimated that there may be another million to describe.
• Species appear (speciation) and disappear (extinction) daily, some will have become extinct without having been discovered.
• To study Living Beings (EV), identification, nomenclature and classification were established as the first challenge.
• Systematics is an area that aims to establish classification systems that express the degrees of similarity between living beings and reflect their evolutionary relationships.
• Taxonomy is the study of organisms in a hierarchy that highlights their fundamental similarities and differences.
• The naturalist Karl von Linné established the bases for the modern classification system, he adopted a hierarchy of seven levels, currently these levels are updated in 8/9 levels: Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species, (Subspecies).
• Linné also established the binomial nomenclature system, that is, all living beings (species) have a scientific name in Latin composed of two words.
  • Examples: Canis familiaris, Canis lupus, Homo sapiens, Aloe vera, Anax imperator, Columba livia, Rattus norvegicus

The tree of life

• Traditionally, living beings have been grouped into 5 kingdoms: Monera, Protoctista, Fungi, Plantae, and Animalia.
• After the discovery of the Archaea and further studies of DNA, the model changed to 3 domains: Archaea, Bacteria, and Eukarya.

Domain: Archaea

• Microorganisms are prokaryotic and unicellular.
• Differ from bacterias due to biochemical and genetic differences:
  • Do not have murein (peptidoglycan) in the cell wall
  • Phospholipids of fatty acids with a branched chain and sometimes a monolayer.
  • Linked with ether to glycerol, instead of ester.
  • Do not form resistance spores
• Archaea have a different evolutionary history.
• More opportunistic than bacteria, can live in harshest environments.
• Extremophiles, Acidophiles, Halophiles, Anaerobic
• Metanogens
• Colon, soils, oceans...

Domain: Monera

• Prokaryotes and unicellular.
• Contain:
  • Murein (peptidoglycan) on their wall
  • Non-ramified fatty acids
  • Ester bond of union with glycerol.
• They have a large surface area-volume ratio.
• DNA with a double-stranded circle.
• Can form resistance spores.
• Contains the most biodiversity
• Contains bacterias such as
  • Lactobacilus (yogurt / cheeses) -Neisseria gonorrhoeae -Mycobacterium tuberculosis -Clostridium botulinum -Salmonella sp -Escherichia coli -Helicobacter pylori
• May form colonies
  • Coccus, Streptococci, Diplococci, Staphylococci
• Different forms of life
  • Pathogens
  • Commensalists
  • Saprophytes
  • Symbionts
• Bacteria, decomposers, and N fixers. Cyanobacteria

Domain: Monera - gram + and gram -

• Bacteria can be differentiated into two main groups: gram+ and gram-

Domain: Monera - metabolism

• Metabolism is the reactions which materials (carbon) and energy (ATP) is obtained.
• Classifications include catabolic and anabolic

Domain: Monera - reproduction

• Reproduction occurs by binary fission, however mechanisms such as transformation, transduction and conjugation can occur.

Domain: Eukarya - Protista

• Eukaryotic organisms that are not plants, animals, or fungi (polyphyletic).
• Unicellular or multicellular (thallophytic organization, without tissues).
• Mostly aquatic, but also terrestrial.
• Classified as autotrophs and heterotrophs.

Domain: Eukarya: Protista Autotrophs

• Photosynthetic organisms
  • Unicellular: microalgae (phytoplankton)
  • Multicellular: algae (thallophytes)

Domain: Eukarya: Protista Heterotrophs

• Contain animals and fungi
  • protozoa
    • unicellular
    • can be free-living, saprophytic, or parasitic.
  • Myxomycetes
    • Multicellular
    • displace like amebes phagocytosing organic matter, then fructify-forming spores.

Domain: Eukarya - Fungi

• Eukaryotes generally multicellular.
• Thallophytic organization.
• Have a cell wall made of chitin.
• Glucogen reserve polysaccharide
• The carbon source is organic matter.

Domain: Eukarya - Fungi - features

• Pluricellular body: mycelium, made of hifas(filaments)
• Reproduction may be asexual or sexual, hapoild form

Domain: Eukarya Fungi - forms

• Can be:
  • Parasites
  • Symbionts (lichens and mycorrhizae)
  • Saprophytes

Domain: Eukarya - Fungi, Lichens

• Symbiosis between an ascomycete fungus and unicellular algae or cyanobacteria.
• Exchange of glucids for water and protection.

Domain: Eukarya - Fungi, Micorrizes

• Mycorrhizas: Symbiosis between a Basidiomycete and a plant.
• Exchange of glucids for water and nutrients.

Domain: Eukarya - Fungi, classification

• Classified by:
  • Zygomycetes (molds)
  • Ascomycetes (Lichens, yeasts and some mushrooms)
  • Basidiomycetes (Mushrooms).
• High importance of cycle of materia

Domain: Eukarya - Plantae

• Vegetable kingdom or plant kingdom.
• Includes all eukaryotic, multicellular organisms with true tissues (cormophytes or protocormophytes)
• Have chlorophyll as a photosynthetic pigment: photosynthetic metabolism = autotrophs
• They have a cell wall made of cellulose.
• The energy reserve polysaccharide is starch.
• Originated in the Silurian (400 m. a.) from a group of green algae, therefore are terrestrial organisms.
• Although secondarily, they have colonized the aquatic environment, both salt and fresh water.
• They are found in almost all ecosystems: deserts, humid tropical zones, frozen tundras, high altitudes and underwater.
• Plants also include embryophytes such as,
  • Bryophytes ("mosses")
  • Pteridophytes ("ferns")
  • Spermatophytes ("vascular plants")

Domain: Eukarya, Superdivision BRIOPHYTA

• Superdivision BRIOPHYTA features
  • Small plants
  • Organisms that conquered the terrestrial environment and faced all the changes
  • Dependent of water for vegetation growth and reproduction
  • Protocormophyte organization (no real tissues)
  • Different than seaweed embrions

Domain: Eukarya, PTERIDOPHYTA

• Superdivision PTERIDOPHYTA features -Vascular plants with true tissues.
  • Dominated the T during the Paleozoic (before the apparition of spermatophytes)
  • They have dominated the terrestrial environment but are still dependent on water for their reproduction.
  • They have specialized conductive tissues but they do not have flowers, fruits or seeds.
  • Non ramified
  • Do not have secondary growth
  • Examples include horsetails(Equisetidae) and ferns (Filicopsida)

Domain: Eukarya, Spermatophyta

• Division SPERMATOPHYTA Features
  • Vascular plants with specialized conductive tissues
  • Characterized by seed (sperma = seed, phyta = plant)
  • The ability to reproduce independently of water.
  • They can branch by generating axial buds

Domain: Eukarya, Spermatophyta, Gimnospermas features

• SubDivision: Gimnosperms (Conifers)
  • Gimno = naked
  • Don't have seeds proctected by fruits
  • Sexual ordans grouped i structures known as cone
  • Examples include: pine, fir, cedar, cypress, juniper, sabyne, yew.

Domain: Eukarya, Spermatophyta, Angiosperms features

• Sub Division: Angiosperms (Flower plants)
  • Angio = amphora -Ovary proctected by specialized structures
  • Features:

    • Monocots: Contains only onc cotyledon

    • Dicots: Contain two Cotyledon

Domain: Eukarya, Animalia

• With a great morphological diversity
• Found in all habitats
• Multicellular (all with tissues, organs, apparatuses and systems)
• Eukaryotic cells without cell wall.
• Most move, and have autonomous movement.
• Collagen is the main structural protein.
• The main energy reserve is lipids and secondarily glycogen.
• Heterotrophs and feed by ingestion.
• They reproduce mainly sexually, although some can do it asexually.
• All are aerobic
• Diploid organisms (only gametes are haploid)
• They can be dividied into invertebrates and vertebrates.

Domain Eukarya Animalia - Invertebrates

• Can be categorized by symmetry, or lack of symmetry. - Invertebrates with no symmetry include porifera. - Invertebrates with radial symmetry includde cnidaris and echinoderms - Invertebrates with bilateral symmetry can further be categorized into groups with non-articulated feet vs groups with articluated feet (artropodes) - Some invertebrates with no feet include platyhelmints, moluscs, nematodes, annelids, gasteropods, bivalves and cephalopods

Domain: Eukarya - Animalia - VERTEBRATES

• All vertebrates have a dorsal nerve cord protected by the vertebral column. - Two major types of vertebrates are fish (pisces), tetrapods, and amniotes.

Domain: Eukarya - Animalia - VERTEBRATES, Pisces

• Are poiquiloterms
• Fish are all aquatic.
• Fish breathe through gills.
• They have scales
• They are ovipares or ovoviviparous.
• two major groups
  • Condrictis No bones, scales, and have an unequal caudal fin. No swim bladder. Sharks, rays, and the manta rays have this.
  • Osteïctis Have bones and scales, an equal caudal fin, and have a swim bladder.

Domain: Eukarya - Animalia - VERTEBRATES, Amphibians

• Amphibians poiquiloterms
• Amphibians were the first in leaving aquartic environments
• They have skin and pulmonar respiration
• They classify in :
  • Urodels (with tail): tritons (newt) and salamanders.

Domain: Eukarya - Animalia - VERTEBRATES, Reptiles

• Reptiles (Poiquiloterms) Can be divided in to ::::
  • Reptiles Tetrapods complete independent with lungs
  • Amniotes

Domain: Eukarya - Animalia - VERTEBRATES, Aves

• Aves (Homeoterms.)
• Aves have been evoluted by Reptils species with was survive the extinción
• Some species have peak and no theets
• All species have feather
• All species Are oviparous
• Aves Have pulmonary respiration.
• They classify in voladores i no voladores

Domain: Eukarya - Animalia - VERTEBRATES, Mamifers

• Mamals (Homeoterms)
• Mamals are been evolved by ancient Retpils.
• Have theets
• HAve body cobertura with hair .
• Principaly viviparos (ovípars)
• Mamalls have mammary glands.
• Pulmonary respiration.
• Contains two large grops species of tree - Monotremes (Monotremes ) with characteristics reptilianes
• The - There (embryo to ¢ uter)
• Marsupials
• Placentaris.