M03-Biology

Change 3.5 bya to 100,000 ya

From first life to Homo Sapiens emergence from Africa

Naturally occurring hydrocarbon groups were significant players in what happened on space ship Earth as it orbited the sun endlessly for millions of years, seemingly without change. As Earth’s dynamics stirred it’s elements, atoms did what atoms do, especially those free to move about in a world of water.

After 1 billion years of trial and error, atoms discover four methods of replication.

(1) Photoautorophs: harness light to derive organic compounds from carbon dioxide – the method of plants and algae.

(2) Chemoautotraphs: feed on carbon dioxide derived from inorganic substances as hydrogen sulfide and ammonia.

(3) Photoheterotrophs: use light to make ATP molecules where input carbon is in organic form.

(4) Chemoherotrophis: consum organic molecules for energy and carbon – the method of fungi & animals.

billions of years ago: :3 2.7 2 1.7 l.2 .6 .6 .6

Bacteria prokaryotes process food, making things we take for granted – and cause most major diseases.

Archaes prokaryotes inhabit extreme conditions and give off methane gas – they occupy animal digestive tracts and digest grass.

(a) 3 billion yr old fossil, one of many kinds in western Australian rocks that are about 3.5 billion years old. (b) Bacteria on head of a pin., these orange rods are modern bacteria, each about 5 mm long. A pin prick can cause infection, remember to flame the tip of a needle before using it to remover a splinter, heat kills the bacteria.

Prokaryotes outnumber all eukaryotes combined. More prokaryotes inhabit a handful of fertile soil or the mouth or skin of a human than the total number of people who have ever lived. Prokaryotes thrive in habitats too cold, too hot, too salty, too acidic, or too alkaline for any eukaryote. In 1999, biologists discovered prokaryotes growing on the walls of a gold mine 2 miles below Earth's surface.

A bacterial disease, Bubonic plague (Black Death), spread across Europe killing an estimated 25% of the human population in the 14^th century. Tuberculosis; cholera, many sexually transmissible diseases, and certain types of food poisoning are bacterial diseases.

Most bacteria are benign and some very beneficial. Those in our intestines provide important vitamins, and others living in our mouth prevent harmful fungi from growing there. Prokaryotes recycle carbon and other vital chemical elements back and forth between organic matter soil and atmosphere. Prokaryotes decompose dead organisms in soil and at the bottom of lakes, rivers, and oceans returning chemical elements to the environments as inorganic compounds used by plants, which in turn feed animals. If prokaryotic decomposers disappeared the chemical cycles that sustain life would come to a halt eukaryotic life would be doomed. In contrast, prokaryotic life could persist in the absence of eukaryotes, as it once did for 2 billion years.

Archaea (ancient) inhabit extreme environments, as hot springs and salt ponds, where few other organisms can survive. There are halophiles (salt lovers) that thrive in Utah's Great Salt Lake and seawater-evaporating ponds used to produce salt. There are thermophiles (heat lovers) that live in very hot water; some even populate the deep-ocean vents that gush superheated water hotter than 100°C, the boiling point of water at sea level. There are methanogens, archaea that live in mud at the bottom of lakes and swamps that produce marsh gas bubbling up from a swamp. Great numbers of methanogens inhabit the digestive tracts of animals aiding in the digestion of cellulose in their nutrition. Humans, intestinal gas is largely the result of their metabolism. Animals belch large volumes of gas.

(a,b,c) diversity in shapes (d) “salt-loving” archaea in evaporating ponds (e) mobile prokaryote

(a) Prokaryotic with branching chains of rod-shaped cells, common in soil, where they break down organic substances. Most secrete antibiotics, which inhibit the growth of competing bacteria, used by pharmaceutical companies to produce antibiotic drugs. (b) A multi-cellular species with a division of labor, box highlights cell that converts atmospheric nitrogen to ammonia. (c) bright ball in photo is a marine bacterium discovered in 1997 (the two smaller spheres above it are dead cells) This prokaryotic cell is about the size of a fruit fly's head. (d) Prokaryotic flagella locomotion appendages are entirely different from the eukaryotic flagella. At the base of the prokaryotic version is a motor and set of rings embedded in the plasma membrane and cell wall. This spins like a wheel, rotating the filament of the flagellum. (e) Bacillus anthracis that produces the deadly anthrax disease in cattle, sheep, and humans. There are two cells here, one inside the other. The inner cell survives trauma and can resumes growth.

Sludge is cleaned by anaerobic prokaryotes which decompose organic matter, converting sludge to useful landfill or fertilizer after chemical sterilization. Liquid wastes are treated separately from the sludge.

Eukaryotic, membrane housed cells, emerged 1.7 billion yrs ago, containing DNA replication codes.

Membrane packaged cells captured specialized small cells, above left, and kept them as specialized organelles serving a colony of specialized functions. Their genetic codes were combine creating new critters, each dedicated to it’s own survival. This was possible by evolving a housing membrane of “double door’s” – food comes in waste goes out – one layer at a time, preserving the cell’s integrity.

Plant cell left and animal cell right, similar but different

Sunlight powers plant chemistry, while animals and fungi live off plants –nature recycles it’s parts.

Most DNA is contained in the Nucleus Synthesis of mRNA to cytoplasm to synthesis of Protein

Mitochondrion and Chloroplasts and organelles in cytoplasm also contain DNA. Each human mitochondrion contains about 15,000 nucleotides of DNA, encoding 37 genes. Compared with that of nuclear DNA, which contains some 3 billion nucleotides encoding perhaps 35,000 genes.

(a) Dinoflagellate, with its wall of protective plates. (b) Diverse diatoms with glassy walls. (c) Unicellular green alga with a pair of flagella. (d) Volvox, a colonial green alga.

(a) Green algae, an edible species (b) Red algae abundant in the warm coastal waters, contribute to coral reefs when cell walls are hardened by minerals. (c) Brown algae includes the largest seaweeds, known as kelp, which can grow to a length of over 60 m in a single season, the fastest linear growth of any organism. Kelp forests provide habitat for many animals, including a great diversity of fishes. Algae is a major producer of oxygen in earths atmosphere.

Plant are multicellular eukaryote that makes organic molecules by photosynthesis.

Living on land poses very different problems from living in water. Light and carbon dioxide are available above-ground, while water and mineral nutrients are found in the soil.

(a) Most plants have symbiotic fungi associated with their roots which absorb water and essential minerals from the soil for the plant. The sugars produced by the plant nourish the fungi. (b-c) Leaves are the photosynthetic organs of plants, exchange of carbon dioxide and oxygen between the atmosphere and the photosynethic interior of a leaf occurs via microscopic pores through the leafs surface. A waxy layer called the cuticle coats the leaves and other aerial parts of most plants. For the shoot system to stand up it must have support, not a problem in water, plants use lignin, a chemical that hardens the cell walls.

There are two plant vascular transport tissue: xylem, consisting of dead cells with tubular cavities to transport water and minerals from roots to leaves; and phloem, consisting of living cells that carry sugars from leaves to roots.

Land required a new mode of reproduction, land plants sperm reach the eggs by traveling within pollen, which is carried by wind or animals. The egg remains within tissues of the mother plant and is fertilized there.

Photosynthesis: sunlight water and CO₂ in and Oxygen and Sugar out.

Million yrs ago: 600 450 380 350 150

Green Algae Mosses Ferns Conifers Flowering plants

Ferns (seedless vascular plants) Conifer "coal forest” of the Carboniferous period

(a) Flowering Plants (b) Fungai Mushroom have a tightly packed stem that extend upward from a massive root system growing underground where the cottony threads decompose organic litter.

Ecosystems would collapse without fungi to decompose dead organisms, fallen leaves, feces, and other organic materials, thus recycling vital chemical elements back to the environment in forms other organisms can assimilate.

(a) Sponge (b) Anatomy of a sponge, to obtain enough food to 3 ounces a sponge must filter 275 gallons of seawater. (c) flatworm

(a) round worm (b) parasitic round worms Mollusks: (c) a variety of gastropods. (d) This scallop, a bivalve, has many eyes peering out between the two halves of the hinged shell. (e) Octopus, a cephalopod without a shell, have large brains and sophisticated sense organs, a successful mobile predators. Its brain is larger and more complex, than that of any other invertebrate and shown remarkable learning ability.

Annelids. (a) Giant Australian earthworms are bigger than most snakes. (b) Sandworms have segmental appendages that function in movement and as gills. At right is a fan worm, which lives in a tube it constructs by mixing mucus with bits of sand and broken shells and use their feathery head-dresses as gills and to extract food particles from the seawater. (c) A nurse applied this medicinal leech to a patient's sore thumb to drain blood from an accumulation of blood around an internal injury.

Annelids (a) Anatomy of an earthworm. Annelids are segmented both externally and internally, many internal structures are repeated, segment by segment. The body cavity is partitioned by walls (two shown here). The nervous system (yellow) includes a nerve cord with a cluster of nerve cells in each segment. Excretory organs (green), which dispose of fluid wastes, are also repeated in each segment. The digestive tract, however, is not segmented; passing through the segment walls from the mouth to the anus. Segmental blood vessels connect continuous vessels that run along the top and bottom of the worm. The segmental vessels include five pairs of accessory hearts, the main heart is simply an enlarged region of the dorsal blood vessel near the head end.

Arthropods (b) Arthropod characteristics of a lobster. The whole body, including the appendages, is covered by an exoskeleton. The two distinct regions of the body are the head plus thorax and abdomen. The head bears a pair of eyes, each situated on a movable stalk. The body is segmented, but this characteristic is only obvious in the abdomen. It has a tool kit of specialized appendages, including pincers, walking legs, swimming appendages, and two pairs of sensory antennae. Even the multiple mouthparts are modified legs, which is why they work from side to side rather than up and down (as our jaws do). Spiders and scorpions and insects are all examples of arthropods.

Anthropods (a) Scorpions are nocturnal hunters, among the first terrestrial carnivores, preying on herbivorous arthropods that fed on the early land plants. Scorpions have a pair of appendages modified as large pincers that function in defense and food capture. The tip of the tail bears a poisonous stinger. Scorpions eat mainly insects and spiders. (b) Spiders are usually most active during the daytime, hunting insects or trapping them in webs. Spiders spin their webs of liquid silk, which solidifies as it comes out of specialized glands. Each spider engineers a style of web that is characteristic of its species, getting the web right on the very first try. Besides building their webs of silk, spiders use the fibers in many other ways: as droplines for rapid escape; as cloth that covers eggs; and even as "gift wrapping" for food that certain male spiders offer to seduce females. (c) This magnified house dust mite is a ubiquitous scavenger in our homes. Each square inch of carpet and every one of those dust balls under a bed s are like cities to thousands of dust mites. Unlike some mites that carry pathogenic bacteria, dust mites are harmless except to people who are allergic to the mites' feces.

(A) Grasshopper & beetle (B) Metamorphosis of a monarch butterfly. (a) The larva (caterpillar) spends its time eating and growing, molting as it grows. (b) After several molts, the larva encases itself in a cocoon and becomes a pupa. (c) Within the pupa, the larval organs break down and adult organs develop from cells that were dormant in the larva. (d) Finally, the adult emerges from the cocoon. (e) The butterfly flies off and reproduces, nourished mainly from the calories it stored when it was a caterpillar. Crustaceans. (C) A grass shrimp. (D) barnacles with shells of calcium carbonate (lime), the jointed appendages projecting from the shell capture small plankton. (E) Millipedes, with two pair of short legs per body segment, eat decaying plant matter. Centipedes are carnivores, with a pair of poison claws used in defense and to paralyze prey, such as cockroaches and flies.

Enchioderms (a) The mouth of a sea star is located in the center of the undersurface. The inset shows how the tube feet function in feeding. When a sea star encounters an oyster or clam it grips the shell with its tube feet and positions its mouth next to the narrow opening, then pushes its stomach out through its mouth and through the crack in the mollusk's shell and digests the soft tissue of its prey. (b) sea urchins mainly graze on seaweed and algae. (c) Sea cucumbers have five rows of tube feet.

Millions yrs: 560 550 540 510 410 380 350 200 350

Chordate Chordate Vertebrae Jaws Lungs Legs Eggs Feathers Hair

Sharks Bony fish Amphibians Reptiles Birds Animals

(a) Shark of the cartilaginous class (b) A bony fishes class. Vertebrates (c) Vertebrates are named for their backbone, a series of vertebrae as apparent in snake skeleton, the bony skull protects the brain. (d) lancelets owe their name to their bladelike shape and wiggle backward into sand, leaving only their head exposed to filter food particles from the seawater. (c) This adult tunicate, or sea squirt , a filter feeder that goes through a larval stage. (e) Chordate characteristics

Not all amphibians have aquatic larval stages as the familiar tadpole-to-frog, Lobe-finned fish had skeletal supports extending into their fins Early amphibians had limbs for movement on land

(a) Bull snake has reptilian adaptations to living on land. Snakes evolved from lizards that adapted to a burrowing lifestyle. (b) Hunting in packs Deinonychus used its sickle-shaped claws to slash at larger prey. (c) Bird wings are airfoils, which have shapes that create lift by altering air currents.

(a) Monotremes, such as this echidna, are the only mammals that lay eggs (inset). (b) The young of marsupials, such as this brushtail opossum, are born very early in their development. They finish their growth while nursing from a nipple in their mother's pouch. (c) In eutherians (placentals), such as these zebras, young develop within the uterus of the mother. There they are nurtured by the flow of blood though the dense network of vessels in the placenta. The portion of the afterbirth clinging to the newborn zebra is the placenta.

Mammals

Mammals evolved from reptiles about 225 million years ago, before dinosaurs. During the age of reptiles mouse-sized, nocturnal mammals lived on a diet of insects. Mammals became much more diverse after the downfall of the dinosaurs. Most mammals are terrestrial. There are 1,000 species of winged mammals as bats and about 80 species of dolphins, porpoises, and whales. The blue whale is the largest animal that has ever existed. Placental mammals make up almost 95% of the 4,500 species of living mammals. Dogs, cats, cows, rodents, rabbits, bats, whales plus monkeys, apes, and humans.

million yrs ago: 58 40 40 35 15 8 8 8

Prosimians, New World, Old World, Gibbons, Orangutans, Gorillas, Chimpanzees. Human

4.5 to .2 million years ago.

Plants and Animals are inter dependent

Homo Sapiens (modern humans) originated in Africa about 250,000 and emerged from Africa about 100,000. By 30,000 they are in Siberia, by 14,000 in Americas and by 1,600 in remote Pacific islands.

The last 6 sheets on TP scale

Bacteria Archaea Eukaryote Millions of years Ago

Eukaryote cannot survive without Prokaryotes, Bacteria and Archaea

who can survive on their own and did for 2 billion years

Much of this was unknown prior to WW2