Bio- The Origin of Life, Universe, and Everything

The Big Bang Theory

• about 13.8 billion years ago all energy and matter were at the same spot in the universe

• it exploded

• very small particles went flying away from the point of singularity

  • point of SINGULARITY because it only happened once

• After the big boom

  • as universe cools atoms form

  • then clouds of atoms come together to form the first galaxies and stars

  • in these stars heavier elements were formed

    • including carbon, oxygen, nitrogen

    • things that stuff is made of

  • first generation of galaxies died and formed second set of galaxies including the milky way

• 4.7 billion years ago the sun is formed

• 4.5 billion years ago the earth formed

Early environment

• water

  • shallow oceans

  • lots of rain

• lots of energy

  • heat

  • lightning

  • UV

  • radiation

  • volcanoes

• Gasses

  • nitrogen

  • carbon dioxide

  • hydrogen

  • carbon monoxide

  • methane

  • ammonia

  • no oxygen or ozone

• contains things that can lead to the creation of life

Organic Molecules

• Oparin, Haldane hypothesis

  • energy acting on the gasses in the early atmosphere resulted in the formation of organic molecules

• Miller and Urey Experiment

  • simulated the atmosphere

  • found amino acids

  • repeated and found nucleic acids formed in the same way as amino acids

• meteorites and comets contain organic matter

First Living molecules

• probably RNA

  • simpler than DNA- simpler things come before complicated ones

  • self replicate

  • store info

  • direct synthesis of proteins

  • act as a catalyst

First cells

• iron sulfide

  • columns contain spaces that can concentrate organic molecules

• liposomes

  • fat bubbles can contain organic molecules

Oldest fossils

• stromatolites

  • prokaryotic

  • lack a nucleus or other organelles

Early cells and energy

• heterotroph hypothesis

• first cells were heterotrophs- eating energy rich molecules in the early oceans

• once they had eaten most of the food available autotrophs became abundant

• Autotrophs produce oxygen

  • oxygen is reactive and toxic to many early organisms

  • organisms either became extinct or adapted with aerobic respiration

Eukaryotes

• cells with nucleus and organelles

• 1.4 billion years ago

Margulis

• endosymbiont hypothesis

• explains the formation of the nucleus and membrane bound organelles

• mitochondria/chloroplast- once individual organisms that got engulfed in the membrane

  • one membrane from being a prokaryote

  • another from engulfment

• first multicellular organisms

Speciation

Species

• group of individuals that can breed with one another to produce fertile offspring in nature

• evolution acts on species not individuals

Background

• niche- ecological role of an organism

  • what it does and where it lives

  • no 2 species can occupy the same niche at the same time

• Reproductive Isolation- part of the population is separated so that they can’t breed with the rest

  • leads to evolutionary change

Isolating mechanisms

• morphological- things have to match

• behavioral- mating rituals

• geographic- change in geography

• temporal- time

The Process- Darwin’s Finches

1. founding fathers and mothers

2. separation of populations

3. changes in the gene pool

4. reproductive isolation

5. sharing the same space- ecological competition

Patterns of Evolution

• divergent evolution- adaptive radiation

  • one original species fives rise to many diverse forms

  • Homologous structures- similar origin but a different appearance/function

• Convergent evolution

  • evolution produces species that are similar in form or function

  • analogous structures- similar in appearance/function but a different origin

Rate of evolutionary change

• gradualism- evolution occurring by a slow steady change

• punctuated equilibria- long stable periods with short periods of fast change

  • often associated with mass extinction