Week 5 Flashcards
What is stratigraphy
Studying the composition and order of rock layers
What is relative time ?
Rocks or fossils are older or younger relative to each other.
What is absolute time ?
Absolute time in evolution refers to determining the exact age of rocks or fossils, which can be measured through radiometric dating or other methods.
rocks have quantifiable age
Name the 3 different types of rocks
Igneous: or “Magmatic” – coming from magma, or volcanoes!
Metamorphic: Rock that has
metamorphosed – changed – due to heat and pressure into different forms and chemical composition.
Sedimentary: formed by the
deposition of small particles
(sediments) by wind, water, ice, or oceans, and cemented together.
What is an igneous rock
When lava cools, trace
amounts of radioactive
materials are “locked” into
the minerals.
These radioactive isotopes
allow igneous rock to be
dated to an absolute age: we
can use radiometric dating
to find out how old they are!
Their features often tell us
what major geologic events
were occurring at the time.
What is sedimentary rock ?
Sedimentary rocks are created by the deposition of particles (sediments) such as sand, silt, and organic matter, often in bodies of water. Over time, these layers harden and form rock. Typically where fossils are found .
What is layering (stratification)
As new layers of sediments are deposited on top of older layers, they form a distinct stratigraphy, with older layers at the bottom and newer ones at the top.
Explain the fossilization process
Organisms that die in or near these sedimentary environments can become buried in the sediment. Over time, their remains may be preserved as fossils within these layers. Each layer can capture different organisms, depending on the environment and the time period.
When measuring time in geologic history,
we also need a consistent, physical basis, what would you use ?
Radioactive decay of different elemental isotopes can
provide exactly that consistent measure.
What are parent isotopes
the unstable isotopes that decay
What are daughter isotopes
the products of the decay process.
What is a half life
A half-life is the amount of time
required for half the amount of
parent isotope to decay into the
daughter isotope.
How can we deduce how different organisms are, or are not, related
By comparing key traits between and within groups
What is the 3 domain system
classification revised
based on analysis of
DNA
– Found two groups of
very different
prokaryotes
– One group, Archaea,
more similar to
eukaryotes (Eukarya)
than to the other group,
Bacteria
Name the 6 kingdoms
Bacteria
Archaea
Protista
Fungi
Plantae
Animalia
Name characteristics of bacteria
Simple unicellular organisms
Name characteristics of archaea
Archaea are simple unincellular organisms that often live in extreme environments
Characteristics of Protista
Unicellular and are more complex than bacteria or archaea
NAme characteristsics of fungi
unicellular or multicellular and absorb food
characteristics of plantae
multicellular and make their own food
characteristsics of animalia
multicellular and take in their food
Name characterstics of living organism s
- Grow and Reproduce
- Respond to the environment and its changes
- Evolve and Adapt
- Have a Metabolism
- Have an Organized Structure
- Are Composed of Organic Molecules
What is the basic unit of life
Cells
Name the fundamental components of cells
- Cytoplasm (a gel-like substance composed of water and
dissolved chemicals needed for growth), - Plasma membrane (also called a cell membrane or
cytoplasmic membrane) which contains the cytoplasm
and defines the cell from its environment. - DNA, in the form of at least one chromosome, which
contain the genetic blueprints of the cell. - Ribosomes, organelles used for the production of
proteins based on sequences in the DNA.
Name 2 basic cell types and their characteristics
- Prokaryotic
* Usually < 0.005mm
* No organelles
* No nucleus - Eukaryotic
* Usually 0.02-0.05mm
* Organelles
* Nucleus
Both ___ & ___ are prokaryotic organisms
Archaea and bacteria
Who came first ? Prokaryotes or Eukaryotes
Prokaryotes have existed for 2.5 billion years, as opposed to
Eukaryotes, which came 1 billion years later!
What is the earliest fossil ?
Stromatolites
The first eukaryotes
Oldest fossils of multicellular life measure up to 12 cm across and date back 2.1 billion
years (unlike any living life form)
When did Algae first show up
1.6 billion
YA, but is not recognizable until
1.2 billion YA.
What are the first animals that we recognize ?
Sponges - 650 MYA
When did we discover early animals
Ediacarab period - 575 MYA
When did early marine life start ?
– the Burgess Shale in B.C. –
505 MYA
Created by mudslides
into cold, deep, oxygen-free water where bacteria could
not decompose the soft-bodied animals.
Left excellent impressions of a host of marine fauna!
What was the cambrian explosion ?
The beginning of many living groups of animals.
Predators first appear
Chordates
Jawed fish
Trilobites (cousins of horseshoe crabs)
What is the movement to land
475 MYA
Plants moved to land with the help of fungi, first as
algae, then as plants that resemble today’s mosses
and liverworts.
What is cladoxylopsids
The first trees 380 MYA
Had xylem to carry water up
the tree from the roots, but
the structure was actually
more complex than modern
trees!
When did insects appear
418 MYA
What are the oldest known vertebrates with legs
tetrapods – 370 MYA
What are synapsids
predecessors to the dinosaurs – 320 MYA
When was the dinosaur period
230 MYA – 65 MYA
What are melanosomes
organelles that make colours – in several fossils.
Carboniferous period
Forests of Fern, Horsetails,
and proto-gymnosperms
made up the Carboniferous
period, 360 – 300 MYA,
make up most of our coal
deposits today.
When was the rise of the mammals
After the Dinosaurs – Rise of the
Mammals
50 MYA – 10 MYA
Introduction of hominins
7 MYA – 1 MYA
