4.7 Human Evolution U4 Flashcards
(24 cards)
Describe protists?
Most = unicellular
Auto- or Heterotrophs
“Plant-like” or “Animal-like”
Some have:
Cell walls (cellulose)
Chloroplasts
Ex:
Amoeba, slime molds, paramecium
Describe Plants?
Multicellular
Autotrophs
Have:
Cell walls (cellulose)
Chloroplasts
Ex:
Trees, flowers, mosses, ferns
Vasc and nonvasc
Describe Fungi?
Most = multicellular
Heterotrophs
Decomposers!
Have:
Cell walls (chitin)
Ex:
Yeast, mushrooms, mold
Animal Evolution traits?
Multicellular
Invertebrates
Body cavities, organs, brain, digestive systems, etc!
Terrestrial
Arthropods first! Exoskeletons!
Chordates
Notochord!
Vertebrates
Backbone + skull!
Amniotes
First FULLY terrestrial!
Amniotic eggs!
What are primates?
Order within Class Mammalia (~55-65 MYA)
What are the basic Suite of traits for primates?
Eyes
Forward-facing, convergent
Trichromatic color vision
Large brains
Reduced nose/smell
Hands/feet
5 digits
Opposable thumbs/toes
Tactile pads, flat nails
Long/slow life/development
Social
What are hominidae?
Family of primates
What is the support for Hominidae language?
Anatomy: fossilized remains show that structure of larynx and shape of vocal tract could provide range in speech/vocalizations
Development of tools requires planning/communication
Hominids were social creatures- nonverbal communication (body language, facial expressions, etc) would be important in communication
Describe Hominidae?
Brains
Larger, complex
Intelligent behavior
Make and use simple tools
“Language “
Recognition
Larger size
No tail
What is bipedalism?
Walking on 2 feet
~1st: Australopithecus
What did bipedalism lead to?
More efficient way to travel/cover longer distances
Changes in the anatomy primarily in the lower extremities
Weight bearing femur
Feet helpful for shock absorption/stabilization
More use of upper extremities
Hands to use tools & objects
What are Australopithecus?
genus of extinct hominids that lived in Africa
First bipedal primate
Experienced increase in brain size over time
Primitive tool use
What are homo erectus
Increased brain size!
Larger size
Migrated out of Africa
Asia, Europe
More efficient walking
Tool use
Use of fire
Fossils have been found in more regions of the world (Africa, Asia, Europe).
Characteristics
Larger brains than previous hominids
More efficient walking- longer distance
Evident through limp proportions and pelvic shape
Tools
Like handaxes!
Most likely for food (cutting/butchering meats, plants)
Some scientists believe projectile weapons (spears) were developed during this period to aid in hunting/defense strategies
Fire
Archeologists have found hearth sites where homo erectus lived which contained burned bones, wood, ash, etc. Helpful for warmth, cooking, etc
What is lucy fossil and what is the significance of it?
Lucy is a famous fossil that belongs to this species
Significance
One of the most complete early hominid fossils found- great for studying anatomy
Provided evidence of bipedalism and timeline: adapted lower extremities
What are homo habilis
Increased brain size!
Use of tools
Likely some language
Are an extinct group of hominids, lived in East Africa (woodlands, grasslands). Diet consisted of meat/plants- tools helped with this!
Characteristics
Associated with earliest use of stone tools primarily used for handling meat (chopping, cutting)- demonstrates increased cognitive abilities!
What are homo neanderthalensis?
Similar brain size to us!
Strong
Language
Death-related rituals
Buried
Weaponry, flowers, food, gifts, etc.
Belief in afterlife!
May have lived/interacted/bred with Homo sapiens!!
Characteristics
Lived in Eurasia, strong/muscular/thicker bodies/utilized animal hides/fur to help with cold environment
Skilled toolmakers (hunting, woodworking)- allowed for hunting or large animals (bison, mammoths)
Burial sites have been discovered containing objects (tools, bones, etc), multiple people buried together, deliberately positioned/arranged- suggests rituals/belief in afterlife?
Coexisted with homo sapiens, there is evidence of interbreeding! Have found populations that carry homo neanderthalensis DNA in genomes
What are homo sapiens?
~200,000 MYA
Better tools
Clothing
“Out of Africa” theory
Aka modern humans
Characteristics
Bipedalism
High cognitive function (decision making, planning, emotions, language)
Advanced toolmaking
Tools for butchering, hunting (blades, spears) and eventually for farming, metalwork, etc
Clothes
Important for protection from the environment, most likely made from plant/animal hides. Contributed to further technological development (dying, weaving, sewing, etc). Also allows for movement into newer/more diverse environments
Out of africa theory
What are the reasons it seems like humans arent evolving?
We’re generalists
We’ve reduced the effect of certain selective pressures
B/c technology, medicine, agriculture, etc
What are examples of huans still evolving?
(Lack of) Wisdom teeth
Adapting to environments
High altitudes, free-diving, etc.
Disease resistance
Cape Verde malaria resistance, etc
🡱 Medical dependency
“Deleterious” alleles, head/pelvic size (C-sections)
Reproductive traits
Earlier/longer reproductive time, late menopause
Selection against harmful traits
Higher blood pressure/sugar/cholesterol
Anatomical changes
Extra forearm artery (median artery)
🡱 Autoimmune disorders/allergies/asthma
Better sanitation, etc.
What are the parts of a virus?
Capsid = protein coat
Envelope = lipid membrane
Some, not all!!!
Genome = DNA or RNA
Glycoproteins = attachment/entry
What does a virus need to reproduce?
A host cell
Viral Replication
What is the evolution of viruses
Tend to evolve faster than humans/hosts
Mutation rate
Population size
Quick lifecycles
What are examples of viruses affecting our evolution?
Placenta
Reptile/mammal ancestor gained a gene from a virus, allowed evolution of placental animals!
COVID-19
Changes to many aspects of human behavior, including:
Sociability
Exposure to other microbes
Dramatically increased chance of being hospitalized/dying from COVID if you have a certain DNA sequence on chromosome #3
From Neanderthals!!!
Human/Chimpanzee Divergence
Around 30% of protein adaptations after we diverged from chimps, were driven by viruses!
